My machine is haunted
 

Hi, I have a 1956 singer 99k electric and if I leave it plugged in when not in use it starts to sew on its own and I have to unplug it and leave it for a few minutes before I can plug it back in again.
Has this happened to anyone else and what should I do ?

Yes it has. The most common reason is deteriorating capacitors. They are square or round things placed in the pedal or near the three pin socket under the hand wheel on knee lever models. There is info to be found on the web if you know what to search for. Not all pedals are like, there are a few varitions on them, some have one, others have two. You can simply remove them and it will be fine. You can replace them with new to. They are there to prevent electrical interferance in other appliances like TV and Radio. Here's a blog post on it.

Those capacitors are for noise suppression. The machine will run without them, but expect interference on wireless devices. I don't know how much power-line noise interferes with modern high-frequency communications like Wi-Fi, but it will affect lower frequencies like radio and television.

A electronics shop should be able to source a capacitor for you. Try to get a poly-film capacitor as they don't have any polarity like electrolytic caps.

Been there with my 301! Very spooky when it happens... I replaced the foot pedal and she behaves now.

errr Capaictors in a 1956. I'd be surprised. Hmm I guess the Chevy 265 had a condenser ( actually a capacitor) Anyway, yea,. A new foot pedal may do the job. Welcome aboard, Andyb

I have a 1934 99K, it came with motor and lights, and the small solid hand wheel. When I got it, it had two cylinder shaped capacitors (not sure if it's the correct term in all cases), just a bit larger than an AA battery, a wire comming out of each side of them. I guess they can have been a later additon, and I always thought they looked a bit odd. Later I have realized it was the regular way about it back then. They were wired on to the electrical socket, just under the hand wheel.

My machine blew up with a bang and it was caused by these cylinder shaped thing. There was literally a bang from the machine, a fuse blew and the lights went out, but no visible signs of an explotion. I handed it in for repair and rewiring, and it came back with all original parts (motor and knee cotroller) except for the old cloth covered wiring, the capacitors were just removed, not replaced. I was afraid the repair guy would return the machine with a note saying it wasn't repairable, but it came back in working codition with a stitch sample under the presser foot.

The old bakelite pedals work fine, as well as the metal versions, it's not a must to replace them, but they can need need a good cleaning and sorting out. I know the new pedals should in theory be better, but for some reason it isn't always the case. You can end up with just the same speed issues as an old one that needs adjusting.

When I first got my Viking Epic, my foot pedal would continue to sew when I took my foot off. Had to punch it with my foot to get it to stop. They replaced my foot pedal and I no longer have the issue. It happened at the quilt retreat so thought it was because so many of us were plugged in at the same time.

Capacitors are a finite item because the materials used deteriorate over time.

Really old capacitors used wax paper as the separator, and those would fail as the wax melts away from hot climates. It's also why antique tube radios shouldn't be plugged in until a technician looks it over.

You never want to leave the sewing machines plugged in while unattended.