Sheet Metal Design

[Akash Rastogi]

Quick search of others asking the same question and a search in CD media will also get you results for your questions.

Here's one that answered a lot of my questions when I started learning about sheetmetal: http://www.chiefdelphi.com/media/photos/35696

[JohnSchneider]

If you remember our robot from last year, we actually used several thicknesses... .125, .060, and I *think* we actually used .250 on something...though it was overkill...Different sizes for different applications!

[roystur44]

Team971 uses .090" 5052 H32 in their designs. Last year we switched from .125" aluminum because we can save up to 27% in weight of our chassis. Also the laser processing time is much faster using a thinner gauge material. 95% of the robot parts are designed from one thickness. The team builds a competition and practice robot so we nest the parts on a sheet to utilize as much material as possible and to decrease our process time on the laser to cut down on costs. Our fab sponsor is happy about that.

It's been an evolution since 2006 and the .250 thk chassis but the team's CAD group is getting real good on how they design the folds, joggles, rivet holes and lighting patterns to maximize strength and chassis stiffness. They are confident so we are thinking of going with .060 5052 this year.

Figuring out if the parts are stiff enough and light comes from experience and iteration of the chassis design. I always suggest to go for lightweight design and make extras then at the end of a competition season do a review and save the info in your robot toolbox for next time.

[PhantomPhyxer]

I am happy to see that most Teams are using Aluminum. It is light an strong when used properly. I would suggest that if you are useing Solidworks. You should go the next step an have one of your mentors teach you Stress Analysis using your computer model. Finite Element Amalysis does not optimize a part but you can iterate on a solution by just changing the thickness of the material and re-running the problem.

When designing think of an "I" Beam. The top and bottom web are very critical in bending. The center web between the top and bottom flanges carry the shear. So, if you keep the flange the same thickness but seperate it by a larger distance then the the moment of inertia is increased and the bending strength increased.

If you ask a more specific question I will try to answer it.

You might also try in using a Ballistic grade of Aluminum like 5083 that is work hardened.

Norman Collier

[AustinSchuh]

Paper is a great way to teach sheet metal, since it is cheap and easy. Design something using 5 thou thick material in Solidworks, make a drawing, print it out, cut it out, and then put it together. Last year we had a sheet metal paper bridge competition and had students CAD up a bridge, build it, and then we had a competition.