oreo1912

My 500A has a speed problem. When I am running it, it will speed up or slow down without regard to foot pedal pressure. Is this a motor or a foot pedal problem? Can a foot pedal be taken apart and cleaned?

bkay

Yes. I've done it. This Youtube tutorial is long and detailed. There are some shorter ones, but I can't find them. If I remember correctly, they are all titled for the 401, which has the same controller.

bkay

Quilterman

It can be a motor problem. The bearings can start to lock up or if the machine has been over oiled the oil gets down
into the brushes and on the commutator. The motor can easily be removed. Then it can be taken apart and degreased
with an electrical contact cleaner and then the commutator and brushes lightly polished with a 600 grit emery paper
to remove oxidation caused by the oil.

This sounds like a big procedure but actually isn't hard to do on these type motors.

Mickey2

Bad capasitors in the pedal can cause speed issues like you describe, it's easy to remove them. You can replace them with new if you want, but they work fine with out too. If it's the case, it will likely get worse and you will be forced to sort it out.

Another thing is basic oiling and cleaning, dry and gummed up parts can make a machine misbehave in all kinds of ways too.

Cari-in-Oly

Mickey it's very rare to find capacitors in any Singers in the US.

Cari

Dressmaker

I was just having the same issue with my 500a. Make sure the foot peddle is plugged securely into the side of the machine. That was the problem i my case. Good luck.

oreo1912

Many thanks for the suggestions. Already checked the plug. I just oiled and cleaned it last week. Think I will investigate the foot pedal cleaning.