Can I do this?

Can I machine a heat sink out of the endcap of a pneumatic tank and ziptie it to the little yellow part in a motor that shuts it off, along with cutting a hole in it for the heat sink to stick out of? If not, can I just cut ventilation holes in the motor?

You will not be able to modify motors in ANY way, but as long as your heatsink is made of legal VEX parts, you can use it. There is no requirement to use parts for their intended purpose.

Burn Out Issues?


You may not modify motors in ANY manner, except to change out gears, put IMEs on, repair motor wires, or put labels on them. Other than that, this is forbidden. The heat sink can be used though as long as it’s made from VEX parts and no modifications to the motors are needed.

I assume you’re probably talking about the PTC in the motor. I would not even think about messing with that, as doing so could get you kicked out of tournaments and VEX Worlds.

The motor casing is not a very good conductor of heat. Metal is great at moving heat about. Plastics, not so much. Ideally you would put fins of some metal on the motor and have the heat dissipate through the metal and interact with the air. Like a CPU heat sink, the metal picks up the heat and the fins interact with the air to distribute it out. Fins are why baseboard heat radiators (electric and water based) and car radiators have all those thin metal fins all over - it makes for some great heat transfer.

Let’s look at the coefficients of heat transfer here for our materials.



You want to put some metal on the heat generator (the metal motor case) but unfortunately rules do not allow that. So best case is placing something metal like a rack gear bracket around the motor and squishing it to the sides. Aluminum is a better heat conductor as you can see from the linked data. But not much heat is flowing through the plastic motor case to the metal around it.

Contact surface plays another role so try not to have screws touching, just the pure metal. More surface area means more heat transfer ability.

You can try and maybe use some thermal imaging to see your results.

Engineering rocks! Can’t entirely program your way away from physical properties!

This is so cool. (Pun maybe?)

It may be cool, but totally illegal for competition. You can only use vex parts of Plexiglas type materials. No machining of non vex metal would be allowed in my opinion.

I am suggesting making a metal “heat sink” using Vex parts and see if it helps.

I personally don’t think it will do a lot given plastic stinks at conducting heat away, but it may help. Plastic is great at electrical resistance though.

This experiment makes for a great design notebook item with real data and real engineering elements of heat transfer.

Oh… gotcha… ok. I am not sure how it would do without a heat sink compound though. Good idea though