Exciting engineering challenges with great prizes

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NASA Regolith Advanced Surface Systems Operations Robot (RASSOR) Bucket Drum Design Challenge

NASA is seeking to challenge the GrabCAD Community by sponsoring an open competition in which participants design a bucket drum for RASSOR that will provide the maximum amount of regolith extraction and retention while remaining free of obstructions during loading and unloading.

Regolith excavation is desired in future space missions for the purpose of In Situ Resource Utilization (ISRU) to make local commodities, such as propellants and breathing air, and to pursue construction operations.

RASSOR is a teleoperated mobile robotic platform with a unique space regolith excavation capability. Its design incorporates net-zero reaction force, thus allowing it to load, haul, and dump space regolith under extremely low gravity conditions with high reliability.

RASSOR uses counterrotating bucket drums on opposing arms to provide near-zero horizontal and minimal vertical net reaction force so that excavation is not reliant on the traction or weight of the mobility system to provide a reaction force to counteract the excavation force in low-gravity environments.

During loading, the bucket drums excavate soil/regolith by scoops mounted on the drums exteriors that sequentially take multiple cuts of soil/regolith while rotating at approximately 20 revolutions per minute. Inside the hollow drums are baffles that trap the regolith and prevent it from falling back out of the scoops. During hauling, the bucket drums are raised by rotating the arms to provide clearance above the surface being excavated. The mobility platform can then travel while the soil/regolith remains in the raised bucket drums. When the excavator reaches the dump location, the bucket drums are commanded to reverse their direction of rotation, which causes soil/regolith to be expelled out of each successive scoop.

For more information: https://technology.nasa.gov/patent/KSC-TOPS-7

https://www.researchgate.net/publication/261248231_Regolith_Advanced_Surface_Systems_Operations_Robot_RASSOR

RASSOR 1.0/1.5:
https://www.youtube.com/watch?v=d3zRvl2LYJ4&feature=emb_logo

https://www.researchgate.net/publication/261248231_Regolith_Advanced_Surface_Systems_Operations_Robot_RASSOR

RASSOR 2.0:
https://www.youtube.com/watch?v=rAIw7a2VfQ0

https://www.youtube.com/watch?v=sBod90pUfB0

Requirements

  • JUDGING CRITERIA

    1. Successful designs will have a fill ratio higher than 50%.

    2. Short description of how your design works and intended fill ratio

    3. Is the design real? Can the design work? Can it actually be created?

    4. Meets dimension requirements

    5. If the engineer can provide a simulation of the regolith grain, that is a plus.

  • Requirements needed for Submission:

    Maximum total width of scoops engaged at any given time: 175 mm
    Maximum bucket drum mass: 5 kg
    Maximum bucket drum diameter: 450 mm
    Maximum bucket drum length: 360 mm
    A minimum volume of regolith captured: 17.6 liters

  • Submission File Formats

    Renderings
    STEP of design(s)
    Final design STL
    Short description of design/how it works

Rules

  • ENTERING THE COMPETITION:


    If you think an entry may infringe on existing copyrighted materials, please email challenges@grabcad.com.


    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. Warrant, to the best of your knowledge, your work is not, and has not been in production or otherwise previously published or exhibited.
      5) 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.
      6) Warrant participation shall not constitute employment, assignment or offer of employment or assignment.
      7) Are not entitled to any compensation or reimbursement for any costs.
      8) Agree the Sponsor and GrabCAD have the right to promote all entries.

  • 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 "NASADRUMCHALLENGE" 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. Prizes may not be transferred or exchanged. 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.

  • Schedule


    This Challenge ends on April 20th, 2020 (23:59 EST.) Finalists will be announced on April 27th, 2020. Winners will be announced on May 8th, 2020.

Prizes

Prize Winnings

$7000 in Prizes

First Place

$3000

Second Place

$2000

Third Place

$1000

Fourth Place

$750

Fifth Place

$250

About NASA Lunar Surface Innovation Initiative (LSII)

This challenge is sponsored by the NASA Lunar Surface Innovation Initiative (LSII) which is a technology development portfolio to enable human and robotic exploration on the Moon and future operations on Mars.

The RASSOR excavator was developed at NASA - Kennedy Space Center’s Swamp Works. Swamp Works is a technology development group with expertise in In-Situ Resource Utilization. The Swamp Works team uses lean and rapid design and development processes to develop prototype hardware for future missions.

301 comments

  • Tommy Mueller

    Tommy Mueller 12 months ago

    Looks like an excellent challenge, thanks for partnering up to make this happen! Pretty sure I got the scope of the challenge, but I have two quick questions:

    1) Is there an official 3D model of the RASSOR (minus the current drum) or at least some 2D drawings that us participants can use as a reference for design compatibility?

    2) What is the current “Fill Ratio” using the existing drum?

    Tommy Mueller has uploaded 215 CAD models & has left 1864 comments.
  • Daniel Rutkowski

    Daniel Rutkowski 12 months ago

    I have a few questions on the details of the current drum system.

    1) How are the drums mounted/driven?
    1b) Are the designs required to account for the mount/drive?
    2) What are the material/weight limitations of the designs?
    3) Could you provide some information or a video of the current challenges associated with the current design?

    Thank you

    Daniel Rutkowski has uploaded 0 CAD models & has left 2 comments.
  • sanjay padvi

    sanjay padvi 12 months ago

    I am bit confused statement in "Schedule" "This Challenge ends on March 16th, 2020 (23:59 EST.) " ....means ...what is deadline?

    sanjay padvi has uploaded 8 CAD models & has left 10 comments.
  • Jason Schuler

    Jason Schuler 12 months ago

    Tommy:
    1.) We do not have any CAD that we can share of the RASSOR geometry. This challenge is intended to focus on the bucket drum geometry that interacts with the dirt. The entries do not need to include details for interfacing with RASSOR.
    2.) The current fill ratio is between 35% - 40%

    Jason Schuler has uploaded 0 CAD models & has left 5 comments.
  • Jason Schuler

    Jason Schuler 12 months ago

    Daniel:
    1. a&b) See response to Tommy's question #1 above.
    2.) The maximum mass for the design is 5kg. The material choice is open however the existing drum uses a combination of carbon fiber and aluminum.
    3.) The current drum works without any issues however if we can increase the fill ratio it could save significant time/energy during a mission.

    Jason Schuler has uploaded 0 CAD models & has left 5 comments.
  • Jason Schuler

    Jason Schuler 12 months ago

    Sanjay:
    Thank you for catching that. It was a typo that has been fixed. The deadline is April 20th (23:59 EST)

    Jason Schuler has uploaded 0 CAD models & has left 5 comments.
  • joey bevilacqua

    joey bevilacqua 12 months ago

    How do you define the fill ratio?

    joey bevilacqua has uploaded 1 CAD models & has left 2 comments.
  • SHIKHAR SARASWAT

    SHIKHAR SARASWAT 12 months ago

    Really excited to participate in this..!!

    SHIKHAR SARASWAT has uploaded 0 CAD models & has left 1 comments.
  • Paul Desjardins

    Paul Desjardins 12 months ago

    The maximum mass is 5kg. The existing drum combines carbon fiber and aluminum. This call for a new design of digging device. I would suggest that the robot first scoops material in the (solid and resistant) drum to increase weight and allow drilling device of pretty well known design.

    Paul Desjardins has uploaded 0 CAD models & has left 1 comments.
  • Sava Savov

    Sava Savov 12 months ago

    So, there are four drums and the requirements are for one of them? Or the requirements are for one "total drum" for each of the two sides where the machine digs?

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Clint Gates

    Clint Gates 12 months ago

    Why is the design a combined digger and hopper? It's more efficient to have separate machines for the jobs. This applies to farming, mining, factories, and much more.

    Clint Gates has uploaded 0 CAD models & has left 2 comments.
  • Andrew Lesh

    Andrew Lesh 12 months ago

    Are there any CAD files or images you can share of RASSOR 2.0's drum? The IEEE paper you linked has an image of interior geometry of the RASSOR 1.0 drum (https://www.researchgate.net/profile/Rachel_Cox12/publication/261248231/figure/fig2/AS:702678908805125@1544543115946/Bucket-drum-without-end-cap-to-show-baffles-RASSORs-solution-to-the-issue-of.jpg), so it would be really helpful to see the geometry of the second revision as well.

    Andrew Lesh has uploaded 0 CAD models & has left 2 comments.
  • Andrew Lesh

    Andrew Lesh 12 months ago

    Also, what is the fill ratio of each RASSOR drum revision tested so far?

    Andrew Lesh has uploaded 0 CAD models & has left 2 comments.
  • Dodi Budzyn

    Dodi Budzyn 12 months ago

    Great challenge! I was trying to figure it out from rules but I still have dubts so I will just ask: are non US citizens and people who don't live in US allowed to take part in the competition? I am asking for all Europeans here:) Thanks in advance if somebody helps to figure it out!

    Dodi Budzyn has uploaded 0 CAD models & has left 1 comments.
  • Dhruv Gandhi

    Dhruv Gandhi 12 months ago

    does the bucket drum size specifications refer to the inner storage drum or the whole thing?

    Dhruv Gandhi has uploaded 8 CAD models & has left 19 comments.
  • Kamen Rusev

    Kamen Rusev 12 months ago

    My question is: it will work only on sand type of material or gravel and all kind of rock shapes?

    Kamen Rusev has uploaded 55 CAD models & has left 266 comments.
  • Jeffrey poe

    Jeffrey poe 12 months ago

    @ClintGates Because the extra weight and space would be exponentially more expensive. Also because a combine harvester doesn't fit in the shuttle cargo hold.

    Jeffrey poe has uploaded 0 CAD models & has left 4 comments.
  • Clint Gates

    Clint Gates 12 months ago

    @Jeffrey poe Reinventing the wheel should not be the goal.
    The current design has great mobility but will clog up because it does not have anything to grind the material. The only limiting factor to aggregate size is the openings of the buckets. While the base request for design is for increased fill of the barrel, the requirements also list, "5. If the engineer can provide a simulation of the regolith grain, that is a plus." This implies the current design has issues dealing with clogging, and material larger and more solid than loose soil. The current design will also suffer from torsion of the arms and barrels.

