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NASA challenges you to design an attachment system for an ISS habitation experiment.
NASA is seeking to challenge the GrabCAD Community by sponsoring an open competition where participants design an attachment system for an experiment on the International Space Station (ISS). This challenge is in support of NASA’s Logistics Reduction project.
The ISS is a low Earth orbiting research laboratory that is home to six crew members and many experiments. The ISS is also used as a platform to test future spacecraft systems. Although the ISS has standard interfaces to house many types of experiments, some experiments require unique attachment mechanisms.
The overall function of the Experiment Attachment System (EAS) is to attach a future experiment of set volume and mass to seat track interfaces in the ISS. The experiment will be mounted to a plate and the EAS will need to interface with the experiment plate and the seat track. The EAS will need to raise the plate 8.65 inches above the seat track interface.
The main goals of the EAS is to minimize weight and maximize ease of assembly/installation/removal. Astronaut time is valuable and since the EAS will be assembled on-orbit, it is important for the design to be sturdy enough to withstand the loads but also be simple enough (number of connections and parts reduced) to assemble quickly on orbit. It typically takes longer to assemble hardware on orbit than it does on the ground. It’s ok to have multiple parts go into a structural assembly but the intent is to minimize the number of subassemblies assembled on orbit. Hand installation is preferred but tools are acceptable. Assembly should use standard tools that you can find in your garage.
Take a look at the NASA’s previous GrabCAD Challenge to get insight into creating parts for ISS. For helpful hints on designing for manufacturing, check out GrabCAD Blog.
Your entry must include:
• Description of system
• STEP/IGES
• Renderings
• Load calculations
• Assambly procedure
You are encouraged to include: Pro-E files
Technical requirements:
• Shall be capable of providing a rigid connection to the seat track
• Shall conform to the following sharp edge human factors:
- Exposed edges 0.25 in thick or greater shall be rounded to a minimum radius of 0.12 in.
- Exposed edges 0.12 to 0.25 in thick shall be rounded to a minimum radius of 0.06 in.
- Exposed edges 0.02 to 0.12 in thick shall be rounded to a full radius.
- The edges of thin sheets less than 0.02 in thick shall be rolled or curled.
• Shall have a minimum factor of safety of 1.25 (yield) and 2.0 (ultimate) when exposed to a crew load of 125 lbf applied in any direction as indicated on the attached EAS Envelope drawing
• Shall have a deflection of less than 0.5 inches at the load point when crew load is applied in any direction as indicated on the attached EAS volume drawing
• Reaction load and moment limits for the seat track shall be limited to less than the values defined in Table 1, with coordinate system as shown in Figure 1 for each individual axis. These limits pertain to each attachment point. As a general guideline, you should maximize spacing between seat track attachment points to minimize the interaction between load points. Please see "Download Specifications" for Load & Moment limits
• Shall conform to the installed envelope depicted in the attached EAS Envelope drawing. Please consider tool access needs within the provided envelope.
• Shall conform to a launch envelope of either:
a) 26 inches by 14 inches by 16 inches
b) 17 inches x 14 inches x 16 inches
• Shall weigh less than 20 lbs
• Shall use Aluminum, Stainless Steel, or Acrylonitrile-Butadiene-Styrene (ABS). Note 1: Please refer to ABS mechanical properties listed in the prior NASA challenge.
Note 2: We understand that the materials listed are limiting. However, these are cost efficient materials used by NASA and are well understood. You may choose more exotic materials for smaller parts of the EAS (ex. Titanium pins) but NASA will evaluate how those selections impact cost. Please define your assumptions on material strength in the loads calculation.
• Devices such as self-tapping screws and bolts shall not be used
Judging criteria:
Judging criteria will be based on achievement of accomplishing criteria listed above, including:
• Pass/Fail – Meet the loads, volume, weight and interface constraints
• Rating – Optimizes assembly and installation simplicity
• Rating – Ease of manufacturability
• Ranking – Minimizes the weight of the structure
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 Challenges 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 "NASAEAS" 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 April 10th, 2016 (11:59pm UTC). - The finalists will be announced by April 28th, 2016. - The winners will be announced by May 5, 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!
$3,000 in prizes for top 5 places!
$1,500
$800
$400
$200
$100
The winning designs will be selected with the help of experts from NASA Logistics Reduction and GrabCAD.
The main goal of the Logistics Reduction project is to decrease the dependence on earth resupply for space missions. This is done via direct mass reduction, re-purposing logistics, and conversion of waste into useful by-products (gases, water, solids). We are trying to pack everything for Mars but our suitcase is too full. So we need to be smart about what we take, how we maximize the use of those items, and create new uses for the items once they’ve met their original purpose. Logistics includes crew consumables (food, packaging, clothing, etc), automation of logistics management, and waste management.
Ross Harold
Thilini Schlesinger
Michael Berrill
Michael Friday
Ben EwingHave an awesome idea for this competition? Want to win cool prizes? Sign-up now to upload your entries.
If you don't receive the email within an hour (and you've checked your Spam folder), email us as confirmation@grabcad.com.
179 comments
Sanjeev Dhami almost 9 years ago
It was my dream to make something valuable for NASA and humanity today is the chance thanks for this opportunity.
Ali ZAHI almost 9 years ago
Great challenge!
Thilini Schlesinger almost 9 years ago
We're looking forward to evaluating all the innovative entries from the GrabCAD community!
Tommy Mueller almost 9 years ago
Oooh yea, hello NASA challenge! This would be a great Workbench team entry to go for the win!
Dan Rudmin almost 9 years ago
Does NASA prefer metric or imperial fasteners?
Dan Rudmin almost 9 years ago
I'm looking at the EAS drawing now. Can you add some notes or shading or something to distinguish the mounting plate from the EAS volume? They appear to be combined into the same solid. Also, it seems that the keepout zone is different than the experiment volume. Is this intentional? The experiment zone appears to be larger than the keepout zone, even though it is not dimensioned.
For ease of manufacturing, what kind of quantity/timeline is expected? I ask this to try and guess how much of a burden it is to require manufacturing tooling. Say for 500 units or many years of production, I would discount the time and cost of special tooling more than for a single batch of 12 units.
Marco almost 9 years ago
Looking the previous NASA challenge i couldn't find the young modulus and Poisson ratio of ABS( wasn't necessary on that challenge). But it is important on this one, since we have a requirement of 0.5 or less inches deflection in the load point. Is possible provide these values?
Dan Rudmin almost 9 years ago
What material is the EAS mounting plate? Does it have any flatness specs or other important specifications. How can we determine what kind of loads it can support? Is the EAS mounting plate a fixed dimension or design? Can we specify any mounting features such as holes, counterbores, slots, threads, or bends in the EAS mounting plate? Do any of these plates currently exist? It is unclear why the plate must be a separate component. Will the plate be pre-attached to the experiment or modified by each experiment? If the plate contains a standard interface and is mounted before the experiment, would there be any reason that the EAS can't contain the same interface without the plate?
svpetar almost 9 years ago
Poor people! Let's help them!
