Too late to ask about size, but…..

We have been interpreting the new perimeter rules and have read the blogs and built a bot that will “fit in the box” as Bill’s Blog said. We went to a practice field today and the other team said that we were out of spec. We built a bot that extends to the bumper perimeter and not beyond the 36X40 dimensions. It stays at that size throughout the match, nothing extends. Should we be worried and spend our last two days trying to make it fit inside the bumper perimeter or have we done what the rules have allowed this season?

Please help ASAP, 2 days to go……

A picture would help, but based on your description (if you start within the FRAME PERIMETER) and stay within the volume the whole match, you’re fine.

When you say “extends to the bumper perimeter” does that mean your bumpers are within 36"x40"x24", otherwise known as Configuration A by R03.

Yes, everything starts and stays in that cube.

Er, so what’s the issue then?

Because there have been many interpretations of the “perimeter” this year and the string wrapping answer. We have run with the Bill’s Blog line that said, if it fits in the box, it is ok.

Just had some other teams tell us otherwise and were looking for some other opinions.

These rules should answer your question:

R01: “The ROBOT (excluding BUMPERS) must have a FRAME PERIMETER, contained within the BUMPER ZONE, that is comprised of fixed, non-articulated structural elements of the ROBOT. Minor protrusions no greater than ¼ in. (~6.3 mm) such as bolt heads, fastener ends, weld beads, and rivets are not considered part of the FRAME PERIMETER.”

My Note: This is the definition of frame perimeter, which is included to help understand the next rules. Note the frame perimeter does not include the bumpers, and the bumpers must go on the outside of the frame perimeter. This effectively makes your maximum dimensions for the frame perimeter either 30 in. by 34 in. or 24 in. by 26 in. depending on your chosen frame volume. Note those measurements assume your bumpers are exactly 3 in. thick.

R02: “In the STARTING CONFIGURATION (the physical configuration in which a ROBOT starts a MATCH), no part of the ROBOT shall extend outside the vertical projection of the FRAME PERIMETER, with the exception of its BUMPERS and minor protrusions such as bolt heads, fastener ends, rivets, etc.”

Translation: At the beginning of a match no part of the robot can extend past your frame perimeter.

R03: Maximum ROBOT size, including BUMPERS and all extensions, must be constrained to one of two volumes:
A. 36 in. by 40 in. by 24 in. tall (~91 cm by 101 cm by 60 cm tall).
B. 30 in. by 32 in. by 36 in. tall (~76 cm by 81 cm by 91 cm tall).
The ROBOT must remain constrained to the maximum inspected volume at all times during the MATCH (i.e. A ROBOT may not switch between volume A and volume B without being reinspected).

Translation: After the start of a match, the robot is allowed to expand past the frame perimeter as long as it remains within your chosen volume.

As long as your robot complies with these rules, it should not have any maximum volume issues. Of course, I would recommend reading through the manual to ensure your robot complies with all other robot rules.

See why I am confused, a few replies and conflicting answers….

They aren’t conflicting. Your volume “box” consists of your frame perimeter, your bumpers, and any extensions. However, at match start, you cannot have any extensions (barring minor protrusions). They must be fully “stowed” within the frame perimeter.

None of these answers conflict. Start within your frame perimeter, don’t extend outside the volume at any time.

Man, throwback

Where do you see conflict in these answers?

Here’s your TL;DR answer. Measure your metal frame (without bumpers) - if you’re larger than:

  1. 29.5 X 33.5 X 24 (high)
  2. 23.5 X 25.5 X 36 (high)
    — assuming each bumper is 3.25 inches thick —

If the bot exceeds those measurements at the start of a match, you have a serious challenge ahead of you.

R1-R03 as quoted by Nardavin are quite clear on the definition of “frame perimeter” - it excludes bumpers entirely.

See also R22:

ROBOTS are required to use BUMPERS to protect all outside corners of the FRAME PERIMETER. For adequate protection, at least 6 in. (~16 cm) of BUMPER must be placed on each side of each outside corner (see Figure 8-1). If a FRAME PERIMETER side is shorter than 6 in. (~16 cm), that entire side must be protected by BUMPER (see Figure 8-2). A round or circular FRAME PERIMETER, or segment of the FRAME PERIMETER, is considered to have an infinite number of corners, therefore the entire frame or frame segment must be completely protected by BUMPER(S).

emphasis mine

This rule implies that if you have a corner on your robot’s frame perimeter (it’s outermost edges) its vertical projection must be covered by a bumper. If you have a corner that is above your bumpers (as your description seems to suggest), it is not protected by the bumpers.

Also, I would recommend looking through Q&A or the manual to corroborate claims made on the blog. While they do come from HQ, they are not official game rulings.

Here’s yet another look at the three sizes:

  1. Frame Perimeter - the smallest of the sizes (robot must be within this at the start of the match, then during the match can expand outwards to the limits of the Volume)
  2. Bumpers - the intermediate size (must be completely outside the Frame Perimeter, yet within the Volume Limit, but there can be gaps in the bumper coverage)
  3. Robot Volume Limit - the maximum size (nothing can go beyond this at any time, not bumpers, not robot extensions)

So this is bad, right?

Check the lower right portion and the back.

If I’m reading this as you intended to write it, there is DEFINITELY a problem. You say that you “built a bot that extends to the bumper perimeter…[and]…stays at that size throughout the match.” If you meant the perimeter at the outside limits of the bumpers, then you have a significant part of your robot extending outside of the FRAME PERIMETER. If you mean the perimeter on the INSIDE face of the bumpers, you’re OK.

Constructing the rules a bit, if you have any part of your robot that is over, under, or inside the wood or noodle parts of the bumpers (“minor protrusions” excluded) at the start of the match, you’re in violation of R02.

I’m not sure what you’re referring to by the “lower right portion and the back” but I can tell you 100% those white flaps on your gear holder are not legal.

Yes, that’s too far.
It needs to be brought back inside the chassis, and then maybe redesigned to extend to that position after match start.
Maybe two sheets of Lexan with one of the sheets on slides to be extended.

The flap of Lexan on the front that’s out over where the bumpers will be, also needs to be pulled back.
We did something similar, but to fit within the frame perimeter at the start, we hinged the Lexan instead of bending it there,
Then have a spring release after match start to flop outwards.

One last thing, the Lexan on the side is fastened onto the outside of the frame. That might be putting it out beyond the Frame Perimeter by the thickness of the Lexan.
An easy solution for that is to add a strip of Lexan as a spacer to the chassis on that side-extending the Frame Perimeter out by the thickness of the Lexan to match the Lexan higher up.
If those are welded pieces at the bottom on the face of the Frame Perimeter, then those are your new perimeter and may need Lexan around them to bring the full face of the perimeter out to the same distance.

That’s bad. You’re going to have to slice that off, or figure out a way to actuate it to bring it in.

Robot perimeter is defined by the outermost part on each side.

If, at the start of the match, any part of your robot extends past the inside edge of your bumpers, it violates rule R02. From what it looks like, that does extend past where you would mount your bumpers. Would you mind posting a few more pictures just to make sure though?

Depending on the current dimensions of your robot, you might also be able to extend your bottom frame so that the overhang fits within the frame perimeter. You would only be able to do this though if the bumpers, when mounted on that extension, still remain in the maximum volume.