    Reduce the RASSOR size.
    Use existing boring / grinding technology to dig.
    Send at least one Bucket Drone along with the RASSOR. Making more should be a priority once onsite.
    Only Bucket Drones, aka Trucks, should be used to transport material.

    Remember, sometimes smaller is better. Use the weight and dimension restrictions for multiple proper tools instead of one tool that will break itself.

    Clint Gates has uploaded 0 CAD models & has left 2 comments.
  • Tucker Albright

    Tucker Albright 12 months ago

    Hi Jason, I have three questions.

    1. What is the torque and speed of the drum's drive system? Are you able to provide a torque/speed/power/efficiency curve? I understand we don't have to interface with the drive system for this challenge, but I would like to know these parameters as they effect the performance of the drum itself (i.e. too large a scoop may stall the system).

    2. Which type of lunar sites do you intend to mine from? Specifically, I'm interested in the particle size of your target sediment. Which version of lunar soil simulant (i.e. coarse JSC-1AC or fine JSC-1AF, etc) are you most interested in mining? Are you able to provide any material data?

    3. How fast do you plan to 'traverse' a digging site? In other words, what is the linear travel speed (not rotational speed) of the drum or rover so that it acquires new dirt? In which direction does the drum travel?

    Many thanks.

    Tucker Albright has uploaded 1 CAD models & has left 1 comments.
  • Dhruv Gandhi

    Dhruv Gandhi 12 months ago

    @kamen Regolith is the material on the surface of a planet/moon. it can be measure from 120 microns to 0.8 cm (got those figures from google)

    Dhruv Gandhi has uploaded 8 CAD models & has left 19 comments.
  • Joseph Gallagher

    Joseph Gallagher 12 months ago

    Does the approach used to mount the drum to the arm/drive system allow for the possibility of a stationary core to the drum, which does not rotate with the rest of the body?

    Joseph Gallagher has uploaded 0 CAD models & has left 1 comments.
  • Jean Alain Alphonse

    Jean Alain Alphonse 12 months ago

    How hard is the Regolith on the Mohs scale?

    Jean Alain Alphonse has uploaded 0 CAD models & has left 1 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 12 months ago

    Is it allowed to be a student to take part of this challenge?

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Jason Homrighaus

    Jason Homrighaus 12 months ago

    How are you defining "Fill Ratio"? Is that based on the total volume of the enclosing Boundary? Total Volume of the Open space of the Model? etc?

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Kesa

    Kesa 12 months ago

    Daniel, You are allowed to enter this challenge.

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • philippe jamel

    philippe jamel 12 months ago

    hello you can imagine a magnet neodym inside to collect more powder : it is a good 3d digger i see but powder is difficult : no water, to collect we put water

    philippe jamel has uploaded 0 CAD models & has left 1 comments.
  • ernie ascherman

    ernie ascherman 12 months ago

    Not looking to make a full submission but have an idea for the fill ratio issue: make a spiral shape inside the cylinder to keep the regolith from falling back out.

    ernie ascherman has uploaded 0 CAD models & has left 1 comments.
  • Anirudh Palaiya

    Anirudh Palaiya 12 months ago

    Do you have to be 18 years or older to participate in this challenge?

    Anirudh Palaiya has uploaded 0 CAD models & has left 1 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 12 months ago

    Anirudh, no! ;) I am 17teen :)

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Aadarsh K s

    Aadarsh K s 12 months ago

    Setup a hydraulic drill under the robot
    This drill help the robot to decrease the hardness of the soil
    When the hardness of the soil decreases vaccum the soil using a powerful vaccum
    Pump

    Aadarsh K s has uploaded 0 CAD models & has left 2 comments.
  • Aadarsh K s

    Aadarsh K s 12 months ago

    Setup a vaccum pump inside the drum so the soil will not go out of the drum

    Aadarsh K s has uploaded 0 CAD models & has left 2 comments.
  • Sava Savov

    Sava Savov 12 months ago

    But there is already vacuum up there on the Moon :)

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Damoor Sahami

    Damoor Sahami 12 months ago

    I'm no good at CAD. But my idea would be to replicate a sea (snail) shell, with a "double layered screw", one (outer layer) that drills up the material and then falls into the inner layer screw which is only a sealed container. The idea with this would also be to be able to drill deeper.

    Damoor Sahami has uploaded 0 CAD models & has left 1 comments.
  • Gewang Aquino

    Gewang Aquino 11 months ago

    Hi, question. Are we allow to use other softwares like sketchup?

    Gewang Aquino has uploaded 0 CAD models & has left 1 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 11 months ago

    yes, I using Blender for that ;)

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Raul Santos

    Raul Santos 11 months ago

    Algum software para simulação do grão de regolito?

    Raul Santos has uploaded 4 CAD models & has left 8 comments.
  • Divy patel

    Divy patel 11 months ago

    Do we have to use a 3d software for submission?

    Divy patel has uploaded 0 CAD models & has left 1 comments.
  • Kesa

    Kesa 11 months ago

    @Divy you have to create a CAD File so yes a 3D Software is required to create your submission

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Jacob Mosier

    Jacob Mosier 11 months ago

    Anyone know if there is a required/suggested materiel?

    Jacob Mosier has uploaded 1 CAD models & has left 3 comments.
  • RocketNut

    RocketNut 11 months ago

    I can not read web link.because it is in German.

    RocketNut has uploaded 37 CAD models & has left 52 comments.
  • RocketNut

    RocketNut 11 months ago

    An I quote from challenge out lined above:::
    ======================

    During loading, the bucket drums excavate soil/regolith by scoops mounted on the drums exteriors that sequentially take multiple cuts of soil/regolith while rotating at approximately 20 revolutions per minute. Inside the hollow drums are baffles that trap the regolith and prevent it from falling back out of the scoops. During hauling, the bucket drums are raised by rotating the arms to provide clearance above the surface being excavated. The mobility platform can then travel while the soil/regolith remains in the raised bucket drums. When the excavator reaches the dump location, the bucket drums are commanded to reverse their direction of rotation, which causes soil/regolith to be expelled out of each successive scoop.

    =============

    Meaning the drum is the correct.

    RocketNut has uploaded 37 CAD models & has left 52 comments.
  • Trevor Owens

    Trevor Owens 11 months ago

    So what is the minimum age required?

    Trevor Owens has uploaded 4 CAD models & has left 26 comments.
  • Ananth Narayan

    Ananth Narayan 11 months ago

    Does the concept of bucket has to be modified or any new idea for the same purpose can be laid.?

    Ananth Narayan has uploaded 64 CAD models & has left 308 comments.
  • Bintang Farhan

    Bintang Farhan 11 months ago

    can we add electrical component to the design?

    Bintang Farhan has uploaded 3 CAD models & has left 63 comments.
  • Narendiran Rajasekar

    Narendiran Rajasekar 11 months ago

    yes we can add.

    Narendiran Rajasekar has uploaded 2 CAD models & has left 1 comments.
  • Trevor Jamieson

    Trevor Jamieson 11 months ago

    Why two rotating drums? Could this not also be accomplished by dragging a scoop/bucket behind the "rover" body? Similar concept to a scraper.
    A single arm attached near the midpoint would still allow for the device to be self righting. Easier to clean if clogged with wet material. Not really affected by material size being "mined". Fewer moving parts. Potentially faster.

    Trevor Jamieson has uploaded 0 CAD models & has left 1 comments.
  • Trevor Owens

    Trevor Owens 11 months ago

    How do you make a (Rassor) Drum that light?! Even out of carbon fiber!

    Trevor Owens has uploaded 4 CAD models & has left 26 comments.
  • mahboub el idrissi zakaria

    mahboub el idrissi zakaria 11 months ago

    I want to participate, can anyone help me how

    mahboub el idrissi zakaria has uploaded 0 CAD models & has left 1 comments.
  • V.Novacov

    V.Novacov 11 months ago

    Could you explain,how many drums have to be or what is the overal size of the drums( one or two).

    V.Novacov has uploaded 19 CAD models & has left 50 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    All of the information is in the above description under requirements, the only thing not immediately clear is that the requirements are for 1 drum(there will be 4 on the machine)

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • walter pfeiffer

    walter pfeiffer 11 months ago

    I think it is better to send an origami shop, with actuators on each leg to make it mobile and use it as a controlled environment to work.

    Outside put solar panels and inside a series of tesla charging modules to make the load wireless and that the work is done without stopping.

    We would put a conveyor belts to remove the waste material and when setting up several tents a large mobile area could be covered.
    ❤☜(゚ヮ゚☜)

    walter pfeiffer has uploaded 1 CAD models & has left 1 comments.
  • rahadyan muhammad

    rahadyan muhammad 11 months ago

    Hi Do we have to design the opening with minimum 5cm width(like older design) or we could make it smaller?

    rahadyan muhammad has uploaded 6 CAD models & has left 22 comments.
  • Captain Anonymous

    Captain Anonymous 11 months ago

    I don't like the design of the RASSOR rigolith excavator. Digging in dry sand is one thing, fairly easy. Digging in a field of mixed sand and and rocks of different shapes and sizes will be comletely different and more difficult. Add a little moisture from water or some other liquid and clumping or sticking to the inside will be a huge problem.

    The drums as they are, are prone to clogging with rocks or clumps of rigolith. Some rocks may make it in one way but then turn sideways when inside and form a clog.

    What happens when one side doesn't pick up anything and is empty? The whole device will be off balance and prone to tip on it's side.

    I feel a more open claw or bucket is needed. Something that can easily be cleaned out, no matter the consequence

    Captain Anonymous has uploaded 0 CAD models & has left 6 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    There is no rain on the Moon. Also reglith is a fairly fine material even its largest particles are quite small generally less than 1cm.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 11 months ago

    Captain Anonymous - NO your idea is completly Wrong!

