Show off your skills and solve real design problems
3D Technology challenges you to design a Donkey Calf Raise Attachment for a Smith machine.
The specifications, requirements and technical details will be updated by January 27 based on your questions and feedback. This gives enough time for everyone to ask questions, talk with 3D Technology, and make sure GrabCADrs know what to work on and what 3D Technology expects of the winning entries.
You must include:
- STEP of IGES file.
- 3D and 2D CAD file.
- Brief design notes explaining the rationale behind the design.
- Description of design materials and dimensions.
- FEA stress results to verify design can handle up to 1500 pounds of compressive force (updated on Feb 3).
Design requirements:
- The basic model should be light in weight but strong enough to support up to 1,500 pounds.
- The design should have a locking mechanism or quick release clamp that will allow the device to lock onto a smith machine Olympic barbell (25mm to 28mm).
- The locking mechanism or quick release clamp should have rubber padding that fits around a Smith Machine Olympic Barbell handle so as not to damage the barbell.
- The locking mechanism or quick release clamp apparatus should be able to withstand 1,500 pounds.
- The locking mechanism or quick release clamp should be able to attach and unlock from the smith machine barbell in a quick manner without any tools.
- The lower back padding should be designed to fit comfortably on the lower back even if an excessive amount of weight is used.
- The new design should be modern, ergonomic, durable, appealing to the eye, comfortable.
Additional requirements (added Feb 3)
- Material can be anything that the designer sees fit to use.
- Some form of padding should be used on the attachment clamp so as not to damage the barbell.
- Design dimensions will be left up to the designer.
- Max manufacturing cost: $300
The competition is open to everyone. Multiple entries are acceptable. Team entries are welcome - prize will be transferred to team leader. Participants may only win one prize per Challenge.
Tag your entry with “DONKEYCALFRAISE” when uploading to GrabCAD. If you submit through the "Submit entry" button, this should be added automatically. Only entries with valid tag will participate. Only entries uploaded to GrabCAD through the "Submit entry" button on this Challenge page will be considered an entry. Private entries are not eligible.
By entering this competition, you 1. Warrant that the work is your original work. 2. To the best of your knowledge, it is not, and has not been in production or otherwise previously published or exhibited. 3. Neither the work nor its use infringes the intellectual property rights (whether a patent, utility model, functional design right, aesthetic design right, trade mark, copyright or any other intellectual property right) of any other person.
______________________
If you think an entry may infringe on existing copyrighted materials, please email challenges@grabcad.com.
Applicants are not entitled to any compensation or reimbursement for any costs. The applicant’s participation shall not constitute employment, assignment or offer of employment or assignment.
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.
Only public entries will be considered. Any private submissions will be made public at the Challenge deadline.
We will release the finalists before the final announcement to give the Community an opportunity to "vote" for their favorites in the comments. The jury will take these into consideration when picking the final winner. This new addition is based on feedback from you!
Winning designs will be chosen based on the rules and requirements. This Challenge ends on February 19, 2014 (11:59pm UTC). Winners will be announced by March 19, 2014.
Void where prohibited.
Awards for TOP 3 places
$1,000 cash + GrabCAD scrapbook
$500 cash + GrabCAD scrapbook
$250 cash + GrabCAD scrapbook
The sponsor may offer the winner an opportunity to continue working on contract basis.
The jury is comprised of experts from 3D Technology and GrabCAD.
3D Technology, located in Houston, Texas is a Drafting company that provides complete 3D Modeling and detail-drafting services. Our goal is to provide our customers with professional, detailed, high quality 3D models, Computer Aided Design (CAD) drawings and other CAD drafting services.
If you don't receive the email within an hour (and you've checked your Spam folder), email us as confirmation@grabcad.com.
74 comments
bj over 10 years ago
Thanks for presenting a fun engineering problem!
How are you going to (un)lock the barbell from its frame??
Rafael Acosta over 10 years ago
Yes as BJ states I think the trick part of the deign will be how to unlock the barbell from locks, but I think I have an idea it will be fun doing this challenge since I am sick of doing Donkey calf raises with a partner on my back.
Juan Carlos Bravo over 10 years ago
I have a question, What manufacturing methods will you use for the metal parts?