Dan Rudmin almost 9 years ago
Are 45 deg chamfers considered to be a sharp edge under the exposed edge requirement? If no, is there some equivalency for minimum chamfer width and minimum edge radius?
Michael Friday almost 9 years ago
Thanks for your questions Dan. Here are some answers to a few of them.
Does NASA prefer metric or imperial fasteners?
Either is acceptable.
They appear to be combined into the same solid. Also, it seems that the keep out zone is different than the experiment volume. Is this intentional?
Yes, it was intentional. Keep out zone shows where the experiment volume will interface with the mounting plate. The dotted lines just show a block volume similar to the experiment volume.
Is the EAS mounting plate a fixed dimension or design?
Other than the dimensions and keep out zone described, we can adapt the plate design to accommodate that EAS.
Can we specify any mounting features such as holes, counter bores, slots, threads, or bends in the EAS mounting plate?
Yes, as long as it doesn’t interfere with the keep out zone. Otherwise, we won’t be able to attach the payload.
Do any of these plates currently exist?
No.
I'll get answers to the rest of your questions soon.
Michael
Michael Friday almost 9 years ago
For ease of manufacturing, what kind of quantity/timeline is expected? I ask this to try and guess how much of a burden it is to require manufacturing tooling. Say for 500 units or many years of production, I would discount the time and cost of special tooling more than for a single batch of 12 units.
We are only building 2 units.
It is unclear why the plate must be a separate component. Will the plate be pre-attached to the experiment or modified by each experiment? If the plate contains a standard interface and is mounted before the experiment, would there be any reason that the EAS can't contain the same interface without the plate?
The experiment will be used in multiple locations. One of which requires it to be held in place above the seat track, which requires this attachment system to be built. We need to move it between locations without having to reinstall the experiment itself, therefor we are using the mounting plate as the interface.
Dan Rudmin almost 9 years ago
Thanks Michael.
Goofy almost 9 years ago
What are we actually making??
Dan Rudmin almost 9 years ago
How much of the mounting plate design is within the scope of this challenge? Should we just treat it as an aluminum plate of fixed thickness and only design the perimeter profile? Is it open to weight reductions? Will the mounting plate travel within the launch envelope with the EAS or does it ride with the experiment? You say that we can adapt the plate design to accomodate the EAS. Does that mean that features can stick out from the mounting plate beyond 0.25" provided they don't interfere with the keepout zone? What kind of load path connects it to the 125 lb crew load? Can we treat it as a rigid body for simplicity, or should we make some assumptions about the experiment interface?
André Ferreira almost 9 years ago
@Goofy I think we are making the connection between the EAS Envelope and the 2 seat tracks, for a easy assembly on the ISS while in orbit. Please anyone correct me if I´m wrong.
André Ferreira almost 9 years ago
And develop a new optimized EAS
Zulfiqar Islam almost 9 years ago
Yes, I ran into the same problem.
The fix is like this:
1. Click on the zip file. WinRAR window will open.
2. Browse within the WinRAR window to find three files.
3. Double click the PDF files to open those from WinRAR window.
4. Save the opened files to a place of your choice.
5. For png file, you may need to have a photo editing software to open it and then save it.
Michael Friday almost 9 years ago
Some more information about the mounting plate: The mounting plate is shown on the drawing as the .25 inch reference dimension on top of the EAS volume. Everything in the box below that is the volume that we can use for the EAS. The material will be 6061-T6 Aluminum, .25” thick within .020. Its thickness is fixed, however, adding a bend for something like a mounting tab would be fine, as long as it doesn’t interfere with the experiment we’re attaching. Other than designing or defining the way the plate attaches to the EAS, design, modification and logistic planning for the plate are beyond the scope of this competition.
Also, 45 deg chamfers aren’t considered sharp edges.
Marco almost 9 years ago
Only to become more clear:
Screenshot comment
Are suppose to design the connection between the seat track (blue) and the mounting plate (green) and this one must not pass the brown boundary?
While the red solid is the payload.
I am correct? Or there is something i missed?
Dan Rudmin almost 9 years ago
There are still a few details that are unclear about the constraints on the mounting plate interface design:
Based on the dimensions, it seems like the mounting plate won't fit into the launch envelope with the EAS. That seems to imply that it will ride in some separate container. Is that correct? Also, is the experiment pre-attached to the mounting plate, or will the top surface be accessible? You mention it's possible to have features or bends and brackets sticking out from the mounting plate to interface with the EAS. Can you quantify any constraints on those features? I assume a 12 inch flange would be too large, but maybe not? Is the weight of the mounting plate and fastening system considered as part of the total weight? Does the mounting plate need to extend to the maximum limit of the EAS volume, even if the additional surface is not needed for any attachment features?
Allan almost 9 years ago
@Marco I believe the Red in your jpg are the Keep Out Zones for the EAS. According to the NASA diagram Quote: ARE INFINITE ABOVE THE MOUNTING PLATE AND PROJECT 1.00 BELOW THE MOUNTING PLATE INTO THE EXPERIMENT ATTACHMENT SYSTEM ENVELOPE End Quote. The EAS Envelope is your Brown part. However...
@Michael Friday Michael I dont believe the plate has a hole in it the shape of the Keep Out Zone; as the dotted line of the KOZ does not project down 1" below the mounting plate in your drawing.
Thus, (alternatively) is the "1.00 BELOW" to take account of mounting fixtures or fittings that atch the experiment to the mounting plate and therefore should be avoided, i.e. are within the stated KOZ.
If so, is the 1" measured from the top surface of the Mtg Plate or the underside?
Handily1 almost 9 years ago
What is the length of the Seat Tracks (2) and their end position from the EAS Envelope?
Dan Rudmin almost 9 years ago
@Handily1 About 72" based on the link given:
https://en.wikipedia.org/wiki/International_Standard_Payload_Rack
Handily1 almost 9 years ago
What is the length of the seat track? Is it relative to the EAS design?
Handily1 almost 9 years ago
@Dan R - Thanks for the link - Very interesting. Provided a good insight into the ISS Quarters.
Ben Ewing almost 9 years ago
Hi all. We just added a PDF on experimental mounting holes to the downloadable spec folder!
Michael Friday almost 9 years ago
@Marco, yes your picture is correct.
@Dan, the plate won't be launched in the same container as the the EAS. The experiment will be attached to the plate first, then plate to EAS. Later it will be removed and installed in other locations. The plate itself is not considered part of the EAS, there for it's weight is not part of the 20 lb limit that you are restrained to. Also, any features that you want to add to the plate must reside withing the volume of the EAS and stay out of the keep out zone that is shown.
@Allen, correct, it's so that the EAS doesn't interfere with mounting hardware on that side. So assume 1 inch below the bottom surface. There is not a large hole going through the plate, there will only be 4 thru holes which are shown on a new file that we have had uploaded.
Michael Friday almost 9 years ago
All, please see the new file we've added: Experiment Mounting Holes - grabcad.pdf. This will help with your assumptions for load paths between the experiment - mounting plate - and EAS. Remember the plate is .25 inch thick, except for the quanty 4, .391 in diameter through holes. The weight of the plate is not considered part of the EAS weight.
Michael Friday almost 9 years ago
@Ben, thanks!
