3-2-1 Liftoff! ULA Rocket Hardware Challenge

Design an attachment bracket for ULA’s current Atlas V Centaur launch vehicle.

About this Challenge

Sometimes it really is rocket science. ULA is challenging the GrabCAD community with a competition where participants design a launch support attachment bracket for ULA’s current Atlas V rocket. The design will subsequently be evaluated for application on ULA’s next-generation Vulcan Centaur rocket, which will transform the future of space launch. ULA has successfully delivered more than 100 missions to orbit, and your design could contribute to missions that provide critical capabilities to save lives, explore the universe and connect the world.

Technical Specifications

The internal boattail support bracket will be used during ground processing at the base of the Atlas V payload fairing (see illustration below). It will be used at numerous locations around the vehicle upper stage, acting as a support point for work platforms on the days leading up to launch. The bracket remains with the upper stage of the rocket during flight. Launch vehicle weight has a first order effect on the performance of the system, so minimizing weight, such as in this bracket, dramatically improves payload weight to orbit.

All portions of the bracket must remain within the envelope shown in the Part Design Envelope drawing (see Download Specification button). The part will be fastened to the vehicle interface at datum A using 4 bolts shown as holes (marked Hole Pattern D) in the envelope drawing. A load from the work platform will be applied uniformly on a surface located at datum B and will be fastened using 2 bolts shown as holes (marked Hole Pattern E) in the envelope drawing. The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole.

Maximum part weight: 0.1 lb
Minimum wall thickness: 0.040 inches
Ultimate load (due to work platform): 600 lbf applied uniformly in the negative Z direction (illustrated on the envelope drawing)
Required material: Ultem 9085 (material properties below)

Material Properties
Ultem 9085
Material Strength Allowable: 4500 PSI
Specific Gravity: 1.34
Young’s Modulus: 325 KSI
Poisson’s Ratio: 0.41
Non-Dissolvable support material

Your entry must include:
Description of the bracket
STEP/IGES formatted files
Renderings
Mass, Volume
Load calculations
ULA Compliance Certification form (you will see this form once you click on "Submit an Entry" button)

The ULA Rocket Hardware Challenge marks the first time GrabCAD has hosted the opportunity for community members to design a piece of rocket hardware with ULA, and as a result, award eligibility is different for the ULA Challenge than other GrabCAD challenges. U.S. federal laws and regulations restrict eligibility to receive awards in this challenge. For more information about U.S. export control law, visit the below sites:
International Traffic in Arms Regulations , Office of Foreign Assets Control. The ULA 3-2-1 Liftoff Challenge is open to U.S. and non-U.S. applicants. When you sign up for this challenge, you’ll be asked to fill out a ULA Compliance Certification form to verify award eligibility for all team members. ULA will use this form to screen participants to ensure legal compliance and compliance with U.S. sanctions, embargoes, and prohibitions, and to make sure that the awards will be presented in accordance with these laws and regulations.

To learn more about designing for metal additive manufacturing, check out GrabCAD Blog.

Requirements

YOUR ENTRY MUST INCLUDE: • STEP/IGES formatted files • Description of the bracket • Any render or image files (jpeg, png, etc) • Mass, Volume • Load calculations • ULA Compliance Certification form
TECHNICAL REQUIREMENTS: Please see above for complete technical requirements.
JUDGING CRITERIA: Judging criteria will be based on achievement of accomplishing criteria listed above, including:
Pass/Fail – meets the part design requirements
Minimize final part mass
Minimize total part material volume including print support material as measured in cubic inches
Unique features that leverage additive manufacturing technology
Use of good design practices (e.g. proper load path, sufficient radii, etc)
Ease of installation – takes into account tool access clearance, bolt/nut clearance, etc
Cleared for Open Publication, August 11, 2016, 16-S-2501

Download specification

Rules

ENTERING THE COMPETITION The Challenge is open to everyone except employees and families of GrabCAD and the Sponsor. Multiple entries are welcome. Team entries are welcome. By entering the Challenge you: 1. Accept the official GrabCAD ULA Special Challenge Terms & Conditions. 2. Agree to be bound by the decisions of the judges (Jury). 3. Warrant that you are eligible to participate. 4. Warrant that the submission is your original work. 5. Warrant, to the best of your knowledge, your work is not, and has not been in production or otherwise previously published or exhibited. 6. Warrant neither the work nor its use infringes the intellectual property rights (whether a patent, utility model, functional design right, aesthetic design right, trademark, copyright or any other intellectual property right) of any other person. 7. Warrant participation shall not constitute employment, assignment or offer of employment or assignment. 8. Are not entitled to any compensation or reimbursement for any costs. 9. Agree the Sponsor and GrabCAD have the right to promote all entries. If you think an entry may infringe on existing copyrighted materials, please email challenges@grabcad.com.
SUBMITTING AN ENTRY Only entries uploaded to GrabCAD through the "Submit entry" button on this Challenge page will be considered an entry. Only public entries are eligible. We encourage teams to use GrabCAD Workbench for developing their entries. Entries are automatically given the tag "ularocket" when uploading to GrabCAD. Please do not edit or delete this tag. Only entries with valid tag will participate in the Challenge.
AWARDING THE WINNERS The sum of the Awards is the total gross amount of the reward. The awarded participant is solely liable for the payment of all taxes, duties and other similar measures if imposed on the reward pursuant to the legislation of the country of his/her residence, domicile, citizenship, workplace, or any other criterion of similar nature. Only 1 award per person. All judging decisions are final. All winners will be contacted by the GrabCAD staff to get their contact information and any other information needed to get the prize to them. Payment of cash awards is made through PayPal. All team awards will be transferred to the member who entered the Challenge. We will release the finalists before the announcement of the winners to give the Community an opportunity to share their favorites in the comments, discuss concerns, and allow time for any testing or analysis by the Jury. The Jury will take the feedback into consideration when picking the winners. Winning designs will be chosen based on the Rules and Requirements. - Entry deadline is October 23, 2016 (11:59pm UTC). - The finalists will be announced by November 18, 2016. - The winners will be announced by December 9, 2016. Void where prohibited.
SPEC REFINEMENT We want to make sure that you have all of the information that you need to tackle the challenge. As such, in the first week of a challenge we may refine the specifications or offer clarifications based on member feedback. Please ask any questions that you have!

Prizes

: $4,500 in prizes for top 3 places!
1st Prize: $3,000 and ULA merchandise prize pack
2nd Prize: $1,000 and a ULA hat
3rd Prize: $500 and a ULA T-shirt

About the jury?

The jury is comprised of experts from ULA.

About United Launch Alliance

With more than a century of combined heritage, United Launch Alliance is the nation’s most experienced and reliable launch service provider. ULA has successfully delivered more than 100 satellites to orbit that provide critical capabilities to save lives, explore the universe and connect the world. Our vision is that we will unleash mankind’s potential in space.
For more information on ULA, visit the ULA website at www.ulalaunch.com.
Join the conversation at www.facebook.com/ulalaunch, www.twitter.com/ulalaunch and www.instagram.com/ulalaunch.

247 comments

Winston Jennings about 8 years ago

My kind of challenge!!!

Winston Jennings has uploaded 279 CAD models & has left 883 comments.
Ridwan Sept about 8 years ago

Finally, after slept for a long time. Good luck for every one !!!

Ridwan Sept has uploaded 220 CAD models & has left 1659 comments.
Ernesto Chavez about 8 years ago

You had me at "rocket".

Ernesto Chavez has uploaded 4 CAD models & has left 84 comments.
Paul about 8 years ago

Moar challenges :)

Paul has uploaded 15 CAD models & has left 272 comments.
Flaviano Crespi about 8 years ago

The .jpg file attached for download is difficult to read, it can mislead.
We can have a .pdf version?
Thanks in advance.

Flaviano Crespi has uploaded 344 CAD models & has left 1632 comments.
Marco about 8 years ago

I assume the dimensions are in inches?

Marco has uploaded 11 CAD models & has left 51 comments.
Marco about 8 years ago

Btw the eCFR links don't work in the challenge page, in order to access the correct link you need click in the links from the submission page

Marco has uploaded 11 CAD models & has left 51 comments.
Ernesto Chavez about 8 years ago

Have to agree with Flaviano. I can barely read what's in the title block.

Ernesto Chavez has uploaded 4 CAD models & has left 84 comments.
Frederik Vollbrecht about 8 years ago

I uploaded a 3D file (ipt, step, stl) for all participants.

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
souihi sami about 8 years ago

The .jpg file attached for download is difficult to read, it can mislead.
Can we have a .pdf version?

souihi sami has uploaded 7 CAD models & has left 4 comments.
SolidTweaks about 8 years ago

Interesting challenege. Not my stronger area. So good luck everyone. Looking forward to seeing innovative designs.

SolidTweaks has uploaded 12 CAD models & has left 443 comments.
Marco about 8 years ago

So there is no factor of safety criteria? Displacement? What is the bolts especifications?

Marco has uploaded 11 CAD models & has left 51 comments.
Gregory Schiller about 8 years ago

As the ULA person who helped get this challenge started, I'm thrilled with the participation, enthusiasm and great questions after only a day. We are working to get the answers to you shortly - please standby. I look forward to seeing all the competition entries. and thanks to Frederik for loading the visual!!

Gregory Schiller has uploaded 0 CAD models & has left 2 comments.
Gregory Schiller about 8 years ago

Sorry for the lack of clarity in the JPG file. We are also working to fix that.

Gregory Schiller has uploaded 0 CAD models & has left 2 comments.
Frederik Vollbrecht about 8 years ago

no problem Gregory Schiller, may you could review the file to verify it's accurate.

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
Bieber Alexis about 8 years ago

I don't really understand the "point" of this challenge, I mean there is a "specification plan" with measurements and all, but what do we have to do with it ?
So we have to design an inner structure of the part ?
Thank you in advance for clearing me out !

Bieber Alexis has uploaded 321 CAD models & has left 718 comments.
Dan Rudmin about 8 years ago

Can you give some more information about the printing process? What kind of overhang can it tolerate? What size features can it produce? Is post-machining possible?

Dan Rudmin has uploaded 2 CAD models & has left 51 comments.
Dan Rudmin about 8 years ago

There's a lot of important information missing about all of the things that contact this part? What are the mounting surfaces like? Flat? Do they have a flatness tolerance? Surface roughness? Any idea what the friction coefficient is at the interface? What about bolt loads? What size are the bolts and the bolt heads? Nuts? Is there a washer? How much tension or torque are the bolts under?

Dan Rudmin has uploaded 2 CAD models & has left 51 comments.
Enrique Carrasco about 8 years ago

Hi,
Are all dimensions in inches?

Enrique Carrasco has uploaded 3 CAD models & has left 6 comments.
Pigeon Valérian about 8 years ago

Hi, I don't really understand the sentence "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole."
The diameter of mater around the hole must be 2 times the diameter of the hole or the distance between the edge of the hole and the edge of the mater around it must be 2 times the diameter of the hole ?

Pigeon Valérian has uploaded 1 CAD models & has left 2 comments.
Yohann Panthakee about 8 years ago

Are there more photos of where it will be used on the rocket.

Yohann Panthakee has uploaded 50 CAD models & has left 103 comments.
Ankur Biswas about 8 years ago

can you please give more information about ULA Compliance Certification form?

Ankur Biswas has uploaded 5 CAD models & has left 3 comments.
Marco about 8 years ago

Just to make clear regarding the holes distance: The minimum diameter its 2 x D or 3 x D using the center of the hole?

Marco has uploaded 11 CAD models & has left 51 comments.
Enrique Carrasco about 8 years ago

What are the surface area requirements for the work platform where Datum B is shown?
Can we have a footprint of the system/object to be attached?

Enrique Carrasco has uploaded 3 CAD models & has left 6 comments.
Jahaziel Perez about 8 years ago

I am assuming everything in the drawing is in inches...right?
Any other contact surface required apart from Datum B?
Can the footprint of Datum A be reduced?
Is the 0.6radius used for load bearing or just positioning?

Jahaziel Perez has uploaded 1 CAD models & has left 6 comments.
David Badgett about 8 years ago

Greetings,

thank you for your interest in the challenge. Responses to the first few questions:

Q:[The .jpg file attached for download is difficult to read, it can mislead. We can have a .pdf version?]
A: A pdf will be uploaded shortly with improved resolution.

Q:[I assume the dimensions are in inches]
A: Yes, inches.

Q:[Did I get it right that the part has to remain as a hull with at least 0,04in walls and just gets optimized "inside".]
A:It is not a requirement to maintain the shape shown in the PDF. The final part must simply fit in the provided design envelope and conform to the envelope’s shape (e.g. curvature) at the interface points (e.g. datum A). The .04in requirement refers to the minimum thickness for final flight part walls, features, or members.

