[Tom Line]

Our robot issues in the Michigan State Finals were directly due to multiple end-welds failing on our arm after a collision. Our long fix was to do exactly what 254 does - gussets welded in place. If you are into the physics of it, a simple free body diagram will show you how it decreases forces and torque on the weld by orders of magnitude.

Edit: And when you rivet the gussets in place, remember that it takes at least 3 rivets in a row to make a decent joint. 2 rivets in a row just makes for a wiggly mess.