pic: 397 Bumper Configuration

The question I pose to you is simple, is this a legal configuration for bumpers? If it is not please cite the specific rules and or Q&A which makes it illegal. We are trying to determine if we should proceed and would like to avoid asking repetitive questions to the GDC.

Thank you for your input.

it is as long as each segment of the bumper is at least 6’’ long, at least that’s what i think.
oh and you need an opening for the trailer hitch to feet in.

Ok, I’m not sure exactly where in the drawing you are planning on putting bumpers. Having said that I believe you could make a legal configuration out of this frame provided the two front flat surfaces are 6" long each.

Assuming the robot is 28X38 your bumper perimeter is 132" and yoiu need to cover 88" with bumpers.

It appears that there would be no reason not to cover both long sides with this design giving you 76". To properly cover the corners you would then need 2 6" segments on each of the short sides for a total of 24" which brings you well over the required 88".

If the angled pieces on the front are supposed to be bumpers these are not “official” bumpers and would count for robot weight and volume (and this cannot extend outside the bumper perimeter and would be illegal in the configuration shown. Removing these bumpers (and enough in the back to make a space for the trailer hitch would result in a legal configuration.

If the two angled front pieces are bumpers, this is illegal. Bumpers must be on the bumper perimeter, which is defined by wrapping a string around the robot.

It looks to me like you have a short bumper segment on the front end that curves into some sort of picker-upper device. According to my interpretation of <R08>, the bumper segments that angle into your picker-upper are not legal bumpers because they are not on the bumper perimeter. Additionally, the front segments look a little short - the plywood backing needs to be at least 6" long.

My team actually had a discussion about a similar area on our robot last night!

Hopefully this helps you out.

The angled sections are 6in long and we were going to put them there to satisify the corner bumper rule. and oops i did forget to add the hole for the trailer. So if we removed the small section would that be legal even though <R08> I. BUMPERS must protect all exterior corners of the BUMPER PERIMETER. is not satisified?

If you removed the angled sections and the rest in that area was 6" long or more, you’d probably be fine.

The one thing I’m wondering is–are bumpers allowed inside the robot’s BUMPER PERIMETER, if they aren’t treated as BUMPERS?

Ok, so…

I’m going to say no, since the segments of the front bumpers that lie on the two diagonals won’t be considered BUMPERS, since they don’t lie on the BUMPER PERIMETER. (<R08>L)

Also, ignoring the diagonal bumpers, the two segments on the front BUMPER PERIMETER look to be too short (min. 6") to qualify as BUMPERS. (<R08>A)

Keep in mind my response is not official in any way.

Yeah, I was wondering that myself. My only question is how does that work with polygons with 5 or more vertexes? Rather than try to illustrate with text I will give you points to plot, if I have a polygon with vertexes A= (0,0) B=(0,10) C=(10,10) D=(5,5) and E=(10,0) We know point D does not fall along the bumper perimeter. By your own argument the BP would be a polygon bounded by by ABCE. My primary question is that the rule states "BUMPERS must protect all exterior corners of the BUMPER PERIMETER (see Figure 8 - 2). " (From R08 I) The corner formed by BCE needs to be protected but obviously we cannot because there is no frame there. The logical thing would to run bumpers across angle BCD but as you said this is illegal because CD is not along the bumper perimeter.

Bumpers not attached to the BP would have to be counted as part of the robot (including weight).

L. The BUMPERS must be fixed to the BUMPER PERIMETER.


The Bumpers must protect all the exterior corners of the BP not necessarily the corners of the robot frame.


From all the hours I’ve spent reading on this subject, I’ll agree with Adam, it’s not legal, you need to have 6" minimum bumpers on the front, not angled back. It’s the combination of the Q&A response that you need BUMPERS on both sides of each corner of the BP, the rule that BUMPERS must attach at the BUMPER PERIMETER, and the minimum length of 6".

Wide robots are looking pretty good this year.

Non-standard bumpers could be included on the angled faces leading to your collector if you desired. They would not have to meet any BUMPER standards, but would be counted in size and weight of the robot.

The short front sections of the robot must be protected with Standard BUMPERS. Part of the requirement of those is that the combined section of plywood, noodles and cloth must be at least 6" long, and not extend past the exterior corner of the robot. (Noodles and cloth alone can - in fact MUST - extend past the frame to protect the corner.) The entire length of the BUMPER must be supported by the main frame.

I have deleted this post because of my (now) better judgement.

It’d be pretty upsetting if the GDC reverses what they’ve already stated very clearly. All corners, both sides, 6 inches. It’s intent has been pretty clear in the rules. That still leaves you 16 inches on a long robot to get a ball.

“Wrapping” the string so it touches just the outside edges of your robot and defining that as the bumper perimeter has been pretty well understood too (in my opinion).

If this suddenly changes to allow teams more leeway, other teams that have made serious design decisions that can’t be changed would be rather disadvantaged.

if I were you guys I would put a horizontal path for balls in front of the wall, if just 8" long. I think you may be hitting balls faster then they would be sucked up and you will not get as many balls as you could.

I couldn’t agree more. If they change I will be very upset and requesting extra build time!

And you know this because… ?

Making blanket statements about what the GDC will or won’t do, and on what schedule, is perhaps a bit presumptuous. A wise person, even if acting upon inside information obtained through unofficial backchannels, would probably remain silent on this topic lest his prognostication not bear fruit. This would be particularly true when the schedule for any such discussions might be altered for any of a considerable number of very valid reasons (as has already happened several times). Likewise, anyone that had obtained such inside information would be wise to keep it to themselves lest they find that, having proved that they cannot keep such information to themselves, their backchannel might be slammed shut and never to re-open.


I think the only thing making it NOT legal is the shortness of the front 2 stubs. The inner slants I don’t think count as bumpers because they are not “the outer-most set of exterior vertices”, they are just extra safety for the field.:slight_smile:

Least I hope thats the only reason. We at 1745 have a very similar frame( but our short stubs are greater than 6".

As for the GDC making a ruling on this. I personal do think this will happen( not that I have inside information . . cause I don’t). but mainly because figure 8-2 has an angled frame and it shows the line to follow the angles( granted they are outward angles) . . that picture does kinda muck things up and you know what they say about pictures vs words.

…If FIRST doesn’t want us to lawyer their rules, then why do they make them so damned hard to understand? I mean honestly, if you don’t want us snaking for loopholes, make the rules clear! This bumper fiasco is meant to keep our robots safe, but instead end up hindering so many teams. If FIRST wishes that competition be boiled down to a bunch of driving boxes, they’ll get what they’ve had last year: A game that was boring to watch.

</crotchety complainer>

I’m going back to building…