Questions about pneumatic wheel legality

[subzero]

My team has encountered a problem that from what we have read we believe is illegal. Our pneumatic wheels extend beyond our frame which reading Q&A and talking with other teams we have come to the conclusion that this might be illegal. Any thoughts would be greatly appreciated! Picture is in link below.
https://www.facebook.com/photo.php?f...type=3&theater

[cgmv123]

Having things that extend beyond the frame is not inherently illegal. The issue is that things that extend beyond the frame define the FRAME PERIMETER, which may make attaching legal BUMPERS problematic.

[epylko]

R2 and R4 will give you guidance on the FRAME PERIMETER and what can extend beyond it (and when it can).

[Jon Stratis]

subzero - it sounds like you have a problem. I'll be one of the LRI's up in Duluth for your event (there are 6 of us between the two events this year... it's overkill, but useful for a week 1 event!), and I just sent you a PM if you want more direct help.

The gist of the rules is that your 120" frame perimeter is determined by wrapping a string around the robot. In this case, it seems that the strings will wrap around the wheels. Is this distance greater than 120"? If it's not, then we have some room to work with. The bigger issue is bumpers - you need to be able to properly mount bumpers outside of those wheels. That means extending some frame into the corners of the robot and the ends of the bumpers (if you do 8" bumpers from each corner. if you cover the entire side, you'll need additional supports). As a second year team, you haven't had to deal with bumpers before... definitely something to get addressed now!

[GeeTwo]

Assuming that the wheel rotates, this is flat out non-compliant. The [convex] frame perimeter must be composed of fixed, non-articulated pieces of the robot. (R2, with convex being derived from the first sentence of R2's blue box.)

[Sperkowsky]

We are using versaframe to fix this same issue on our bot. Essentially we just have a little U of versaframe attached with Gussets to each corner of the drive train. We had a couple of freshman make it and it looks good.

[MrForbes]

another way to fix the problem is to use shorter belts, and move the wheels so they don't extend past the frame.

[longilive]

Put something solid over (above) the wheels and have it stick out barely past the wheels (so you can use it to define the frame perimeter). You can use this as a bumper mount as well.

[engunneer]

Originally Posted by Sperkowsky

We are using versaframe to fix this same issue on our bot. Essentially we just have a little U of versaframe attached with Gussets to each corner of the drive train. We had a couple of freshman make it and it looks good.

Can you share a picture? As an RI, I would worry that these are not long enough based on the description to support an 8" bumper, but I would have to see it. There are versions of interpretations of you described assembly (such as it is) that are legal, but also some that are not.

Originally Posted by longilive

Put something solid over (above) the wheels and have it stick out barely past the wheels (so you can use it to define the frame perimeter). You can use this as a bumper mount as well.

Same comment. That would work if the structure is wide enough. Then they would need to be sure their overall frame perimeter is less than 120 as they would have to extend it at least 4" (1" in each corner) based on the picture

[Sperkowsky]

Originally Posted by engunneer

Can you share a picture? As an RI, I would worry that these are not long enough based on the description to support an 8" bumper, but I would have to see it. There are versions of interpretations of you described assembly (such as it is) that are legal, but also some that are not.



Same comment. That would work if the structure is wide enough. Then they would need to be sure their overall frame perimeter is less than 120 as they would have to extend it at least 4" (1" in each corner) based on the picture

Sorry when I said little u I meant 26" long u

[Jon Stratis]

Just a nitpick here... But a lot of these posts seem to be saying/implying that something needs to go in front of the wheel. That is not actually the case. Something (greater than 1/2") needs to go into each corner, and that something needs to protrude past the wheel in order to define the frame perimeter. Another something needs to be extended less than 8" from the corner to properly support the bumper, and must extend that support to the edge of the bumper, assuming an 8" bumper (and must be at least 1/2" at the edge). All this can be accomplished without having any frame material in front of the wheels themselves, And actually be accomplished easily assuming there is enough room in the FRAME PERIMETER to accommodate the corner pieces.