Say I opened up the internal gearing section of a 393 and removed some or all of the stock gears and in their place used a gear made from any of the allowable materials in VEX U, would this be permissible? Specifically:
A. Using a VEX 393 on a comp. robot in VEX U without a full kit of internal gears
B. Putting something else, made out of legal VEX U materials inside the motor housing where the gears normally go.
Assuming that we leave the PTC alone and don’t otherwise alter the motor.
While I’m here,
C. What if we did attach something to the motor that altered the thermal characteristics of the motor, something like a peltier block or heat sink that draws heat away from one side? Assuming that again, we left the PTC to do it’s job.
All of the following clarifications are only permissible in VEX U. In VRC the motor should be considered sacred, and only to be modified via the means described in the special exceptions listed in <R15a>.
Yes, this is legal in VEX U.
Yes, this is legal in VEX U, provided that the materials being placed inside the motor housing are legal VEX U materials.
If these modifications are significant enough to improve the thermal characteristics of the PTC they would be considered modifications of the PTC per <R15> and be illegal if they fail the PTC inspection. If you improve it within legal ways so much that it fails the PTC test, it is illegal.
Also, cooling electronics would not be legal per since they are not used for “sensing” or “processing”.
If you’re cooling the PTC, you’re not in fact allowing it to do its job. So in summary, any of the modifications you’ve described in question C are most likely illegal.