Q:[So there is no factor of safety criteria? Displacement? What is the bolts especifications?]
A:The static load case provided is the max combined load case for the bracket. Note that the loads provided are ultimate loads, which include the desired design safety factor. The holes in the design envelope allow for the bolt size required. Per the technical specs description material needs to be maintained around these holes equal to 2 times the diameter of the bolt hole (i.e. material must be maintained within the area between the edge of the bolt hole and a circle concentric with that hole that has a radius of 2.0 bolt hole diameters).

We will continue to provide clarification and responses to the remaining at the next opportunity.

Thanks,

Dave

David Badgett has uploaded 0 CAD models & has left 5 comments.
Frederik Vollbrecht about 8 years ago

Guys, if you upload samples from the sketch, be accurate! I paid attention that the sample is perfect. Think about your mates... If someone will use your parts as a base for calculation and this base is completely wrong... I would freak out if i had to start all over again!

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
Fredrik Lie Larsen about 8 years ago

Could you please include the Shear Modulus, Yield Strength and Tensile strength for the material?

Fredrik Lie Larsen has uploaded 15 CAD models & has left 64 comments.
Marco about 8 years ago

Fredrik Lie Larsen you dont need these values. Since you need consider the material in a isotropic elastic state. When you do your calculations, your von misses stress should not pass 4500 PSI.
The material have around 10000PSI Tensile Strengh, so the factor safety for this challenge is around 2

Marco has uploaded 11 CAD models & has left 51 comments.
Frederik Vollbrecht about 8 years ago

dudes... come on... google: http://www.stratasys.com/materials/fdm/~/media/83DA2BBEE7DE4A669CFEF6B1FCA118AA.ashx

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
Ian Sayers about 8 years ago

They have included "Ease of installation" as a judging criteria, but that's not really possible to design for without seeing all the components that interact with it, including the fairing, the platform, and the fasteners.

Ian Sayers has uploaded 45 CAD models & has left 41 comments.
Ian Sayers about 8 years ago

I might be missing something, but this part in the drawing is about 20 cubic inches in volume. If the S.G. of Ultem 9085 is 1.34 gm/cm3, then the part as modeled in the spec would weigh almost a full pound if printed in Ultem, right? The maximum weight req specified is 0.1 lbs, so just to be clear, they want a 90% reduction in weight from the version in the drawing?

Ian Sayers has uploaded 45 CAD models & has left 41 comments.
Michael Hellessey about 8 years ago

Hi guys, awesome challenge, looking forward to submitting a solution! I have a question about the design requirements though, you say "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole."

however the 0.27in holes are only 0.36in from the nearest edge. Which requirement takes precedent here, the slot, or material thickness?

Thanks.

http://i.imgur.com/96XTD4T.png

Michael Hellessey has uploaded 5 CAD models & has left 3 comments.
Chintan (CK) Patel about 8 years ago

Will you provide some animation video or video link, how to use of this bracket?
So we can imagination more effective design.

Chintan (CK) Patel has uploaded 32 CAD models & has left 49 comments.
Oleg Nashelskiy about 8 years ago

I second Michael Hellessey's question.

Oleg Nashelskiy has uploaded 0 CAD models & has left 1 comments.
Manoj Adavitote about 8 years ago

How to get a ULA Compliance Certification form?

Manoj Adavitote has uploaded 1 CAD models & has left 2 comments.
Frederik Vollbrecht about 8 years ago

Automatically when u upload a file via submit

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
steff evans about 8 years ago

Hi Matthew/David. Can I ask, is there a requirement for surface 'B' to remain 'intact' (i.e. is something sealed against this), or can the final surface area be reduced, providing the design constraints are met? Thanks.

steff evans has uploaded 2 CAD models & has left 11 comments.
Gary Nelson Harper about 8 years ago

I concur With Mr. Rudlin's synopsis. To what and how is the item to be mounted? Is it released? If so, is at what point? Post boost phase? or does it stay with the upper stage? Is it's release mechanical or explosive? The last project of this nature I worked upon, involved a large frozen O'ring that ending up not far from a pier in Cocoa Beach. It is rocket science... anything that can go wrong, will.

Gary Nelson Harper has uploaded 7 CAD models & has left 24 comments.
Ernesto Chavez about 8 years ago

@Gary, the tech specs above say the bracket remains with the upper stage during flight.

Ernesto Chavez has uploaded 4 CAD models & has left 84 comments.
Piotr Zaborowski about 8 years ago

I would like to raise a question which has been put here by @Ian Sayers; according to the requirements we should decrease the weight by 90%. Is that correct?

Piotr Zaborowski has uploaded 24 CAD models & has left 32 comments.
Don B about 8 years ago

wow. wow... and wow. this one should be interesting. can we get pics of the final product in place on an actual rocket? cradle to grave here please.....

Don B has uploaded 18 CAD models & has left 74 comments.
Frederik Vollbrecht about 8 years ago

What i understand is, that the goal is a Part with less or equal 0,1 lb. The origin part is only a envelope.

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
David Badgett about 8 years ago

Some more answers to your questions:

Q:[There's a lot of important information missing about all of the things that contact this part?...]
A: Information such as friction and bolt preload should be neglected. Boundary conditions can be applied directly to the bolt hole geometry, without regard to the details of the fastening system. Treat the design as an idealized part, subject to the loading, fixity, and material allowable provided.

Q:[Are there more photos of where it will be used on the rocket.]
A: Unfortunately no. This competition is uniquely different than other competitions due to ITAR concerns. We strived to construct a competition that enabled full participation but recognize we would have some concerns imposed by ITAR. We ask that participants do their best with the information we are able to provide to aid your designs.

Q:[can you please give more information about ULA Compliance Certification form?]
A: The form is included so that we may ensure ULA complies with US laws as stated in the terms and conditions of the competition.

Q: [What are the surface area requirements for the work platform where Datum B is shown? Can we have a footprint of the system/object to be attached?]
A: Surface area of Datum A and B need only meet the edge distance requirement around the attach fasteners and provide a contact patch (note that the magnitude of loading would be unchanged).

Q: [Any other contact surface required apart from Datum B? Can the footprint of Datum A be reduced? Is the 0.6radius used for load bearing or just positioning?]
A: See above

Q: [They have included "Ease of installation" as a judging criteria, but that's not really possible to design for without seeing all the components that interact with it, including the fairing, the platform, and the fasteners]
A: Similar to the question of photos, unfortunately we are limited in the amount of information we can provide about our rocket system. We ask that you do your best with the information we are able to provide. This criteria also refers to clearance between proposed design features and the bolt locations. Just ensure that somewhat normal tooling can be used to tighten the bolts on the end adjacent to the part designed (e.g. allowing room to be able to turn a wrench or something similar is a good idea)

Q: [I might be missing something, but this part in the drawing is about 20 cubic inches in volume. If the S.G. of Ultem 9085 is 1.34 gm/cm3, then the part as modeled in the spec would weigh almost a full pound if printed in Ultem, right? The maximum weight req specified is 0.1 lbs, so just to be clear, they want a 90% reduction in weight from the version in the drawing?]
A: The geometry provided is not an existing part, it only shows the maximum allowable design space that your design must stay within.

Q: [... you say "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole."however the 0.27in holes are only 0.36in from the nearest edge. Which requirement takes precedent here, the slot, or material thickness?]
A: The “slot” you are referring to is part of the bulk extruded design space that was provided. Only the indicated datum, hole locations and diameters need be preserved.

Q: [Can I ask, is there a requirement for surface 'B' to remain 'intact' (i.e. is something sealed against this), or can the final surface area be reduced, providing the design constraints are met? Thanks.]
A: See previous questions on surface area

Thanks,

Dave

David Badgett has uploaded 0 CAD models & has left 5 comments.
Jared Kizer about 8 years ago

Thank you, David Badgett, for clearing up those uncertainties as best as you can. I'm not surprised at all to find ITAR restrictions limiting the information you can give us. This is so far looking to be a very nice challenge! Thanks for bringing it to us!

Jared Kizer has uploaded 1 CAD models & has left 3 comments.
Marco about 8 years ago

I think i still have i doubt regarding: "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole."

So i created a image:
http://i.imgur.com/njbiruz.jpg

which one of the circles need be should be the minimum distance from the hole?

Marco has uploaded 11 CAD models & has left 51 comments.
Nathaniel Andresmooi about 8 years ago

Previous answer from Badgett: "Per the technical specs description material needs to be maintained around these holes equal to 2 times the diameter of the bolt hole (i.e. material must be maintained within the area between the edge of the bolt hole and a circle concentric with that hole that has a radius of 2.0 bolt hole diameters)."
A *concentric* circle with a *radius* of *2* bolt hole diameters. So the diameter of the footprint of the bolt head resting area must be 4 bolt shaft diameters in total minimum. Note two different hole diameters are present 0.22 and 0.27

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Nathaniel Andresmooi about 8 years ago

@David Badgett Can we assume all faces with a hole are at a required material dimension lets call it height. That the support face for the bolt head must be at that measurement position? Could we get a shaded drawing showing which faces must remain as they are position wise. These could change shape but not height for area around fastener.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Luis Filipe Ferreira de Moraes about 8 years ago

What is the specific gravity unit used in the material specs? lb/ft^3?

Luis Filipe Ferreira de Moraes has uploaded 8 CAD models & has left 30 comments.
Frederik Vollbrecht about 8 years ago

Specific gravity is without units https://en.wikipedia.org/wiki/Specific_gravity

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
Magnus Budge about 8 years ago

Should the center of gravity, mass and volume be close to each other?

Magnus Budge has uploaded 41 CAD models & has left 26 comments.
khalad albadi about 8 years ago

Are we allowed to use solidworks to design it?

khalad albadi has uploaded 0 CAD models & has left 1 comments.
javier alfonso davila galvez about 8 years ago

to CAD design I can use the solidwork

javier alfonso davila galvez has uploaded 0 CAD models & has left 1 comments.
Nathaniel Andresmooi about 8 years ago

No sure why specific gravity is supplied rather than material density.
Ultem 9085
Specific Gravity: 1.34
Translation (1.34) x density of H2O (1000kg/m^3) or (62.4lb/ft^3)
Supplied units are English or Imperial.
(Volume ft^3 of part) X (83.616/ft^3) will yield your part weight in pounds

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Ian Sayers about 8 years ago

I see that one judging criterion is to minimize support material used in 3d printing, and that seems very much at odds with the main goal of decreasing part weight. All the most effective ways of decreasing part weight that leverage 3DP, like latticing and skeletonizing inherently increase the support material used.

Ian Sayers has uploaded 45 CAD models & has left 41 comments.
Nathaniel Andresmooi about 8 years ago

I think what they meant by minimize support material was only to reduce final cleanup. Depending on the orientation of your print you can have a lattice with low amount of support structure.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Ernesto Chavez about 8 years ago

Question about the .27 inch diameter bolt holes (hole pattern "E"). Going by instructions, the concentric circle of material that needs to be kept around those holes ends up having a diameter of 1.08 inches. It technically violates the design envelope requirement by as much as .048 inches if you sketch it out: http://i.imgur.com/PRfMO2F.jpg

Does the design envelope requirement take precedence over the bolt hole material in this case? Can we make the concentric circle of material for this hole pattern smaller in diameter so it is still within the design envelope?

Ernesto Chavez has uploaded 4 CAD models & has left 84 comments.
Marc St-Germain about 8 years ago

How the bolt head have to sit on the surface? Actually, the 2 bottom bolt heads are sitting only on half the head... (holes are splitted in 2 parts).
Are the bolt heads needs to take place inside the enveloppe?
What are the bolt head sizes (dia. + height).
Will you use washers with the bolts?

Marc St-Germain has uploaded 7 CAD models & has left 3 comments.
Francisco J. Erenas Rivas about 8 years ago

with so few data, this seems a riddle......

Francisco J. Erenas Rivas has uploaded 41 CAD models & has left 84 comments.
Valerii Kazymirchuk about 8 years ago

Ernesto Chavez good question «Question about the .27…..»

Valerii Kazymirchuk has uploaded 22 CAD models & has left 23 comments.
Marco about 8 years ago

It is possible to create 2 parts? Or must be 1 piece only?

Marco has uploaded 11 CAD models & has left 51 comments.
David Badgett about 8 years ago

Greetings,

great feedback and discussion so far. Some more points:

Q:[The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole." which one of the circles should be the minimum distance from the hole? (jpg)]
A: The material edge should be at least 2*D away from the center of the hole.

