[RonnieS]

Originally Posted by MichaelBick

Building a light robot is all about materials and geometry.

We use 2" x 1" x 1/16" wall 6061 aluminum tube everywhere, except for the drive side rails. The tube is plenty strong for FRC purposes. The only issue we have ever had with 1/16" wall tube is crushing the tube by over tightening screws. Using 7075 aluminum instead of steel and #10 screws instead of 1/4-20 helps a lot too.

As far as geometry goes, try to triangulate and use flanges to build rigid but light structures. We also try to use as little lightening as possible, preferring to use thinner materials instead.

Minimize your bolt use and get some aluminum rivets. You would be surprised how much lighter your robot gets if you go through and design the entire bot first with material applied correctly. When you just pick up parts and start building you don't have a grasp for real weight until you pull out the scale and realize your 20 pounds over.

-Ronnie