And before you ask about electrical noise from the motors, heres what I posted elsewhere about your question
How quiet do you want the motors?
Granted I understand electrical feedback through the circuitry, but that has
NEVER been an issue for any of the JRK sim builders. We use 5k pots as recommended by Pololu. I would be interested if you have found "noise" causing a problem with the jrks. No one else has.....
Myself and others have run the JRK down to 5ms response rate with a SMOOTH motion, so electrical noise is NO ISSUE.
Dont add capacitors on the motors anywhere, even that will cause an earth leakage and effectively destroy the jrks.I found on the boat winch motors a little capacitor across the terminals to reduce noise in the car, but it had to be removed as the jrks were playing up.
If its mechanical noise, it may be the metal gears you have fitted.
Finding a "silent" motor, well good luck. Some motors make a bit of noise.
I've used wipers in the past, and some were a tad noisy, but nothing to write home about.
The big worm gears are very quiet, just a normal motor noise, but again all good.
I have heard the boat winches people use are noisy, but thats from the gearing, not the motor itself.
Otherwise, good job there....