Michael Friday almost 9 years ago
@Handily, that length along the track that you will be able to use is 22.10 inches. The link Dan shared is nice reading, however, there are other restrictions we have to consider for this experiment. Refer to the EAS Envelope for details of the volume available for the EAS.
Dan Rudmin almost 9 years ago
@ Michael Friday: The plate itself is not considered part of the EAS, there for it's weight is not part of the 20 lb limit that you are restrained to. Also, any features that you want to add to the plate must reside withing the volume of the EAS and stay out of the keep out zone that is shown."
You have placed a lot of design constraints on the EAS, but almost no constraints on the attachment plate. It seems like the optimal solution according to your criteria for weight and simplicity and rigidity would be to shift the majority of the EAS structure into the EAS attachment plate with a bare minimum of rail attachment hardware making up the separate EAS component. The resultant attachment plate would be quite a bit heavier and take up most of the volume of the EAS, but neither of those criteria are factored into your judging s ystem. I suspect that this wouldn't actually be a desireable design but I can't find anything in your criteria or evaluation that would preclude it or rate it poorly. Can you comment or give any more information about realistic limitations to the attachment plate design?
Dan Rudmin almost 9 years ago
I would suggest that you create a separate drawing which lays out clearly the constraints on the EAS mounting plate attachment feature geometry. If those "attachment features" can in fact extend all the way to the mounting rails or encase the 1" deep keepout zone, then you should state that is the limitation. I realize I some of these questions seem very pedantic, but when given a black box problem without any context, the specific details of the boundaries of that box are really critical. It's difficult to apply common sense to this challenge without context or any means to evaluate the greater objective.
Michael Friday almost 9 years ago
Dan, this challenge is to design an EAS that will hold the .25 inch mounting plate in place as shown. Any weight and structure designed would be part of the EAS structure and must be able to be installed and removed from the plate leaving the plate completely flat along its bottom surface. I think you need to give me an example of what you mean by shifting majority of structure from the EAS to the plate.
Dan Rudmin almost 9 years ago
Michael, this is the first time I have heard the requirement that the plate must be completely flat along its bottom surface. (Bottom is kind of ambiguous in space) It also contradicts your previous statements that the plate can have attachment features such as bends or brackets protruding from it as well as the statement "any features that you want to add to the plate must reside withing the volume of the EAS and stay out of the keep out zone that is shown". It would really help if you explicitly stated somewhere the maximum and minimum volume for attachment plate features. Even if the maximum is the 0.25" plate width or identical to the EAS volume.
Marco almost 9 years ago
Michael,i have some questions:
1- the seat track resistances already have the safety factor included or not?
2-What is the manufacturability criteria? e.g. Using a 3D printer located on Earth is fine for some components of the EAS?
3-The way the mounting plate should attach i still a mystery. So some questions:
A-It is possible to add bend and flanges in the edge of the mounting plate? If yes, what it is the dimension constrains?
B-It is possible to make holes in areas outside of keepout zones? If yes, can we have parts of EAS in the top side of the Mounting plate so it can be fixed?
Ps. I am considering the top side the surface between the mounting plate and the experiment.
Cory Duce almost 9 years ago
That there have been no entries yet even after 3 or 4 days leads me to conclude that I'm not the only one confused about the goals and requirements of this design challenge are.
Handily1 almost 9 years ago
1. Is there s Standard CAD Model available of the Seat Track that matches the MS Std and the Mounting Envelope?
2. There are mounting hole for attaching the tracks to framework shown on commercially available tracks.
2a. Question: What is NASA's requirement for mounting the tracks?
Ben Ewing almost 9 years ago
Hi https://grabcad.com/allan.bowers-1, our apologies! I went ahead and fixed that. Entries should now be showing on the challenge page.
Ben Ewing almost 9 years ago
Thanks for the feedback Cory Duce. What do you find confusing? If you have specific questions about the specs, this is a great place to ask them!
Allan almost 9 years ago
@Ben Great thanks.
Dan Rudmin almost 9 years ago
What are the positional and angular tolerances on the attachment plate location and orientation relative to the seat track?
How will the 0.5 inch deflection under load criteria be evaluated? I will guess that most of the real world deflection will come from joint deflection, not material strain. And these designs are going to have weird joints which don't lend themselves well to computer simulation.
Allan almost 9 years ago
Am I correct in assuming that the 125 lbf load applied in any direction as indicated on the attached EAS Envelope drawing shows that the point of load is 20 inches perpendicularly from the surface of the mounting plate? If this is correct dont we need detail of the experiment mass so that the load can be correctly applied at that point? We have the Mtg plate material specs as advised in one of Michael's posts and that would be sufficient if the point of load was on the surface of the plate, but it appears that it is not.
Niels Ceusters almost 9 years ago
Are we allowed to use parts like springs and so?
Marco almost 9 years ago
It is possible to use bolts to assembly components on Earth? (astronauts will not interact with these bolts to re-assembly the EAS on orbit)
Handily1 almost 9 years ago
@Michael Friday,
1. You stated the Seat Track length to use is 22.20 inches, the same as shown in the EAS Envelope Drawing for the EAS Envelope.
2. Yet the seat tracks shown are much longer.
3. Is the EAS Envelope Drawing in error?
4. Could you please clarify the Seat Track overall length?
5. If it is actually longer, what is the location of the ends of the seat track in relation to the 22.20 inch EAS Envelope?
Handily1 almost 9 years ago
What are the sizes of the corner radii for the EAS Mounting Plate?
Michael Dimou almost 9 years ago
Mr. @Michael Friday ,
do you want to design and articulation?
Paul Berg over 8 years ago
I understand the details of the Seat Track and Stud that goes in the seat track. I am not sure if the studs lock into the track by design.
Do we need to come up with a method to secure the studs of the EAS into the seat track.
OR can we move forward knowing that the EAS is locked into seat track because it has the studs as described in the spec?
Michael Friday over 8 years ago
@Marco:
The plate needs to remain flat. Yes, you may add thru holes, tapped holes etc, for bolting or other hardware needed to attach to the plate. Whatever hardware you plan to use will be part of your EAS. You may install through the top side.
Michael Friday over 8 years ago
@Handily1:
The tracks are already installed. Is your question about mounting the EAS to the tracks?
The envelope shown in the EAS drawing is correct, the extra length of track shown in the drawings is for reference only. Other hardware is attached in those locations and limits us to the envelope shown.
Michael Friday over 8 years ago
@Dan, good questions as usual, will get back to you.
Paul Berg over 8 years ago
How are the studs secured to the seat track?
Dan Rudmin over 8 years ago
I'm pretty sure the studs are not part of the seat track. You should include that feature or some equivalent into your EAS design
Marco over 8 years ago
I believe we are suppose to design the stud, here is why:
If the stud design wasn't necessary, wouldn't be a reason to give the design and the resistance of the seat track used in the ISS.
Also, the the the first requirement:
"Shall be capable of providing a rigid connection to the seat track "
Say we need provide these rigid connection.
Marco over 8 years ago
Michael Friday I was reading your comments again. In one of them you said that the plate will be fixed in other locations. So I ask:
The location where the plate will be fixed on the other location is inside the keep-out zone?