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Captain Anonymous

    Captain Anonymous 11 months ago

    We have no idea what we're going to run into on the surface moon or elsewhere. We've only landed on the moon around six times and barely scratched it's surface. Once we try and dig more than a couple inches everything could, and probably will, change. No it does not rain on the moon, but there are regions that still contain ice. If they are going to dig for ice with this device so they can produce oxygen, the drums will clog, guaranteed.

    Captain Anonymous has uploaded 0 CAD models & has left 6 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    I don't know Cap, those nasa guys seem pretty confident in their design parameters.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    I mean the surface of the moon is effectively a vacuum which pretty much eliminates the possibility of moisture.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    Does the Outside Diameter have to be fixed at all times or is it possible for it to have a Closed, Digging mode that is 450 and an open, Empty mode that is larger than 450?

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    Does the Drive system Use a Stepper/Feedback system allowing it to be positioned at a particular point in its rotation? Does it have the ability to operate at different speeds or is it a fixed speed setup?

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • javad kazemi

    javad kazemi 11 months ago

    Hi
    I am proud to work with good designers $ And thanks for the patience and accuracy of Julie's comments .
    I have the experience of designing a mahjong sample last year.
    Thank you so much for trusting a large group of NASA engineers and managers.
    I had three questions about the new challenge.
    1. Should the sampler sample from the surface, or do the layers below the soil surface sample? Or how deep should it penetrate the soil?
    2. Is the 5kg weight based on the gravity of the moon or the planet's gravity?
    3. How many drives can the drive bucket be able to drive?
    With respect
    javad kazemi

    javad kazemi has uploaded 23 CAD models & has left 39 comments.
  • Briac LE RAY

    Briac LE RAY 11 months ago

    Hello,
    I am asking the community working on this project.
    I do not have any license for a CAD (I wish I could use SolidWorks) and thus am struggling to try to have FreeCAD work, which is not a very successful task.
    Could you share which tools you are using for doing your prototypes, and which tool you use to make the animations? :)
    Cheers!
    Briac

    Briac LE RAY has uploaded 0 CAD models & has left 3 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    You might look at fusion 360. It is free to students, hobbists, and startups. Also Houdini offered a free non commercial version that is quite powerful but has a fairly steep learning curve. Lastly google sketch up is free.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Captain Anonymous

    Captain Anonymous 11 months ago

    Some others I might add are, Blender which is my go to tool kit for CAD. www.blender.org. An excellent program that will do everything you wish and it's absolutely free. Others that are equally as powerful are a couple of the more prominent game engines, Unreal Engine (www.unrealengine.com) and Unity (www.unity.com). Both of these are also free to download and use. But these two have licensing agreements when you make over a certain amount of money with them.

    No matter which program you end up with, there will be a steep learning curve. If you're new to CAD, expect at least a thousand of hours of learning to be some what proficient.

    Captain Anonymous has uploaded 0 CAD models & has left 6 comments.
  • Briac LE RAY

    Briac LE RAY 11 months ago

    Thank you for your comments Jason and Capt'ain! Much appreciated!

    Briac LE RAY has uploaded 0 CAD models & has left 3 comments.
  • Flaviano Crespi

    Flaviano Crespi 11 months ago

    @Briac LE RAY
    In addition to the other programs already reported, you could use: Creo Elements / Direct Modeling Express
    It is available for download and free use.
    It has a very rapid learning curve because it is totally non-parametric and history free.
    You will be able to see the tutorials on Youtube.
    It has the following limitations:
    - max 60 parts (enough for this project)
    - can export only in STL, not in STEP

    Flaviano Crespi has uploaded 315 CAD models & has left 1522 comments.
  • Briac LE RAY

    Briac LE RAY 11 months ago

    Thank you Flaviano I appreciate your help. :)

    Briac LE RAY has uploaded 0 CAD models & has left 3 comments.
  • Dylan Domb

    Dylan Domb 11 months ago

    Is there an axle that goes through the drum and if so, what is its diameter?

    Dylan Domb has uploaded 9 CAD models & has left 16 comments.
  • abhishek singh

    abhishek singh 11 months ago

    can there be multiple people in a team?

    abhishek singh has uploaded 0 CAD models & has left 1 comments.
  • BENJAMIN  OKELLO

    BENJAMIN OKELLO 11 months ago

    Interesting challenge from NASA, looking forward to submitting my design.

    BENJAMIN OKELLO has uploaded 49 CAD models & has left 42 comments.
  • Flop berry

    Flop berry 11 months ago

    what is the problem with NASAs design. What is the reason to find a new design? Please let us know what your design is lacking for us to improve it.
    Thank you

    Flop berry has uploaded 1 CAD models & has left 1 comments.
  • Jacob Mosier

    Jacob Mosier 11 months ago

    "Maximum total width of scoops engaged at any given time: 175 mm" is this dimension parallel with the diameter or the width of the drum?

    Jacob Mosier has uploaded 1 CAD models & has left 3 comments.
  • Ben S

    Ben S 11 months ago

    Does the mass of any welds count against the 5kg restriction?

    Ben S has uploaded 1 CAD models & has left 1 comments.
  • Adam Edmonds

    Adam Edmonds 11 months ago

    I hope judging is done after the due date because I have revised my design multiple times. good luck to everyone. 11 days left.

    Adam Edmonds has uploaded 6 CAD models & has left 3 comments.
  • Joe Z

    Joe Z 11 months ago

    Can anyone recommend software to run the simulation?

    Joe Z has uploaded 0 CAD models & has left 1 comments.
  • Sava Savov

    Sava Savov 11 months ago

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 11 months ago

    must be the design symmetric?

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Levi Owens

    Levi Owens 11 months ago

    so why do you have to be over 18 to be eligible to be considered?

    Levi Owens has uploaded 1 CAD models & has left 15 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 11 months ago

    Jeff : what do you mean?

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Levi Owens

    Levi Owens 11 months ago

    why is the reason you have to be 18 to win?

    Levi Owens has uploaded 1 CAD models & has left 15 comments.
  • Brady White

    Brady White 11 months ago

    What does STEP and STL mean?

    Brady White has uploaded 1 CAD models & has left 1 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    Brandy, They are 3D File Formats,

    Jeff, If I had to guess the reason is that in entering the contest one is surrendering certain legal rights and claims to the intellectual property that is created and as such entrants would be required to be of age to legally release those rights as with most legally binding contracts.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 11 months ago

    Just a Side, no criticism intended and I know there is a lot going on, but it would sure be nice if the organizers spent a little more time responding to questions related to this contest. Some are silly but many are legit and the final outcome could only be improved with the information disseminated.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Daniel Voloshkevych

    Daniel Voloshkevych 11 months ago

    Jeff: i am 17. And a moderator has write to me that I can enter this challenge. And where you have see that information??? Because I don't see it EVERYWHERE XD

    Daniel Voloshkevych has uploaded 0 CAD models & has left 34 comments.
  • Kesa

    Kesa 11 months ago

    If you have any questions that haven't been answered please let me know by sending a private message. Some may have been lost in the volume of messages in this forum. I will try to get them answered as fast as possible.
    Thank you

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Andrew Nick

    Andrew Nick 11 months ago

    Here is some answers to some questions in the comments:

    How are you defining "Fill Ratio"? Is that based on the total volume of the enclosing Boundary? Total Volume of the Open space of the Model? etc?
    Fill ratio is volume of regolith collected versus total internal volume.

    Does the Drive system Use a Stepper/Feedback system allowing it to be positioned at a particular point in its rotation?
    Yes we have closed loop position and velocity control.

    Does the drive system have the ability to operate at different speeds or is it a fixed speed setup?
    Yes we have closed loop position and velocity control. We can reliably operate through a full range of velocity.

    Does the Outside Diameter in the specification have to be fixed at all times or is it possible for it too, for example, have a Closed/Storage mode that is 450 and an open, Digging or Empty mode that is larger than 450?
    The 450mm diameter is a maximum, but it can be smaller and change size during operation if needed, as long as it doesn’t exceed the maximum diameter.

    Does the system have any provision for Electrical, Mechanical, Hydraulic or Pneumatic actuation of Components built within the Drum? or do any actuations have to be solely powered by the forward or reverse rotation of the input shaft?
    It does not currently, but there are no restrictions for incorporating actuations inside, but keep I mind it is a continuously rotated joint. So for example a slip ring would be required to pass electrical connections.

    Is there an input shaft that should be designed around or is there a fixed flange of some fixed dimension that needs to be accommodated?
    The bucket drum is currently driven from a flange on the side and does not protrude internally. The inside is up to you. However, if your design defines the input actuation interface include your design intent in your explanation.

    Does shaft volume need to be accounted for in the drum filling ratio?
    The bucket drum is currently driven from a flange on the side and does not protrude internally. The inside is up to you. However, if your design defines the input actuation interface include your design intent in your explanation.

    Andrew Nick has uploaded 0 CAD models & has left 1 comments.
  • TristanDC

    TristanDC 11 months ago

    I'm a bit puzzled by the whole concept for RASSOR, so I thought I'd "throw" this idea out there:

    Why collect 'small' amounts of regolith that then have to be transported numerous times by a small rover back to the factory?

    Throw it.

    Much like a snow blower ( aka snow thrower) that us Canucks and northern Americans are so familiar with.

    Snowblowers can throw 25 to 40 ft. On the moon with 1/6th the gravity and no atmosphere you'll get great distance.

    You could put up a screen at the collection site (if needed) to catch and funnel it into your factory.

    Covering over the new moon base structure with a protective layer of regolith will be a cinch.

    Incidentally, the blade on a snow blower rotates/scrolls in from right side and in from left side (opposing direction cancelling out force from opposite side).

    For my 2 cents, I think NASA would be better off creating an all-purpose vehicle much like a farm tractor that is modular / can have different tools attached to it to achieve specific functions.

    TristanDC has uploaded 0 CAD models & has left 3 comments.
  • Ananth Narayan

    Ananth Narayan 11 months ago

    Does the weight should not exceed 5kg for the whole system or for the single bucket with 3 or 4 scoops. Greatly confused with the term bucket.

