pic: GUS Team 228's Prototype Sheet Metal 6WD Chassis

[artdutra04]

Originally Posted by AustinSchuh

How do you tell if your designs are strong enough? Do you do FEA? Something else?

If it's a "unique" part we do calculations and/or FEA on the part. But for the majority of parts, we use past experience and intuition, as there isn't enough time in the FRC build season to fully analyze every part. By managing flange locations carefully (flanges strain harden the material) and properly cross-bracing sheet metal parts, you can create strong structural members with relatively thin materials.

The most important thing when working with sheet metal is that many designs may only work as a complete system. Whereas many non-sheet metal drive bases work just fine alone, many sheet metal designs would fail without the cross bracing of all the other mechanisms and structure. For example, here is the chassis for our 2010 robot:



Alone, it would never have survived a single practice round. But with all the other parts and mechanisms (swerve pods, kickers, electronics belly pan, superstructure, etc), our drivetrain/chassis was more than strong enough to survive pretty hardcore New England defense unscathed with a Regional banner. (The bearings in our swerve pods and our kickers were a different story. Live and learn. )

Originally Posted by mplanchard

At 2010 you can create multi body sheet metal parts, the cut list will create a seperate representation for each body. You can also now use Mirror part in an assemby for sheet metal parts and my favorite new feature, based on the sheet metal vendor I used to work with, you can export a sheet metal body directly to .dxf or ,dwg format. From the part, right-click on the Flat Pattern feature and click Export to dwg/dxf

Our main sheet metal machine shop sponsor is a SolidWorks shop, and has a plugin to take the SolidWorks files, adjust the K-factors to match their machines, flatten them out and nest as many as possible in a sheet of metal. Our team took a tour of their facilities before the 2007 FRC Kickoff, and it was what helped make me a huge fan of working with sheet metal.