Ravichandra J P over 10 years ago
Nice challenge. By the way, second paragraph ends with, "....... such as a squat shown in the image to the right.". Where? in wikipedia?
Sara Sigel over 10 years ago
@ravichandra See the main image. The Smith Machine is the rack holding the barbell.
Doug Davey over 10 years ago
What is the diameter of the bar?
How does one know if the attachment is center? ..... if not, what stops the system from being imbalanced to one side (this can not be good)?
Do you have to have a person helping you?
paultahar over 10 years ago
does it looks really dangerous exercise??give huge load at spine, I hope it doesn't cause low back pain.
Ruan Pretorius over 10 years ago
@Doug, I hope I can help, the diameter is 28mm (smith machine Olympic barbell (28mm in diameter). and on the machine self, there is two supported shafts that guide the bar up and down (Like shown on first picture
)If the Calf Raise Attachment is a bit off-center - it won’t really matter, the bar will still go up vertical. It’s always important to have n buddy with you
Doesn’t matter how big or small you are, your legs can fold in at any time.
Jonathan Brazeau over 10 years ago
What is budget scope? Preffered manufacturing methods for the metal, clamps and padding???
Leon van Rijn over 10 years ago
What are the expectations? What are the reasons you need a new design? What is wrong and what do you expect to be improved?
Hevi over 10 years ago
@Leon van Rijn +1
Joe Pollock over 10 years ago
My back hurts just looking at that picture.
ZC Design over 10 years ago
Can we get the model in the original image that includes the smith machine and the human model?
It would help with reference and make for some better quality renders showing the device in use.
ZC Design over 10 years ago
If we wanted to add a brand to our model would we use 3D Technology as the brand?
Jonathan Brazeau over 10 years ago
HAHAHAH @ Joe Pollock!
Leon van Rijn over 10 years ago
is it desirable that both back supports (or more that 2) have independent joints and therefore can pivot/hinge independent from eachother?
Steven Clark over 10 years ago
Am i allowed to summit an entry using a solidworks student version?
Hevi over 10 years ago
@ Steven Clark - you can always upload .STEP .IGES file
Bryan Morris over 10 years ago
Very excited about this challenge. Being a Certified Personal Trainer, this hits home pretty hard!
Fabian Jones over 10 years ago
Steven, as long as you submit a STEP or an IGES, you will be OK
Fabian Jones over 10 years ago
This piece of exercise equipment is not dangerous at all as long as you perform the exercise correctly. Any exercise can be harmful if done incorrectly.
Fabian Jones over 10 years ago
Designers Check out the web site: http://lifehardcore.wordpress.com/2013/12/03/smith-machine/
Look at the 1st image of the woman doing a bench-press. Do you see the locking pin at the bottom left side of the image. You place the locking pin at whatever height is best suited for you. In the case of the Donkey calf raise; you set the locking pin at the best height and set the smith machine barbell on the locking pins and there is no need to rotate the bar. You just attach the Donkey Calf raise apparatus and get into position to perform the exercise.
Hevi over 10 years ago
So what we should do with your "attachment"? There's no need for additional locking system in vertical axis (like u said - there is locking pin)... I was thinking about whole locking system - now I see theres no need for it; so we just need to design some mount for barbell? ;)
Fabian Jones over 10 years ago
Exactly!
Fabian Jones over 10 years ago
Smith Machine and human model [AutoCad] available for download!
Fahad Rafi over 10 years ago
anybody did FEA? steel yields, FOS ~0.4 when this much load is applied.
paultahar over 10 years ago
i got 6.9 FOS
Maryan Talevski over 10 years ago
Can I use any Freeware 3D modeling software or SolidWorks Student Version or do I have to use some software specifically?
Fabian Jones over 10 years ago
I don't care what software you use just as long as you submit a STEP or an IGES, you will be OK
Sara Sigel over 10 years ago
CAD files (neutral, 3D and 2D) should be added to entries before the deadline to be considered - apologies for the miscommunication!