    Ananth Narayan has uploaded 64 CAD models & has left 308 comments.
  • Ravi Maurya

    Ravi Maurya 11 months ago

    Jury, could you please specify the maximum dimension of the Regolith rock that is being loaded inside the drum. I have been reading a lot about regolith on the moon. Some website says the diameter of the regolith rock is in between 0.1 cm to 1 cm whereas some website specifies up to 10 cm. Even in the research paper provided along with description about RASSOR 1.0/1.5 says that it was designed to accommodate stone up to 5 cm in diameter. All the videos shared show that the RASSOR is being tested with the sand grain (whose maximum diameter is only 2 mm).

    Ravi Maurya has uploaded 20 CAD models & has left 32 comments.
  • Nolan Lach

    Nolan Lach 11 months ago

    It should be like an auger but instead of throwing the dirt, it collects it. This also means it can go further into the moons surface and collect more resources.

    Nolan Lach has uploaded 1 CAD models & has left 1 comments.
  • Jason Schuler

    Jason Schuler 11 months ago

    Ananth: The 5kg mass limit is for one bucket drum. In the example of RASSOR 2.0 there are 4 bucket drums, 2 on the front 2 on the back.

    Ravi: We did not specify a maximum rock or scoop size for this challenge. The primary goal for RASSOR is to excavate the granular regolith, if there are larger pebbles mixed in we want to accommodate them but they will likely have to be filtered out before the regolith enters the processing plant that will extract the oxygen or water. During testing we have seen that taking a full scoop (~5cm) of regolith can cause it to jam and not fully enter the drum. Therefore we try to actively limit the digging depth to roughly half the scoop height (~ 2.5cm).

    Jason Schuler has uploaded 0 CAD models & has left 5 comments.
  • Tommy Mueller

    Tommy Mueller 11 months ago

    24 hours left!

    Tommy Mueller has uploaded 215 CAD models & has left 1864 comments.
  • Filip Šabacký

    Filip Šabacký 11 months ago

    on the way

    Filip Šabacký has uploaded 2 CAD models & has left 13 comments.
  • Sunoj Kashyap

    Sunoj Kashyap 11 months ago

    Waiting for the Results ! !!!!! ! !!!!! !

    Sunoj Kashyap has uploaded 4 CAD models & has left 14 comments.
  • Sava Savov

    Sava Savov 11 months ago

    There are hard days and nights ahead for the jury to look at all these projects for one week. I suspect that it will be more than one week until first results come up. Maybe two weeks will pass...

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • MiDesys

    MiDesys 11 months ago

    Just came on my mind. Guys what to you think of idea for simulating moon gravity in way that you put water in some container and inside some material, plastic granules which have little bit bigger density for representing the regolith?

    MiDesys has uploaded 1 CAD models & has left 22 comments.
  • Tommy Mueller

    Tommy Mueller 11 months ago

    So if 1000 pounds of salt in 180 gallons of water creates a 30% salt solution, enabling you to float effortlessly atop the water. This can create an anti-gravity environment, as all weight and tension can be dropped.
    ...
    My Guess: Maybe adding an appropriate amount of salt to help your experiment?

    Tommy Mueller has uploaded 215 CAD models & has left 1864 comments.
  • Vaclav Lhota

    Vaclav Lhota 11 months ago

    Not bad idea. A friend of mine was thinking about similar conditions. No purely in water, just make the substance wet a bit. But something tells me you won’t get anything reliable. I could try it with a 1:3 scaled model I want to print if my design gets the chance:)

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Sava Savov

    Sava Savov 11 months ago

    I think it is possible with any material heaver than water - if a hollow balls are used - with adjusting the size of the balls , different gravity can be simulated.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Sava Savov

    Sava Savov 11 months ago

    But rotating the drum in water....

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • MiDesys

    MiDesys 11 months ago

    MiDesys has uploaded 1 CAD models & has left 22 comments.
  • Vaclav Lhota

    Vaclav Lhota 11 months ago

    But the snow travels here almost like in zero gravity:)

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Sava Savov

    Sava Savov 11 months ago

    Yes, but when we move something in the water (the drum), the water starts to move too and that will affect the trajectories of the granules, and the drum will be full of water which must be replaced by the granules ... I don't know... Probably a magnetic field in vacuum can be used to simulate the conditions - here I go in field in which do not know much - in fact nothing :)

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Dexter Gomes

    Dexter Gomes 11 months ago

    Applying this principle also might help https://m.youtube.com/watch?v=My4RA5I0FKs

    Dexter Gomes has uploaded 4 CAD models & has left 20 comments.
  • Dexter Gomes

    Dexter Gomes 11 months ago

    Some fine-tuning will be needed 😅

    Dexter Gomes has uploaded 4 CAD models & has left 20 comments.
  • geo

    geo 11 months ago

    @Dexter: amazing video. I never see this effect.

    geo has uploaded 33 CAD models & has left 815 comments.
  • Bintang Farhan

    Bintang Farhan 11 months ago

    Does anybody know how many finalist will be chosen?

    Bintang Farhan has uploaded 3 CAD models & has left 63 comments.
  • Vikranth Guda

    Vikranth Guda 11 months ago

    HELP! i just missed the deadline. Pls is there any chance to send the design? I can send it right away

    Vikranth Guda has uploaded 1 CAD models & has left 4 comments.
  • Vikranth Guda

    Vikranth Guda 11 months ago

    its only 22:15 est now and the deadline is till 23:59 est right? Pls somebody tell me whom to contact...

    Vikranth Guda has uploaded 1 CAD models & has left 4 comments.
  • James Ehlers

    James Ehlers 11 months ago

    Same question as Vikranth. It's only 11:18 EST and the rules say we have until 11:59 EST but I can't submit.

    James Ehlers has uploaded 0 CAD models & has left 1 comments.
  • Poste Scriptum

    Poste Scriptum 11 months ago

    Well, 23:00 isn't 23:59 Eastern Standard Time (my time zone).
    The door shut down one hour ahead of the deadline.

    Poste Scriptum has uploaded 0 CAD models & has left 2 comments.
  • Ankush Sharma

    Ankush Sharma 11 months ago

    the rules are rules, its 11:19 est and my entries were uploading, I spent so much time and you guys have closed the portal, this is not fair, please open it

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Ankush Sharma

    Ankush Sharma 11 months ago

    who ever is the concerned person please look into it, deadline is 23:59 and not 23:00 est

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Ankush Sharma

    Ankush Sharma 11 months ago

    still 30 mins left, I was uploading my entry and its heart breaking to see such irresponsible behaviour honestly, rules are rules.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Staffan

    Staffan 11 months ago

    Closed early, couldn't submit entry.

    Staffan has uploaded 1 CAD models & has left 1 comments.
  • Fred Lee

    Fred Lee 11 months ago

    Wow, I spent a lot of time and effort to make this deadline. I'm devastated!

    Fred Lee has uploaded 1 CAD models & has left 2 comments.
  • Ankush Sharma

    Ankush Sharma 11 months ago

    GrabCad team please open it for 30 minutes so that all of us who are suffering from this early closure of submission portal could at least submit if not consider for final evaluation. We all have worked super hard and things like this really hurt.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Tim W

    Tim W 11 months ago

    I would not mind a quick extension on that deadline as well...

    Tim W has uploaded 1 CAD models & has left 3 comments.
  • Vikranth Guda

    Vikranth Guda 11 months ago

    Exactly Ankush. Extend the deadline just enough to compensate for the early closure.

    Vikranth Guda has uploaded 1 CAD models & has left 4 comments.
  • Jason Schuler

    Jason Schuler 11 months ago

    *** If you were unable to upload your entry because of the early cutoff please send me a private message. I will work with the GrabCAD team to make sure we give you a chance to upload. ***

    I am blown away by the response to this challenge! There are so many innovative and high quality entries. The jury will definitely have a tough time on this one!

    Jason Schuler has uploaded 0 CAD models & has left 5 comments.
  • Bintang Farhan

    Bintang Farhan 11 months ago

    I've submitted my work, but there's no simulation in it. I still want to show illustration of how the design work, I 3D Printed the parts and makes videos of it. Can I still add the videos to my submission? The design is not and will not change

    Bintang Farhan has uploaded 3 CAD models & has left 63 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    @Jason Schuler thank you sir for responding, I hope that Grabcad reacts positively by extending the deadline so that we all can submit our entries.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Kesa

    Kesa 10 months ago

    Attenetion, We heard that some people were unable to upload their models due to the Challenge closing 2 hours earlier than it should have. We have reopened the challenge so people have a chance to upload their models. We apologize for this inconvenience

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    Thank you

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Tim W

    Tim W 10 months ago

    Thank you Kesa.

    Tim W has uploaded 1 CAD models & has left 3 comments.
  • Sava Savov

    Sava Savov 10 months ago

    I hope it is allowed for all to update their entries in the reopened period, too? - I am asking because I updated mine.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Kesa

    Kesa 10 months ago

    Thats fine Sava

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Kesa

    Kesa 10 months ago

    We have closed the entries for the NASA Challenge. Thank you for everyone who participated in the challenge, we will let you know the top finalists next week. Again thank you for the amazing entries.

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Raul Santos

    Raul Santos 10 months ago

    the competition is over can i add a high resolution image to my design?

    Raul Santos has uploaded 4 CAD models & has left 8 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    Thank you Kesa, I have upload the files before closure of the extended deadline but its not showing in the entries. Here is the link:
    NASA RASSOR BUCKET DRUM
    Can you confirm whether my entry has been submitted or not?

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Sava Savov

    Sava Savov 10 months ago

    It was there 1 hour ago - it was the last entry, I think

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Tommy Mueller

    Tommy Mueller 10 months ago

    I saw it there too Ankush Sharma

    Tommy Mueller has uploaded 215 CAD models & has left 1864 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    yeah, I don't know if this is a bug in the site thats causing it.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Tim W

    Tim W 10 months ago

    Did anyone else see that there was "about 12 hours left"? Shouldn't have waited until I was done with work.... anyway here was my project

    Linked Rotating Buckets for NASA Regolith Challenge

    Tim W has uploaded 1 CAD models & has left 3 comments.
  • Raul Santos

    Raul Santos 10 months ago

    posso atualizar imagens de meu design?