Additional comments on a previous response:
Q:[…however the 0.27in holes are only 0.36in from the nearest edge. Which requirement takes precedent here, the slot, or material thickness?]
A2: If there is a conflict between maintaining 2D edge distance and the design space boundary, the design boundary will take precedence. In this case, the designer can elect to use the reduced edge distance for the full circumference.

Q:[Can we assume all faces with a hole are at a required material dimension lets call it height. That the support face for the bolt head must be at that measurement position? Could we get a shaded drawing showing which faces must remain as they are position wise. These could change shape but not height for area around fastener.]
A:We won’t be able to provide more pictures at this time, but we can clarify the issue further. The design space envelope has been provided in the specification. The non-design space (or that which cannot be removed) is that minimum area around each bolt hole that is located on a datum. Everything else is fair game.

Q:[Should the center of gravity, mass and volume be close to each other?]
A: This is not one of the requirements.

Q:[Are we allowed to use solidworks to design it?]
A: The file formats for each submission are listed in the requirements. The choice of software that is used is not dictated.

David Badgett has uploaded 0 CAD models & has left 5 comments.
Ernesto Chavez about 8 years ago

Well that answers my question, thanks for the response David Badgett

Ernesto Chavez has uploaded 4 CAD models & has left 84 comments.
Jack Bricusse about 8 years ago

I keep getting heavily deformed results when running my simulation, am I missing something? Even under minimal force I still get the same result. Any help will be much appreciated. Jack [Solidworks2014, Simulation]

Jack Bricusse has uploaded 3 CAD models & has left 8 comments.
David Yoon about 8 years ago

Jack, I'm not sure if your issue is just you misinterpreting the results, but FEA programs, by default, show extremely exaggerated deformations in the visualization. It can be changed within the settings to show less exaggeration or none at all.

David Yoon has uploaded 1 CAD models & has left 2 comments.
Jack Bricusse about 8 years ago

Thanks David, I do have the option to remove the deformation. I thought it might have been some error in the custom material input etc.

Jack Bricusse has uploaded 3 CAD models & has left 8 comments.
Nathaniel Andresmooi about 8 years ago

Often the deformation is upscaled by a factor of 10 or even 100 or possibly more. This is due to it being difficult to see the style in which it deforms when there is a very small change. Try to find what color shade equates to what measured amount of deformation.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
David Yoon about 8 years ago

David Badgett, can you clarify if designing the bracket to be two separate pieces is allowed or not? My understanding is that this is design for a single bracket instead of two mirrored brackets.

David Yoon has uploaded 1 CAD models & has left 2 comments.
Mikhail Osanov about 8 years ago

I have two questions regarding the non-design space. Should the minimum area around each bolt hole be uniformly maintained through the thickness? Can it taper as it travels through the structure?
Thank you!

Mikhail Osanov has uploaded 1 CAD models & has left 8 comments.
razi berg about 8 years ago

what is the "ULA Compliance Certification form" and how do I include it in my entry?

razi berg has uploaded 8 CAD models & has left 14 comments.
Nathaniel Andresmooi about 8 years ago

@David Badgett I realize your hands are tied about what you can disclose. A set of required surfaces is really a must though. There have been a few models that completely eliminate a few of what I assume are support surfaces for the boat tail interface. Flat faces where something is intended to rest. Precisely will the platform ONLY rest on the circular 4 x bolt radius platforms. Must the resting surface be at that specific height location to engage the platform.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Nathaniel Andresmooi about 8 years ago

Is the part an exposed feature? Are aerodynamics an non-issue?

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Atakan Zeybek about 8 years ago

How I can define ULTEM 9085 on solidworks ? can you answer me with message to me .Thank you...

Atakan Zeybek has uploaded 11 CAD models & has left 1 comments.
Nathaniel Andresmooi about 8 years ago

@Atakan Zeybek
https://www.youtube.com/watch?v=5AmoCh8sR5U
Here is one of several tutorials on creating materials in solid works.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Haekal Al Fatah about 8 years ago

About the ULA Compliance Certification form.
Where I can get the form?

Haekal Al Fatah has uploaded 1 CAD models & has left 1 comments.
Zulfiqar Islam about 8 years ago

I am having difficulty keeping the weight limit of 0.1 lb with maximum strength of 4500 psi. Any suggestion?

Zulfiqar Islam has uploaded 41 CAD models & has left 69 comments.
COrteX PI about 8 years ago

Is it legal to participate (and to be awarded) if we are developping similar sensible equipments in other country ?

COrteX PI has uploaded 4 CAD models & has left 5 comments.
at about 8 years ago

@COrteX PI: your country might try you for treason for working on another country's rocketry. You'd win $3,000, a cigarette, and a blindfold ;-)

at has uploaded 0 CAD models & has left 22 comments.
at about 8 years ago

@Zulfiqar Islam: in the description of your bracket, specify it for lunar use only....

Seriously, the entire point of this contest is to come up with the answer you are seeking.

at has uploaded 0 CAD models & has left 22 comments.
Mohamad Al Homsi Al Safadi about 8 years ago

what is " ULA Compliance Certification form " and how could i get ?

Mohamad Al Homsi Al Safadi has uploaded 18 CAD models & has left 2 comments.
Sebastian Argyelan about 8 years ago

I am having problems with the material, can somebody please help me and give me the material saved as a CATIA (CATMaterial) ?
Thanks in advance!

Sebastian Argyelan has uploaded 34 CAD models & has left 30 comments.
Dario Senkic about 8 years ago

Where can one find the "ULA Compliance Certification"?

Dario Senkic has uploaded 3 CAD models & has left 5 comments.
Marco about 8 years ago

How the force is applied? Its from another piece. I am asking that because the force distribution can be different. Meaning that portions of the bracket with less stiffness will receive less load, if the force is applied from other piece.

Btw. since the last answer we now have minimum radius of 2*D around every hole center where material must be preserved.

Marco has uploaded 11 CAD models & has left 51 comments.
Dario Senkic about 8 years ago

Paulina, thank you for answering. But unfortunately there was no pop-up or similar, and I've already submitted two entries. Would it be possible for you to provide a link instead?

Dario Senkic has uploaded 3 CAD models & has left 5 comments.
Alexey Gromov about 8 years ago

Hello. I have a question about the bolt connection of bracket and rocket. Probably bolts made of metal. The load on the bolts is transmitted directly to the bracket or the metallic sleeve installed in it?

Alexey Gromov has uploaded 10 CAD models & has left 49 comments.
Nathaniel Andresmooi about 8 years ago

Could a browser popup blocker interfere with Grabcads ULA Compliance Certification form popup.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Sebastian Argyelan about 8 years ago

Hy, can somebody please tell me the "Yield Strength" and the "Thermal Expansion" of the material?

Sebastian Argyelan has uploaded 34 CAD models & has left 30 comments.
Ryan Politowski about 8 years ago

hey is there a specific factor of safety that our design needs to reach?

Ryan Politowski has uploaded 4 CAD models & has left 2 comments.
razi berg about 8 years ago

when I do the simulation do I need to make the holes fixed, the back panel or the very beginning of the holes?

razi berg has uploaded 8 CAD models & has left 14 comments.
Ravi Jangir about 8 years ago

Hello Team ULA, I have a few questions here:
1. Is it possible for you to provide with an assembly of model you provided and size of bolts used? As seen for bolt pattern E there are bolts of different length used for top two and bottom two.
2. Do we have to maintain the datum surface A,B,C without any changes?
3. Finally the question about the surface around the hole. As mentioned in the competition 'The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole.' does that mean the distance from the bolt hole edge to the edge of material is 2*Dia?

Ravi Jangir has uploaded 0 CAD models & has left 2 comments.
Marco about 8 years ago

Ravi Jangir they already answered some of these questions:
here is some of the previous comments:
1- Q:[Are there more photos of where it will be used on the rocket.] A: Unfortunately no. This competition is uniquely different than other competitions due to ITAR concerns. We strived to construct a competition that enabled full participation but recognize we would have some concerns imposed by ITAR. We ask that participants do their best with the information we are able to provide to aid your designs.
2- Q: [What are the surface area requirements for the work platform where Datum B is shown? Can we have a footprint of the system/object to be attached?] A: Surface area of Datum A and B need only meet the edge distance requirement around the attach fasteners and provide a contact patch (note that the magnitude of loading would be unchanged)
3-Q:[The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole." which one of the circles should be the minimum distance from the hole? (jpg)] A: The material edge should be at least 2*D away from the center of the hole.

Marco has uploaded 11 CAD models & has left 51 comments.
Ravi Jangir about 8 years ago

Thank You for the apt reply Marco.
I believe my second question was to know if we need to retain the datum surfaces/planes A,B & C. As datum A has a curve which will be attached to the rocket, similarly the plane of datum B & C are important? And we have a constraint on position of all the bolts.

Ravi Jangir has uploaded 0 CAD models & has left 2 comments.
Marco about 8 years ago

From what i understood, you can crop these areas, but the actual face must have the same profile. For A you need keep the radius, while for B you need keep a contact plane in the exact distance from the holes. C is just used to give the tolerance of the holes.

Marco has uploaded 11 CAD models & has left 51 comments.
Matthew Perry about 8 years ago

Hi everyone! We are seeing some great design submissions so far. Keep up the great work! We've compiled answers to many of your latest questions below. If you don't see an answer to your specific question, please refer to previous responses from our Jury. Best of luck!
____
Q: [Can you clarify if designing the bracket to be two separate pieces is allowed or not? My understanding is that this is design for a single bracket instead of two mirrored brackets.]
A: The Bracket can be two pieces if they satisfy the requirements
Q: [Should the minimum area around each bolt hole be uniformly maintained through the thickness? Can it taper as it travels through the structure?]
A: Uniformly maintained
Q: [Is the part an exposed feature? Are aerodynamics an non-issue?]
A: The static loads provided are the loads to be used (see previous questions / responses)
Q: [I am having difficulty keeping the weight limit of 0.1 lb with maximum strength of 4500 psi. Any suggestion?]
A: 0.1 lb is essentially an objective for your design. Designs will be assessed based on minimizing mass pursuant to this objective.
Q: [Is it legal to participate (and to be awarded) if we are developing similar sensible equipments in other country?]
A: This is not a facet of US ITAR restrictions
Q: [How the force is applied? Its from another piece. I am asking that because the force distribution can be different. Meaning that portions of the bracket with less stiffness will receive less load, if the force is applied from other piece. Btw. since the last answer we now have minimum radius of 2*D around every hole center where material must be preserved.]
A: For simplicity, the required loading is applied uniformly to the designed interface surface
Q: [Hello. I have a question about the bolt connection of bracket and rocket. Probably bolts made of metal. The load on the bolts is transmitted directly to the bracket or the metallic sleeve installed in it?]
A: For this exercise, loads and boundary conditions are applied directly to the bracket

Matthew Perry has uploaded 0 CAD models & has left 1 comments.
Nathaniel Andresmooi about 8 years ago

So just to clarify these new details that ADD DIMENSIONS etc are Must Haves. People skipping them cannot plead ignorance of the new details despite it being in this the comments section?

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Robert Ostman about 8 years ago

well this challenge clearly only applies to those engineers ho have a fancy engineering software, like siemens nx... cost of such software.. about 70,000 USA dollars... there is no other way to provide what the challenge is asking..

Robert Ostman has uploaded 7 CAD models & has left 87 comments.
Nic about 8 years ago

Robert, I would suggest Autodesk Fusion 360, it has more CAD functionality in one package than those costing $$$. Simulation is included to guide your challenge design. You can get a free full licence as a maker/hobbyist. I'm not affiliated with Autodesk, just giving a recommendation based on experience. Enjoy and good luck.

Nic has uploaded 26 CAD models & has left 92 comments.
Dario Senkic about 8 years ago

I'd like to add that both Autodesk and Dassault offer fully functional (including FEA) student versions of their respective software for free. That includes (but not limited to) Inventor, Solidworks and as mentioned above, Fusion360.

Dario Senkic has uploaded 3 CAD models & has left 5 comments.
Ryan Politowski about 8 years ago

anyone have issues trying to submit an entry, mine froze up and i had to restart. now i dont see my model within the entries tab. unless it takes a day to be posted, idk.

Ryan Politowski has uploaded 4 CAD models & has left 2 comments.
Nathaniel Andresmooi about 8 years ago

There are several free and student versions of FEA software that one can get. http://www.autodesk.com/education/free-software/inventor-professional
Is one example. You will need to acquire the skill set to use the different softwares and do the modeling. That's likely acceptable and normal.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Frederik Vollbrecht about 8 years ago

May have a look to this:
http://www.solidthinking.com/Inspire2016.html

Frederik Vollbrecht has uploaded 1 CAD models & has left 237 comments.
Dario Senkic about 8 years ago

Ryan, you could try replacing the previous upload by uploading the same files again.

