Gearbox Modification

I would appreciate feedback on rules interpretation re modification to the Snowblower motor/gearbox (AM-2235). We’d like to re-make the output shaft to extend from both sides of the gearbox. This will making a “harvester” design simpler. See images below.

Thanks in advance.


In my opinion, R33 would prohibit remaking the output shaft as it does not fall under any of the exceptions. R33A seems to apply to minor modifications of the shaft, IE, filing, tapping etc. The modifications you would make to the motor is pretty major and would alter its base form. If this were a CIM motor I would say no way…

But that’s just my opinion. Q&A?

Since you are only modifying the worm-gear transmission for the motor, and not the actual DC motor itself; it should be legal.

I have to say, your frisbee transport system is brilliant.

But does the snowblower motor fall under the window motor catergory where the transmission is integral?

I personally disagree, as R33 does not ban modification of gearboxes, only motors, and the snow blower motor gearbox is not explicitly deemed as integral to the system.

However, please do ask the Q&A, as that will be the only official answer you’ll be able to get (as a note: ask it as something like “Are we allowed to replace the gearbox on the snow blower motor (part #)?” or “Is the snow blower motor’s gearbox considered integral to the snow blower motor?”, not with reference to your specific design modification, because if you do that they’ll probably say that they can’t rule on individual designs).

The integral mechanical and electrical system of any motor may not be modified. Motors, servos, and electric solenoids used on the ROBOT shall not be modified in any way, except as follows:

A. The mounting brackets and/or output shaft/interface may be modified to facilitate the physical connection of the motor to the ROBOT and actuated part.

While the gearbox on the snowblower motor is not explicitly prohibited from modification; it would seem odd to me to disallow it on the windows and not the snowblower since it seems to share the same design ad the window motors.

I would like it if I could make that modification or something similar.

First Q&A # 148 asks about using the window motor gear box with other motors. Answer…no rule prohibiting this.

Thanks everyone for your help: LH Machinist, Coffeeism, slijin, Joe.Quirkand WileyB-J. Much appreciated!

I think the intent is to prevent modifications to motors. The gearbox is integral to the Window “Motor” and Snow Blower “Motor” as it can’t be used without the gearbox. I think modification of the shaft is within the spirit of the rules. I’ll proceed with making the new shaft while maintaining ability to revert to unmodified design.

I went to the Q&A section of FRC. I posted this question but am not sure if I did it properly.

Here are the relevant manual statements and Q&A’s if found:

The intent of this rule is to maintain the maximum power level for each ROBOT, yet still allow teams to modify mounting tabs and the like, not to gain a weight reduction by potentially compromising the structural integrity of any motor. The integral mechanical and electrical system of the motor is not to be modified.

Note that for the Window motors, the gearbox is considered integral to the motor, thus the motor may not be used without the gearbox.

Q233 Q. We have a AndyMark am-0914/pg71 gearmotor assembly which was supplied to us in our KOP and it is not listed on the table in R32 but it is listed in the competition manual, section 4 2013 Technical resourses. Are we missing something in the table or is this an error? (1 Follow-Up Questions)

A. [R32] regulates motors, not motor/gearbox assemblies (except where the gearbox is considered integral to the motor, see [R33]).

Q148 Q. If we remove the gear boxes from motor part number 262100-3030 or 262100-4040 and do not use the motors is it ok to use the gear boxes with other motors

A. There are no Rules prohibiting this.

Q250 Q. Table 4-1 under the Andymark PG entry only shows am-2161 and am-2194, not am-0914 which was supplied in the Kit of Parts both in 2012 and this year. Is this a legal motor?

A. The am-0914, as supplied in the KOP, is not a motor, it is an assembly of a motor (am-2161) and a gearbox.