    Raul Santos has uploaded 4 CAD models & has left 8 comments.
  • Levi Owens

    Levi Owens 10 months ago

    yeah, that was a little weird, because last night it said 13 hours left then this morning it said 11 hours left, and I know I slept for more than two hours. :)

    Levi Owens has uploaded 1 CAD models & has left 15 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    when is the finalist announcement

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Miftah Khan

    Miftah Khan 10 months ago

    Great concept

    Miftah Khan has uploaded 0 CAD models & has left 1 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    where they will announce the finalists? Here in the comments or where? :)

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    On board the ISS, Yuriy. We are all waiting for ya here

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    lol... what? why me? haha

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Guillermo Altenhofer

    Guillermo Altenhofer 10 months ago

    I think that the calculations should be done with an irregular grain and think what happens if we find a stone.

    Guillermo Altenhofer has uploaded 1 CAD models & has left 1 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    No design will prevent from contact with a big piece of rock, unless it does some geo radar or area scan before. That’s why buckets turn max 20 rpm. If the shovel hits something, telemetry sends it, the program stops and executes a relevant sequence.

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    And its not our task to make a Design where NOTHING would stuck.

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Kesa

    Kesa 10 months ago

    Hello everyone,
    Just wanted to give everyone a heads up. Due to the amount of entries the judges need to evaluate in this challenge. We will be announcing the finalists by Friday this week. Thank you for your patience.

    Best,
    Kesa
    GrabCAD Community Manager

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Fair enough, but don't miss the launch:)

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    Haha good one. ;)

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Brandon Waldaias

    Brandon Waldaias 10 months ago

    👍👍

    Brandon Waldaias has uploaded 1 CAD models & has left 1 comments.
  • Trevor Owens

    Trevor Owens 10 months ago

    sounds good!

    Trevor Owens has uploaded 4 CAD models & has left 26 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    is it true that the finalist will be announce today? :D Or are our jobs soooo good, that they need still 2 more weeks? :P

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    No Yuriy, Kesa only needs more time to gently express that the jury needs one more week. Just be patient, look into the sky and have a nice cup of tea...

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    oh okay thanks :) yes I will. :)

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Kesa

    Kesa 10 months ago

    Finalists are now Announced. Thanks for participating in the Challenge!

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    So many entries with great simulations and I'm surprised to see the some entries with least info being selected. Anyway congrats finalists.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Good luck to everybody!

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    I have great sims but they didnt want my entries :/

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    I'm surprised to see entries with hypothetical and no simulation based fill ratios being selected.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Kesa

    Kesa 10 months ago

    Remember to show good sportsmanship as the challenge is winding down to a close. Any entrants that show any toxic behavior will be suspended from GrabCAD.

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    Well I don't want to be the bad guy here, so would like to pitch the judges for one last time. Here is my entry NASA RASSOR BUCKET DRUM and would love to see if judges can give one last shot at it, it has a fill ratio of 76% with a meaningful simulation.
    I'm not against anyone but I think the entries with more realistic and meaningful simulations of fill ratios and other stuff should be selected and there are many such entries beside mine.
    Also I'm writing this because we were asked for our feedbacks.
    Thank you.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Tommy Mueller

    Tommy Mueller 10 months ago

    Kesa +1

    Tommy Mueller has uploaded 215 CAD models & has left 1864 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    I am so surprised that they have selected many entries WITHOUT a simulation... but there was standing that simulations are a plus :(

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Sava Savov

    Sava Savov 10 months ago

    And I was expecting that there will be almost one entry from the type: "the shovels fill a bucket and then the bucket turns when unloading", because it looks very effective way to operate.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    I am puzzled ! So list announced is just for shout, laugh and with rate your fellow participants :) ?

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Boris Abdul

    Boris Abdul 10 months ago

    Hey folks , you didnt loose your entire life .Live , create and enjoy the life and do not post weird messages here . A special congrats to @tommy mueller , I knew from the beginning that this guy has a creative beast inside , keep rocking mate !

    Boris Abdul has uploaded 2 CAD models & has left 4 comments.
  • Dexter Gomes

    Dexter Gomes 10 months ago

    Congratulations to all the finalists as well as all the other participants, great work!

    Dexter Gomes has uploaded 4 CAD models & has left 20 comments.
  • Ares

    Ares 10 months ago

    In my opinion, the Commission should give a short comment to each project to give everyone the opportunity to better understand why one project was rejected and another not. I don't want to make controversy and I don't want to be bad with anyone, but simply to learn from mistakes to improve in the future. In any case, congratulations to all for the published works. See you at the next challenge.

    Ares has uploaded 12 CAD models & has left 12 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    Ares: I agree! Because I for example I have nice simulations but they didnt take it

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Juan Ventura

    Juan Ventura 10 months ago

    Congratulations to the finalists. I had fun in this challenge and learnt a lot from it. Let's behave like adults and provide unbiased and professional feedback to the finalists and if possible learn from them too. Cheers!

    Juan Ventura has uploaded 1 CAD models & has left 1 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Guys never mind. The jury might justify better their favourite designs, that's true. But they were probably busy and couldn't pay that much attention to this part (that's why they needed one week more, in my opinion:). Whatever is behind is actually not our bussines and it's not important. We all worked hard, learned new things, inspired each other and that's what counts. For the benefit of all!

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    I am eager to see real official finalists.

    Can anybody find drawbacks of my design ?

    NASA (RASSOR) Bucket Drum Design Challenge with Design VPR 21

    Thanks !

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Aurelian Z

    Aurelian Z 10 months ago

    Congratulations to all the finalists.

    Since we have been asked for our opinion on the designs:

    1. Some of these designs use flaps with hinges to block regolith from escaping. The revolute joint getting jammed with dust will not be their only failure mode.

    Did you ever use a piece of cardboard to "jam" a cabinet door that won't stay closed?

    Given the right rock size, these flaps will get stuck. Not at the hinge, but on the other sides, between the flap and the drum body. Living hinges not only do not help with this failure mode, but they might make it worse.

    2. Another issue is with designs with an external helix that pushes regolith towards scoops at one end. These cannot work unless a large part of the helix edge is engaged at all times. If the 175 mm limit on scoop engagement is there for a functional reason, these designs won't do.

    That leaves 4 designs that I see as functional and I would rank in this order:
    - NASA Regolith Drum E3 by tommy.mueller-1
    - Regolith Drum Cartridge Light Weight V2 by jason.homrighaus-1
    - RASSOR Bucket Drum V3 by kyle.st.thomas-1
    - RASSOR Bucket Drum by michael.r-32

    With the exception of the 1st design, the fill rate claims are significantly exaggerated.

    Aurelian Z has uploaded 4 CAD models & has left 1 comments.
  • Dario D'Amico

    Dario D'Amico 10 months ago

    Well, congratulation to the finalist...

    It's a bit disappointing that no solution with the rotating scoops and "fixed" bucket were considered since I think they are the best possible design. It's the only one that guarantees for sure a 100% fill ratio with basically no risk of the regolite jamming into it.
    Several such solutions were presented with Vaclav Lhota even presenting a scaled prototype that looked to work pretty damn good.

    RASSOR_ContainerMod🌒

    A bit disappointing but anyway...

    My favourite entry amond the finalist is

    Regolith Trap

    Very simple mechanism.

    Dario D'Amico has uploaded 14 CAD models & has left 33 comments.
  • Ankush Sharma

    Ankush Sharma 10 months ago

    Dario D'Amico Yes I think a re-evaluation should be carried out because there are many good entries, some even having working prototypes. The main aim of the competition was to have maximum fill ratio and many finalist entries have exaggerated and hypothetical fill ratios. I think Judges should give priority to the function and fulfillment of objectives of the challenge before fancy renders and stuff.

    Ankush Sharma has uploaded 2 CAD models & has left 23 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    I think VERY IMPORTANT is how much energy you are spending for collecting and unloading Regolith. You are in space, energy is very limited. Take a look on your design, like you are on the Moon !

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Sava Savov

    Sava Savov 10 months ago

    @ Aurelian Z Yes, i agree with point 2. My first entry is exactly like these but then I developed it to something new - here is my version with external helices and it works really good - in simulation... I am sure that it is applicable for something here on Earth:) - I am pleased with myself. Watch this: https://www.youtube.com/watch?v=SM_IYEX9U7Y&feature=youtu.be

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • MiDesys

    MiDesys 10 months ago

    @Ankush Sharma: max. fill ratio is important, but i think more important is max fill volume. Cause some designs have 90% fill ratio but low fill volume.

    MiDesys has uploaded 1 CAD models & has left 22 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    @RAHUL I totally agree with you! :( I have spend so much time on the simulation I have then make a great simulation but they have ignored it...
    and I have do some calculations as well

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    Please correct if I am wrong ?

    Fill ratio = (Regolith volume * 100) / Max.dimension volume

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Seb Ruhlmann

    Seb Ruhlmann 10 months ago

    Hi there, congratulations to the finalists! a bit sad to not have made it but i am not here to try and get my way up there :)
    I would like to express a concern about the work of the NASA engineers and why they even proposed this challenge in the first place. With the experience you have on RASSOR i cannot imagine that you did not consider a spiral or a screw design in your former work. Anyone could agree that these are obvious solutions and considering that you did not propose any such designs in your research, one could assume that these are not good solutions for X or Y reasons that you may have tested (but not shared). Therefore, a reasonable assumption would be to try and develop other solutions. Now that finalists are listed and that screw and spiral designs constitute half of them, i feel this challenge to be 'insulting' for everyone. For the participants but mostly for you NASA engineers who, everyone would agree, could (and probably did) already have thought and pondered these designs. If so, finalists are being fooled into thinking that their solution is effective, meanwhile you already know it has flaws. If not, i am shocked that you never considered those solutions before. I can agree that there are indeed some variations in the proposed screw designs that might earn them points but tweaking a spiral is definitely right up your alley.
    Moving parts like doors are tricky... they definitely enhance performance but are higly susceptible to damage, with impossibility to open or close in hopefully rare events, and therefore might require more maintenance from humans on site. I cannot have a firm position on them, i trust your experience of carrying out real-life testing.

