How to service small DC Motors (running slow)

The motor on your tape drive can develop internal friction on the brass bushing. This can be observed by the tape transport speed sounding slow. While these motors are small they are very reliable and can be serviced. The object of the task is to ensure the shaft rotates with minimum friction while preserving the contacts.

Best to eliminate other issues first;

1. Pinch roller (Replace or test with finger tip should take a fare amount of force to stop it turning)
2. Rubber Belts (Replace or ensure they aren't slipping and confirm Auto Stop works)

The motor can generally over come other friction in the drive system. Now read this tutorlal here;

http://www.instructables.com/id/repairing-a-small-DC-electric-motor/?ALLSTEPS

There is a more appropriate motor at the end. My tip once all cleaned re assemble the Brush Gear on the commutator ring first and then slide the casing over the rotor. This way the contacts will maintain the correct position and avoid damage. As per this pic;

I found a motor that was running slow, as it turns out there was an issue with the commutator. Here's how I fixed it;

Hopey, In most cases opening the motor can be very tricky. Some are sealed very tight and so hard to separate it. Even removing the brass alloy pulley can get very tricky.

I am not saying it cannot be done, but it is not at all easy.

That motor in the video is a simple cheap toy motor. It is pretty easy to work on it. This is not the case with cassette motors.

That may be true Royce, but it's the only way to fix a motor without an adjustment pot.
I have one like this in my Hitachi, too much work so I just left it alone and will use MP3 cassettes in it.

BoomboxLover48 said:

Hopey, In most cases opening the motor can be very tricky. Some are sealed very tight and so hard to separate it. Even removing the brass alloy pulley can get very tricky.

I am not saying it cannot be done, but it is not at all easy.

That motor in the video is a simple cheap toy motor. It is pretty easy to work on it. This is not the case with cassette motors.

Click to expand...

Once I find one that needs work I will attach photo's the principals are the same.