Legality of Robot

Quick question, would this current chain configuration (as shown in the photo) be legal, or would it be considered a “sharp object” or another clause against the rules?

Nothing here is inherently illegal from my perspective.

You may consider adding some polycarb guards for those chains, not only to protect from pinch points, but also because things extending outside your robot will get hit, and an unprotected chain coming off mid match isn’t fun. I would also suggest rounding off this end of your rectangular tubing to help allow balls to roll into your intake a bit more smoothly.


Agree on the idea of come kind of covering to protect anyone/anything that might touch that chain while it is moving. G101 and all that. Getting a finger cut off by a sprocket can really ruin your day.

It does not have to be bullet-resistant, just help prevent a tragedy from causal contact. Ask again if you need ideas.

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I’m a big fan of chain guards, especially any place you might stick your hand. In the case of the bottom chain in the picture, consider what it might do to a ball that hits it from the side - i would definitely put a chain guard on that!

The easiest chain guard is probably a polycarb circle. Drill a hole in the middle, tap the end of the shaft and bolt it on. Sure, the chain guard then spins, but it still does its job!


If that chain is moving and is held against one of the cargo balls for some time, it could damage them leading to a Referee calling a Tech Foul (see blue box at end of G301).

Agree with what everyone else has said … it’s almost certainly legal, but I’d still be worried about the possibility of game piece damage.

Good point - I always get wrapped up in something like a full polycarb sort of shield but that is more than you need.

Break the edge of the guard and you’re good to go!


Agree with all! Another possibility is to put the chain run inside the rectangular tube (though you may need a slightly smaller sprocket).

Inspectors at our events have required chain covers on exposed chain like that, where its easy to put your hand then have the robot do something unexpected. We’re making chain guards at the moment too! One simple fix if your competing week 1 and don’t have time to make something fancy, we’ve cut water/soda bottles in half and taped them over the chains before when an inspector asked them to be covered at competition. Ugly, but works in a pinch.

Is there a similar requirement for timing belts? The belts running one of our shooter iterations are on the outside of the robot, so are they required to be guarded?

Would you feel safe contacting a running belt with your finger, or your bumper fabric? Particularly on the toothed side, or next to a pulley?

And can someone or something reach the belts in question easily?

The more you wouldn’t feel comfortable contacting the belt and the easier it is to reach, the more you should think about putting a guard on.

I don’t know, but I would think so. There’s not a specific requirement, it falls under the robot inspectors judgement of what is dangerous. In the case of the OP, the chains are in a place where, if you were trying to check something on the intake you could easily grab it right there without thinking about it. If your looking at an issue on the intake in the pit while the programmers are trying to fix something, it would be a simple mistake to run the intake while someone has their hands on it, no matter the safety rules you follow for enabling.

In our case, the chains are on the outside near the top of the elevator, a natural place to put your hand if your bending over and looking in the robot. Drive chains are not typically required to have covers as they are down low and out of the way, and more obvious and hard to accidently put your fingers in.

I don’t have a lot of experience with timing belts, but if it looks like it could seriously damage a finger, and it’s where a finger could accidentally end up, I’d say cover it for your own safety, as well as making inspectors happy. If you think it’s no dangerous but have a slight concern inspectors might complain, at least have a quick backup idea on how you could over it with something at competition.

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Here’s a pretty simple guard, just a piece of polycarb bent in a vise fastened with 2 bolts w/standoffs.

We had to make a little cut out because one of the pulleys is standing a bit proud.

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If the RI let it pass and someone got hurt, they still got hurt. The safety rules the RI’s are enforcing does not and cannot cover all situations. Teams have to think for themselves about how to be safe.

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