Singer 51W59

[Wizcrafts]

Dikman;

The thread tensioner unit from the Singer 201 is setup for domestic cotton or polyester thread. The spring is probably very light duty. When you crank it down hard to try to tensions bonded thread in leather, you are compressing the coils too far, causing a disruption in the Force. There is no give at all if the coils are all the way in. Further, there is no room for the thread release to push the disks apart.

You should try to find an industrial tensioner unit with a stronger coil spring. Also, make sure the check spring has enough travel and tension. It was probably setup for light duty thread.

[dikman]

Thanks Wiz, I was wondering whether that could be the case with the coil spring. Looks like I'm not finished with it yet. Oh, and there's no thread release on this machine.

[dikman]

I found another cone-shaped spring that fits inside the original (!) so I've added that to give more tension. Seems to work at the moment, but when I ran some stitches on a single layer of 4 oz leather I noticed that if I pulled the bobbin thread (after I'd cut the thread off the machine) that it pulled through the top thread of the last couple of stitches. I'm wondering if the needle is making too big a hole. Except for that it looked good.

I've also fitted a larger pulley to the handwheel. The original was 2 1/4" (inside groove measurement) and the new one is 5", so that has slowed it down quite a bit. It was still hard to start slowly, however, and would take off fairly suddenly. I then realised that with the motor off it was very hard to turn the handwheel, so I started looking at the clutch arrangement. Once I'd figured out how it was supposed to work, I got stuck into it. The friction material (asbestos?) is in good condition, but there was a high spot that was dragging when turning the pulley. The yoke it's mounted on looked like it was supposed to slide slightly, but was extremely tight. I stripped it down, lubed the slide and re-adjusted the support screws on the yoke.

That made a huge difference, as it is now much smoother when it engages. If I can fit a slightly smaller pulley on the clutch shaft that should also help. A handbook on the motor would have been nice, but I can't find one. Yes, I know, a servo motor would be nice but they are rather expensive here, unfortunately.

Next step is to locate some needles. It appears to use an obsolete class of needle, according to the people I spoke to, but they said to take in the existing needles and they should be able to sort out what I need.

[dikman]

With the larger pulley on the handwheel, it works great for sewing denim, giving pretty good slow speed control. Still not so good for leather, however, due to the increased resistance to the needle going in. So, I made up a step-down pulley from my collection of "stuff". The wooden mounting is rudimentary, just to see if it would work - which it does. Went through 1/4" of leather ok, but when I tried slightly thicker the needle snapped in three (probably need a thicker needle for this)! I'm not too worried about that, as I'm probably starting to push it beyond its limits.

The shaft is from the 201K that I gutted, turned down a smidgin to fit a couple of bearings from my spares box. One of the pulleys didn't have a centre boss, so I turned one up for it. Now I just have to figure out a decent mounting for the pulley arrangement. Steel would be nice, but will be a lot of work making the clamps/mounting for the bearings, so I'm thinking making a better one from wood might be adequate (after all, there's no real stresses on the thing).

[Northmount]

Old timers have used a lot of different things for bearings. Oak blocks lubricated with tallow. Wood blocks lined with bacon rind.

Tom

[dikman]

Pondering this, I decided that steel is really the best way to go, so to keep it simple I basically clamped each bearing between plates. Lots of hole drilling, but it's worked out very well. The machine is now very slow (compared to what it was) although it still has a slight problem if the leather is dense/hard/too thick - but I'm working on it. I figure an even larger pulley on the handwheel will not only slow it down to a crawl, but give me even more torque.

The belts are round cross-section neoprene rubber. This stuff is oil-resistant, has some stretch but best of all to make a belt it's just a matter of cutting to length and super-gluing the ends together.

A couple of photos for those who are interested, showing pretty much the finished product, there's not much left to do now but work out what size needles and thread it can handle. (It came with a cone of thread with a faint 40 on it, which appears to be Metric 40/T70/#69).

All been good fun.....

Edited August 11, 2015 by dikman

[dikman]

The final piece of the puzzle - Wiz mentioned a tension release, and I said it didn't have one, which is quite true seeing that I don't have the original tensioner. Anyhow, it got me thinking that it would have had one (once), being an industrial machine. But I couldn't figure out how it would work (certainly not the same as the domestic tensioner that I fitted). The parts listing didn't show anything that was obvious, so I pulled the needle end of the machine apart to try and figure it out - like most things, it was pretty obvious once I worked it out!!!

I bought a Singer 478 for $10 (!) so that I could get another tensioner assembly and should be able to modify it to work like the original. Only problem is that they started using plastic gears in these machines and that included the part in the tensioner that is used to adjust the thread controller spring - and, of course, it's split. I should be able to fabricate one from aluminium, as there's no real stress on this part, and with a bit of luck should be able to get the tension release working.

I haven't done any stitching yet, but used it on the holsters I'm making to pre-punch the stitch holes. I was quite impressed, as I could get it to chug along quite slowly and get a nice even set of holes. It was rather nice watching it go down, up, feed, down, up, feed....all at a very civilised pace!

[dikman]

At the risk of boring everyone, I decided to experiment with thread/needle size. It came with #16 needles and #69 thread, which is what was used to make shoes with, I guess. I bought some #138 thread (on special for $14 for a cone, so I couldn't help myself). The thread actually fitted the #16 needle quite well (no sign of dragging), so I gave it a go on a piece of old stiff 4-5 oz leather. It actually went through it ok, but wasn't pulling the bottom thread into the hole. I put this down to the needle hole being too small for the four strands of thread going through it. Or maybe the leather was too stiff?

The only bigger needle I have is a #21, so I tried that. It worked fine if I turned the wheel by hand, but as soon as I tried using the motor (very slow speed) I started getting runs of dropped stitches, looks like the hook on the shuttle isn't grabbing the thread. Strange how it worked with the smaller needle, but not the bigger one. I'll get some #18 needles next week (out of stock at the moment) and give that a try.

I was pleasantly surprised that it worked at all with the thicker thread.

[Northmount]

Is your presser foot lifting with the leather when running with the motor? That will result in skipped stitches. Try tightening the presser foot spring down some.

Tom

[dikman]

Yes, it is lifting with the bigger needle. Good point. More experimenting today.