Dario Senkic has uploaded 3 CAD models & has left 5 comments.
Nathaniel Andresmooi about 8 years ago

Frederik that's a pretty awesome looking sim program. Though the kind of model its showing is very custom. Low production count maybe unless its planned to be printed? That kind of shape is really complex to machine.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Nathaniel Andresmooi about 8 years ago

Will competitors be held to the required dimensions? I know I see several models that are ignoring them in order to cut weight.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Marco about 8 years ago

Nathaniel Andresmooi some of designs are older than some requirements from ULA teaM anwsered in the comments. Some competitors will not update and others will. Others will not see the commenrs and not design according to the comments. That is the reason I think we have a delay the finalist and final result, so the community can talk about that

Marco has uploaded 11 CAD models & has left 51 comments.
Nathaniel Andresmooi about 8 years ago

That's why I brought up the subject. If they state that the redefined requirements are must have then the people who do not update are out of the running. It's abit rough but if they are pass fail requirements then there is no choice. Those of us keeping track will have made the corrections. Some have FEA some don't. etc what are the hard and fast requirements.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
razi berg about 8 years ago

If I'm making custom supports, do they need to be at least 0.04" as well?

razi berg has uploaded 8 CAD models & has left 14 comments.
Nic about 8 years ago

My question has been asked before, but I'd like some clarification on the material surrounding the bolt holes. The requirements state that material must surround bolt holes out to a radius of 2x(diameter of hole) from hole centre at the surface. Does this rule apply through out the bore of the hole, from entry surface through to exit surface, as a solid cylinder? I understand that the envelope takes precedence. The partly sectioned holes at datum C are really putting me in a head-spin as to whether they need to remain at full depth or be minimised as many entries have done.

If not, is it up to us to determine the required hole depth through simulation? Without knowing which end the attaching bolts are coming from leaves us with a bit of a conundrum.

Thanks.

Nic has uploaded 26 CAD models & has left 92 comments.
Miro K. about 8 years ago

Surface area at Datum B can be reduced? Because this reducing change significantly load distribution on contact area. If this surface located at Datum B can be reduced, simulations results tell you to use small surface (Datum B) located perpendicularly with Hole Pattern "D" - through Hole Pattern "E". Any area outside this hole patterns make things worse - like printing + support material, printing material consumption, bad results in uniformly load on "original" surface area, bigger weight. If this area can be reduced (how much?) the best results are 2 separated brackets.

Miro K. has uploaded 20 CAD models & has left 116 comments.
James Ortega about 8 years ago

My entry did not get the automatic tag "ularocket"

James Ortega has uploaded 3 CAD models & has left 4 comments.
Dennis Risser about 8 years ago

I have two questions. I apologize if they have been answered already, but I don't believe they have.

1. I know there is some "secrecy" about the type of fasteners used, but is it reasonable to assume that all connections are through-bolted (nut and bolt) and that flats should be provided on either side of the required holes?
2. If the answer so question 1 is yes, then is it allowed for said flats to violate the minimum edge distance requirement?

Thanks!

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
omar elzohairy about 8 years ago

Hello all, Can some one please tell me do we have to keep the "curvature" from the fastening side or can it be flattened and still be inside the build range ?

omar elzohairy has uploaded 10 CAD models & has left 14 comments.
razi berg about 8 years ago

Does the surrounding edge material needs to surround the hole through out its length? because in the envelope drawings there are some parts where there is only half of a hole covered, which violates tgis rule if the answer to my question is yes.

razi berg has uploaded 8 CAD models & has left 14 comments.
David Badgett about 8 years ago

Q:[If I'm making custom supports, do they need to be at least 0.04" as well?]
A: Yes.

Q:[My question has been asked before, but I'd like some clarification on the material surrounding the bolt holes. The requirements state that material must surround bolt holes out to a radius of 2x(diameter of hole) from hole centre at the surface. Does this rule apply through out the bore of the hole, from entry surface through to exit surface, as a solid cylinder? I understand that the envelope takes precedence. The partly sectioned holes at datum C are really putting me in a head-spin as to whether they need to remain at full depth or be minimised as many entries have done. If not, is it up to us to determine the required hole depth through simulation? Without knowing which end the attaching bolts are coming from leaves us with a bit of a conundrum.]
A:Edge distance should be maintained through the depth where possible. Hole depth is up to the designer.

Q:[Surface area at Datum B can be reduced? Because this reducing change significantly load distribution on contact area. If this surface located at Datum B can be reduced, simulations results tell you to use small surface (Datum B) located perpendicularly with Hole Pattern "D" - through Hole Pattern "E". Any area outside this hole patterns make things worse - like printing + support material, printing material consumption, bad results in uniformly load on "original" surface area, bigger weight. If this area can be reduced (how much?) the best results are 2 separated brackets.]
A:Yes it can be reduced. Edge distance and maximum stress should be observed.

Q:[I have two questions. I apologize if they have been answered already, but I don't believe they have.
1. I know there is some "secrecy" about the type of fasteners used, but is it reasonable to assume that all connections are through-bolted (nut and bolt) and that flats should be provided on either side of the required holes?
2. If the answer so question 1 is yes, then is it allowed for said flats to violate the minimum edge distance requirement?]
A:Boundary conditions should be applied to the holes that are provided. If the requirements already provided for the interfaces and holes are met then you will be providing “flats” already.

David Badgett has uploaded 0 CAD models & has left 5 comments.
J. F. Gomez about 8 years ago

@David Badgett: Can either of the two hole patterns be modified?

J. F. Gomez has uploaded 22 CAD models & has left 43 comments.
J. F. Gomez about 8 years ago

@Stratasys Staff: Do you have any information on yield strength for ULTEM 9085? I'm having to plug in a value for the simulation so I guessed 9KSI.

J. F. Gomez has uploaded 22 CAD models & has left 43 comments.
Nic about 8 years ago

In lieu of further information regarding how the bracket interfaces with the rocket module structure, could we please get some info on the jig that'll be used for stress testing?

Nic has uploaded 26 CAD models & has left 92 comments.
James about 8 years ago

Will the print be enabled with support material?

James has uploaded 2 CAD models & has left 6 comments.
Nathaniel Andresmooi about 8 years ago

@J F Gomez I would assume that since the slot has been placed there It passes their allowances. I would assume it is filled with a "plate" of some sort that matches the thickness of the slot.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Nikolay Atanasov about 8 years ago

My apologies people but I still can't get the answer of "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole". Probably because my bad English. In the link there is an image of this problem , please see it and tell me the answer (a, b, c, d).
https://drive.google.com/open?id=0B9GgtP5uTj0ITlZsN0NqeXB0MUE

Thank you very much.

Nikolay Atanasov has uploaded 13 CAD models & has left 10 comments.
Andrew Hanson about 8 years ago

@Stratasys Staff answers:
Q: [Do you have any information on yield strength for ULTEM 9085? I'm having to plug in a value for the simulation so I guessed 9KSI.]
A: The ASTM D638 (Type 1, 0.125”, 0.2”/min) tensile strength (yield) of U9085 is 6.8KSI (ZX oriented) and 4.8KSI (ZY oriented), but please use the material strength allowable of 4500KSI in your analysis. The Young’s Modulus is 325 KSI. The Poisson’s Ratio is 0.41.
Q: [Will the print be enabled with support material?]
A: Yes. The print will use the non-dissolvable support material normally used when running U9085 on our commercial Fortus printers.

Andrew Hanson has uploaded 0 CAD models & has left 2 comments.
Nathaniel Andresmooi about 8 years ago

@Nikolay Atanasov "A: The material edge should be at least 2*D away from the center of the hole"
The answer is your b sketch. The diameter of the hole x2. From the center of the hole is the radius of the concentric circle. The diameter of the total circle around hole is going to be 4 hole diameters. David Badgett has described this a couple times.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Nikolay Atanasov about 8 years ago

Thank you guys :) @Daniele Grandi and @Nathaniel Andresmooi.
But see, I think the answer is " d "..... Three people and three different opinions! So I can't accept this as a clear coin and I need an answer from some of the organizers of this tournament.
Thanks again.

quote from -------------------------------------
" My apologies people but I still can't get the answer of "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole". Probably because my bad English. In the link there is an image of this problem , please see it and tell me the answer (a, b, c, d).
https://drive.google.com/open?id=0B9GgtP5uTj0ITlZsN0NqeXB0MUE

Thank you very much. "
-----------------------------------------------------

Nikolay Atanasov has uploaded 13 CAD models & has left 10 comments.
Nic about 8 years ago

Hey Nikolay, the answer is B. David Badgett has answered your question a while ago, "Per the technical specs description material needs to be maintained around these holes equal to 2 times the diameter of the bolt hole (i.e. material must be maintained within the area between the edge of the bolt hole and a circle concentric with that hole that has a radius of 2.0 bolt hole diameters).". It's in a comment from 20 days ago. Cheers

Nic has uploaded 26 CAD models & has left 92 comments.
Nathaniel Andresmooi about 8 years ago

"A: The material edge should be at least 2*D away from the center of the hole" Is actually a Badgett quote. There is a place on the design where they violate this with their own envelope but since they did it it is acceptable. You diagram D is only one diameter from center to edge distance.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Nikolay Atanasov about 8 years ago

Well then , I'll consider " b " as a right answer . Thank you guys!

Nikolay Atanasov has uploaded 13 CAD models & has left 10 comments.
Jan Hedlund about 8 years ago

@Hanson
Just to prevent any misunderstandings.
The allowable stress is 4500 PSI and not 4500 KSI.
See that some use MPa as unit and then the allowable strength is 31 MPa.

Jan Hedlund has uploaded 1 CAD models & has left 3 comments.
Jan Hedlund about 8 years ago

Sorry to say it, but the rules of this competition and lack of crucial information about how to constrain the model for FEM analysis made me delete my entries.

It's quite surprising that so few read the rules of the competition and upload models that clearly violate the rules.
Some education about how to use FEM analysis wouldn't hurt eighter...

Good luck to you all...

Jan Hedlund has uploaded 1 CAD models & has left 3 comments.
Ian Sayers about 8 years ago

4.5 KSI is 4,500 PSI, not 45,000

Ian Sayers has uploaded 45 CAD models & has left 41 comments.
Nathaniel Andresmooi about 8 years ago

My mistake I was tired. 4500KSI = 45,000 PSI or 4.5KSI = 4500 PSI The spec at the top of page references "Material Strength Allowable: 4500 PSI" Andrew Hanson recently said " please use the material strength allowable of 4500KSI in your analysis." I believe he meant PSI.
http://usglobalimages.stratasys.com/Main/Files/Material_Spec_Sheets/MSS_FDM_ULTEM9085.pdf
The flex strength (lower value is 9900 PSI) using the factor of safety of 2 they said they factored in. Approx 4500PSI the value I would guess is right one. (not 4500 KSI)

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Andrew Hanson about 8 years ago

Jan Hedlund and Nathaniel Andresmooi: I apologize for the confusion and typo. You are correct the material strength allowable is 4500PSI (or 4.5KSI).

Andrew Hanson has uploaded 0 CAD models & has left 2 comments.
Ian Sayers about 8 years ago

what load calculations are required for submission? Just the factor of safety?

Ian Sayers has uploaded 45 CAD models & has left 41 comments.
Ian Sayers about 8 years ago

are multiple entries allowed?

Ian Sayers has uploaded 45 CAD models & has left 41 comments.
Nathaniel Andresmooi about 8 years ago

@Ian Sayers The multiple entries question has been asked before yes you can. ULA wanted FEA done which is load analysis done with a modeling program. They instructed us to use Material Strength Allowable: 4500 PSI as they have already included factor of safety in that at a load of 600lb force.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
David Badgett about 8 years ago

Greetings, all. Just a short time left in the challenge, and wanted to communicate my appreciation and excitement for the enthusiasm and innovation we have seen so far. I am also very impressed with the support that the members of the community offer one another, very positive! As a note, we will soon be uploading a document that summarizes the Question and Answer discussion we have had clarifying the specs and the design volume drawing. Keep in mind that the original posted specs and requirements are still valid and sufficient to complete the challenge; we began to see viable designs dropped within the first 24 hrs! The document will capture the discussion to date for any working on the challenge these last few days. Thanks again,

Dave

David Badgett has uploaded 0 CAD models & has left 5 comments.
James about 8 years ago

Is the surface below "Datum B" supported? I am referring to the surface parallel to Datum B and below it in the Z axis.

Thanks!

James has uploaded 2 CAD models & has left 6 comments.
James about 8 years ago

Does the full "B Surface" need to be preserved? Can it be shaved down to reduce the moment on the horizontal bolt flange?