Because i don't want that my fixing system for the EAS interfere with fixing system of the mounting plate in other locations.
Michael Friday over 8 years ago
@Dan, Using standard tolerances, the positional tolerance of the plate to the seat track can be up to +.10” relative to the seat track with an angular tolerance of .5 degrees. For the GD&T minded, the surface profile around the perimeter of the plate relative to the seat track can be .55.
Michael Friday over 8 years ago
@Marco, true, part of the KOZ is for us to mount in other configurations. The other areas will not cause any interference.
Yohann Panthakee over 8 years ago
what units are the measurements in for the specification?
Michael Friday over 8 years ago
The units are in inches.
Yohann Panthakee over 8 years ago
For the MS33601 specification.
Michael Friday over 8 years ago
@Marco and Dan, yes, you need to include the connection to the track as part of your design.
Yohann Panthakee over 8 years ago
For the MS33601 specification
Michael Friday over 8 years ago
Refer to note 3 of MS33601: Dimensions are in inches.
Marco over 8 years ago
Jason IMHO the weight of experiment doesn't matter because: ISS it is on space (0G), therefore can be ignored.
Dan Rudmin over 8 years ago
That's an applied load, not the experiment weight
Allan over 8 years ago
@Marco, i I have read what NASA say of their web site about gravity. 0 gravity is a misnomer. The ISS is in micro gravity which is strong enough to keep it in orbit. The apparent weightlessness that you observe is because the ISS is falling towards earth at the gravitational pull about 240 miles above earth surface. The ISS is moving fast enough thousands of km/hr that it doesn't fall to earth. Whilst the astronauts if weighed in space would at 0 their mass is the same as it is on earth, as with all the other equipment. It would be fair in my estimation to adjust the gravity to about -9.0 m/sec2 for in space FEA, however I am sure that the kick loads of 125ibf has been established for an on earth simulation. As we dont know the mass of the experiment only its volume as indicated by some dotted lines and the load is 20 inches from the mounting plate surface and within the experiment volume the only way I can see to apply that load for sim is with a remote load as I have depicted in a jpg on my entry. I stand to be corrected or guided to the right way to do this as I have previously asked.
see http://www.nasa.gov/audience/forstudents/k-4/stories/nasa-knows/what-is-microgravity-k4.html
http://www.nasa.gov/centers/glenn/shuttlestation/station/microgex.html
http://www.nasa.gov/mission_pages/station/research/news/microgravity.html
Travis Petersen over 8 years ago
Is there a way to edit your entry? I need to change some info in my data document and add some renders. how is this done?
Allan over 8 years ago
Hi Travis, I believe you can Delete a file, view it or download it. So if I have to change something I delete the old and upload a new file in its place. To add renders just click the + button (top right in the filewindow) and upload. It will recognise it is a render if it is a jpg for e.g..
Nathaniel Andresmooi over 8 years ago
Does the force body diagram depicting the seat track describe a 650 lb load per hole or per 4 hole total area?
Allan over 8 years ago
Please advise which research accommodation will be utilised for the attachment of the EAS. It is assumed internal, and if so, which research Lab. Will the EAS be mounted on a Science Rack Facility and if so which one/type for e.g. an ExPRESS Rack? Is there a particular duty cycle that the EAS will be subjected to vis-a-vis; as the EAS is external to the rack exterior, is it expected that the Active Rack Isolation System will keep ISS vibrations typically within ISS requirements. If not does the type of experiment envisaged the need to operate under Microgravity Mode to minimize the vibration environment that the EAS frame is subjected to.
Dan Rudmin over 8 years ago
Can you clarify what constitutes an exposed edge? Is any visible edge considered to be exposed? Would the interior of a hole or counterbore be considered exposed? Also how exactly is the thickness of an edge measured, is it measured along the edge, or the distance perpendicular to the edge to the next nearest edge? What is the minimum angle at which an edge is considered sharp enough to require rounding. You mentioned before that 45 deg chamfers are not considered sharp edges. Is 45 deg the cut-off. Would a 60 degree edge be considered sharp?
Nathaniel Andresmooi over 8 years ago
Are off the shelf parts acceptable in these designs? Do all ideas have to be novel and unique or is it only the final assembly that is required to be new and unique to this project.
Marco over 8 years ago
Michael Friday could you provide the actual data for ABS resistance?
Since the ABS proprieties from last challenge aren't the ABS strengths, its just loads, as you can see:
.
Z Tensile (build direction): 50 lbf,
XY Tensile (-45,45 layup): 121 lbf,
XY Tensile (0,90 layup): 120 lbf,
Flex (-45,45): 359 lbf,
Flex (0,90): 323 lbf,
Z Compression: 1433 lbf,
XY Compression (-45,45): 1316 lbf,
XY Compression (0,90): 1457 lbf.
.
It is possible to provide the tensile/compressive - yield/ultimate strength. also the young modulus?
Dan Rudmin over 8 years ago
I would also be interested to know how they plan to evaluate the strength and stiffness criteria.
Michael Friday over 8 years ago
Young's Modulus for ABS is 320,000 psi, Poisson's Ratio of .35.
Michael Friday over 8 years ago
@Allan and Marco, The 125 lbf load is and applied load that would represent a crew member pushing on the experiment while on orbit. So gravity can be ignored, as like Allan mentioned, everything is falling together. But the induced 125 lbf load, can still occur on orbit.
Michael Friday over 8 years ago
@Nathaniel, off the shelf parts are allowed. However, any fasteners must be captive, springs must be retained such that they can’t come loose from the assembly.
Michael Friday over 8 years ago
@Allan, The experiment will meet the ISS microgravity vibration requirements. We are not levying the microgravity vibration requirements to the EAS as part of this challenge.
Michael Friday over 8 years ago
Comments for your loads analysis and calculations: We expect too much variation in these designs to apply one standard method to everyone. We need you to tell us what assumptions you made, what constraints were applied, and how you applied the loads.
Michael Friday over 8 years ago
For the tracks, the MS33601 spec gives constraints for the dimensions inside the rails only. If you look up different vendors you may find different outer dimensions than what we posted in our drawing. The load and moment limits for the tracks we are using are given as constraints for this challenge.
Thilini Schlesinger over 8 years ago
@Allan, Michael answered your question but I want to make sure that it was clear. In the specification, you will see the seat track loads and moments. You should ensure that your design meets those. Then you will not need the material specification.
Thilini Schlesinger over 8 years ago
A couple of generic comments:
1. Please ensure that you are providing both the loads calculations and the assembly procedures in your drawings. In your procedures, it would help if you labeled the parts to make it easier to understand.
2. One thing that we failed to communicate is that the mounting plate should be able to be removed from the EAS. Most of the submitted designs use fasteners so that is possible but if you are using adhesives or any other type of permanent attachment between the EAS and mounting plate, please consider other methods of attachment.
Thank you!
Thilini Schlesinger over 8 years ago
We will be spending the Easter weekend with our family so we will respond to your comments next week. Happy Easter!
