We are wondering if this cim motor mounting idea was legal.
There are two bolts and on the back of the cim. Could we take those out and replace them with longer bolts so that we could mount it to a plate. This would not change any functionality of the motor it would just be used for mounting
R30 The integral mechanical and electrical system of any motor must 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.
B. The electrical input leads may be trimmed to length as necessary and connectors or splices
to additional wiring may be added.
C.The locking pins on the window motors (P/N: 262100-3030 and 262100-3040) may be
removed.
D. The connector housings on window, door, windshield wiper or seat motors and Bosch motors
(P/N: 6004 RA3 353-01) may be modified to facilitate lead connections.
E. Servos may be modified as specified by the manufacturer (e.g. re-programming or
modification for continuous rotation).
and then the note below it
The intent of this rule 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 for the previous KOP Window motors and the Bosch motor,
the gearbox is considered integral to the motor, thus the motor may not
be used without the gearbox.
I believe that replacing the bolts with longer bolts would fall under Mounting bracket but i would be more comfortable with creating a mounting bracket to wrap to the front of the CIM motor to attach to its normal mounting holes.
Read rule R30. Expect it to generally be interpreted literally. Changing out the bolts in back of the CIM could be seen as modifying the integral mechanical system. At very least it is chancy.
R30 The integral mechanical and electrical system of any motor must 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.
The bolts that go in from the back and hold the CIM motor together, in my opinion, are an integral mechanical part of the motor and not intended for use as a “mounting bracket” or “interface”.
The front does not have integrated bolts that people use - it has tapped holes designed for use as a mounting bracket.
If you do want to secure the back of the CIM you could always attach to the from of the CIM motor and have a bracket around the circular extrusion on the back of the CIM to keep it stable and supported. I’ve never really taken a CIM apart so I don’t know exactly what those bolts hold on the inside or if its just a cover.
it seems like it would be legal according to R30 since we would not gain any weight advantage and if anything we would put stronger bolts in there so the structure would not be compromised. However it seems like according to everyone there is no clear ruling on this and it would be left up to the inspector which is a little risky
Keep in mind the blue boxes are amplifications and not actually the rule. Those bolts hold the motor together. While I agree that it can be done safely, it pretty clearly is a modification.
Keep in mind those bolts are probably metric. In either case long small diameter bolts aren’t standard stock. Without knowing the strength/grade of the original, how do you know your bolt is stronger? More importantly how would the inspector?
While this is the sort of question the Q&A punts on, If I where going to it, I would ask the question
we have made a ball shooter that has the motor inside the wheel. So that the end is just sticking out. We have another method to mount to the back however this method packages the best.
Changing the housing bolts is not the same as changing the mounting bracket.
It could be easily argued that the back housing is not intended to be used as a mounting bracket, and thus does not have the structural strength the front may have (which is intended to be a mounting point).
Any side forces on the shaft will be applied at the front end of the motor, by definition. Securing the motor by the front end will allow the mounting system to resist these side forces better than securing the motor by the rear end. Another way of looking at it is that the lever from where the forces are applied on the shaft is very short if the motor is secured at the front. If the motor is secured at the rear, the same force has a much longer lever to cause the body of the motor to deflect. This could result in your pinion gear not meshing. You may get more vibration, especially under load. The higher torque on the two mounting screws at the back could cause the rear plate of the motor or the mounting plate to deform.