James has uploaded 2 CAD models & has left 6 comments.
Nathaniel Andresmooi about 8 years ago

The only surface specs they have admitted to are the 2*Diameter of a hole distance from center of same hole. Or 4*D centered on hole.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
James about 8 years ago

The constraint for the vertical bolts is unclear. How do those bolts take any load? Seems that by pressing down on Datum "B", that Datum "B" can just move away from those 2 bolts. Any supports underneath? My guess is yes, but it doesn't define that here anywhere.

James has uploaded 2 CAD models & has left 6 comments.
Scott Winroth about 8 years ago

The contest is showing that the deadline has passed but it is only 11:17 pm UTC. Deadline is supposed to be 11:59 pm UTC. Is this correct?

Scott Winroth has uploaded 2 CAD models & has left 4 comments.
igor Nikol about 8 years ago

If it possible add additional files into my entry ULAbra 18 bcut which was added before 11.59 UTC.

igor Nikol has uploaded 14 CAD models & has left 25 comments.
Scott Winroth about 8 years ago

I was able to click on the "submit entry" button and upload my files around 11:15 pm UTC. But now I don't see them on the entries page. It is still only 11:36 pm UTC right now. There should be about 24 minutes left to submit entries.

Scott Winroth has uploaded 2 CAD models & has left 4 comments.
igor Nikol about 8 years ago

It was added in around 11.30 UTC. Thank you.

igor Nikol has uploaded 14 CAD models & has left 25 comments.
James about 8 years ago

This ended before the posted deadline! Where do I submit?

James has uploaded 2 CAD models & has left 6 comments.
Scott Winroth about 8 years ago

James, it appears that the submission deadline ended an hour earlier than it was supposed to. I had the same problem. I have uploaded my files and added the tags rockethardware and ularocket. Hopefully they will still honor the submissions. Good luck.

Scott Winroth has uploaded 2 CAD models & has left 4 comments.
Christopher Tenelsen about 8 years ago

There was no automatic "ularocket" tag in my entry, and I deleted nothing. But I've seen there is no "ularocket" tag in serveral entries as well. Are our entries still valid?

Christopher Tenelsen has uploaded 3 CAD models & has left 5 comments.
James about 8 years ago

Thanks, yes I am trying to get in touch with Matthew Perry. I put 40-50 hours into this. I really hope it doesn't go to waste because of a mistake on this website.

James has uploaded 2 CAD models & has left 6 comments.
Scott Winroth about 8 years ago

I have also sent an email to challenges@grabcad.com to alert them of the issue. If you hear anything about what they plan to do for people that uploaded their files before the 11:59 UTC deadline but weren't able to submit an entry please post it here. Thanks

Scott Winroth has uploaded 2 CAD models & has left 4 comments.
Marcin Szymanski about 8 years ago

Hi all, I have noticed that "ularocket" tag was not working. If you added the model through challenge site, there was "rockethardware" tag added. I think it was the right keyword.

Marcin Szymanski has uploaded 4 CAD models & has left 6 comments.
Joel Soh Andu about 8 years ago

Hi Paulina Perepelkin. Thanks for the clarification and affirmation. I was worried but thanks for letting us know the problem now. Hope you guys will be benefited with the great new ideas and designs.

Joel Soh Andu has uploaded 1 CAD models & has left 1 comments.
Hein Miessner about 8 years ago

Just a note to all judges and participants on the FEA studies done on the entries. Ultem 9085, like many other plastics is a non-linear material. If any of these participants did their FEA study without taking into account the stress vs. strain for this non-linear material, this will mean the results are totally wrong and stresses could be much higher than shown. Meaning safety factors are also wrong.

Doing the correct FEA study not only means taking into account stress vs Strain values, but also using the correct non-linear solver provided by a FEA program to solve it. These factors could mean that most entries claiming certain maximum stress and deformation values, could be totally wrong and out by a large percentage.

I think to be fair to all participants this factor should be checked. It would thus be fair to the participants that perhaps the best entries be properly tested to ensure participants get judged fairly on their designs. Just to mention, I am a certified FEA specialist, thus the concern and knowledge on the subject.

Hein Miessner has uploaded 29 CAD models & has left 66 comments.
steff evans about 8 years ago

Hi @Hein Miessner,

Thanks for your interesting comments regarding Ultem 9085 material non-linearity. It's good to see that people are being rigorous with their analysis.

A simple literature review shows that for a limiting stress of 4500psi (31.0MPa), Ultem 9085 is within the linear portion of the stress/strain curve, see Figure 5 [1]. However, there is some anisotropy in the 'X/Z vs Y' build direction, which could result in erroneous output. However, sensible consideration of the part orientation results in a component which is insensitive to this anisotropy. Thus, a non-linear material solution is not required (and in fact would add unnecessary complexity to a trivial FEA solution).

Other potential non-linearities (large displacement/contact) can be easily understood by the appropriate verification of the load/displacement response and reaction forces. This could be an issue for very flexible designs, but in the large part will not.

However, that said, one major area which is open to question is the element formulation and mesh density used in predicting stress and safety factors. Low-order, coarse meshes will certainly result in an under-prediction of stresses. Without a mesh density convergence study, it is difficult to justify any numerical values for this type of detailed model.

I hope you find my comments constructive.

Thanks,

Dr Steffan Evans
NAFEMS Professional Simulation Enginer (Advanced Level)

Reference
[1]http://www.stratasys.com/~/media/Main/Files/FDM%20Test%20Reports/FDM%20Part%20Quality%20Manufactured%20with%20Ultem.pdf

steff evans has uploaded 2 CAD models & has left 11 comments.
Christopher Tenelsen about 8 years ago

Hi @steff evans, thanks for your really interesting comment. First of all sorry for my english and I'm not sure if I understand your comment in detail... So first I was confused about this challenge because I was sure that it´s not simply possible to do FEA simulations with 3D printed parts (especially for FDM). I had in mind that the biggest problem is the orientation of the layers and that the bonding between these layers ...My professor at my University Paderborn for "additive manufacturing" said that, too. And I know there are still some researches to get FEM Simulations improved for additive manufacturing. So I said to me, okay maybe ULA just can´t assume that the participants know how to do those FEM simulations for FDM parts cause there are barely no possibilties. The safetyfactor of 2 (4500PSI) forced my assumption to be fine with "normal" linear FEM simulations.

Now when I read your comment I´m even happier with my assumption because for me it sounds that you are like an expert for FEM / FEA... But I´m still confused of the facts my professor said to me... and here is the clue and the main reason I answered your comment, it also gave me a big smile on my face.... in your References (link) one of the author is Dr. Eric Klemp (my professor :-D ) and these researches are from the DMRC that belongs to my university, I did some 3D printing workshops there in the summer. "The world is small" As we would say in germany. And this must be totally coincidence.

Still there is the unansweard question if we can assume that all our calculations with the linear or even non-linear method are correct ? Or is it even possible to do these calculations with regular FEM Simulations?

Tanks to you !

Christopher Tenelsen has uploaded 3 CAD models & has left 5 comments.
Hein Miessner about 8 years ago

Hi Steff

I find your comments constructive yes. Up to 31MPa the material is more linear I agree. But with that being said it still is not 100% linear. Some small percentage errors can still be made. And working within such very tight design constraints it might be beneficial to be more exact with the solution.

Also another origin of non-linearity being present in a model that you did not mention is thin walled components. Which are present in many of these designs. These thin walls (up to almost 1mm thin) are more likely to deflect under stretching and bending and can be the cause of induced stresses and deformations that will not be captured using a non-linear FEA model. Also taken into account the lower stiffness of Ultem 9085 compared to lets say metals like normal mild steel, the possibility of big changes in stiffness is high. This means that one needs to abandon the assumptions that stiffness is constant. The non-linear model will allow the stiffness matrix to be updated as the solver progresses through the iterations. Capturing these possible non-linearaties forming. But lets not go into more detail into this factor.

All this being said I totally agree on the meshing issue. 2nd order meshes should be sufficient but there is no way of knowing whether the participants used a fine enough mesh refinement to ensure the aspect ratios of the elements are within limits for accuracy. And also finer meshes in high stress areas to predict more accurate stresses.

Not even to mention the possible mistakes made in over or under constaining the model that would produce inaccurate nodal displacements which will result in very innaccurate stress calculations. And finally making sure the correct contact sets are used relating to either bonded or no penetration contact types. This will also have a great effect on the results. At the end of the day you want to use the software to come as close as possible to the real results.

What I am trying to say is at the end of the day...For everyone to have a fair chance with their designs. The brackets should be tested by a professional with FEA to verify the stress results. It is very easy with FEA to manipulate your results to look more pleasing but they are not really the truth. The designs need to be tested under the same conditions and the same baselines to esnure the best one is actually chosen.

Hein Miessner has uploaded 29 CAD models & has left 66 comments.
Nathaniel Andresmooi about 8 years ago

http://usglobalimages.stratasys.com/Main/Files/Material_Spec_Sheets/MSS_FDM_ULTEM9085.pdf

I don't know if you guys reviewed the data sheet. The supplied value that we were given is the least strong direction ZX orientation. 9900 psi which they divided by 2 and rounded to get 4500psi. (Fairly certain) In the Stronger direction of layers XZ the strength is 16,200 psi or approx 8000psi when divided by 2.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Wilbert Engels about 8 years ago

It's a very interesting discussion of how to use FEA in engineering but in this design challenge, the boundary conditions are the material data supplied by ULA. So it's important - as "Marco" said about a month ago - to make sure that the von Mises equivalent stress doesn't exceed 4,5 ksi and assume isotropic linear elastic material behaviour (up to 4,5 ksi).

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Hein Miessner about 8 years ago

Hi Wilbert. There is so much more to FEA than just material data. That is just the measuring stick for failure and safety factors and a really small part of the total picture when it comes to FEA. The working principal is the most important and how they features of FEA are used to calculate these equivalent stresses in FEA. When used wrong by inexperienced users, FEA becomes worthless when it comes to accuracy and results. And we are not talking here about a small percentage mistake that could be made. The results could be out by a factor of 2 or 3 or even more.

FEA is a junk in junk out type of software. Its really easy to get results, but you can also really easily get totally wrong results. There is a reason why people study FEA for months and years before actually being able to grasp how to use it properly and accurately. Small inputs make big differences. And with FEA it is also easy to "cook the books" to make the results look more favourable. Thus the idea of independantly analizing the designs under the same conditions just to be fair towards all entrants.

@Nathaniel. Yes did review the data sheet. The fact that the material is actually anisotropic makes the whole thing even more difficult. Hence the assumptions to make it easier yes. You can with some more effort correctly define this material in FEA to be simulated with this anisotropy taken into account. But that would possibly be a bit overkill in this situation.

@Christopher. FEA on 3D printed parts is very challenging yes. But with some careful considerations it is possible. We use a lot of 3D printed parts as functional prototypes and some as actual functioning mechanical parts. These are all FEA tested by us during the design phase. Doing FEA on 3D printed parts involves some simplifications and assumptions in order to model it so a solid part behaves as if it was printed. This involves test samples that were tested to determine the exact material properties using a certain infill when printing and sticking with that during production. However at its best this is still an approxiamtion and absolute values for stresses are more dependant on the actual material geometry. We do this in house with 3D printed parts with success to a certain extent that matches the final prototypes during physical testing.

Another route to take, if you have the time which you will need plenty of for this, is explicit modelling of the exact 3D printed part. This requires however complete knowledge of every void space in your 3D printed part. Modelling like this is very time consuming and not to mention the complexities it adds to your FEA analysis. And also the possibility exists that your 3D mesh will be so big with millions of elements that most computers won't even be able to solve it with the available hardware.

Fingers crossed that in the near future we will see FEA software that will come with built in features that will allow more effective and easier analysis of 3D printed parts. I strongly believe that with the fast growth that we have seen over the last couple of years in additive manufacturing in industry that this is a very strong possibility.

Hein Miessner has uploaded 29 CAD models & has left 66 comments.
Wilbert Engels about 8 years ago

Hi Hein,

I know; I've studied mechanics and FEA for years and lots of experience with high end FEA. But that doesn't change the idea behind the challenge.

I think all boundary conditions given provide lots of room for people to use their creativity on a design and start thinking about possibilities in 3D printing, load path analysis, structural design of lightweight constructions etc. without going crazy on using FE software.

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Marco about 8 years ago

Just a observation: whenever there is a challenge with FEA involved, for example:
https://grabcad.com/challenges/airplane-bearing-bracket-challenge and https://grabcad.com/challenges/ge-jet-engine-bracket-challenge
people will argue about FEA parameters.
There is so many variables involved in FEA, that not knowing exactly the boundary conditions or mesh used to evaluate the model by jury can disqualify entrys that could be ok according to the requirements while anothers that are off the requirements can be accepted because it passed in jury internal criteria.
For example, in my opinion the uniformly applied force isnt correct, because force is transmitted by another body face. If this face doesn't deform that easily (metal body) a higher contact pressure would be located in regions with higher stiffness, and that way reducing the stress in some locations of the model.
You guys can be sure that going to be way more discussion about the FEA when they announce the finalists.

