Need help with bumpers

Team 457 is looking for new ways to mount bumpers to our robot if u have any ideas or pics that u r willing to share with us we would galdly appericate it.

How did you do it before?

Team 330 put their bolts in the bumpers last year, IIRC. We just drilled holes in the frame and put the bolts through the holes, then tightened nuts onto them. We’d had a few minor issues in 2006 with blindnuts coming out by pushing.

we bolted them to angle pieces that were welded to our frame but we had problems. so do u have any other ideas to make it easier

What sort of problems? Nuts falling out, bolts not long enough, accesibility?

Try a strip of metal, covered with 1/2 inch foam, and wrapped in duct tape. Bolted it onto the frame, voila. Took all of 5 minutes during the final build day. I don’t recommend it, but we waited too late.

Accessibility has always been an issue for us. This season, we’re going to have a new setup. Imagine the meshing section of a hinge, but all square. Put several of these along the bumper, so bolts can drop in from the top. If this isn’t that clear, I’ll throw a CAD up in a few minutes…

Edit: Image 1 shows the two separate.The bottom section of the plate is threaded. When put together (image 2) the bolt can be dropped into the hole, and threaded in. This should allow us to change out from red to blue bumpers quite easily based on which alliance we’re on.







Not a spec bumper, unless the 1/2 inch foam was pool noodles. I think he’s asking about spec bumpers.

Would that be considered spec? Or do bumper fasteners count towards weight.

Ah, ok. Anyway, do you have any good generic designs? I’m trying to make sure we have a much better bot than last season. Craig, I like that design a lot.

Bolt and blindnut (or ordinary nut, depending which way you want to go) through a hole in the frame. Use on spec bumpers.

The bumper mounts on the frame side would be counted in the robot weight. But the piece on the bumper side, as long as it’s under 15 pounds for the whole setup, is fine.

Gotchya. Thanks.

We had a similar setup on our 2006 bot. Pull 4 pins and they popped right off. It worked very well. We did have to remove the brackets from the bumpers and weigh them with the robot, also the pins.

Last year the bumpers were all hinged together. We had brackets along the back that simply went over the frame. The brackets in front were held on by pins. Remove two pins and the whole thing came off. Just like 2006 we also had to remove the brackets and weigh them with the robot.

We had tiny flanges on our bumpers last year that locked into our 80/20 frame rails. Each bumper was attached with only ONE bolt. Never had a problem taking them on or off.

A crude picture is attached. You can see the three flanges on the left bumper.

Bumper Attachments.GIF


Bumper Attachments.GIF

One thought on bumpers and thier mounting. The plywood and aluminum frame can be a stuctural part of the robot. The mounting can be very critical if a team wants to integrat the bumps into the frame as a structural member.

We used blocks of abs that were mounted to the back of the plywood with some machine screws. They fit into 2x1 aluminum tubing we welded onto the side of the chassis and then we drilled a hole vertically through it all and held it in with a clevis pin and a hairpin cotter pin. For the front and back, we drilled 2 holes that the pins went through, so the pin took the place of the bolt. Looked cleaner and was easier to remove for doing maintenance and inspection. Didn’t have any problems and it held it nice and snug.

Caution!

Bumpers have specific materials, specifications and mounting rules.
It is very important to read the section of the manual that covers this.
Violations will not pass inspection.

Hey… there may be changes for 2008, who knows?

Unless you make custom bumpers, in which case you need to have them fit in the box and 120 pounds (or whatever it is) weight limit and you may as well make them an integral part of the robot. You still need to make sure to have them qualify as bumpers, though.

We weld our aluminum frame together and bolt the bumpers directly onto the frame. We use bumpers on sides only since the front and back are occupied, two bolts and two nuts per side. The bumper nuts are tightened before every match and checked after every match. Finger-tight for demos, since that’s when things go wrong, and wrench-tight for matches despite things going wrong, since that’s when the bumpers are actually needed. We use regular nuts because they need to come off regularly for robot repairs. The bumpers are easy to remove and very sturdy.

We like the idea but hear was are idea of getting them mounted to the frame without the huge block that needs to be mounted to the robot. Basically we are using the robot frame as that piece.