Hi all,
I’m a rookie mentor and I was reading through the bumper rules yesterday. They seem relatively easy to construct, but I couldn’t figure out how teams could attach them both securely and quickly. I assume that teams make 2 sets - red and blue.
Would anyone be willing to share a description or pictures of how they attach their bumpers?
Thanks,
Tim
Team 5822
Some teams make reversible bumpers (there’s a recent thread about it somewhere if you look for it), but lots of teams use small c-channel or angle brackets with bolts or pins that go through them and the frame.
Since the BUMPER ZONE is kind of high this year, relative to the kit chassis, I was thinking we might want to just put some plywood all the way around the robot, extending up as high as we want the top of the bumpers to be. Then attach the bumpers to this. Also, this has the added benefit of making it look like the robot is made of wood! just like in the game animation video.
If you consider doing this, be sure to make the chassis a bit smaller than the maximum size it could be…you have to include the plywood in that 120 inch FRAME PERIMETER limit.
You might not have seen http://www.chiefdelphi.com/forums/showthread.php?p=1500810, which is a good bumper overview.
Teams use a variety of attachments – some have brackets on the bumpers, others put T nuts in the bumper boards and use a knob with a bolt in it on the other side. You can also put the bolts in the bumpers and have the nuts inside the frame, but you need to pay attention to clearances during bumper installation/removal. If you’re planning to have an attachment that comes from inside the frame, ensure that you drill holes prior to drive base assembly and have access in the area you’re planning to attach to.
If you go the bracket route, quick attachment methods include cotterless clevis pins with a ring in the top, or safety pins. A thicker bracket could be tapped and then you could use the knob above to install it.
When deciding your attachment location, make sure that you pay attention to R22, which specifies the vertical location of the bumpers. It’s a common practice to allow for a bit of sag of the bumpers by setting the lower edge of the bumper somewhat higher than the 4" minimum. You’ll have less trouble with sag if you avoid stretch material for the bumpers.
You should be able to swap your bumpers in 60 seconds, ideally without any tools.
Mike here from Robopromo. Definitely look into reversible bumpers. They can make life a lot easier because you don’t have to take them off each time you need to change colors. We can supply you with the pre-sewn material for that and we have an instructional video on how to create them. Here’s the link for that video on our website:
http://www.robopromo.com/category_s/1830.htm
To answer your question about how to attach a bumper, you can get a visual for that near the end of our bumper fabric upholstery video. And here’s the link for that one:
There are many ways to attach your bumpers. A lot of it depends on the design of your chassis. Whatever you do, make sure you do the following:
Make them sturdy enough to survive playing defense through all of your tournaments, hopefully including Championship. Use good quality plywood, not dimensional lumber since it can crack along the grain.
If you are going to build a set of Red and a set of Blue bumpers, make sure that whatever method you use to attach the bumpers allows you to swap between them quickly. It would be great if no tools are needed. The fasteners must be easily accessible. The hardware must stand up to the rigors of gameplay without deforming and jamming.