Fabian Jones over 10 years ago
Designers, please design the release clamp to accommodate a variety of different size Barbells. 25mm to 28mm
jamie over 10 years ago
this is a tricky request Fabian lol. So you want the clamp to accept 25mm, 26mm, 27mm & 28mm. OR 25mm & 28mm Barbell? either way im going to have to get my thinking cap on to modify my model.
Fabian Jones over 10 years ago
The clamp just needs to accommodate 25mm, 26mm, 27mm & 28mm barbells.
Fabian Jones over 10 years ago
The rubber padding that fits around the barbell can conform to accommodate 25mm, 26mm, 27mm & 28mm barbells.
jamie over 10 years ago
Fabian - This is exactly what i have just done to my model. As i couldnt think of another way around reducing the clamp to the smaller diameter. :)
paultahar over 10 years ago
i need exact rubber diameter (inner & outer)
Jonathan Brazeau over 10 years ago
anyone have any good links on how to perform stress testing analysis? Preferably using Solidworks.....thanks.
Paul Hubers over 10 years ago
Why does it have to lock on? Could it just clip on? The first thing that came to mind was the Manta Ray Squat Pad. http://www.verticaljumping.com/images/Manta_Ray_2.jpg
Yuva Balaji over 10 years ago
nice idea but it should withstand 1500pounds keep that in your mind dude
jamie over 10 years ago
a quick question - are we now showing stress results of - 1500lbs or 8400lbs? both are stated above in the requirements.
jamie over 10 years ago
ok as to my question above - after a bit of research most smith machines max out at around 340lbs - and the average man is normally lifting about 200 - 300lbs on a standing calf raise. So surely 8400lbs is abit over the limit when it comes to this exercise and the amount that the smith machine can carry. (although i think it might be able to carry it - its just that there isnt enough room to get that much weight on to it)
Fabian Jones over 10 years ago
Stress test should be done at 1500 pounds. The 8400 pounds is a misprint!
Lalit over 10 years ago
What should be the targeted weight and Factor of Safety?
Ruan Pretorius about 10 years ago
any Body out there that would help me with the FEA stress results? I’ll Split the prize 50/50 if we win?
keith about 10 years ago
Attaching something is the easy bit, the added complication is that with smith machines you need raise the bar and twist to un-latch the mechanism, also same consideration when racking back in place.....
Kris G about 10 years ago
i have seen a lot of nice entries here, but i don't understand... all those designs that fits 25 to 28 mm barbells and the only thing that tighten the barbells is the rubber itself, won't the rubber tear apart with everyday use?
Sara Sigel about 10 years ago
@Christos It's a good idea to state why your solution will overcome everyday wear and tear then! :D
Sara Sigel about 10 years ago
Don't forget to upload your entries - only one day left!
jamie about 10 years ago
is the maximum manufacturing cost just for components plus assembly (ie. does not include tooling costs)
Fabian Jones about 10 years ago
The $300 is total for everything!
jamie about 10 years ago
I think you could machine from solid materials for the price of $300 per product. But you could really reduce the product cost by investing in tooling for die casting / injection moulding. Upfront cost of around $3000 for tooling (out of china) - would give you a part price of $8. Obviously you have to sell alot more to get this tooling cost back. @fabian - do you intend to go down the route of machining from solid??
Jonathan Brazeau about 10 years ago
+1 Jamie. Especially for this sort of product.
Sara Sigel about 10 years ago
Congratulations to all of the finalists! We still have a lot of narrowing down to do, so while we rank and look at entries in depth, give us your feedback. Which one is your favorite? Did we leave anything amazing off the list? See something we should know about? Let us know in the comments...
Jonathan Brazeau about 10 years ago
congratulations to all participants and finalists! my picks to come....
Jonathan Brazeau about 10 years ago
from the finalists, stand outs for me,
Donkey Calf Razor
sturdy clamp, simple design
Saddle Shaped Attachment
sturdy clamp, simple design
Donkey Calf Raise attachment
agree with judges ,nice simple but will clampings ystem work.
https://grabcad.com/library/stand-alone-donkey-calf-raise-xl-attachment-
I like the addition of the arm, think it could work.
The rest are derivatives of each other.
