How to build good bumpers

[MrRoboSteve]

1. Prevent internal robot damage as the cheaper stuff?

Plywood probably does the best job of spreading impact loads, because it's less likely to break than dimension lumber. Strandboard and MDF (particle board) will be the worst due to fastener issues.

2.Cause fewer structural integrity maintenance issues as the cheaper stuff?

I would put quality plywood in the first rank, dimension lumber in the second, and strandboard and MDF in a distant third. Plywood is best because it has grain in two directions. Dimension lumber is good, but hard impacts to the ends can cause dimension lumber to split along the grain, and the impact of that can vary from a minor problem to wrecking your bumper attachment mechanism.

Strandboard and MDF will have trouble with impacts on the edges, and have poor fastener holding, particularly through collisions. Strandboard is a sliver factory.

3.Cause fewer cosmetic maintenance issues as the cheaper stuff?

Fastening fabric via staples to the edge of strandboard could be an issue. Otherwise should not be a difference.

4.Require different tools to deal with a different type of wood than the cheaper stuff?

No meaningful difference in woodworking methods.

5.Be as readily available to teams who realize at competition they want to replace it or build bumper for others with it, like the cheaper stuff is?

11 ply 3/4" birch plywood with a poplar core is probably the least commonly available. That said, you can get it at Menards so it's not like it's tough to get. 3/4" plywood, strandboard, MDF, and dimension lumber are all available at any home center.

if I was planning ahead, I'd rip 5" x 96" lengths of plywood in our shop, as it's much easier on the big table saw than at a competition. That size is more convenient to load into a trailer with our pit than a 4' x 8' sheet of plywood, as we need the walls free to tie down our load.