Wrap Around Bumpers

[easponge]

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?

[Sam N.]

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

[AdamHeard]

Originally Posted by Sam N.

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

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.

[zkaratekid]

Originally Posted by AdamHeard

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.

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

[chaoticprout]

Originally Posted by zkaratekid

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

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.

[Brad Voracek]

Originally Posted by chaoticprout

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.

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?

[zkaratekid]

Originally Posted by Brad Voracek

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?

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

[IndySam]

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.