    I hope you consider engineering in the end and not renderings, animations or proposed simulations, instead try them out yourself and post the results ! A replicable simulation setup would allow us all to admire the effectiveness of the final desings (i truly mean it, i believe in some!) in a comparable fashion, not simply based on trust. But this is a GrabCab challenge afterall, and renders/beauty play a huge role around here too. These are always marvellous to see! As a conclusion, i could not and would not blame you if you did allow large bonuses for these, it fits the platform :) but try engineering ;p

    Best of luck everyone ! I still have to pick my favorites.

    Seb Ruhlmann has uploaded 1 CAD models & has left 8 comments.
  • RocketNut

    RocketNut 10 months ago

    is the finalist list up yet?

    RocketNut has uploaded 37 CAD models & has left 52 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Why do so many people seem to think that a simple robust, highly efficient design somehow represents bad engineering or design? Why do they assume that having not posted a simulation means that the entrant made up the numbers or imagined their full ratios or results?

    Repeatedly throughout the history of design and engineering, it is Often found that the most efficient, reliable and best suited approach to a problem tends to be relatively simple and to many they even seem obvious.

    It’s disappointing to see people badmouthing designers, engineers and even our esteemed guests from one of the greatest engineering enterprises on the planet because they didn’t get selected.

    People look at a simple entry without a lot of razzmatazz and for some reason assume it is simple and somehow not sophisticated. They do not see the many many hours spent after work tweaking and testing and prodding a design to see how far you can take it, how much it can handle.

    Elegance in design and engineering is just as important and just as challenging as running simulations or generating renderings.

    My design went through no less than 60 iterations from where it started. In the process it spun off 5 additional designs both simple and very complex. Each with their own benefits and drawbacks.

    As to the finalists I think it is striking that many are fairly simple and robust. Funny that the keys to success for an unmanned lunar rover would be simplicity, robustness, light weight and reliability.

    I think our esteemed guests from NASA are far more knowledgeable about what types of design challenges they have faced and what their engineering and mission goals are.

    One of the oldest axioms in any professional undertaking is to give the customer what they want(and need). Not what you want or what you think they need.

    Please show some respect, engage in the opportunity to learn and explore, offer your insight and seek insight from others.

    Let’s show our guests why this platform is great and valuable so that there will be more opportunities in the future.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Tommy Mueller

    Tommy Mueller 10 months ago

    Tommy Mueller has uploaded 215 CAD models & has left 1864 comments.
  • Divyakumar Patel

    Divyakumar Patel 10 months ago

    True, I agree with you @Jason Homrighaus

    Divyakumar Patel has uploaded 6 CAD models & has left 2 comments.
  • Seb Ruhlmann

    Seb Ruhlmann 10 months ago

    I agree that simple solutions work best in the end, that's why we all probably started out with ideas in all directions that we then narrowed down incrementally, hence the various iterations. You would be surprised to know how simplistic the core physics principle on which my everyday work is based on is, yet it makes for a not-so-obvious design that you can only guess in context, which is quite magical actually. Many discoveries and incredible inventions are waiting patiently for someone to see them with the right angle, not crazy intricate ways. That's part of the beauty of nature.

    However, you cannot deny that there has been work on RASSOR before us and possibly hundreds of iterations too. In front of this realization I feel that many designs had (/could have) been thought of before we put our hands on it, so it bothers me to see them as finalists (and bothered me too when they were simple entries) although NASA did not prototype them. This said, I stand behind some finalists, which is my personal opinion. I would have written the same comment before the results and even if I were finalist. Does not make any change.

    Having provided a simulation or not in our entries is more a matter of computer power or software license in my opinion. Many of us probably have the skills but no access to such tools, so of course it is fair to not have only finalists with simulations, otherwise it would defeat the sense of diversified community on this platform. I had to use an online CAD software with such bad wifi connection that every click or action took 10 seconds to load. Took me days for a simple design and a few iterations. Lucky I had a black board and lots of chalk...

    Seb Ruhlmann has uploaded 1 CAD models & has left 8 comments.
  • Vishal Gandhele

    Vishal Gandhele 10 months ago

    I think NASA knows what works best for those environments and I respect their decision. Congratulations to all the finalists and also to all the participants who learnt something new in the design process.

    Vishal Gandhele has uploaded 6 CAD models & has left 11 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    Designs based on lift principle are more energy and time efficient than monocoque, so why GC is featuring monocoque and lift principle was left out ??

    example of lift:
    NASA (RASSOR) Bucket Drum Design Challenge with Design VPR 21

    example of monocoque:
    RASSOR Bucket Drum V3

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Tapabrata Samanta

    Tapabrata Samanta 10 months ago

    I think the point NASA is trying to make here is sometimes it is better to go with a system which is more reliable, simple and robust with less probability of functional failure. And, the selected finalists have all these elements.
    I think the guys who came up with non-obvious solutions have shown NASA what not to do. And, that is very important. Just think of the bigger the picture. We should collectively work towards helping NASA in arriving at a decision which would influence the success and failure of the mission. And, to do that we had to be willing to lose “the prize” by coming up with all those non-obvious solutions in an attempt to increase the fill-ratio in a way to find out that these won’t work and eliminate those non-obvious solutions from the list as quickly as possible and leaving behind the obvious ones which had the potential to work from the very beginning.
    So, what I can see here is that, some of us chose to walk the obvious path and some chose to walk the non-obvious path. But, the aim of our individual journey was the same, that was to help NASA arrive at a decision. The very act of collectively participating in an effort to bring this mission to a success instead of trying to change our bank balance just by a few digits, in itself is a win! According to best of its knowledge, NASA has converged to those geometries which would actually work. We already won for now. Can’t you guys see it?

    Tapabrata Samanta has uploaded 2 CAD models & has left 2 comments.
  • Ravi Maurya

    Ravi Maurya 10 months ago

    I would really appreciate if the respected judges have one final look at the idea of "static storage drum" design since it has highest filling ratio and storage capacity. There are more than 10 designs entries regarding that.

    Ravi Maurya has uploaded 20 CAD models & has left 32 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Ravi while those designs do provide a high fill ratio they do not provide a high fill volume. The are very space inefficient devoting a lot of volume to the rotating assembly. The space where those scoops are represents nearly 1/2 of the available working volume for the design. The rotating assembly presents a lot of structural issues due to its need to have lots of buckets and open pass throughs. The design is also prone to catastrophic failure scenarios ie a small pebble could disable the entire drum. If the outer frame were to become bent, again total loss of function.
    Lastly the mechanics required to actuate the drums would be massively difficult to maintain and prevent from becoming damaged due to dust.

    Don’t get me wrong, bucket wheel excavators are very cool (which is what you are talking about) but the are maintence intensive and wear prone which are not great qualities for a lunar based machine

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Victor, how much energy is consumed by all the friction in the system? How will the friction change in the presence of abrasive lunar soil. What about the extra trips required to collect equivalent volume of regolith(full volume approximately half means 2x more trips which would be the most energy intensive part of the operation) what about the power budget. power on the moon is more or less free being solar based.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Tapabrata Samanta Well said sir.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Jason I fully admit your objectives. However, all this is valid rather for a high intensity working machine. On the Moon, the work load won't be that high so I think the main issue is just overall efficiency, energy consumption. Maybe none of our rotating shovels design is considerable and definitely deserve more study, but I still believe it's a very promising concept, considering its purpose, size, work load and location:) But again, I fully respect much higher reliability of a single drum bucket.

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Jason I was worried about the fricition, sure. But there was a big surprise for me, because it's not bad at all! I did some test with 1:3 and 1:6 models. And the filling? Yeah, you can actualy fill it to neraly 30 l. I think that's not bad either. I must say I really enjoyed the creative process and now I'm enjoying the discussion as well:))))

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Vaclav. I don’t disagree with your points either. As you know I played with that design for a while and 1 couldn’t come up with an improvement over what had been presented already and 2 couldn’t find a way to make it work well with superfine dust.

    I really do like that approach. I also entered a design using a highly modified version of the same general concept(tried to combine the rotating scoops with high capacity drum). I spent like two weeks on it!)

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Well, in oposite, I was working on a drum with these traps and I didn’t believe the hinges will work in long term. And I also added a door, which will allow to empty in one turn!! Super simple and works amazing, tested on a 3dp 1:6 model. I could still upload the video. But you know what? I gave up with this guy and focused on that other concept. Evidently, I played a wrong card:D

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    @ Jason. You are absolutely right lift designs with fixed drum and rotating scoops are little bit complicated in comparison to Monocoque.
    Catch Regolith is in the same range like Monocoque design 25-30l.
    But regarding productivity, fixed drum design is min 2-3x bether regarding saving Electricity and Time.
    In reality fixed drum if it is build good, it will move min 2x more Regolith in same conditions.
    So if you ware a mission commander which Rassor would you take: "bike" or "superbike" ?

    Take look and prove me wrong, I would be Really grateful, thanks in advance.

    Example of lift:
    NASA (RASSOR) Bucket Drum Design Challenge with Design VPR 21
    example of monocoque:
    RASSOR Bucket Drum V3

    All the best

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    why sprial drums aren't good ?