Marco has uploaded 11 CAD models & has left 51 comments.
Nathaniel Andresmooi about 8 years ago

ULA should be doing their own final FEA for judging purposes. That way each of the parts who are in the running are using standardized methods. If you did a good job with the way you set up your FEA the results should be similar to ULAs results. And for those that made a decent model they might not be immediately out of the running simply for not having good FEA.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Christopher Tenelsen about 8 years ago

@Hein
Thanks to your informative comment, I feel a bit inexperienced with you FEA pros.

Hope my calculations are correct and that the bracket can withstand the 600 (300 lbf pp). I did my best with designing, printing orientation, flow of force etc. I printed it with my home printer (material: PLA) when I have the time and possibilties I would like to do some real experiment to find out the strength of my design.

Christopher Tenelsen has uploaded 3 CAD models & has left 5 comments.
Wilbert Engels about 8 years ago

@ Marco
I agree with you that there will always be discussion about FEA. In my opinion, it’s easy to loose oneself in going way too deep into FEA when actually performing engineering work. The funny thing is, in this challenge I tried to design the bracket not using FEA but old school mechanics. I only used FEA to check on these calculations and see how a certain stress riser in my design(s) could be negated. I also had to use mechanics to check on the contact/radii singularity at the bolt holes.

About the pressure/force acting on datum B. That might nog be how forces are transmitted in real life. But the same applies to the boundary conditions at the bolts. In this challenge it’s not about real life but just making a design within the rules and boundaries given.

@ Nathaniel Andresmooi
I don’t know if ULA is going to check all designs using FEA; that’s up to the jury who I think, looking at their job descriptions, are surely capable in judging the designs. I really appreciated the comments of mr. Badgett on certain questions: everything was already explained clear enough in the original rules / specifications. BTW why use FEA? I can’t recall ULA asking for FE analysis, only load calculations. See also my comment on mechanics above.

Anyway, I really liked this challenge, I do know quite some about FEA but up till this challenge, little to nothing about AM. I was “forced” to look into those technologies and in the end, I learned something new. Great!

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Nathaniel Andresmooi about 8 years ago

@ Wilbert Engels The reason FEA was fairly forced is that these parts do not lend themselves to hand calcs. The parts are very complex and the math to do the calcs by hand fast gets out of hand.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Wilbert Engels about 8 years ago

Hi Nathaniel,

I agree. If needed, because of complex geometries etc, FEA is a very powerful tool to get answers. But only if used correctly. What I meant in previous posts is that sometimes, or rather often, I get the feeling that people think that use of FEA is a goal of engineering projects, skipping other steps a load path analysis etc.

And then, as Hein Miessner wrote, FEA can be a real "crap in - crap out" kind of software, especially if users don't have proper knowledge of mechanical theory and limitations of (certain) FE software.

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Jack Nguyen about 8 years ago

@Tory Bruno and ULA Team: From 'The Great Rocket Race' article in the Nov. 1, 2016 issue of Fortune (http://fortune.com/spacex-ula-lockheed-boeing-rocket-race/) I wonder why ULA does not (or cannot) build exact copies of the purchased, technology proven, reliable, Russia built RD-180 1st-stage rocket engines, for launch missions planned to year 2030 or beyond, while also working on new reusable engines/boosters like what SpaceX and Blue Origin currently have?

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Nathaniel Andresmooi about 8 years ago

Likely ownership issues. I'm sure that's part of the cloak and dagger of designing parts like this. Besides I think they are trying to find a better method rather than better rockets.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
razi berg about 8 years ago

Will the finalists really be announced today?

razi berg has uploaded 8 CAD models & has left 14 comments.
Dennis Risser about 8 years ago

I take that as a no. Not surprising, considering if you look at the egg drop challenge, they still haven't released the winners even though it was supposed to be done over a month ago.

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
Chintan (CK) Patel about 8 years ago

@Dennis Risser : you are absolutely wrigh..

Chintan (CK) Patel has uploaded 32 CAD models & has left 49 comments.
Adriano Ordoz Barissa about 8 years ago

It has been a while since Ben Ewing did not participate in the jury and organization of the challenges, after he stopped participating I noticed that the results began to delay.
Does he no longer work on GrabCad?

Adriano Ordoz Barissa has uploaded 78 CAD models & has left 391 comments.
James Ortega about 8 years ago

Entry deadline is October 23, 2016 (11:59pm UTC). - The finalists will be announced by November 18, 2016. - The winners will be announced by December 9, 2016. So what is the delay?

James Ortega has uploaded 3 CAD models & has left 4 comments.
mohamed khan about 8 years ago

Hey boys This is Rocket Science so you have to wait until they release may be they have tested our design

mohamed khan has uploaded 50 CAD models & has left 88 comments.
Grant Thomas-Lepore about 8 years ago

Hi all, sorry for the delay. The short explanation - so many good entries! The long answer - sometimes when there are special entry requirements and/or a large number of entries (both of which are true here), it can take longer than anticipated to go through all the entries and give each one the consideration and evaluation it deserves. That said, we should be announcing the finalists tomorrow! Remember that the finalists then go through additional testing and evaluation before we pick the 3 winners by December 9th. Thank you for all your entries, we've seen some truly exceptional submissions in this Challenge that are really something to be proud of.

Grant Thomas-Lepore has uploaded 4 CAD models & has left 33 comments.
Dennis Risser about 8 years ago

Thank you for the update Grant. I look forward to seeing the results! Good luck everyone.

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
James Ortega about 8 years ago

Congratulations to the finalists!

James Ortega has uploaded 3 CAD models & has left 4 comments.
Winston Jennings about 8 years ago

Good luck to the finalists!

Winston Jennings has uploaded 279 CAD models & has left 883 comments.
Winston Jennings about 8 years ago

Congrats Dennis Risser, your interests paid off.

Winston Jennings has uploaded 279 CAD models & has left 883 comments.
Christopher Tenelsen about 8 years ago

Congratulations to the finalists !

But can someone explain me, why the design "ULA ROCKET BOATAIL BRACKET" by richard.spehr gets to the finalists ? It clearly seems like that he violates the requirements while not having any FEA or any other stress calculations and absoluetly does not fulfill the maximum part weight with 0.48 lb by nearly 500% !

Please, richard.spher do not take this personally, but I think this jury-decision is a bit unfair for the other participants.

Christopher Tenelsen has uploaded 3 CAD models & has left 5 comments.
Wilbert Engels about 8 years ago

Also not wanting to criticise Richard Spher but the selection of some of the entries could be taken as an insult by participants that invested a lot of time in their design.

I know, having fun trying to design as close to the limits as possible (in my interpretation), I might have stretched the rules a bit too far but I totally agree with Christopher Tenelsen. I also wonder how black anodizing would be done on Ultem 9085? I thought only aluminum could be treated that way!

But anyway, congratulations to all the finalists. And, Dennis Risser, you got my vote!

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
hartanto prawibowo about 8 years ago

Congratulations for all finalists... good and great for all enteries. Good luck for next step

hartanto prawibowo has uploaded 7 CAD models & has left 10 comments.
Dennis Risser about 8 years ago

Congratulations everyone! I'm excited to see how testing goes on all the final models. Thank you Wilbert, I appreciate it. And congrats to you as well Winston.

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
Vishal Gandhele about 8 years ago

Congratulations to all the finalists...

Vishal Gandhele has uploaded 6 CAD models & has left 12 comments.
Sathish Kumar Sivaraman about 8 years ago

Thanks Grab CAD and ULA Team for this great challenge, Excited to see the test results. Congratulations to all finalist.

Sathish Kumar Sivaraman has uploaded 1 CAD models & has left 18 comments.
Michele Cantatore about 8 years ago

@Christofer Tenelsen, I agree with you ....it seems that the jury has been a little bit surficial....in any case there are interesting designs among the finalists...

Michele Cantatore has uploaded 60 CAD models & has left 40 comments.
David Ornelas about 8 years ago

Congratulations to all the finalist and the other almost 400 other entries. Really cool seeing ideas proposed that can only be 3D printed (lots of out of the box thinking). The possibilities seam endless. Great challenge GrabCAD and ULA!!!

David Ornelas has uploaded 1 CAD models & has left 7 comments.
Josh Garcia about 8 years ago

Thank you GrabCAD and ULA! This was a great challenge. Congratulations to all!

Josh Garcia has uploaded 0 CAD models & has left 2 comments.
Miroslav about 8 years ago

@Christofer Tenelsen, I also agree with you... I would like to know how you going to tighten the screws in the hole pattern "D". Lower two screws rest on only half of the surface. How this fits in your requirement: "The minimum edge distance surrounding all bolt holes shall be 2 times the diameter of the bolt hole."?
Most of this designs requires a fair amount of supporting material that will be hard to remove.
It looks that some of the finalist are chosen by random. My personal (and professional) opinion is that there is far more better designs.
Sorry, nothing personal. Good luck to all!

Miroslav has uploaded 5 CAD models & has left 5 comments.
omar elzohairy about 8 years ago

Congrats to the finalist,
@Christopher Tenelsen I totaly agree with you and unfortunately there are excellent designs that didn't make it to the finalist....
by all means Congrats and good luck to all.

omar elzohairy has uploaded 10 CAD models & has left 14 comments.
Miro K. about 8 years ago

@Christopher Tenelsen I agree with you, and we can continue, ULA_Bracket_Concept_1 by sathish.kumar.sivaraman-1 has exceeded allowable strenght >8x ... this is nothing to that design, do not get me wrong, especially Sathish, your design is nice, but if you do your FEA calculation right, you will see that. I have not checked others designs with FEA, that is role for ula team, not my. But my question is, why were specified rules, when they are not taken into account? Who selected finalists? That tells a lot about ULA responsibility or interest.

Miro K. has uploaded 20 CAD models & has left 116 comments.
omar elzohairy about 8 years ago

@Miro K. Yes you are absolutely right, testing the design results in more than 35,000 psi. I really wonder how did it pass ?

omar elzohairy has uploaded 10 CAD models & has left 14 comments.
Miro K. about 8 years ago

And Sathish provided that result also online, so they can not say "we made mistake in retesting design", because that result is provided.
cmon ULA, was not it in way, where you are selected 1-3 winners, and rest was added randomly? I am asking this not for me, but for rest of perfect designs where was great expectations of progress, but yeah, maybe you clarify.

Miro K. has uploaded 20 CAD models & has left 116 comments.
David Ornelas about 8 years ago

Many times if a designer has a good story of why he designed something a certain way, he can sell me on his idea. The following comments are designed to stir the pot for comments from the 14 other finalist and others 370 plus contestants. It is not an indictment of a certain design but how to improve your next design. To give a comment, you have to be willing to receive a comment. So lets get this discussion started. If I am wrong let me know.

If Datum B is to be respected, then two piece designs should be reevaluated. Not because they are not good, but because of the following: The four mounting holes are clearance holes for #10 fasteners. For the two piece designs, Datum B could be off relative to each other part by +/- .030. So one part could be high and one part low for a total offset of .060. A way to solve this issue would be to add peel ply shim to each part during installation. However peel ply shimming is time consuming and requires the shim to be bonded and lots of measuring to get both parts to be on Datum B. Another way to solve the Datum B issue is to build a tool to hold the two parts together in an assembly. However if you have to build a tool, then the one piece parts should be considered over the two piece parts.

Evaluating Cameron Navarre's two piece design, I believe his design used the “keep it simple stupid” principle known as KISS. The 3 pieces for each side are simple to 3D print. The way the parts fit together is really nice. A tolerance study would be needed to ensure the parts always fit together, otherwise one is hand finishing each part for a perfect fit. This could be time consuming. Also bonding of parts should be considered to build an assembly for ease of installation. I really like this design for its simplicity. He definitely kept it simple. A++. (See my Datum B rant above, I apologize now to the two piece designers)

Evaluating Sathish Kumar Sivaraman's design, I believe this design to be on the opposite spectrum from Cameron Navarre's design. It is not simple at all, but very cool. Very nice on the eyes, and it drive one to keep coming back to look at it. I could see this part in an art museum on a white background and designers standing around it with their hand on their face saying “uhm”. Now back to reality: picture a mechanic with 12 of these parts on a hook around one of the edges of the butterfly wings and the edge breaks as he is climbing up the platform. Now what do you do with the parts? The part seems too fragile. Remember this saying applies to engineering too, “just because you can, does not mean you should”. Still a A++ for thinking out of the box. If I could, I would give you the “So Cool Award!!!!!!”

