Bumpers re: Frame Skewing

[Gwen_McD]

One of the persistent issues our robots have encountered is frame skewing due to corner impacts. Would appreciate any experienced advice regarding the bumper configuration/construction/mounting you have found to minimize or prevent skewing. Thanks!

[MrBasse]

Your bumpers can weigh 20lbs, so screw some angle onto you wooden backing. We use 3/4" aluminum angle that is 1/16" thick and it reinforces ours pretty well. We put one in each corner, and also tie the sides together and use them for mounting to the frame.

[MrForbes]

If you provide a picture of your robot, we might be more helpful.

But the normal way to avoid this problem is to attach a sheet of something flat, such as plywood or aluminum or polycarbonate sheet, to the bottom of the robot.

[engunneer]

Bumpers won't necessarily solve structural issues with a rectangular frame. Do you include any cross bracing to make your frame into triangles?

If you install a floor (such as for the electronics) and use enough bolts (more than 4),it can act as structureto prev ent skew.

[IKE]

If possible, follow Mr. Forbes advice with a thin belly pan to help skewing. If you have ever built a cheap book case, then you will understand the value of a backing or belly pan. That thin piece of cardboard applied to a stick frame will help skewing a ton. Now if twist is a concern... that may require a different solution.

[MrBasse]

I made my earlier comment assuming that you already had your frame solid. I strongly recommend following the advice of everyone else in this thread first. Cross bracing and a belly pan on your frame is going to make the biggest difference.

If you are still concerned with impact, reinforce your bumpers. They are designed to transmit forces more evenly to the frame. The frame is still going to take a hit, but it should be distributed better by the bumpers.

[Gwen_McD]

Thanks very much for all of your suggestions. I suspected this issue couldn't be solved with bumpers, but wanted tried and true advice to be sure. I appreciate your expertise and the time you took to help us.