Dry Ice on Robot?

Would this be allowed or would it violate R08?

I think the answer you’re looking for is

Of course, I’m sure it would speed up processor and drivetrain speeds.

I really hope you’re kidding…

I doubt it, but WHY???

I think that if it is insulated so it cannot come in contact with a human, it could be legal. There is no specific prohibition, and the only hazard I can think of with it is frostbite.

One that we have discussed quite a bit but never had the nerve to try, is a hydraulic system using water as the fluid. It’s not hazardous, it won’t damage very many things, and we’ve been building underwater robots for years so we’re quite familiar with dealing with water and electronics and mechanicals at the same time.

I agree that if done properly then dry ice shouldn’t be a problem, but why?

As for the hydraulic system using water; it would be hard to convince some people that is doesn’t violate R37.

The power for it would come from the robot battery, which powers a legal robot motor, which turns the pump.

It would of course be protected so a human could not accidentally touch it.

Also, wouldn’t the water be then considered a hydraulic fluid?

Even when you are adding more dry ice? I think that might be the sticky point…

Also, wouldn’t the water be then considered a hydraulic fluid?

I’ll get my lawyer working on that one.

It would look cool

What are you using it for?

My opinion would be that if it is doing anything useful (providing cooling) then it is an illegal energy source, as the energy for creating the dry ice did not come from any of the allowed sources of energy that may be used on a robot, and the dry ice effectively becomes a stored energy device.

If it’s a “non-functional decoration” then there would be a very long discussion and evaluation regarding the safety aspects. After which it most likely would be deemed to be illegal.

But what about using it between back-to-back elimination matches to cool off motors?

Every material on the robot took energy to create, that does not mean they are contributing energy to the function of the robot. Wouldn’t the sublimation of the dry ice be a net negative (consumer) process in terms of energy? How could it contribute stored energy to the robot?

We played with that for fun - we put a bunch of crushed up dry ice in the bottom of a shop vac and checked the output temperature. The sublimation rate is not nearly fast enough to affect the temperature.

You’d have a fun argument on your hands if you tried to hold it on the motors yourself. Just used a compressed air can and turn it upside down. Same thing, safer, and probably faster too.

Hmm would that classified as stored energy by deformation of a robot part (where in this case the deformation would be freezing)? IMO you also have a valid point about it not being stored energy; it seems like it would be “stored entropy.”

As to how you could use dry ice to provide power to a robot… https://www.youtube.com/watch?v=si1iGuigAiQ). Maybe you could use the Stirling engine to power a fan to cool your motors? :cool: The energy for this would, as you point out, not be coming from the dry ice but from the ambient temperature, and under those terms could be ruled illegal.

I would rather touch dry ice than an 8 inch pneumatic wheel spinning at 5000 RPM…:rolleyes:

Well if one had a water block that could easily/quickly clamp over a motor, they could set up a water cooling system, and then have the radiator sitting in a cooler full of dry ice. Maybe even have it set up so a robot battery could be used to run the pump…

That seems like it’s so much overkill though.

It depends how hard and how long you have to touch each thing.

Hmm… I like the illegal energy source interpretation, but really… wouldn’t it be a perfectly legal energy sink? Thermodynamically, energy would flow from the warm chassis and motors into the ice… the robot itself would be an energy source. <edit… I see a few other thermodynamically-inclined respones to this idea popped up while I was writing this!>

Further to this thought, even if dry ice were to be considered an “energy source”, would it not be included under the “deformation of robot parts”. After all, the energy would come from the thermodynamic expansion of a gas, which is specifically legal in a closed-loop gas shock… which means the gas is a robot part and it is allowed to deform. I challenge anyone to find a rule prohibiting phase changes!

A logical thought experiment… would it be legal to leave the dry ice on the motors while queuing, then remove it immediately before going on to the field? I’d say “yes”… which means that having thermal gradients is legal.

(An interesting thought… for teams using off-board compressors… chill the air in your aluminum storage tanks, and place them above your warm motors… as the match goes on you might get a bit more energy out of them.)

If we really wanted to find excuses to not allow Dry Ice on the robot, we could try classifying it as “compressed air”, and as it was compressed by a source other than the compressor then it might not be legal. However since “air” is primarily nitrogen, and Dry Ice is CO2, that would really be stretching it.

In short, however, if the dry ice was handled safely, and placed on the robot in a secure manner, unlikely to injure competitors or officials, and unlikely to damage the field or other robots… it would be up to the event officials to explain under what rule they were disallowing the dry ice. If they couldn’t do that, then they would be obliged to rule the dry ice legal.

And why not? I mean, it’s just dry ice! I shared the same “gut feeling” as the cat at the top of the page, but after looking at all the rules… I’d have to pass it at inspection.


This would probably be a major sticking point. I can’t think of an RI that would look at a container of dry ice (even a completely safe one) and not question it. There also is a clause on the RI checklist about liquids and gasses used on the robot, and I can’t think of what it exactly says off the top of my head.

Interesting arguments though