Transplanting an Efka Servo

[NCArcher]

I mentioned in another thread that I had transplanted an Efka servo from one machine to another. I thought others may benefit from my experience.

It was reasonably easy to do and took me a few hours all up.

I purchased a Consew 226R for a really good price but it had the original clutch motor. I had a Juki 555, that I picked up for nothing, that I had been using for light work that had an Efka servo motor.

As the Consew was going to be my main machine I decided to have a go at transplanting the servo from the Juki over to the Consew.

Getting the old clutch motor off was no problem and was straight forward.

Getting the Efka off the Juki was another matter. The Efka, while on the Juki, also controlled a number of other things like an automatic backtack and a thread cutter. Once I sorted out all the cabling it was OK. Just needed to work out what I needed to keep and what I could junk.

The Efka is quite large and heavy and I struggled to get it onto the Consew table. With a bit of swearing, and a few ratchet straps to hold it in place while I bolted it in, I got it done.

The Consew has a nice cast iron base, which I wanted to keep, but that meant that room was at a bit of a premium. It took a bit of fiddling to get the motor in so that it cleared the cross brace at the back and still allowed the knee lift to work.

I had to tilt the motor a bit to make it fit which meant that I had to enlarge the belt slot in the table. I have plenty of woodworking tools so that was no problem.

The motor also has a combined needle positioner and speed feedback encoder. I tried running the motor without it but it wouldn't even turn over.

I then had the brilliant idea of just plugging the encoder in to get it to run and work it out later. I couldn't mount the encoder on the handwheel as the Juki had a special fitting for mounting the encoder and I couldn't swap the handwheels over.

I turned the machine on and the motor immediately ramped up to full speed and stayed there no matter what I did. The motor had seen that the encoder was plugged in so was waiting for a speed feedback. When it didn't get any feedback it assumed that it wasn't going fast enough so went faster and faster and faster. 

So I needed to work out how to mount the encoder. 

The encoder was mounted on the Juki by way of a bracket that was fixed to an extension  of the handwheel shaft.

I removed the bracket and drilled and tapped holes in the Consew handwheel to fix it in place.

It also need a way to prevent it from rotating.

I initially drilled a hole in the table and fixed a piece of all thread in place (there's a slot in the encoder for this) but it meant that I had to disconnect it whenever I wanted to tilt the machine back.

I changed that to a bent rod mounted on the machine so that it moves with the machine when I tilt it back. I had to drill and tap a couple more holes for this bracket as well.

The last mod I had to make was to the foot pedal connection. The Efka is a lot bigger than the clutch motor and the rod was a lot further over the pedal connection.

I made up a temporary clamp to hold the rod to the pedal. I will bend up a rod to suit sometime in the future.

The motor works beautifully. No programming on these ones. A few switches and trim pots to set the min and max speed and the needle positioner settings. I have it set at a minimum of around 1 stitch/sec and a max of ......?? much faster. I can single stitch if I'm careful with the pedal.

I had to recalibrate the needle positioner but that is a 2 sec job.

All in all, very happy with how it turned out and how it performs.

 

Edited August 27, 2017 by NCArcher

[dikman]

Thanks cobber, excellent write-up. I've seen these 555's come up from time to time, but have ignored them because they don't suit my needs.I'll keep my eyes open now, 'cos if I can get one (or similar with the Efka servo) at a good price I now know I can use the motor.

That stand looks the same as my Singer, except without Singer on it. Really nice stand.