Out of the two models I made, was so surprised to see this particular concept in the finalists, GC, you always surprise me with your choices! I really liked the other model and thought it would be chosen out of the two, but for sure my model has potential, one thing I would have liked to do is round the corners on the backbone so nothing sticks into your back ).
Good luck to all, may the best DESIGN win!
Joe Valverde about 10 years ago
Hi Sara, great to the finalist picked! All very worthy entries.
I think there is slight confusion with my design, it is ment to attach to the smith machine via the clamping system, and rotate horizontally when the user moves it into position. I put stand alone as the title, as I believe it stands out from the crowd, and could be propped up against a wall when not in use.
Joe Valverde about 10 years ago
I particuallylike,the x-PAD for its unique colour scheme,it wouldcertainlyattract new users.
I also like Johnathons clamp with the multiple foam bars, provides great support.
Goodluck all
Ian M about 10 years ago
Well done to all the finalists. There are two that stand out for me, the X-Pad and the Butterfly design. Both of these are modern clean looking attachments and will perform the job they are designed for. The X-Pad looks like its been designed for the 21st century Gym, a refreshingly modern take of a functional attachment. As gyms try and attract new clients then this is sure to impress.
Well done again and best luck to all the finalists.
Armin Yousefi Kanani about 10 years ago
Calf Crusher Strap" by bryan.morris-1 and RV Donkey Calf Raise Attachment by ricky-29
Armin Yousefi Kanani about 10 years ago
Donkey Calf Raise Attachment "Calf Crusher Strap"
RV Donkey Calf Raise Attachment
Kris G about 10 years ago
Congratulations to all the finalist.
My top three entries without specific order:
https://grabcad.com/library/donkey-calf-razor-v
https://grabcad.com/library/donkey-calf-raise-attachment-v
https://grabcad.com/library/donkeycalfraise-concept-1-v
I would like to make some adjustments to my design, move the neck at the center of the surface under the clamp to minimise displacement,shorten the neck to minimise movement during the exercise and give more wall thickness to some specific areas.
I think those are the changes i would make during the product development.
Good luck to all finalists
Sara Sigel about 10 years ago
Look for final winners to be posted next week. Sorry for the delay!
Jonathan Brazeau about 10 years ago
This one will be interesting! thanks Sara.
Erika about 10 years ago
I like so much this model: RV Donkey Calf Raise Attachment .
I think that is beautiful strong and functionally.
jamie about 10 years ago
when are results going to be released?
Bryan Morris about 10 years ago
Everyone did a great job and the finalists were well deserved. I only hope that safety is a main concern with the final product. The donkey calf raise is a great exercise to increase calf strength but can be dangerous is done incorrectly. I hope to see the end result on the shelves one day!
Sara Sigel about 10 years ago
Winners are announced! Again, we apologize for the delay.
http://grabcad.com/challenges/donkey-calf-raise-attachment-challenge/results
.
Thank you to all participants! 3D Technology is really excited about the solutions you created and found your feedback throughout the Challenge to be really helpful in increasing focus on safety and comfort. You can expect them to pick and pull the best features from all of the winners as they pursue this product. Great work GrabCADrs!
Jonathan Brazeau about 10 years ago
Congrats to top three! Great challenge!
Tommy Mueller about 10 years ago
Workout people's calves everywhere are gonna get ripped with muscle!
Congrats you guys!
Ricky
paultahar
Stefan Gales
jamie about 10 years ago
well done to the winners - one of the better challenges on GC
Stefan Gales about 10 years ago
For me it was an honor to be a finalist.
Thank you GrabCAD. Thank you 3D Technology.
Thank you GrabCADrs.
Fabian Jones about 10 years ago
Thank you to the winners and everyone who participated in the Donkey Calf Raise Attachment Challenge. I got more than I ever could have bargained for. Trying to pick a winner was a very difficult task. There were so many great designs. Now let’s go get some defined calves.
Fabian Jones
3D Technology
Jonald Trump about 10 years ago
Congratulations to the winners, nice work.
Kris G about 10 years ago
Congratulation to the winners. I really enjoyed this challenge.
Jonathan Brazeau about 10 years ago
Lol. Must have missed the e-mail for this...obviously congratulations to all the finalists! Thank you to Fabian and 3D tech for the opportunity!
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