Javier Valdes over 8 years ago
There are still some key questions above that has not been an answered and in other cases the answer gives misleading information. In engineering things are black or withe, gray is an invitation to trouble. This is a great challenge and I'm sure many are eager to participate but confused (as me). Please clarify/define the followings rules:
1) Attachment method to mounting plate
-Can we access and install fasteners from the top of it? (Z in the track coordinate system)
-If yes, how high in Z are we allow to intrude and how big? do we need to have these bolts attached to a cable (captive) or can they be free?
-If no, can we assume the fasteners can be installed from the bottom in any free space? Can the tread of the bolt exceed the top of the plate? If yes, how much?
(by the way, if only top access is allowed but we can't go over the .025" thickness, the only option left is countersunk screws which in turn are going to be non-captive!)
-Can we add a hole with Helicoil in the plate?
-Are we allowed to modify the bottom of the plate (with I understand is flat)? If yes, by how much (X,Y,Z)?
-Is the 1.0" bellow the bottom of the plate (experiment contour) still a "stay away zone"?
2) Seat track attachments
-The moment limits are going to be huge! the experiment 125lbs load is quite "tall" (Z) and away. Are you going to enforce this(I guess so)? but the calculations needed (360 deg around) are mind blowing. If we don't provide FEA, are you going to do the calculations for every entry? (can you simplify this rule? like in every 45 deg?)
3) Shall have a deflection of 0.5"
-All the entries are going to be some kind of mechanim-kind. How are you going to calculate this?
Again, I want to thank NASA to bring this challenge. Please take my comments as a way to make it more clear and fair to all of us.
Thanks!
Matti Kumpulainen over 8 years ago
Allan.
I don't know what is right answer of your question. But i give a way how i did it.
I make pillar of about 4 inch from mounting plate. I make this in same part than plate because its simplifies how FEA calculates. This pillar is 20 inch tall and its top is small 1/4 inch cube where forces are easy to put in right directions. Cube needs to be just as big that force is not making biggest yield in there. In bottom of pillar is big 2 inch fillet so 1/4 inch plate is not forced too much in tomb corners.
I made seat tracks from 6061-T6. I think any material is possible because we need to show that forces are not over given table. And because outside dimensions are not given I only stay inside and top of track.
Good luck to all who scratch their head in this puzzle! And remember the main goals: weight and simplify in assembly. ;)
Allan over 8 years ago
Thanks Matti, very helpful indeed. I am much obliged.
Nathaniel Andresmooi over 8 years ago
@Javier Valdes To help answer your #2. You should be able to get by with just a few directions. For example max load at the farthest edge of the plate for the seat rack being calculated should be peak load. Assuming your design doesn't contain lots of flexible members that change position. (which isn't allowed design is to be rigid not moveable.) Moment will be plate dimension plus distance to the seat rack in that axis/direction.
Javier Valdes over 8 years ago
Thanks for your advice Nathaniel.
Javier Valdes over 8 years ago
NASA Team, in my previous comment, I referred mistakenly to Z as height above the tracks when I should have said Y.
Marco over 8 years ago
Better explained human edges factor with pictures.
http://msis.jsc.nasa.gov/sections/section06.htm
Nathaniel Andresmooi over 8 years ago
Good link Marco. You're welcome Javier.
Thilini Schlesinger over 8 years ago
@Allan. I can see how that is frustrating. I think Matti gave you some good feedback. However, I do want to point out that even if you are doing FEA, it's always a good idea to do a few hand calcs to make sure you're setting up your model correctly.
Thilini Schlesinger over 8 years ago
@Javier. Good questions.
1) Attachment method to mounting plate
-Can we access and install fasteners from the top of it? (Y in the track coordinate system)
Yes, you can install fasteners from the top.
-If yes, how high in Y are we allow to intrude and how big? do we need to have these bolts attached to a cable (captive) or can they be free?
We didn't specify a height limit but we don't expect the fasteners to protrude several inches into the free space. If they do, we would like to understand why you chose those fasteners. Yes, the fasteners should be captive.
-If no, can we assume the fasteners can be installed from the bottom in any free space? Can the tread of the bolt exceed the top of the plate? If yes, how much?
(by the way, if only top access is allowed but we can't go over the .025" thickness, the only option left is countersunk screws which in turn are going to be non-captive!)
The fasteners can be installed from the bottom but it will be harder for crew access (refer to the crew access location in the EAS envelope drawing). We didn't limit you to 0.25" (I think you meant 0.25 instead of 0.025) inches. That was just the thickness of the plate.
-Can we add a hole with Helicoil in the plate?
Yes
-Are we allowed to modify the bottom of the plate (with I understand is flat)? If yes, by how much (X,Y,Z)?
What do you mean by modify?
-Is the 1.0" bellow the bottom of the plate (experiment contour) still a "stay away zone"?
Yes but only 1" below the keepout zones of the plate.
2) Seat track attachments
-The moment limits are going to be huge! the experiment 125lbs load is quite "tall" (Z) and away. Are you going to enforce this(I guess so)? but the calculations needed (360 deg around) are mind blowing. If we don't provide FEA, are you going to do the calculations for every entry? (can you simplify this rule? like in every 45 deg?)
Yes, this is a criteria so it will be enforced. Let me get back to you after I talk with our stress and design engineers about the best way to clear up that requirement.
3) Shall have a deflection of 0.5"
-All the entries are going to be some kind of mechanim-kind. How are you going to calculate this? Please clarify this question. Are you asking how NASA is judging this criteria?
Dan Rudmin over 8 years ago
It appear that the attachment plate does not conform to the sharp edge criteria. If we design near the edge of the plate it will be important to know if the edges are radiused or not. Can you confirm that the attachment plate does in fact have 90 degree edges as shown in the drawing?
Dan Rudmin over 8 years ago
Also, does the sharp edge criteria apply to exposed fasteners. It seems that a standard hex head or socket head will have edges that are too sharp.
Javier Valdes over 8 years ago
Thilini, thank you for your comments and answering my questions. Let me clarify question 3: All the EAS entries need to be assembled / unfolded in space (a finished EAS does not fit the launch envelope). All the entries will probably have some joints and multiple fasteners. In real life you will have tolerances between all of them. The more parts and joints you travel thru from the point you apply the load to the "landing" fixed one, the more tricky it gets to predict a deflection. Add to this that the parts will "deform" in an optimized way in a FEA (trying to reduce the weight and keeping it bellow 1.25 / 2.0 yield). This is a serious and complicated study. My question: I wonder if NASA will do their own calculations and analysis for each EAS entry?
Nathaniel Andresmooi over 8 years ago
@Javier
Bare minimum Nasa will have an engineer review your calcs and dimensions very closely. Ultimately they are responsible for the safety of their astronauts. That said you are tasked with making your device safe and to spec before they ever have to look at it.
@Dan
Just call out what edges will need made non sharp. We aren't responsible for making the device. If you have an edge in your design that looks like it will violate sharpness spec then call it out and specify the detail to be radius-ed. They will decide if the fastener is safe. Keep in mind all small parts that must be handled by the astronauts are an issue.
