Sizzling Elna Supermatic

Uh-oh. Here I go again--elbow deep in my Elna Supermatic.

I can't begin to tell you how many countless hours I've spent disassembling, reassembling, and adjusting this machine. It's not that there was so much wrong with it to begin with, but it did need some routine maintenance. The bobbin/race area needed cleaning up, and the old motor pulley had a flat spot, which made the machine sound like a weed whacker when running.

Then I decided to upgrade the cam holder. This Supermatic had the original, screw-down cam holder. The cams were a pain to remove. Later Supermatics came with a push-button cam holder--when the button is pushed, the cam pops up on it's own. Long story short, I upgraded my machine with the newer style cam holder, since all the cams I had were intended for this type anyway.

I did all that work on it, and then it sat unused because of the melting noise suppression capacitor on the inside of the machine. This capacitor prevents interference with other appliances in the home, like the radio, or T.V. Take a look at the photo on the left and follow the white wire away from the silver, flat-head screw (on the right side). Where this wire ends, you will see the bottom of the capacitor, and a large glob of brown wax. You can also see the wax has splattered around the inside of the machine . . .


 . . . and on the inside of the base of the machine.

This was a problem from the first. The machine sizzled the first time I used it. It was the capacitor. The bottom was cracked, and some of the wax had melted out of it. And once I heard that the darn thing could actually explode unexpectedly (and very loudly), I became afraid to turn on the machine. What can I say? I'm a chicken.

Now that I've been doing a lot more decorative stitching, I want access to all those fancy stitches I could be stitching out on my Elna Supermatic. So, I decided to disconnect that pesky capacitor. Even after examining wiring diagrams, though, I wasn't sure if disconnecting one wire from the terminal would be enough. And I wanted to make sure that no more power is running through the capacitor.

It has six wires: three on the top, three on the bottom. Only two are easily accessible from the bottom of the machine. Space is tight around the motor inside this machine, and I couldn't see where the rest of the wires were connected. After some disassembling last night, I found I couldn't get the machine apart because two of the screws holding the top and bottom half together were really stuck. Then this morning, it occurred to me.

I have one of these. So I used it, and a flashlight, to see around the motor. I could finally see where the three top wires, and one bottom wire were soldered--none were attached to the power supply.











So I cut out the two white wires from the bottom. I should probably mention at this point that  the machine was unplugged and any remaining charge in the capacitor had plenty of time to dissipate. As you can see, one of the wires is discolored. This is the wire that was attached to the part of the capacitor that was melting away.

And this is what the inside looks like now. When I first plugged it back in, it ran on it's own, and I was sure I had just made matters worse. However, when I took the bottom of the machine off again, I noticed I forgot to put the spring back on the peg. See it dangling there at the top of the photo? It supports the weight of the knee lever, and keeps it from running the machine until it's pushed.

I put it back, and the knee lever worked correctly again. After that, I did an hour or two of sewing, stitching out some cam samples, playing with the tension, and some of the feet. There was no more sizzling noise coming from the machine. I didn't electrocute myself. Nothing exploded, or caught on fire. So--I would call this project a success! And (bonus) my Kenmore circular decorator fits this machine--just imaging the possibilities. I'm glad I can use my Supermatic again. :~)