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More Sewing Machine Shenanigans

So, when last we left...me...I was delightedly exploring my new (and by new I mean 1930s) BSM 3a sewing machine and figuring out whether I could make the original motor work.

I'd decided to try connecting it directly up to the mains and seeing if it would run at all before deciding whether to order a new pedal for it. Unfortunately the chap who sold it to me had snipped off the damaged power cord very close to the casing:

I carefully strip back the tiny amount remaining on the three wires. The sheaths are old and very soft rubber, and break further back than I intended, leaving even less insulation - there's now a distinct risk of a short between them.

I have a spare power cord from an old microwave, and strip the ends back ready to attach, but looking at the stubs on the motor decide to take a safer and easier tack than trying to solder to them and keep everything insulated.

Instead I cut off the section of microwave cord I've already stripped, remove the outer sheath and strip the other end of the three inner wires....

...then solder one to each stub, and carefully sheath it with heat shrink tube, pushing it down as firmly as I can to the base.

I'm left with three flexible but fairly robust wires I can join onto without worrying about them shorting out. And actually one of the neatest soldering jobs I've done, which I'm pretty pleased with.

The join to the rest of the power cord is a bit less neat. In my defence, it's only supposed to hold just long enough to test whether the motor spins up - once it's tested, I'm expecting to break it apart again and install the foot pedal with some extra cord and much neater joins.

I plug it in with much trepidation and...nothing happens. Which is when I finally realise what that black housing on the side of the motor casing is. Unlike the more modern motors I've looked at where the pedal is in line on the power cable itself, this was designed to have a separate pedal which plugged into this socket, and without it the motor won't run at all.

I can buy a pedal and try wiring it in there, or just try bridging the pins in the socket, but I'm getting a stronger version of the feeling I always have that me goofing around with mains voltage is a bad idea, and I'm starting to doubt my initial belief that if a shorted pedal doesn't blow up the machine a direct circuit with mains voltage will be fine - a shorted pedal is probably still providing some resistance.

In the end, I decide to take the easier route and treat the old girl to a brand new upgrade, especially since I've found a substitute motor for only £26 with excellent reviews.

The motor is a nice heavy solid-looking unit with all the necessary fittings and fits neatly into place using the original screws from the machine.

...moment of truth...

Deep joy!

There's still some resistance at that same point in the rotation of the machine which makes it hard for the motor to get it started and causes slipping at low speeds. However, after a bit more exploring I find this reciprocating rod under the body which doesn't seem to catch any of the oil from the various holes, and with a couple of dabs on the bearings it's further improved.

I also switch the cheap pink plastic belt back to the rubber one which came with the machine - it's quite badly perished but still hanging on and provides much better traction - and find yet another oil hole next to the shuttle. With a few drops of 3-in-1 in this one, the action is almost entirely smooth - in fact I think this is where the majority of the friction was coming from.

Just realising how many places you need to oil the machine makes you aware of the complexity of the mechanism - how many places metal has to move on metal to exact tolerances (all manufactured without the benefit of computerised equipment or much of the sophisticated production line gear we take for granted these days) for the machine to work - and she's still running almost as smoothly as she was over 70 years ago.

Finally, and with the help of a couple of videos by a lovely woman who may actually be the Queen's elocution teacher, I get the machine threaded and a piece of scrap corduroy under the foot...

...and produce a couple of wobbly but robust lines of stitches. Happy days.

See you soon!


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