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Victor. I did look and I like the concept as I stated before. I would like to better understand where you are coming up with your energy consumption estimates. 2x efficiency in the real world is way way way beyond Bike/superbike comparison. That is a very tall claim. In many processes efficiency increases of 5-10% are really good and you are claiming 100% or more. Can you share how you arrived at those conclusions I’m very curious

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Spiral drums are good and hell reliable. They only can't get rid of bigger rocks, if they collect some. Especially in designs with longer narrow, curvy sections. And then, in long term, as you collect more and more, you increase the risk some will stuck and then you know what's gonna happen:)

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Yuriy Voloshkevych

    Yuriy Voloshkevych 10 months ago

    oh yeah i know... thats why they probably dont take mine... :)

    Yuriy Voloshkevych has uploaded 2 CAD models & has left 15 comments.
  • Ravi Maurya

    Ravi Maurya 10 months ago

    Jason Homrighaus, You're wrong about the high volume ratio. Designs with static storage drums provides highest regolith capacity. If designed carefully with all practical data it can stored upto 40 liters. Even the design I submitted has a capacity of 31 liters. Which I guess hardly 4-5 other designs have. About getting damaged by dust - its gonna be the same as in case of orignal RASSOR 1.0 and 2.0. If those designs can sustain it so as other. If you're worried about getting dust in the mechanism than the designs that have trapping door mechanism won't last for a minute at moon's surface. I do get the structural part that it might not be as strong as compared to monocoque designs but there are ways to prevent that. Some of the designs have taken that into consideration too.

    Ravi Maurya has uploaded 20 CAD models & has left 32 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    @ Jason. Friend, in short, on a just one feature, and if you look closely, but it have more ... : (for example, same conditions)
    Lift designs, have 40 revolution for loading and 0.5 to unload, that is 40.5 revolution
    NASA (RASSOR) Bucket Drum Design Challenge with Design VPR 21
    Monocoque designs, have 40 revolution for loading and 40 to unload that is 80 revolution
    RASSOR Bucket Drum V3
    If you put that on Moon surface, you will have almost double productivity, minimum ...
    All the best

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Sava Savov

    Sava Savov 10 months ago

    @Yuriy, now as I look at your simulation it can be seen that there are some problems with spiral drums. It looks that in the process of digging they can be filled enough but while digging they throw back some of the regolith which they just have been taken. And it is not clear how much regolith they can hold after the filling is finished and when the car start moving to the unloading depot. I too made some tries with spiral for my drum and saw its behavior. Didn't liked it much and that's why I started to look for another solution.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • GalaxyRobotics

    GalaxyRobotics 10 months ago

    Victor:
    But my monocoque design : NASA RASSOR Drum Design
    can fill in 6 rotations and empty in 5. That is just 11 rotations total. I think the issue of monocoque and lift designs are case specific, some designs will be better than others.

    Congrats to finalists!

    GalaxyRobotics has uploaded 3 CAD models & has left 18 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Ravi. 3 of my monocoque designs match or exceed that volume. And that assumes they only achieve an 80% fill ratio in the containers. 32l,33l and 36l respectively

    This is the same for numerous other designs. There are two main types of monocoque drums that I saw. The ones that use baffling with multiple scoops per volume and those that use single scoops per volume. The multiple/volume style(of which the NASA rassor drum is one) suffer from the nature of the material. In general they are limited to around a 50-60% fill ratio because the material will leak out through at least one of the openings.

    The second style of single opening per cavity (of which there are several in the finalists) offer the greatest potential fill ratios albeit at a slower fill rate. The key is that the great majority of the material that they capture is positively contained within the volume until released. Additionally they can make maximum use of the available 52liters of the defined volume compared to any other designs.

    I in particular really like the helix style drums as I really think they can pack the greatest volume. I fiddled with them but kept trying to have an open middle but I didn’t try the approach used by some of the finalists and realize now that that was the way to go for maximal potential.

    As some have pointed out some of the monocoque designs utilize very narrow channels which I think is risky. That is part of why I continued to maintain a relatively large oversized intake that can only actually cut about 1/3 of its opening. This is due to the shape of the other cartridges limiting the depth of cut.

    Honestly the engineering challenges of this application are pretty intense and every drum concept is a compromise No matter how simple or complex.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Victor, in ideal conditions and assuming your monocoque design fills at the same depth of cut as it unloads. A lot of the monocoque designs have oversized intakes and as such will unload faster than they load so maybe you will see 30% improvement with a bucket wheel.

    But now you have to consider the other factors, first off is weight. Monocoques can easily weigh 1/3 what a bucket wheel system can.with a cost per KG to the moon of well over 1 million you can bet your life that weight is a major influencing factor in these designs. Second is reliability, what is the long term viability of a bucket wheel mechanism in a highly abrasive environment? No one really knows for sure but we can pretty reliably that a monocoque with no moving parts has a near 100% reliability

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Ravi Maurya

    Ravi Maurya 10 months ago

    I give up. Not going to explain any more. But again as I said earlier, It would be an honor if the Judges of "RASSOR Bucket Drum Design Challenge" give another thought of considering other designs. People are expecting a lot of great work from NASA. I would personally never want a great design submission go unnoticed that might just change future on moon. So I request the jury to take quality time and have a one last look on entries.
    Thank You

    Ravi Maurya has uploaded 20 CAD models & has left 32 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    @ Jason. With all do respect, we in engineering don't gamble with "maybe you will see 30% improvement" You are right that Monocoque without moving parts is by definition more reliable in comparison to lift, but if you compare those systems over operational time, bigger rocks can ruined Monocoque and lift will remain operational. Remember, we have rocks in all sizes.
    Test it, and see what numbers will going to say:
    Lift designs example:
    NASA (RASSOR) Bucket Drum Design Challenge with Design VPR 21
    Monocoque designs example:
    RASSOR Bucket Drum V3
    All the best

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Sava Savov

    Sava Savov 10 months ago

    About the entries with outer and inner helices: I started with this concept from the very beginning and can say something about them. It is much better the inner helices not to be as huge - they must be narrow bands mounted on the inside diameter of the drum cylinder. That increases the fill ratio - I tried it. When the inner helices are like they are now, there comes an unexpected effect of obstruction the filling. And I have a feeling that it is not good the outer helices to make more than one turnover around the drum cylinder because the drum moves in radial direction ...? but i may be wrong in that - not sure.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Victor when I said maybe 30% I was saying that if it takes 1/3 the revolutions to unload then load then the rough calculation would be a 30% improvement using a fixed drum rather than 100% you claim. It’s not a gamble it’s simple math.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Dominik Höber

    Dominik Höber 10 months ago

    @sava: i agree with your opinion on the throw back of regolith by inner helixs, but as you can see on the double helix drum by stephan weissenbock, there is used a kind of lock to prevent this.

    Dominik Höber has uploaded 0 CAD models & has left 1 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Victor. I would also note your assertion that a lift system is somehow immune to a large rock issues is disingenuous they are just as susceptible however there is a greater risk in that if the bucket system jams, (ie rock stuck between drum and scoop) the entire drum is rendered useless. If a channel in a monocoque gets a rock jammed in a scoop, there are other scoops and even with a rock jam, the monocoque intake can continue to injest material albeit at a slower rate.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Bucket system can't jam by a large rock as there is small space between these two surfaces. These two surfaces move separately in different directions and the only thing that threatens them are small fragments that have exactly the size of the gap between the two surfaces:) But this can be overcome by sufficient torque while minimizing contact surfaces. There is just no way how to block the shovel entry. You can scratch it, damage any other parts of course (as any other monocoque body) but you can't jam it that easily by larger rocks.

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Sava Savov

    Sava Savov 10 months ago

    I am starting thinking that main reason they did not choose any of the solutions with the rotating scoops and "fixed" bucket is that the arms of RASSOR can take a lot of crooked positions?
    http://prntscr.com/s9ttph
    https://www.researchgate.net/publication/261248231_Regolith_Advanced_Surface_Systems_Operations_Robot_RASSOR

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Raul Santos

    Raul Santos 10 months ago

    Congratulations to the finalists, I am sad to not be able to reach the final, but happy to participate, I would like to receive some feedback on my designs, this was my first challenge and unlike the finalists my projects are simple with divided chambers. I invite everyone in the community to send me feedback on what could be improved or what could be done differently, it will be very important for me to receive any message!

    Raul Santos has uploaded 4 CAD models & has left 8 comments.
  • Sava Savov

    Sava Savov 10 months ago

    I looked at your last design.I highly doubt that with this geometry the drum can fill 70%. I made some simulations with simmilar geometry and I think I know what will happen - after the first revolutions, when the fill ratio reach, let's say 30%, the regolith inside will start to fall right behind the opening and will start to make the filling process difficult. That will lead to a situation in which some of just captured from the scoop regolith will be thrown back outside. Maybe the fill ratio can reach more than 50% but this throwback...- is something like tango -"two forward one back" . But you made a simulation - isn't it shows the things as I descripted it?

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • MiDesys

    MiDesys 10 months ago

    About stones and rocks. One way prior collecting regolith is to send destoning machine wich will separate and collect all stones and rocks from regolith. After regolith is cleaned, RASSOR can be send to collect it.

    MiDesys has uploaded 1 CAD models & has left 22 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    I was thinking of a simple, lightweight plow or a rake, mounted on RASSOR

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Raul Santos

    Raul Santos 10 months ago

    thanks :) @Sava Savov, how did you calculate the fill rate?

    Raul Santos has uploaded 4 CAD models & has left 8 comments.
  • Sava Savov

    Sava Savov 10 months ago

    I think that more important is the volume that must be captured and it must be more than 17,6 liters. The required fill ratio is given more for orientation because for the given outer dimensions can be assumed that the internal volume will be around 35 liters. So if we fill the internal volume of the drum more than 50%, we will probably get more then 17,6 liters regolith.
    But if the drum has internal volume 45 litters a smaller fill ratio will do the job ( 44% fill ratio will be enough).
    I personally made my drum with 35 liters internal volume and in simulations I "calculate" the fill ratio just by watching - it can be seen if the drum is filled more or less than a half.
    BTW it is very important to do the simulations with granules that are more close to the size of the bulk material. For example I made my simulations with 20 mm diameter balls and I had a lot problems until I find a shape for the drum that can collect some more than 50% of its internal volume. But then one of the participants here (it seems he deleted his profile after announcing the finalists) made a new simulation with my drum and with smaller balls - 8 mm diameter. The result was dramatically better - I think that the fill ratio become 100%. It seems the centrifugal forces play a big role when filling - when the mass of a single granule (ball) is smaller, the influence of centrifugal forces decreases.
    You can see here one and the same drum but how different the fill ratio is with 20 mm balls and with 8 mm balls (20 rpm).
    With 20 mm balls:https://www.youtube.com/watch?v=E2oC0B5MYG8&feature=emb_logo
    With 8 mm balls: https://www.youtube.com/watch?v=DQ-GpTodRec&feature=youtu.be

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Victor Production .com

    Victor Production .com 10 months ago

    We all, are making a profit from this, in one way or another, besides nothing's over, until it is over ! :) All the best to all !