Evaluating the one piece designs, Datum B is maintained on a plane (unlike two piece designs) and the curvature of Datum A drives Datum B to be perpendicular to Datum A.

Evaluation all designs:
On installation of the one piece parts onto the fairing, it is always best to use the same length fasteners. If the fasteners are different lengths (as I saw on a few designs), imagine a mechanic on a platform 20 feet in the air who installs a short fastener and a long fastener in the wrong holes. Now he comes back down to the engineer and says the fasteners have the wrong grips. If it can go wrong it will.

I did see few designs that showed fasteners, washers, nuts, fairing and platform in their design. There was only one design that showed a tool interface into all six fastener installations. Evaluating all of these features shows that the designer looked at his interfaces and understood them.

I saw only a few designs that had a strong Part Description. As engineers you need to know how to explain or sale your design.

All had some sort of stress analysis as required. I am far from being an analyst so the stress guys need to comment about material, section properties and free body diagrams, FEM, etc.

David Ornelas has uploaded 1 CAD models & has left 7 comments.
David Ornelas about 8 years ago

Concerning comments about how the judges evaluated then entries: I believe the judges saw what I saw when I looked at many of the entries. Many entries did not have the following included or meet the technical requirements below. Evaluating was performed per the Judging Criteria below.
YOUR ENTRY MUST INCLUDE:
STEP/IGES formatted files
Description of the bracket
Any render or image files (jpeg, png, etc)
Mass
Volume
Load calculations
ULA Compliance Certification form
TECHNICAL REQUIREMENTS:
All portions of the bracket must remain within the envelope shown in the Part
Design Envelope drawing.
The part will be fastened to the vehicle interface at datum A using 4 bolts shown
as holes in the envelope drawing.
A load from the work platform will be applied uniformly on a surface located at
datum B and will be fastened using 2 bolts shown as holes in the envelope
drawing.
The minimum edge distance surrounding all bolt holes shall be 2 times the
diameter of the bolt hole.
Maximum part weight: 0.1 lb
Minimum wall thickness: 0.040 inches
Ultimate load (due to work platform): 600 lbf applied uniformly in the negative
Z direction.
Required material: Ultem 9085
JUDGING CRITERIA: Judging criteria will be based on achievement of
accomplishing criteria listed above, including:
Pass/Fail – meets the part design requirements
Minimize final part mass
Minimize total part material volume including print support material as
measured in cubic inches
Unique features that leverage additive manufacturing technology
Use of good design practices (e.g. proper load path, sufficient radii, etc)
Ease of installation – takes into account tool access clearance, bolt/nut
clearance, etc.

David Ornelas has uploaded 1 CAD models & has left 7 comments.
Wilbert Engels about 8 years ago

Hi David,

Congratulations on making it to the final, but I don't quite understand your last post: I know what was said about what had to be included in each entry, the technical requirements and judging criteria. But most of the finalists don't fullfil these.
Don't get me wrong, but your design is one of the designs that don't meet (all of) the requirements: 4500 psi (31 MPa) is exceeded in large areas of your model as can be seen in the stress plot you've encluded!

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Ernesto Chavez about 8 years ago

Have you considered the possibility that maybe ULA's FEA setup might have been different to what any of the participants had? I find it hard to believe that they would purposely select finalists that didn't meet their stress analysis requirements, leading me to believe their FEA must've been setup in such a way that can't possibly be discussed with us due to ITAR. Therefore while some of the finalists' entries may have failed with our own FEA setups, perhaps they didn't with the way ULA did their setup. Who knows, just a thought.

Ernesto Chavez has uploaded 4 CAD models & has left 84 comments.
Wilbert Engels about 8 years ago

Hi Ernesto,

I don't think ITAR has something to do with FE setup. Also, in this challenge, the conditions were exactly specified. So it shouldn't make a difference at all. The issue is selecting entries that do not meet the requirements at all, looking at the info given by the participants themselves (or even lacking required information).

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
David Ornelas about 8 years ago

Thanks Wilbert for replying. As I stated early in one of my two comments, I leave the stress analysis to the analysts of which I am not. But I tried. I did notice that at least 7 other designs are very similar in look, mass and volume. Their analysis shows 4500 psi limits. So I believe I was on the right track, but a poor analysis. I believe the testing will proof the designs. I hope my comments are not seen as harsh; that was not my intent. In my real life I am use to hashing details out with team members in an open and honest matter. Oh, I am NOT right all the time. Thanks again

David Ornelas has uploaded 1 CAD models & has left 7 comments.
ANOUAR BARODI about 8 years ago

Congrats to the finalist, and good luck to all !!!

ANOUAR BARODI has uploaded 98 CAD models & has left 1654 comments.
Jack Nguyen about 8 years ago

Here's my review of the 15 finalists...

https://www.dropbox.com/s/z4ujh95cxmimbja/ULA%20Finalists%20Review%20by%20JN.pdf?dl=0

Have a look... and chime in if you agree or disagree. -JN

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Dennis Risser about 8 years ago

While I would agree with your analysis on some of the models, where the violation of the minimum edge distance rule is blatantly obvious, there are many models that I would deem as passing. Many of the models violate the rule to such a small degree to likely be within the build tolerance of the part. Further, if you truly don't violate this rule, you have sharp edges on your part which are just a stress risers. For example, if you look at my part, you will see the only reason it violates this rule is because of a fillet at the top edge. I would imagine the judges would appraise this with some tolerance in mind.

Also, is your 4 bolt pattern normal to the curved envelope or are they all parallel? Hole pattern D should be normal to the surface with an arc length of 2.21 inch measured at datum A.

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
David Ornelas about 8 years ago

Jack,
“Wow”, you did an excellent job of evaluating the finalist designs. Like Mr. Risser stated many of us including myself did not meet the 2D edge distance requirement. I suspect you are an Aerospace guy, so you understand why we use twice the diameter for edge distance. Others might not know, so I will explain. We use 2D for the bearing area of a fastener that is being pulled in Shear. We do this so the fastener does not break out of the material in shear. So the bearing material at the fasteners that get installed onto the vertical Datum A face is being pushed up while the load on Datum B is being pushed down by 600 lbs. Therefore as long as 2D is maintained on the vertical side of the 4 fasteners, I believe this OK. That being said the two fasteners on Datum B are being loaded in Compression/Tension and do not encounter the pull out issue, since the load is vertical. Therefore I believe the 2D requirement is not as necessary but a good rule of thumb. Also, as material thickness goes up, edge distance could go down to save weight. All that being said you are right in showing my 2D interface on Datum B being short, but my answer is fastener and hole is being loaded in compression not bearing. There would be some small reaction forces are in bearing. At the other location (bottom of Datum A), I believe I still have 2D. The chamfer removes material but at the bottom edge, it is still 2D.
Jack thanks again for you input, really nice evaluation!!!

David Ornelas has uploaded 1 CAD models & has left 7 comments.
Jack Nguyen about 8 years ago

@Dennis Risser:
1) “I would imagine the judges would appraise this with some tolerance in mind.” – If tolerances as shown in the Part Design Envelope drawing title block are applied (.xx dimensions has +/-.03), your part and many of the others may be in the clear. That said, IMHO, all dimensions on the Part Design Envelope should be “Basic” (no tolerances). For example, with said tolerances allowed, Hole Pattern “E” location can be .62 to .68 from the front surface… and the .45 x 2.10 recess/slot can be as small as .42 x 2.07, or as big as .48 x 2.13… Really?!

2) Hole Pattern D is normal to curved surface Datum A in the Part Design Envelope used. Unless something went wrong with my import of your *.STEP file into SolidWorks, the part I got has Arc Length of 2.155949 inch measured at Datum A for Hole Pattern D; Mass = 0.08971 lbs.; Volume = 1.85306 cubic inches.

@Jason and @David Ornelas: I appreciate your feedback and compliments with my review of the finalists. -JN

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Wilbert Engels about 8 years ago

Hi Jack,

Like Jason, I agree, no point in defining rules and not judging accordingly. About the 2D dimension around the holes in pattern B, the rule was changed a bit by ULA. In this pattern, the edge distance can (and should) be reduced. But, also according to ULA, the (2D) edge distance should be applied over the whole bore length of the hole.

@ David Ornelas, it’s not a general rule of thumb to use 2D as a requirement. In i.e. European regulations, 1.5D is used; in some cases even 1.25D. No matter what, you always have to check for bearing stresses, tear-out, etc. As for your remarks on your design: I think it’s dangerous to assume being on the right track by making or having a design similar to others. The stress peak of 16,741 psi that you show in your stress document, is a local one and could be “explained” and/or reduced. But, in other large areas, 4500 psi is exceeded significantly. A good overall design can be ruined by poor details. BTW It would be very interesting to see stress distributions in the junction between the vertical plane (to the upper bolts) and the horizontal plane, leading to datum B.

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Nathaniel Andresmooi about 8 years ago

Without hard and fast defined geometry for *connecting structures* to the launch module and *load structures* to the walkway FEA is kinda out the window. I would be interested in how many people maintained the angled mounting bolt holes as called out on the blueprint.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Vivek Gandhele about 8 years ago

What an awesome response to a great challenge! Nice concepts and implementations; such a joy! Very congratulations to all the very finalists so all the very best engineers!

Vivek Gandhele has uploaded 1 CAD models & has left 1 comments.
Miro K. about 8 years ago

well done Jack!

Miro K. has uploaded 20 CAD models & has left 116 comments.
Lauri Link about 8 years ago

Why bracket remains with rocket during flight? If weight is so important why you just remove it before launch?

Lauri Link has uploaded 50 CAD models & has left 98 comments.
Nathaniel Andresmooi about 8 years ago

Since the brackets have something to do with the maintenance and assembly I would guess when you remove the walkway you wouldn't have a good place to work from? Where will you stand while you pull brackets if the walkway is gone? These are probably the smallest part of the walkway they can leave attached.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Jack Nguyen about 8 years ago

@Wilbert Engels:
Thanks for your input. I missed that the (2D) edge distance should be applied over the whole bore length of the hole and did not take this requirement into account with my review of the finalists (https://www.dropbox.com/s/3g6fdu3vu3uw68b/ULA_Finalists_Review_by_JN.pdf?dl=0).

@Nathaniel Andresmooi:
“For simplicity, the required loading is applied uniformly to the designed interface surface”, and “For this exercise, loads and boundary conditions are applied directly to the bracket” were answers from Matthew Perry. We also know that, at a minimum, the bracket will contact the launch module with the (2D) edge distance patch areas specified. IMHO, ample information has been provided to properly perform FEA. Still, the correct boundary conditions (translation and rotation about coordinate axes are free or fixed) must be applied to yield good results… over-constraining or under-constraining the part will not yield good results.

@ Miro K.: Thank you. -JN

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Nathaniel Andresmooi about 8 years ago

@Jack Nyuyen I realize that was what was stated. My point was that the actual minimum surface area at a datum be it the top seat or the brackets back is not defined. It's a loading surface it should be defined it mates with something. Even though they called out the 2D distance around mount holes. They did not say this was the location of loading. Which part described the actually loading points? “For simplicity, the required loading is applied uniformly to the designed interface surface” , and “For this exercise, loads and boundary conditions are applied directly to the bracket”(Matthew Perry) -A designed interface surface should call out a concrete surface(s) with boundaries or minimums and a location. The best we can do is to pick some surface and press run on the FEA. We needed something like -minimum 1 square inch totall loading area centered on cordinates x,y,z or centered on geometry in sub sketch G coincident with plane T. All the structure can be designer created but the mate planes and location cannot. Unless they are making the maintenance way Afterward.

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Wilbert Engels about 8 years ago

@ Nathaniel Andresmooi, Why would a minimum surface need to be defined? The surface load on datum B (pressure) combined with the allowed maximum equivalent stress will yield the surfaces needed; in all parts of the bracket!

@ Jack Nguyen, I hope you didn't take my reply as criticism; it wasn't intended like that. Just wanted to show that some designs would (also) fail to meet that requirement. To my opinion, you did an absolutely great job on judging the finalists' designs.

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
aziz ismaily about 8 years ago

so who the winner??

aziz ismaily has uploaded 0 CAD models & has left 1 comments.
Nathaniel Andresmooi almost 8 years ago

@Wilbert Engels The minimum surface area is perhaps unneeded. But they did need to specify where the walkway has places the bracket can touch. If its one flat solid bar then the bracket can support it anywhere along it. But the support face location and size was never mentioned

Nathaniel Andresmooi has uploaded 5 CAD models & has left 240 comments.
Jack Nguyen almost 8 years ago

@Wilbert Engels, Thanks again for your comments. Your reply was not taken as criticism. I just wanted to acknowledge that the requirement you mentioned was not reflected in my review.

