U Shaped Frames and Bumpers

[JGillen]

If we have a U shaped frame, with the opening used for pickup, can we leave that section open without bumpers, or are bumpers required to cover the entire frame?

[EvanJ]

Any gaps in your bumpers have to be 0.5" or less.

[GaryVoshol]

See the blue box on R101 that shows a V-shaped robot with an open side. The side across the V is part of the FRAME PERIMETER, just as the space across your U-shaped ROBOT would be. It needs a BUMPER, as noted no gaps more than 1/2 inch.

[Case0823]

[Mara1]

Hello. Wondering if UShaped chassis are illegal this year. Reading the bumper rules it seems so, but the v chassis illustration is confusing. I can’t find any explicit statement saying no ushaped chassis. Just wanted to clarify what the chassis possibilities are before we get too far down the brainstorm road.

[Aaron_Li]

The rules you should look at are:

Rule R401

Rule R410

Some useful threads:

R401 Is this new? (Significant bumper rule change)

[image] What’s up with this? Is there any reasoning for this change in bumper rules? It would explicity disallow things like corner bumpers only and intakes that push the ball through the frame(such as 1690’s 2022 robot).

R401 changed, bumpers all around

[IMG_4195] big change

2024 Robot and Inspection Rules changes

My annual Robot and Inspection rules changes topic. As before, I will make this a wiki. My first pass will be things I notice on my first reading, and I will update with a more in-depth later this afternoon, and through the season. Feel free to DM me with corrections to keep the topic easy to read, especially on kickoff day. Added ~kickoff + 6 hours, updated kickoff + 8 hrs: I’ve dredged through the R&I rules. I will note changes to R & I rule numbers, but not chapter, section, figure, or t…

[bobbysq]

Seems pretty clear to me:

Rule R401

Are you referring to the R101 graphic by the “v chassis illustration”? That just means that if you did have a cut out in your frame, the frame perimeter would still only follow the outside of the robot. (and would therefore need to be completely covered by bumpers in a way that complies with R410 as per R401)

[Patrick3357]

Its probably a good idea to sketch what you are thinking but, you can’t have a concave FRAME PERIMETER due to the way it is defined in the blue box on R101. FRAME PERIMETER is an imaginary surface not the actual chassis perimeter. Bumpers must follow the FRAME PERIMETER not the robot’s frame. The maximum unsupported length of the bumper is 8in. Put this all together, you can have a U shaped robot, but the FRAME PERIMETER will still be a rectangle and bumper will have to go straight across the open side of your frame, to keep the bumper supported, the opening in the frame must not be more than 8".

[Mara1]

Ok. Thanks for the clarification. So from what I am reading here, looks like you could have a u shaped chassis (providing opening is no more than 8"), you just need a bumper across the opening, which defeats the purpose of the ushaped chassis. Effectively making ushaped chassis for all intent and purpose, indirectly-“illegal” this year.

[Patrick3357]

Pretty much, Yep.
No loop holes for a though bumper intake, anything wider than 1/2" will have to above or below bumpers, not through.

[Mara1]

Ok. Thanks. Appreciate it.