My team accidentally cut the metal for our chassis too short. We are trying to find a way to make it work still and we were wondering if there is a minimum frame perimeter. The manual specifies that there is a maximum of 120 inches but does not say anything about a minimum. Also, if we end up not being able to use what we have from this year, would we be able to use our chassis from last year or are there rules against that?
Nope, no minimum. We are planning on doing a 119.5" frame perimeter to ensure we don’t accidentally go over 120".
I encourage you to go through the manual page by page and read it. Only takes a couple of hours. To answer your question though, it’s illegal to reuse your drivebase from last year.
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Replacement frame parts are available from AndyMark, for about $25 per piece, plus shipping.
Without knowing exactly what size you cut it to, it’s hard to say whether or not you can make it work.
But as said, there is no minimum size rule, only maximum size. You do need to make the robot work, and if it’s too small to assemble, or you would lose functionality with it being the size it is, then you ought to buy new frame members, and be more careful cutting them this time.
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Just carefully twist it once1 so that you have a Möbius frame, and you’ll get double the length.
1 Void where prohibited.
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Has anyone used a smaller frame perimeter and faced issues during past competitions? (With our metal it would have perimeter of about 100 inches)
@lindee0309 Many teams build smaller robots for Stronghold to get under the low bar at 15" and had to cross defenses. That game was brutal on robots we had major repairs at least 4 times that year. All due to wear and tear.
I don’t see DEEP SPACE as violent due to relatively flat play surface and 1 defender. Our lesson learned from Stronghold, is building it simpler AND if it can break it likely will break. So we now always bring spares of everything we can and over build it strength wise
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I’ve seen smaller robots do exceptionally well at competitions and some do poorly. The main thing that determines success isn’t usually the frame, but what’s above it.
This year’s game has some advantages to being smaller – less weight means easier climbs. And that cargo is only 13" in diameter. If you’re good with space planning (find the person on your team who’s best at tetris and make sure he/she’s on design), there’s no reason you can’t do well with a slightly smaller chassis.
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Although there was not a frame perimeter (just maximum size), 148 made a small robot compared to most and they did incredible last year.
I believe the only rule regarding minimum size is the 6" bumper minimum. Go nuts.
The issues you would face are based on clearance, (smaller robots do not go over obstacles as well) and fitting all of the mechanism’s within your frame.
If you have a side that is less than 12" long, you can just cover the whole thing per R24. This most frequently comes up when people are building something that isn’t a rectangle. The minimum frame perimeter is, for practical purposes, the amount required to fit all the required components. If you’re clever about packaging, that can be shockingly small.
Basically for you this is going to come down to can you fit all the stuff you want in the perimeter you have. If the answer is yes, you’re good to go.
Or, in some cases, inside of it (148 won champs with a significantly smaller robot than everyone else in 2008, and there really wasn’t much of anything above the frame).
The only rules regarding minimum size are implicit. You’re require to have a roboRIO. That has a size. It must be fully contained within the frame perimeter for the starting configuration. Anything else that may be required has the same logic.
As long as you can fit those minimum required components inside, you’re meeting minimums.
Alas, this year’s game does not let you score by simply driving laps around the field.
Not at all, your frame perimeter could be 3" for all FIRST cares.
Be careful with the definition of the frame perimeter in R1. Our frame perimeter is a hoop of 1x1 tubing about 7" off the ground. Our drive train “chassis” is slightly smaller.
Good luck with your season!
David
While there is no defined minimum frame perimeter, there is a practical one. You still need to be able to fit the required components - like a RoboRio, PDP, Radio, VRM, Battery, and Main Breaker. I feel confident saying that would be impossible with a 3" frame perimeter. However, it has been shown that you can fit everything you need, including a drive train, within the dimensions of a Powercube. I actually saw one driving around at an off-season last fall. That is probably close to the practical minimum limits of the frame perimeter.
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In 2018, our robot Uppercut was also significantly smaller than everyone else, and it did a bit more than laps around the field.
Build as small as you can… IF you trust yourself to make good decisions regarding the tradeoffs of being small.
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I agree with JVN make it as small as you can for your given functionality. Smaller is more maneuverable, lighter and can squeeze through situations a max robot can’t.
I would never design a robot that pushes the size limits. This literally puts you in a box for iterations and damage making you too big.
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Ohhhhh…I so want this to be a thing now. How small can you actually make a functional robot to play the game? Score a few points? Maybe you could fit it on level 2 next to another robot to score the elusive extra 3 sandstorm points for having 3 robots start on level 2. …