On the back of a previous article about a repair I did on the rather wonderful Elna SP sewing machine, a reader got in touch. She was a genuine sewing aficionado and had several top of the range current machines, but she used the trusty Elna SP for many smaller jobs, where the other machines didn’t quite cut it.
All Elna SP machines are getting on a bit and parts are either re-manufactured, scarce or secondhand, if you can find them. Having said all that, a well-maintained Elna will run for many years and last much longer than new metal on sale now.
The foot pedal on this machine had gone pop, bang, finito. It smelled terminal.
Knowing that parts for this machine are rarer than hens teeth and I do like a challenge, I took on the job. I’m based in Worthing, West Sussex and the machine was located in Scotland, so after a short wait, the knackered pedal arrived in the post.
The pedal is held together with four small self-tapping screws and came apart easily. The reason for failure was two-fold. The copper leaf contacts had arced excessively and caused major pitting in the contact strip (see slide show) and the probably ensuing resistance had caused the main resistor to overheat, causing the winding to fail.
The contact surfaces were easy-ish to fix, or rather breathe new life into as all they needed was cleaning and re-shaping. The resistor was a bit trickier to mend. Getting hold of a replacement was going to be near impossible, so the only thing to do was to try and repair it. Without that particular style of resistor, of that value, it wouldn’t work again. Luckily, there was some excess resistance wire on the thing and I managed to twist it in to the broken section. Soldering was not an option, since the wire was an alloy that wouldn’t take to solder and in any case, these things get hot in normal service. I twisted both ends of the break to form a new section, while maintaining the same length of windings on the resistor, essential if I was to match or get close to the original specification. Difficult. Luckily, after a few goes, I managed it and the applied a little heat-conducting (and therefore dissipating) paste to the join.
With the pedal reassembled, I was only able to test it with my meter, since the sewing machine was far too heavy to post. The pedal tested as a closed circuit (OK), which was a result. I then had to wait for the pedal to be collected, taken back to Scotland and tested. Fortunately, my fix worked and the machine sprang in to life, without a hitch or missed stitch.
Now, a word of caution with this one. This is NOT the best way of mending something like this and all I’ve probably done is prolong it’s life a little longer. There are generic sewing machine pedals that would work with this machine and will be fine, when this one fails in future, but that’s not the point. The main thing is that something that was broken is now working and even if it’s not the best fix, at least it will run for a bit longer. Happy days.
Cost of replacement: (generic part) £15-30. Cost of repair, my time, a bit of solder and several cups of tea.