Wrap Around Bumpers
 

I saw several teams with bumpers that wrapped all the way around the robot (233, 71, 135, etc..) as seen on 233 in this pic.

How exactly were they made, is the plywood two seprate pieces for perpendicular sides, or is it bent around?

Thanks

Any tips for attaching bumpers? 294 still hasn't found a way to do it that isn't cumbersome. We're making a prototype base now and want it as realistic as possible so were building the bumpers and mounts as well.

EDIT. Brad: It really threw me off too. Thanks for the advice on the flaps, that solves our main issue.

Re: Wrap Around Bumpers
 

Wow, teams have bumpers that wrap all the way around? That's pretty cool.

The way we do it is just extend the pool noodle and then cut it off at a 45 degree angle. We wrap the fabric all the way around, and if we used the same color it may look like it wrapped around. (http://www.chiefdelphi.com/media/photos/28201)

We just attach it per the manual, but on the bumpers we have flaps so we can get a nutdriver through the pool noodle, (these flaps are velcro'd on), and then you just get a hand on the backside and you hold a wing nut. We also have the aluminum angle on em.

If teams do have a continuous piece I'm interested how they did this too.

Re: Wrap Around Bumpers
 

I'd like to know how 135 did their bumpers... It was so nice looking and circular(ish), it was definitely continuous.

Actually, I think I asked at one point but I don't remember the answer...

Re: Wrap Around Bumpers
 

you mean, everyone doesn't have the ability to heat thier wood and give it some curve? :p

I do also say that looks sweet!

Re: Wrap Around Bumpers
 

The wrap-around bumpers seem like they'd work a lot better than the regular four piece or so set ups... but can anyone who's done this kind of bumper tell me how it's taken off and on?

Re: Wrap Around Bumpers
 

Hm, the wrap around concept seems interesting. However, i recall several instances this year when we had to take our side bumpers off in order to get onto a ramp. We still left our front and rear bumpers on for pushing/defense.

I don't think you an do that with the wrap-arounds.

1351 takes store-bought steel right-angle brackets (two planes of geometry) and we have a welder gusset them into right-triangles. That's OVER-KILL.

We only used steel for our side bumpers. Our front and rear bumpers were mounted with quarter-inch aluminum right angle. We had plenty of spares and a hammer ready because we thought they would bend under the force of impact. ----They held like a dream.

As long as you make sure that all force of impact gets translated through your chassis, you'll be fine. The bumper mount's only purpose should be just to hold the bumper in the bumper zone.

hope this helps
Sam

Re: Wrap Around Bumpers
 

Thanks for the advice... but the problem we had this year was that they were a pain to take on and off, not that they had weak attachment.

Overall, the bumpers held up well (except the front and back which we added last minute and expected to fail because they were only supported on each end at first), we just need a better way to attach them.

This year, it took about 2-3 minutes and a hex wrench to take the bumpers on and off.

Anyone have a faster method? We Usually have our drive between two plates so wing nuts are a pain; we were thinking cotter pins might work well.

EDIT: to keep this thread from getting too long, can we hold off posting until someone who did that style bumper replies.

Re: Wrap Around Bumpers
 

Our wrap around bumpers are hinged at the corners. There are four custom brackets, two that simply slide onto the frame on the back and two that attach to the front of the frame with two bolts with wing nuts. The whole assembly goes on and off in a matter of seconds.

BTW if you have an attachment method different from the one described in the manual they are not counted as part of the bumpers. Our brackets must be weighed with the robot.

Re: Wrap Around Bumpers
 

yeah 1138 uses cotter hairpins to hold the bumpers in the place. They work well and only take about 5 seconds to take the bumpers off. You just have to watch your clearance and makes sure that the cotter pin fits in snuggle against the backing material

Re: Wrap Around Bumpers
 

What Stanley said. After working with frustrating and hard to get to bolts last year, the cotter pins work well and are easy to put on and off, i'd use them again for sure.

Re: Wrap Around Bumpers
 

But if you use cotter pins does that still count as a standard assembly? We thought about doing something like that to make it really simple but we decided against it because we didn't have the weight or size to weigh those in with our robot, and were worried if they decided that it wasn't a safe mounting method. It pretty much says you -have- to use a bolt and fastener system in the manual... What are your guys' opinions on that?

Re: Wrap Around Bumpers
 

we went to So. Cal, Boilermaker, and Nats with this set up and none of the inspectors had a problem with this set up. The bumpers rules seems just a little open to opinion and we interpreted as it needed to be hard mounted to your robot