1/2" gap in bumpers, is this acceptable?

[Chris is me]

That gap seems like the amount of space a somewhat flexible bumper could easily unintentionally leave if slightly jolted or something. Or, to be more clear, I'm pretty sure I've seen robots pass inspection without the two fabrics exactly touching all the time.

That being said, it's not too long of a fix.

[EricH]

That's... not a 1/2" gap. More like a 1"-2" gap.

I'd go with Peter's suggestion: unwrap the end, cut the noodles, and replace with a vertical section of noodle. You've got time now (and presumably some extra noodle sections laying around), so fix it now and fix it right so you don't have to fix it in a big hurry at the competition.

[Foster]

That's... not a 1/2" gap. More like a 1"-2" gap.

It's 1/2" wide gap that is 2" long.

We have oodles of noodles (oh how long have I waited to post that!) around the shop, so we'll do a quick fix and upgrade the plans for the "red" set.

Thanks to all that replied either here or via PM's.

[GaryVoshol]

You didn't follow the instructions exactly, and this is the result. (And I don't mean that to sound condescending, I'm just stating a fact.)

Originally Posted by <R07>

L. Joints between BUMPER segments and the radial projections of corners must be filled with “soft” BUMPER materials. This may be done with short pieces of vertically oriented pool noodle, by wrapping the pool noodles around the corners, or by beveling the ends between adjacent segments so they form a tight and complete protective surface (see Figure 8 – 2).

Notice the corner labeled "Not OK" in Figure 8-2. Also notice the word "filled" in the rules. I never stopped to think about this before, because the last year I actually worked with the bumpers was before the filled corner rule came into effect. My first reaction would have been, easy, just make the noodles longer and it will work. I guess you've inadvertently proved I would have been wrong. Using a 5" vertical noodle works because it naturally moves around the end of the backer board, whereas an extended horizontal noodle ends up sticking out straight.

Unfortunately I think you'll have to fix it.

Edit: You might also be able to get away with lengthening the noodles on the "butted" end to achieve full corner protection, but you take a risk of that not passing because it doesn't match one of the three ways mentioned in the rules. I think I recall a Q&A last year that said it was OK. If this is your solution, you might ask Q&A, because last year's rules don't apply to this year's game.

[Al Skierkiewicz]

Foster,
As much as I hate to go against Gary, the intent of the the bumper rule is to have no hard parts in the corners that can contact another robot. At first it would seem like this picture is a violation but I think if you hit the upper right corner of the bumpers, you would not be able to hit the hard parts of the two bumper sections nor the corner of the frame. Of particular note are these paragraphs in R07...
A. BUMPERS must provide complete protection of the entire FRAME PERIMETER of the ROBOT (i.e. BUMPERS must wrap entirely around the ROBOT). The BUMPERS must be located entirely within the BUMPER ZONE when the ROBOT is standing normally on a flat floor, and must remain there (i.e. the BUMPERS must not be articulated or designed to move outside of the BUMPER ZONE).
and
N. “Hard” parts of the BUMPER (i.e. plywood backing, fastening system, and clamping angles) may extend up to a maximum of one inch beyond the FRAME PERIMETER. “Soft” parts of the BUMPERS (i.e. pool noodles and cloth covering) may extend up to 3½ inches beyond the FRAME PERIMETER.

The only thing that appears to be a little long is the top bumper section. The hard part cannot extend past the corner of the frame by more than an inch. In this view I cannot tell whether the wrap of cloth is over a hard part or not. Touch would be the only way I could tell.

[WGRAY]

Does your plywood overlap the corner and butt your other corner, if it does you are also in violation.

[GaryVoshol]

I agree with Al, I believe the bumpers meet the intention of the rule. If you were at his event, he'd pass you (subject to the hard parts, which to me looks like you might be OK, but like Al I'd have to feel it). But what will the inspector at your event say? Do you want to risk it?

[sanddrag]

What I'm concerned about is there is a segment of bumper left flapping in the breeze. This could potentially become snagged on something. I hate to say it, but legal or not, I would not want to compete with a bumper quite like this. You have time, go ahead and redo it a bit.

[Foster]

What I'm concerned about is there is a segment of bumper left flapping in the breeze.

There isn't a segment "flapping". The part that is sticking out is the two 2" pool noodles wrapped in fabric.

We have noodle bits cut to fill in the gap and our Master Bumper Builder will do the quick fix this weekend.

Thanks again for all the input!

[Foster]

New improved bumpers showing better fit and the new spiffy red color. We put another section of foam in the bumper end.

[Jon Stratis]

Originally Posted by Chris is me

That gap seems like the amount of space a somewhat flexible bumper could easily unintentionally leave if slightly jolted or something. Or, to be more clear, I'm pretty sure I've seen robots pass inspection without the two fabrics exactly touching all the time.

That being said, it's not too long of a fix.

Of note here - in some previous years, it was NOT required to have soft bumper material in the corners. Specifically, i know our first year (2007) we build our bumpers with no material at all in the corners, and they were perfectly legal.

Since then, we've cut all of our pool noodles at 45 degrees to fill the corners nicely.

[joek]

Originally Posted by eagle33199

Of note here - in some previous years, it was NOT required to have soft bumper material in the corners. Specifically, i know our first year (2007) we build our bumpers with no material at all in the corners, and they were perfectly legal.

Since then, we've cut all of our pool noodles at 45 degrees to fill the corners nicely.

we do too, i think. (BTW, never leave the robot supported by it's bumpers for an extended period of time, we did that to last year's bot recently, and the bumpers are squished down to half their normal size)

[3286]

I think we may be in the same boat, but there are worse possible things to have to do than fix some bumpers. In perfect hindsight and looking at the rules I can also see a disconnect between the text portion that says the bumper backing plywood is the same length as the side of the robot. ( Im paraphrasing but we all can see where this comes from ).

So if one builds the plywood to the dimension of the robot and then covers the plywood you might not get a gap in the corners but you won't necessarily get the foam and cloth covering to extend much further than the end of the backing piece either. This is basically where we are at.

You can see in the attached photos how our bumpers meet in the corners, I suppose the worse case scenario is now to open them back up and stuff a vertical piece of noodle in the corner to fill it out a bit, and then cover it back up and hope there are no gaps in the fabric.

Would be great if these are legal, but again, for us there are a lot of other and bigger fish to fry in the time remaining.



Mike

[Chris is me]

Originally Posted by eagle33199

Of note here - in some previous years, it was NOT required to have soft bumper material in the corners. Specifically, i know our first year (2007) we build our bumpers with no material at all in the corners, and they were perfectly legal.

I'm referring to 2009 with my post, which has similar bumper rules other than allowing for cuts.

[O'Sancheski]

the one thing you have to make sure of is at the meeting point of the two bumpers, they have to form a perfect L shape..