Nathaniel Andresmooi over 8 years ago
From a previous answer "off the shelf parts are allowed. However, any fasteners must be captive, springs must be retained such that they can’t come loose from the assembly. " By Friday to me.
Dan Rudmin over 8 years ago
Could you elaborate a bit on what the definition of a captive fastener is? Do you mean impossible to remove or just not normally loosely floating? For example if a fastener is installed in the assembly that is used for tightening a joint but if it were turned CCW far enough it would eventually fall out. Is that fastener considered non-captive?
Nathaniel Andresmooi over 8 years ago
If I were to guess without re-reading the safety spec (which someone linked). Captive would mean the part has to be permanently tethered or have some sort of stop or feature that prevents it from coming all the way out. Like a T shape on the end. You don't want ANY small parts floating around the shuttle or station to possibly get lost (no hardware stores in space) or to even damage (short out an important panel) something or get inhaled by an astronaut. Lots of reasons to have any part where at all possible be attached and unintended to come free.
Thilini Schlesinger over 8 years ago
@Nathanial, thanks for all the great responses back to the community! You were exactly on the right page!
@Javier, Nathanial is correct. We will have an engineer review your calculations and FEA to determine if they are correct. By the way, still working on your other questions.
@Dan, the fastener in your example is not captive. A crew member could easily unscrew that fastener during disassembly of the EAS. Once it's loose, we call it Foreign Object Debris (FOD). Our concern is that these small parts could get into air vents or hardware air intakes and cause damage. A captive fastener needs to have a feature that keeps the fastener from floating away once completely disengaged from the interface. One type of captive fastener comes with a retaining ring. Here's a site from Alcoa (https://www.alcoa.com/fastening_systems_and_rings/aerospace/en/product_category.asp?cat_id=545) that explains some options for captive fasteners. I'm sure there are more designs that can be found by doing a Google search.
Marco over 8 years ago
Thilini Schlesinger would a nut applied inside of 3d printed part be captive?
Since it is possible to insert the nut during the manufacturing process.
Allan over 8 years ago
@Thilini I looked at the Alcoa site yesterday and wondered if part of the EAS was assembled before deployment, i.e. on earth and was not required to be dissembled once the experiment was removed, would that necessitate a captive screw? For e.g I am sure there are many parts that make up equipment on the ISS which are not intended to be 'serviced' or stripped on-orbit an likely do not all have captive screws.
Nathaniel Andresmooi over 8 years ago
@ Thilini, no problem at all I'm currently an Engineering student so I understand the need for communication in the learning process. The teacher learns as much trying to express something as the student does learning something new.
On a side note what are the hiring conditions at NASA of recent :) ?
Technical Question: Does the station possess a small Vice in their Garage Workshop? I don't personally need it but I can see many future assembly repair disassembly operations being very awkward in zero G. Particularly if someone manages to over tighten an assembly. I see a mental picture of one person bracing holding something while the other tries to crank on the other end.
Nathaniel Andresmooi over 8 years ago
@Marco I would say that's an almost a definite yes. Though if they were to print another one in orbit they would need those loose components to do so. Also the 3D print would need to be very safe so as to not break there and loose that nut into the ISS.
Thilini Schlesinger over 8 years ago
@Marco, as long as the nut cannot come out of the 3d printed part without having to tear it apart, that is ok.
Thilini Schlesinger over 8 years ago
@Nathanial, NASA is always looking for innovative minds. Since you are a student, you are in a great position to apply to internships at various NASA centers. Here's our internship website if you're interested: http://nasajobs.nasa.gov/studentopps/employment/iep.htm
Thilini Schlesinger over 8 years ago
@Allan, you are correct. There are parts on ISS that are not captive. If the parts are installed on the ground and will not need to be serviced, then there is less of a need of captive fasteners. However, we've had a lot of hardware that didn't have plans to be serviced but ended up having to be disassembled anyways. It takes longer for the crew to deal with noncaptive fasteners in their installation or removal procedures because they have to account for each part and store it away when not in use. That's why we prefer to use captive fasteners in our design.
Ray over 8 years ago
What is the bed size [ read maximum printed part size ] of The ISS onboard 3d printer? I assume it is a fused filament printer using ABS correct?
Matti Kumpulainen over 8 years ago
Hi, In Nasa site it says prizes are $5,000 and here its $3,000.
which one is right?
http://www.nasa.gov/feature/nasa-experiment-attachment-system-eas-challenge
Ray over 8 years ago
1 last question on the manufacturing of the EAS. Can we assume that NASA [ or the subcontractor ] that will actually manufacturing the EAS will have CNC and TIG welding capabilities ?
Dan Rudmin over 8 years ago
@Matti: They probably paid $5000 to GrabCAD and the website took a $2000 cut.
Ben Ewing over 8 years ago
Hi Matti and Dan, looks like a small typo! The prize pool is indeed $3,000 with $1,500 going to 1st place. Best of luck tackling this challenge!
Aaron over 8 years ago
NASA does not allow welded components for space flight.
Is there an atomic atmosphere concern with this project?
Ray over 8 years ago
You sure Aaron? https://www.youtube.com/watch?v=38t3UbfmcwE
Michael Friday over 8 years ago
Ray, we have CNC, milling and cutting abilities in our machine shops. Welding, while can be done, is very difficult to certify for space flight.
Nathaniel Andresmooi over 8 years ago
@Ray If it were me I would submit a welded version and a machined version and just let them pick between them. If the welded part is super easy to make compared the machined one they might consider. I assume they don't have to do much testing when its machined. While with welding they will probably have to make one then section it (chop it up) and look at weld joints. I believe the end product they are seeking from this competition is something they can check very quickly and make asap. Sending it up on the next available milk run to the ISS.
Ray over 8 years ago
I'll stay away from welded joints. It would've been cheaper to build with welds but safety first. ty for the reply.
Leon van Rijn over 8 years ago
I downloaded the specifications but now I am unable to delete 1 of the files.
._NASA Challenge Supporting Docs.
won't delete in any way. A pop-up window tells me that the file no longer exists in the current path, but it is there. Even restarting the entire pc of trying to move it to a differetn location and delete it later is impossible.
Anyone suggestions?
Nathaniel Andresmooi over 8 years ago
@Leon I ran into the same issue. It has something to do with the way their zip file and file ownership works. I was able to drag and drop the offending file into a copy of the unopened zip file of the technical requirements. Don't unzip it before hand. You are trying to move and replace is the option that worked for me.
Michael Friday over 8 years ago
We have re-evaluated the crucial load cases that we would like the participants to include I their analysis. Side loads can be considered negligible, therefore that case can be ignored. We only need to see results for the vertical case (normal to the plate), and front horizontal case (parallel to the tracks).
Nathaniel Andresmooi over 8 years ago
I agree that there should have been a single reference set of axis early in the competition. However everyone has had to deal with the same degree of difficulty up till now for competition purposes. I would say the new spec is useful because they have cut their load calcs down to esentialy two. 1) Normal to the plate which is to say 90 degrees straight into or straight out of the plate. Which translates to either pushing or pulling straight into the plate. Thought I assume you will still need more than one test location on the plate because its not symetrical that is to say the same shape overall. 2) Horizontal to the plate still at the same height as orginaly posted. This being parrell or in the same direction as the tracks. Luckily this change only pertains to final load modeling and math. Not predesign. If they changed the predesign requirements I would say they threw the baby out with the bath water too.
