Bumper articulation question


#1

Question about bumpers not being “articulated”. If we build “C” shaped bumpers, with the top and bottom of the “c” (short pieces) attached to the long piece with small hinges, so that the C can “open up” and then close around the frame, and be attached in a fixed position, is that OK? So the bumpers would be “articulated” when they are OFF the robot, but fixed in place when ON the robot; no hinge-action could happen when the bumpers are installed.

The idea is to have a connection to stabilize the short pieces, which would only have one bracket each, but still be able to take the piece off the frame by removing the pins and opening the hinges.

I think this is OK but just wanted another opinion.


#2

I have seen this done successfully in the past. Be aware of potential interference issues with the hinges and the corner of your frame, and the 1" limit on hard parts of the bumper. Ensure everything is rigidly attached when on the robot - you don’t want it to come off and be flapping as you drive around! Additionally, sometimes teams are in a hurry and pick up the robot by the bumpers - make sure your attachment can handle that!


#3

Thanks for the reality check. We are aware of all the issues you raise. This will actually make ‘lifting by the bumpers’ more secure than our prior bracket design, that is one reason we are doing it.

Hard parts can extend 1" from frame perimeter, right? So the 3/4" backing plus another 1/4"; but our plan is to inset everything so the backing is pretty much flush with the frame.


#4

R31 lists the legal recipe of a BUMPER. R31F (optionally use metal brackets to attach BUMPER segments to each other) lists the legal attachment option. Hinges are not listed and I can see some RI not being down with a hinge being a type of bracket.

Personally I would not do this as if your attachment/removal process requires the articulation you have an unhappy making challenge at an event if you don’t pass Tech. We typically make C shaped BUMPERS and use a bracket (on BUMPER) and pin on FRAME PERIMETER system. The brackets drop down over the pins and and are secured using R clips. A simpler version substitutes nuts & bolts for the pins and clips.


#5

Good point. We’re considering further.


#6

We’ve done one piece hinged bumpers for years, and never had a problem passing inspection.