Attaching a gear to a SIM motor

[aceshigh2729]

how do you do it w/o opening up the motor.

[Madison]

The output is keyed for a 2mm x 2mm machine key.

You can purchase gears and hubs that are broached for the CIM output shaft at www.andymark.biz or broach another item yourself.

Do not take the motor apart as that is an illegal modification and you will be unable to compete with that motor.

[aceshigh2729]

we need to know how to attach gears w/o using a gearbox

[AJ R]

http://andymark.biz/am-0320.html

This hub fits directly to the cim. Im not sure if it comes with a key or not, so it might have to be ordered separately.

Originally Posted by Madison

Do not take the motor apart as that is an illegal modification and you will be unable to compete with that motor.

Could you cite a rule for this? I had interpreted past rulings as the motor windings cannot be modified, nor the magnets, but the casing could be machined and modified for mounting reasons (and machining the case would require removing the front plate).

[EricH]

<R54> So that the maximum power level of every ROBOT is the same, motors and servos used on the ROBOT shall not be modified in any way, except as follows:
A. The mounting brackets and/or output shaft/interface of the motors may be modified to facilitate the physical connection of the motor to the ROBOT and actuated part.
B. The gearboxes for the Fisher-Price motors are not considered “integral” and may be separated from the motors.
C. The electrical input leads on the motors may be trimmed to length as necessary.
The intent is to 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 FIRST will not provide replacements for modified parts.

The only questions are, is machining the case a legal modification, and if it is, are you allowed to open the motor to do it? If it's to facilitate mounting, yes. Otherwise, no. As for the second part, it's anybody's guess.

[Madison]

Originally Posted by CraigHickman

Could you cite a rule for this? I had interpreted past rulings as the motor windings cannot be modified, nor the magnets, but the casing could be machined and modified for mounting reasons (and machining the case would require removing the front plate).

<R54> So that the maximum power level of every ROBOT is the same, motors and servos used on the ROBOT shall not be modified in any way
A. The mounting brackets and/or output shaft/interface of the motors may be modified to facilitate the physical connection of the motor to the ROBOT and actuated part. , except as follows:
© FIRST 2010 FIRST Robotics Competition Manual, Section 8 – The Robot, Rev G Page 25 of 33
B. The gearboxes for the Fisher-Price motors are not considered “integral” and may be separated from the motors.
C. The electrical input leads on the motors may be trimmed to length as necessary.
The intent is to 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 FIRST will not provide replacements for modified parts.

Where the CIM motor is concerned, I would not consider its casing to be a "mounting bracket" or "output shaft/interface."

The Nippon-Denso motors contain mounting brackets that are obviously not integral to the mechanical operation of the motor. The CIM is not as clear cut.

[MrForbes]

Originally Posted by Madison

Do not take the motor apart as that is an illegal modification and you will be unable to compete with that motor.

What if I don't modify anything when I have it apart? I only press on a gear? (such as a Dewalt pinion)

[EricH]

Originally Posted by squirrel

What if I don't modify anything when I have it apart? I only press on a gear? (such as a Dewalt pinion)

Yeah, there's the rub. The question, which somebody who actually has a Q&A account should ask, is: "In the process of performing a legal modification to a CIM motor, it may become necessary to take it apart and put it back together. Is it legal to do so, provided that nothing else is done besides removing a piece, legally modifying it (e.g., adding a mounting hole), and putting it back in?"