Aaron over 8 years ago
Yes Ray, I'm sure. Ive only been working for NASA a short time (6 years), but I stopped throwing in welding ideas for flight items awhile ago. As Mr Friday said, it's very difficult to get certifications on welds. It's very easy to quantify a mechanical joint or a nut/bolt assembly, but we don't like having to guess if a weld is perfect or not.
Bill Kapok over 8 years ago
Why aren't the six corner radiuses on the experiment mounting plate clearly specified ?
Are these all the same : 1" or 1/2" or what ?
A PDF document isn't suitable for measuring / scaling.
Thank you.
Nathaniel Andresmooi over 8 years ago
@Bill Kapok Since the plate doesn't exist you could request a specific radius on corners? Say if the radius was part of your mounting system. We have already been told we can suggest plate modifications in any area outside the keepout zones. Like mount holes or slots. If the modifications are minor and don't effect plate to weaken it.
Ray over 8 years ago
TY Aaron, I didn't realize you worked for NASA. I can understand the reasoning. thanks again.
Bill Kapok over 8 years ago
The description of this design contest states: "The EAS will hold a NASA provided 0.25 inch thick mounting plate".
The footprint of that plate is set by NASA and the corners' radiuses are part of the outline.
This mounting plate shall be removable and fit other location(s) / attachment systems.
Therefore, the all around compatible outline ought to be shown explicitly on the EAS Envelope.pdf drawing, including the corners' detail.
That shape has also a bearing on the local stresses in the plate, depending on the attachment system.
Nathaniel Andresmooi over 8 years ago
Since the plate has undefined features it might be nessesary to make it out of unobtanium for testing purposes. That is to say not account for warp in the plate and only for warp in the designers structure.
Dan Rudmin over 8 years ago
@Nathaniel: the option of modifying the plate was changed according to Friday. You can only remove material from the mounting plate. Nothing can be permenantly added which protrudes from the plate's original dimensions
Bill Kapok over 8 years ago
Mr. Nathaniel, you say: Unobtanium ?
Per M. Friday: "The material will be 6061-T6 Aluminum, .25” thick within .020. Its thickness is fixed, ..."
Also, in the real world, outside of the academia, an engineer can't just ignore what is beyond his interface.
The mounting plate will warp and that deflection will be additive to the other displacements.
That plate needs to be attached somehow to the EAS and knowing (not guessing) how much of edge is available for grabbing (beyond the keep out zone) would be nice.
The net edge is the length between the side intersection points, minus the rounded portions.
Hence the question.
Dan Rudmin over 8 years ago
It's impossible to guess how the plate will deflect without some knowledge of how it is connected to the 125 lb applied load. My best interpretation of the criteria is that the plate should be treated as rigid, and 0.5 inches of deflection is the maximum that the EAS can add to the experiment in addition to any deflection between the experiment load and the plate.
Nathaniel Andresmooi over 8 years ago
I realize that word smithing isn't my greatest skill. I only say that we might be able to ignore the plate if its already been intentionaly over-built. I haven't done a simple bending test on the plate. Using the dimensions they have given us we can do so. If the plate happens to have a resistance to bending far in excess of our other parts it may become comparatively negliable. If it bends like tissue paper it will need to be thoroughly restrained and supported to prevent warp of the plate. Either way I wouldn't chose to place features at the very edge of the plate. In the world of engineering where you are paid for objective results you are expected to get the job done and not become deadlocked in indecision. It really depends if someones design requires that edge detail I suppose. Mine will not.
Allan over 8 years ago
@Dan Hello Dan, they say max deflection is at the point of load. If the plate is rigid can you still make that measurement?
Dan Rudmin over 8 years ago
I just put a 20" antenna that sticks out from the plate as a deflection indicator. The force is applied to the plate top surface as a remote load.
Allan over 8 years ago
Brilliant just what I have done too. Saves mucking around modelling geometry and taking up time to solve /mesh etc. I have applied the remote load at the experiment mounting holes but I suppose the mtg plate acts as a load spreader so perhaps the load should be applied to the whole plate surface?
Bill Kapok over 8 years ago
Looking at the TOP View of the EAS Envelope.pdf, does the horizontal edge of the EAS Envelope line up with the centerline of the circular apertures on the Logistic Tracks or does it intersect the slot on the L-Track at a half-way between the circular apertures ?
It is understood that there would be a slight offset from these positions to account for the 0.1” overall clearance distributed to both ends.
So, is the reference line at the center of the circular holes or at the half way between these ?
Thank you.
Michael Friday over 8 years ago
All, thank you for your feedback. Since the location and orientation of the experiment platform could change we decided a specific coordinate system was not needed. Because, like you said, it is arbitrary. We are having a revision to the EAS envelope drawing uploaded to help clarify the two load conditions we would like to see analysis for. We are doing this to reduce the number of calculations required to have your design considered in our competition. If you have already submitted one with more loads cases we will accept it.
Michael Friday over 8 years ago
@Bill, The designs we’ve seen so far have not needed the corner radius defined. However, we understand your design may. Please assume a 1 inch corner radius for each of the 6 corners of the plate.
Also, The EAS envelope can be aligned along the track to accommodate your design.
Jonathan Brazeau over 8 years ago
25 entries.....lol
Nathaniel Andresmooi over 8 years ago
if its anything like the last challenge people are waiting till last day to submit because they feel people copy things.
Michael Friday over 8 years ago
All, we are looking forward to seeing the last round of designs. Please remember to include CAD files in STEP or IGES format, your assembly procedures and loads analysis.
eyup fındıklı over 8 years ago
I have some issuse when downloading specification. I can't reach unzipped files. Please is anyone can confirm me?
Nathaniel Andresmooi over 8 years ago
Just download spec zip file. Open like a normal folder don't bother to unzip. It worked for me could access all the pdfs and files contained in it.
Nathaniel Andresmooi over 8 years ago
Next time knowing more specific locations of all experiment hardware would be cool rather than a large keepout area. Makes the design simpler and more efficient.
Nathaniel Andresmooi over 8 years ago
@Friday Not sure if anyone noticed but plate itself exceeds the shipping dimensions. Plate could fit corner to corner with nothing attached but isn't experiment preassembled?
Marco over 8 years ago
@Nathaniel, Michael Friday already metion in ealier comments that we dont need to worry about how the mounting plate will be launch to the ISS
Nathaniel Andresmooi over 8 years ago
@Marco I remember that but he also mentioned that we can request plate changes. Specificly could the narrow way plate width be changed from say 20.1 to 20.5 in order to better preserve keepout zone.
Dan Rudmin over 8 years ago
Not many entries. I think the loads analysis really put the hurt on competitors who don't have access to expensive software licenses or fast computers.
simon swanepoel over 8 years ago
i tried submit at 9pm and it says the deadline has passed
Dan Rudmin over 8 years ago
What time zone?