@aziz ismaily, the winners are scheduled to be announced by this Friday, December 9.

…and IMHO, if winners are announced from the posted list of finalists (seen failing to meet one or more specified requirements), ULA, GrabCAD, Stratasys, all participants, everyone loses. The underlying message shouts out to the world that specified requirements, quality and excellence in our work does not matter.

Rather, I suggest the jury announce that this Challenge is re-opened with a new entry deadline date, etc. Everyone has a second chance to get it right—all participants with their revised/new entries and the jury in announcing well qualified finalists. -JN

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Enrique Carrasco almost 8 years ago

@Jack Nguyen,
I think your assessment on some of the finalists is not accurate.
Starting by the 2D Edge distance on the Surface datum B, it was highlighted before the deadline that the 2D could not be achieved due to envelope violations to what ULA Team responded that the envelope has precedent to the 2D ED.

As Wilbert Engels mentions the 2D is a good practice but is not a hard rule, we sometimes use 1.25D or 1.5D on metallic and 3D on composites in Aerospace, everything is about the load case and the particular interface of each hole.

Being said that, you don't want to have a hard corner to match 100% the envelope since for sure you will have stress concentrations but these are assumptions that everyone on the finalist section took into consideration IMHO.

Regarding the envelope violations and overweight, in this one I do agree with you that it should be a direct disqualification but at the same time I have to say that I found it quite hard to design something under 0.1lb that meets the load case with such a small allowable (4.5ksi), so as you should probably know in any industry, safety goes before weight and I think that if ULA choose an overweight finalist they recognize that the design could be strong enough and the weight penalty doesn't represent a high liability to pay.

Anyhow, this was a fun challenge and I wish you all the best to the all the coming ones :)

Have a great one!

Enrique Carrasco has uploaded 3 CAD models & has left 6 comments.
Jack Nguyen almost 8 years ago

@Enrique Carrasco: The same part design envelope was used to check each bracket per the specified requirements. The reference ED circle shown on surface Datum B is less than 2D radius when touching the envelope corner (the envelope has precedence). Some brackets met this ED requirement (#4, #12, #13, #14); many did not. Are you suggesting brackets that met the ED requirement at Datum B are poor designs because they have a hard corner to match the envelope 100%?

Regarding stress values and their location on the part, let’s have properly performed FEA tell the story. Further, let’s refrain from making wild assumptions about what and why deviations from the specified requirements the jury may allow. Just focus on the deliverable meeting or exceeding expectations as spelled out in the technical specifications… and not a bunch of excuses why it cannot be done. Keep in mind; this is a Challenge and not some easy task.

Thank you Enrique for your input. -JN

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Enrique Carrasco almost 8 years ago

@Jack Nguyen,
You're totally right! Let's just wait and congratulate the winners without doing any wild assumptions on what the jury took into account while choosing the winners.
Have a great weekend.

Enrique Carrasco has uploaded 3 CAD models & has left 6 comments.
Grant Thomas-Lepore almost 8 years ago

Hi all, we're still finalizing the last few details before announcing the winners. We should be announcing the winners this coming Monday. It has been tough to narrow it down!

Grant Thomas-Lepore has uploaded 4 CAD models & has left 33 comments.
Dan Hubert almost 8 years ago

When will the winners be announced???

Dan Hubert has uploaded 6 CAD models & has left 9 comments.
Grant Thomas-Lepore almost 8 years ago

The winning design was so good that we've added some extra surprises with regard to the prizes! It took longer than expected to finalize the legal details but tomorrow afternoon we should have some exciting news. Stay tuned!

Grant Thomas-Lepore has uploaded 4 CAD models & has left 33 comments.
Grant Thomas-Lepore almost 8 years ago

Hi all, the results have been posted. Congratulations to our winner, Nic from Australia for taking home 1st place. ULA was so pleased with the performance of this design in testing that they *tripled* the first place prize to $10,000! Lots of congratulations to 2nd place finisher Vishal Gandhele from India, taking home $3,000 and to 3rd place finisher Winston Jennings from Jamaica taking home $2,000. Finishing in 4th and 5th places both Stanislav Petrek and Cameron Navarre deserve an Honorable Mention. The entries were phenomenal and the judging wasn't easy! There is more information on the Results page as well.

Grant Thomas-Lepore has uploaded 4 CAD models & has left 33 comments.
Winston Jennings almost 8 years ago

Thank you ULA and Grabcad for such a wonderful and exciting challenge. It was truly amazing with all the great entries and exciting prizes.Congrats to the winners and I hope to see more challenges like this in the future.

Winston Jennings has uploaded 279 CAD models & has left 883 comments.
Vishal Gandhele almost 8 years ago

Thank you for the wonderful challenge and congratulations to the winners!!!

Vishal Gandhele has uploaded 6 CAD models & has left 12 comments.
Stanislav Petrek almost 8 years ago

Hello. thank you Grabcad and ULA for nice interesting challenge. I was learning a lot of new things about 3D modeling and 3D printing during this great challenge. Of course congrats all finalists and winners. I didnt hope that I would between finalist. and now I am 4th. I am looking forward for next great challenges.

Stanislav Petrek has uploaded 22 CAD models & has left 48 comments.
Dennis Risser almost 8 years ago

Let's take a minute to reflect on this challenge a bit.

First off, I see a general lack of interest from the GrabCAD side of things. The contestants are held to a hard deadline, why aren't the judges? In industry, if you have a deadline, you make it, or you lose money. Perhaps the additional money was to make up for the fact that the results were almost a week late in getting announced.

This might not seem like a big deal, but consider the position from ULA's perspective. They pay out $4500 (or in this case, $15000) and in return they get almost 400 designs to pick and choose from. That's pretty good return on investment. For example, I probably had 40 hours into my design. Assuming everyone did the same (big assumption, I know), ULA is getting 16,000 man hours for less than a $1/hr. Now granted, many of these man hours are not performed by degreed engineers, but the fact still stands that ULA makes off with a hell of a deal. Add to that all the free advertising and publicity and it's a win-win for them. For the finalists to appear as if someone picked them from random, it's a bit depressing.

The second thing I don't see is a review of the finalist/winning designs. I don't expect the judges to test every single design, but I would expect some feedback on the 15 finalists, and particularly some feedback on the winners themselves. Let's see some FEA performed by ULA, let's see some feedback on WHY they won. Instead we get a quick blurb that basically says, "yeah, they were all really great, but these are better."

Right about now, you'll be noticing I was one of the finalists and I didn't win. Was my design perfect? No! There were many things I noticed after submitting and things that were pointed out by other members. I would like to point out that while I may not completely agree with Jack's assessment, his approach was more thorough in presentation than that given by the judges themselves. If you really want to make this into a learning experience for the contestants, give some quality feedback on the designs. I want to know how I would make my design better, and I'm sure the information would be beneficial for the other participants as well.

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
Juan Callón almost 8 years ago

Congrats to the finalists and winners!!

Juan Callón has uploaded 19 CAD models & has left 85 comments.
Pigeon Valérian almost 8 years ago

As Dennis Risser, I ask if it's possible to have a little feed back of what did not work on the design of the other finalists.
It's my first challenge and I'm not professional so I'm proud to have been chosen as finalist!
Congrats to the winners!

Pigeon Valérian has uploaded 1 CAD models & has left 2 comments.
Nic almost 8 years ago

Big thanks to ULA and Stratasys for allowing the GrabCAD community the opportunity to compete. I'm so happy that my efforts have come out on top of a great field of competitors. Everyone that submitted an entry should be congratulated as a contributor and being constructive with their free time. Never thought I'd be given a chance to be involved in putting something into space. Consider this guys childhood dreams accomplished.

I've been a GrabCAD member since the early days and this is my first win. So stoked to get that winners badge on my profile! Thanks to GrabCAD for their innovative platform and professional service. I'm getting better with every challenge and I've learned everything through my peers here at GrabCAD. Thanks again and looking forward to the next challenge. Cheers.

Nic has uploaded 26 CAD models & has left 92 comments.
Cameron Navarre almost 8 years ago

I want to thank ULA, Stratasys and GrabCAD for the opportunity to participate in this fun and challenging contest! This contest started during a period where I was between jobs, and I am extremely grateful for the opportunity it gave me to both practice, and expand upon, my design skillset. I also wanted to recognize all of those who participated in this contest. I was continually impressed with the creativity displayed in the many submitted designs. I immensely enjoyed looking at, and gaining inspiration from, all the unique approaches to the design challenge. I'm looking forward to more design contests!

Cameron Navarre has uploaded 2 CAD models & has left 5 comments.
Miro K. almost 8 years ago

Congratulation!
31MPa was allowed strength (4500psi), nr1 design under load 600lbf rise to 120MPa (17400psi), which is 4x exceeded ... using simple words: if you ignore rules 4x, you win 3x first price :D ... Final tip for rest of us: The more rules you ignore, the greater is your price!

Miro K. has uploaded 20 CAD models & has left 116 comments.
David Ornelas almost 8 years ago

Congratulations to Nic Adams for winning 1st place, Vishal Gandhele for 2nd place, Winston Jennings for 3rd place, Stanislav Petrek for 4th place,
Cameron Navarre for 5th place. Great job guys!!!!!!

David Ornelas has uploaded 1 CAD models & has left 7 comments.
Wilbert Engels almost 8 years ago

Congratulations Nic, truly nice design, very nice shapes. But as Miro K. mentioned, I think your analysis was done using wrong boundary conditions/load application. At least not according to the design rules (I found about 108 MPa which agrees quite nicely with Miro K.’s results).

Sad to see this GrabCAD challenge turning into a CrapCAD challenge. BS story to distract attention from the incompetence selecting the finalists and now the winners. Someone must have been smoking something bad or sniffing glue while analyzing entries: “The most common discriminators that became apparent during the challenge were edge distance, PART STRESS, and support material”.

Wilbert Engels has uploaded 5 CAD models & has left 20 comments.
Dennis Risser almost 8 years ago

Like Miro and Wilbert, I find maximum stress in Nic's model to be 108 MPa. However, this was right at the edge of the bolt hole, and since this is where the fixture was applied, it very well could be bogus information. Much more telling are the very large areas of material at 2x yield stress or more across the part. These areas are nowhere near a stress riser, so the results should be fairly accurate. A possible reason for this discrepancy lies in how Nic executed his FEA - he applied a force to a constrained titanium plate, and fixed the bracket to a wall, when it was reiterated by the GrabCAD team numerous times that all constraints and loads must be applied directly to the bracket.

Don't take this the wrong way, Nic. Your design is very organic and well thought out. However, I'm dismayed that such glaring errors in a design netted first place. I wish one of the judges would post some factual evidence to back up their decision and prove me wrong.

If it was so difficult to choose a winner, why decide to suddenly up the prize money 3x? Instead, why not distribute that additional $10k to the finalist, or at least the placing positions, so everyone gets a little something? I don't see how honorable mention is any better than being a finalist. Let's kick some money to 4th and 5th too, at least.

I approached this challenge with excitement, a chance to show my skill. Based on the late posting of results, the general lack of information and feedback from the judges, and the disregard for design rules, I have no further interest in entering more of these challenges. Honestly, it was a big waste of time.

Dennis Risser has uploaded 1 CAD models & has left 8 comments.
Jack Nguyen almost 8 years ago

Here’s my review of ULA bracket by Nic Adams:
https://www.dropbox.com/s/uoouttgnp3bswrs/ULA_Bracket_Nic_Adams.pdf?dl=0

IMHO, there are no *Winners* in this challenge… only a few *Lucky* participants awarded unmerited prize monies and meaningless accolades. Without question, the biggest *Losers* are ULA, Stratasys, and GrabCAD. -JN

Jack Nguyen has uploaded 2 CAD models & has left 8 comments.
Stanislav Petrek almost 8 years ago

Hello everybody, I would like to know the conditions taken into consideration while making the decision about the winner. I would like to know why my design has been on 4th place. If it is possible, please let me know the comparison of my design and the winner´s one because they are very similar . I have no idea why his one is better than mine. For example I am mainly interested in the comparison of the stress analysis.

Stanislav Petrek has uploaded 22 CAD models & has left 48 comments.

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Deadline Passed
Total entries 337

Who’s in the jury?
Scott Sevcik
Stratasys, Head of Aerospace, Defense & Automotive
Andrew Hanson
Stratasys, Applications Engineer Aerospace & Defense, Automotive
Matthew Perry
ULA Additive Manufacturing
Tory Bruno
ULA CEO
David Badgett
ULA Structural Engineering

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