    Victor Production .com has uploaded 1 CAD models & has left 22 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Ktan this is hell crazy!:D Write a book about it

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Sava Savov

    Sava Savov 10 months ago

    I know what Ktan1 is talking abouot - about the so called "spec work". https://youtu.be/DsstOs-K7gk

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Filip Šabacký

    Filip Šabacký 10 months ago

    Hi to jury team (Brad, Andrew, Drew, Jason) - why there is no entry in the finalist list with not rotating inner drum? - for example this one:
    Regolith Advanced Collector (RAC)
    I think this idea should be there...

    Filip Šabacký has uploaded 2 CAD models & has left 13 comments.
  • Sunoj Kashyap

    Sunoj Kashyap 10 months ago

    Congratulation for every one, I feel people who put their personal time and submitted designs, At least they should get some badges or something in Grabcad , now its like We done something for nothing

    Sunoj Kashyap has uploaded 4 CAD models & has left 14 comments.
  • Stephan Weißenböck

    Stephan Weißenböck 10 months ago

    We conducted more tests and simulations with small improvements, as already proposed in the description, and can conclude, that the fill ratio of new test simulations increased significantly to up to 90% or more.

    Stephan Weißenböck has uploaded 2 CAD models & has left 7 comments.
  • Elie VILLAIN

    Elie VILLAIN 10 months ago

    Happy to be among the finalists! Again, I would like to thank GrabCad and the LSII for organizing such an interesting challenge. It was a real pleasure to participate; I worked a lot and learned a lot, especially whith the simulations. A lot of fun ! May the best win :)

    Elie VILLAIN has uploaded 6 CAD models & has left 46 comments.
  • Trevor Owens

    Trevor Owens 10 months ago

    I think everyone did a good job, just the finalists put their time to create amazing! designs and simulations and deserved to be a finalist. GOOD JOB whether you are a finalist or not you all gained experience doing this so at least it's not all for nothing :D
    Yes, there were many good designs, including all of yours, but there were 352 designs and only 10 of those were chosen, so I think the judges did their best to decide, looking at all of the specs and their time too, so we could give them some credit for it.

    Trevor Owens has uploaded 4 CAD models & has left 26 comments.
  • Sava Savov

    Sava Savov 10 months ago

    Elie, your solution is really genius! I like it very much! Although
    in fact, almost the same result can be reached without any moving parts or mechanism.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Kesa

    Kesa 10 months ago

    Hello Everyone,
    I have been seeing a lot of negative comments as of late on this challenge. The judges have made their decision based on these individuals being experts in their field. We understand that some may feel frustrated that their design and hard work were not selected but all decisions are final. Please show good sportsmanship and that GrabCAD is a place of learning & creating, full of great community members.

    Best,
    Kesa
    GrabCAD Community Manager

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Vaclav Lhota

    Vaclav Lhota 10 months ago

    Well, thumbs up for detailed feedback Luděk!!

    Vaclav Lhota has uploaded 3 CAD models & has left 54 comments.
  • Sava Savov

    Sava Savov 10 months ago

    So, who is the best, Ludek?

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    I have provided some comments related to Ludek's study. I would classify it as poorly executed and poorly designed at best. Please take a look at the study and the comments and perhaps provide some commentary.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Added some updated simulations on my entry. Obviously too late for judging but Ive been working hard to get accurate behavior related to friction between the drum and the particles. Most recent sim behaves similarly to some of the real world models with larger particles. Still working to simulate Static Clumping that is discussed in some of the research. The angle of repose as the drum fills seems to match some of the data on regolith simulants. Once I get the model finalized I may try some of the other drum designs to see how they work. though Im not sure how to properly simulate some of the moving components in Houdini.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    From what I have been seeing, the depth of the cut is a critical factor for how different designs behave. Its seems that the magic number falls in the 30% to 50% of the intake opening. This prevents clogging of the intake charge in the chute and allows the material to slide properly. Speed of rotation seems to be a lesser concern as long as the cut depth is not too deep. It also appears that a variable rate of feed/rotation may be beneficial as the drums near capacity it may be beneficial to slow the rotation and reduce depth to allow the material more time to settle. It seems like once the fill reaches a cresting wave flow things start jamming up hard which is what I think we were seeing in Ludek's study.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    http://grainflow-dynamics.com/index_files/GM_Walton_et_al_Effects_of_Gravity_Cohesive_Powders_2007.pdf

    This is a really interesting paper that I wish I had found a month ago which discusses the topic of powder and grain behavior in rotting drums(specifically with a focus on Lunar Regolith handling). Offers some great insight into various aspects and considerations that impact the movement and fillability of a drum as we are all looking at them. In particular the cresting behavior is something I witnessed in a number of the simulations I ran and may indicate the benefit of friction reducing coatings on the inside of the collection drums to reduce the sliding friction of the granules within the drum, if they can be kept from rotating and cresting the fill ratios become much much higher.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Caleb Clausing

    Caleb Clausing 10 months ago

    I like the simulations, and that paper is interesting. The way that the material moves inside the drum is important for my design, so it's cool to see how much research has already been done. Although the paper also mentions a ton of challenges too that I didn't even realize. It would be cool if there was a simple way to test a physical model in an environment that was close-ish to the lunar environment because like you mentioned, moving parts are hard to work with in simulations. But thanks for sharing!

    Caleb Clausing has uploaded 1 CAD models & has left 9 comments.
  • Luděk Čechura, LC - machinedesign

    Luděk Čechura, LC - machinedesign 10 months ago

    Thumbs up - Jason Homringhaus !!!!!!

    Luděk Čechura, LC - machinedesign has uploaded 3 CAD models & has left 10 comments.
  • Luděk Čechura, LC - machinedesign

    Luděk Čechura, LC - machinedesign 10 months ago

    PS. You are on the right path, if you put a small space in your ego head, there will be a huge space for thinking. Big things are waiting for you. I wish you a good trip! Ludek

    Luděk Čechura, LC - machinedesign has uploaded 3 CAD models & has left 10 comments.
  • Jason Homrighaus

    Jason Homrighaus 10 months ago

    Ludek, thanks for the Kudos but I would like to point out that the simulation seems to refute some of what your study showed but this is a good thing. IT shows us that there is a lot more going on here and this is how the process is supposed to work, find a stumbling block, seek to understand, work the problem and define better performance. sometimes through physical changes and others through operational changes.

    the drums do seem to fill properly to capacity if properly loaded as far as feed and speed. A broader evaluation of any design would be warranted to determine the best feed rate and cut depth for any given design, it is not just a question of raw rate a loading or speed of discharge.

    Jason Homrighaus has uploaded 7 CAD models & has left 46 comments.
  • Luděk Čechura, LC - machinedesign

    Luděk Čechura, LC - machinedesign 10 months ago

    Yes, the test is not a laboratory output. It only has to verify the basic function of the design. It is to show that theory and practice are sometimes far apart. The output can be - a reason for further reflection. Sometimes the problem is bigger than it is at first glance. I think it's good to show it physically, rather than debating theoretically for a long time.

    Luděk Čechura, LC - machinedesign has uploaded 3 CAD models & has left 10 comments.
  • Kesa

    Kesa 10 months ago

    WInners will be annouced soon

    Kesa has uploaded 2 CAD models & has left 164 comments.
  • Stephan Weißenböck

    Stephan Weißenböck 10 months ago

    Congratulations to all! And special thanks to NASA for offering this opportunity and including our design in the top 5.

    Stephan Weißenböck has uploaded 2 CAD models & has left 7 comments.
  • Clix

    Clix 10 months ago

    I would like to thank for the opportunity to be again in the world of ideas to NASA and GRABCAD, i consider contests a inspirational way of view things an an opportunity to meet special people, so nice to meet you guys! can wait to see your work next time :)

    Clix has uploaded 15 CAD models & has left 322 comments.
  • Sava Savov

    Sava Savov 10 months ago

    Congratulations, Clix! You passed the last line :). All good to all, till next time.

    Sava Savov has uploaded 23 CAD models & has left 146 comments.
  • Michael R

    Michael R 10 months ago

    What an awesome challenge! Thank you NASA and GRABCAD for making it possible for so many people to contribute their efforts and ideas towards a mission this profound. It has been an inspiring opportunity and an incredible learning experience. Congratulations to everyone!

    Michael R has uploaded 1 CAD models & has left 7 comments.
  • MiDesys

    MiDesys 10 months ago

    Congratulations to all! I think we all learned a lot from this challenge. It's very glad for me to see that first three places go to USA although there where better submissions.

    MiDesys has uploaded 1 CAD models & has left 22 comments.
  • Elie VILLAIN

    Elie VILLAIN 10 months ago

    Congratulations to all the winners ! :)

    Elie VILLAIN has uploaded 6 CAD models & has left 46 comments.
  • Kyle St.Thomas

    Kyle St.Thomas 10 months ago

    I want to extendHUGE thank you to the NASA team working on RASSOR, thank you for allowing us as a community to have a small part in helping develop the future of space development. I look forward to following your work on the rover as you refine it in the coming months and years, and congratulations to all the other finalists in this competition. :D

    Kyle St.Thomas has uploaded 3 CAD models & has left 4 comments.
  • V.Novacov

    V.Novacov 10 months ago

    The all chalanges is a a big boolshits.Еverything is set up.

    V.Novacov has uploaded 19 CAD models & has left 50 comments.
  • geo

    geo 9 months ago

    With 350 entries and 10 winners, there must be 340 losers.
    I think the drum solution is a dead end.
    In my solution, only the cutting edges for the construction industry are heavy and the open collecting container has to withstand very low forces.
    The competition was ok, even if I didn't win :-)

    geo has uploaded 33 CAD models & has left 815 comments.
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