Marco over 8 years ago
Does anyone found a way to delete the folders and files of original.zip after extraction? For some reason I cant delete
Thilini Schlesinger over 8 years ago
Thank you to everyone for your submissions! We appreciate everyone's feedback through this process. It was a tough challenge and we've been very impressed with the solutions! Now we have the hard task of evaluating the entries. The finalists will be announced on April 28th and the winners on May 5th.
Marco over 8 years ago
I would like to thank the NASA Logistics Reduction team for bringing this challenge and I hope for others in the future. And also thank Thilini and Michael for answering the questions of grabcad community about some design criteria.
Good Luck to all contenders
Francisco J. Erenas Rivas over 8 years ago
There are many very good designs, and not whether the mine will go to the final or not, but anyway I would like to know, if possible, the position he has been my design, 6 position or 57 position, would it be possible to know ?
More than anything, to take courage for the next time ...
a greeting
Matti Kumpulainen over 8 years ago
When I look designs there are many with genius features to make me envy. My design is focused only to make weight as light as possible, its ranking qualification. Maybe I even go too far and lost needed factor of safety. How many of you really try to got weight down at all costs? Or do I miss some important point?
Thank you all who participate and organizer of this challenge. This was very educational for me.
Marco over 8 years ago
@Matti from my understanding of the judging criteria will be, but NASA team can tells us the correct way.:
1-Pass/fail: if at least one of the loads, volume, weight and interface constraints isn't ok, the design is disqualified.
2-The design that passed on 1 will be evaluated in a ranting from 0 to 10, for example, on assembly-installation (#parts and #movements maybe) and manufacturability (cost? time? material? complexity? in my opinion).
3-If there is a tie between design on 2, total mass will be tiebreaker criteria.
This is just my opinion on how i think will be the judging criteria.
Travis Petersen over 8 years ago
I got into this, not as an engineer, but as a hobbiest. I did not realize that you had to have FEA. I didnt even know what it was. lol Unfortunately I found out after I was invested in the design. I designed mine to be strong but kept in mind weight requirements.. I cam e in a few pounds under max, stayed in the safety guidelines, and just tried to keep it structural. My big thing was I didnt want any tools involved in assembly. It was fun, and now I know I need to learn FEA.
Dan Rudmin over 8 years ago
It's about 2-10k $/lb to get stuff to the space station, so no point saving a lb if it requires rare and expensive processes.
Nathaniel Andresmooi over 8 years ago
Nasa also gave us a pretty hefty weight alotment so we should have been ok. Safe and reliable with any kind of added value ideas.
Allan over 8 years ago
Don't know whether to laugh or cry. Have just worked out I could have made my T-Slots form Surfaces instead of Solid geo and this would have saved hours I am sure in processing the FEA. Well this will help for the next challenge I suppose.
DWP over 8 years ago
I'm glad I have read the comments even if four days later. Otherwise how could I know that weldings are not allowed ? :o)
Ben Ewing over 8 years ago
We are happy to announce the finalists for the NASA EAS Challenge: https://grabcad.com/challenges/nasa-experiment-attachment-system-eas-challenge/results. Take a look and let us know which finalist is your favorite! Next, the judges will be taking an in depth look at all of the entries with regards to the judging criteria. Congratulations to the finalists and to everyone who entered!
Marco over 8 years ago
Thanks Ben Ewing for the information. I am glad i am one of the finalist designs. Can we expect questions regarding the design in the following week? Since i have some ideas for modifications, but didn't change duo deadline, what would make manufacturability easier and final product with cleaner design in some parts.
Matti Kumpulainen over 8 years ago
Congratulations to all finalist! Now I’m eager to wait and see who wins!
Because I think target wrong from given task and not qualify to finales, I now ask 15 minutes of your valuable time, my fellow engineers. I like to learn as much as possible from this challenge.
Please look my design and give any feedback and your feeling is there failing features etc. I want to hear your concerns of how can my design survive in real world. I think wrong when I look this only weight optimizing challenge. That’s because I think if I can save pound I can spend up to same amount to more expense manufacturing process. And because I find out its about 20000USD per pound to take things to orbit I have most advanced processes and materials in use.(http://behindtheblack.com/behind-the-black/essays-and-commentaries/the-costs-of-space-cargo/ )
Now I like to see your point of view, if it’s positive it’s always welcome. But mostly I want to hear your findings of fails and problem areas. Most fascinating for me are comments from industrial design, usability, manufacturing and material.
Thank you and good luck to your future challenges!
Direct link to my design:
Concept for NASAEAS
Please give your feedback messages to my design page comments, so we keep things nice and clean.
Nouryos Youns over 8 years ago
I hope the Judges can give some time to write a comments at each design of all the entries, in the same way they have Orally discussed,( why and in which points ) the design has excluded, logically we could in that way Convinced, and from another point avoids conflicts.
Not Only that, but also we as the designers spent at least 20 days on your design idea, could be helpful for us to refine your work and gain more experience from a very advanced Company . and for the next challenge for You, we will be more motivated... and innovative . because I think the participants "other than me" in this challenge ware the one of the most good designers in this site .
I think the other participants Agree with me in this point .
Ben Ewing over 8 years ago
Hi all, I'm happy to announce the winners for the NASA EAS Challenge: https://grabcad.com/challenges/nasa-experiment-attachment-system-eas-challenge/results. To pick the winners, the judges took an in depth look at all of the finalists in terms of the judging criteria. For a little more information on the judging criteria, be sure to read the description at the top of the results page! Congrats to the winners and thank you to everyone who participated!
Thilini Schlesinger over 8 years ago
Thank you to everyone that submitted designs, the finalists, and now the winners! You made evaluating very difficult since there were so many innovative designs! Congratulations!
Dan Rudmin over 8 years ago
Out of curiosity, what was NASA's manufacturing approach for bending 6061-T6 plate and modelling the residual stresses?
Javier Valdes over 8 years ago
3 of the 5 winners does not pass the sharp corner criteria! It was one of the aspects that made this challenge so difficult. Also, there is non-captive hardware, another very, very tricky one. Anyway, thanks NASA for bringing this challenge, it really made me think and ponder the multiple solutions. I will try to post my tougths and feedback in more detail soon.
Marco over 8 years ago
Gratz to all winners . All thank you NASA for bringing this challenge( i hope for other in the future).
I thought that also javier, all corners need be rounded, and because of that will increasing the manufacture time ( and some egdes in some of the design cant be rounded). On the text that explain how the analysis was made, there is no mention of the sharp corner criteria.
Dan the residual stresses could be removed if after the bend the heat treatment is remade( but this could lead to distorntions)
Stanislav Petrek over 8 years ago
Hello all. many thanks people from Grabcad and NASA for oportunity to participate on this interesting challenge. But congratulation all other winners. I am happy that my EAS was chosen like the best design :)
Francisco J. Erenas Rivas over 8 years ago
Congratulations to all participants, the finalists and winners. Proud to work for NASA, I just hope that in upcoming contests take into account the language and translate all the challenges different languages, although translators work well, the nuances are not clear and it is difficult to understand.
I'll be waiting for new challenges.
a greeting
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