Not only does 1714 build their robots entirely out of plastics, they are also perennially successful. Their 2012 robot was incredible, and their 2013 robot was one of the more successful climbers in Archimedes this year.

We use our bellypan for shear and torsional strength. We used 1/8" 6061, which worked well, but 5mm baltic birch should work just as well if you are looking to use less resources.

We used 1/8" 6061 aluminum sheet that we routered out in a rather minimal diamond pattern, leaving mounting locations for electronics and things, and it came out to about 3.7 pounds if I recall. It was quite stiff.

I like doing this because the bottom pan serves as the welding jig for the frame rails and crossmembers. It helps line everything up. We rivet the side rails and crossmembers to the bottom pan, then weld the joints.

In 2012 we used 1/8" ABS which was okay, but a little soft and flexible. We had to brace it.

3/16" for a bellypan would be a bit overkill…

Also a 1/8" sheet of 7075 would be quite expensive (well maybe not crazy expensive, but you could probably get two 6061 pans for a 7075 pan price wise) and overkill. 254 and many of the westcoast teams use 6061-T6 bellypans pocketed @ .125" Thick.

971 does a cool job of utilizing a turret punch to make their belly pan:

I believe its .060 or .090 5052 AL. Travis/Austin/971 can clarify.


Thanks, I just assumed they were using 7075 because they use it for so many other things

Torsional strength about which axis?

I would not advice anybody to use/machine G-10 unless they really had a need and that it is the best material. For FRC robots poly carbonate works for most applications.

From the G-10 MSDS:
“Dust generated during grinding, cutting, or drilling fiber glass reinforced plastic produces respirable fiber shaped plastic (organic) particles whose concentration increases proportionally with dust concentration. These particles are not classified as carcinogenic by IARC or NTP. However, prolonged inhalation of dust can produce lung disease.”

7075 isnt used that much. Mostly in places that steel would be used in industry like gears and shafts.