dikman

I think I've finally got this thing to where it should do what I want (the phrase "famous last words" sprang to mind when typing this!), courtesy of my speed reducer. The servo motor has a 45mm (1 3/4") pulley, going to a 120 mm (4 3/4") pulley which drives another 45 mm which goes to the handwheel (about 3" I think). This lot, coupled with the servo, lets me run about 1 stitch per second and can drive through 1/4" hard veg with no effort at all. I'm pretty sure it will do 3/8" (if I want to) but the limiting factor is probably going to be the height of the presser foot. No matter, it should be more than adequate for my needs.

I've done the same trick using a screwdriver, place the blade on the object under scrutiny and stick the handle against your ear-hole! (Don't try it the other way around, not a good idea).

I like it, a nice little piece of gear. If the price was right I'd buy it too (just in case? ). Probably worth it just for the pulley stack.

That Juki sounds nice, no belts to worry about. My little servos have a few parameters in the "manual" that look interesting, but there doesn't seem to be any way to access them (which makes me wonder why they put them in!!).

Makes my 8" pulley look awfully small!!!!!

Oops, you're right about the needle plate (and feed dog). It's a bit hard to tell about the feet, though, but they look a bit on the small side. The fact that it has that arm cover plate, however, suggests that it was originally used as an edge binder. It also has the flip-down edge guide (which you wouldn't need with the binder). A peculiar mix, but could be a good buy if the price was right.

Further confirmation that needle positioners don't like speed reducers being fitted! I can't fit a larger pulley to replace the handwheel on my Singer 211G166, so although the servo has slowed it right down I figured that fitting a reducer would help with low speed torque. I made a reducer and using what pulleys I had handy gave me a 2.2:1 reduction. I fired it up and the needle moved a couple of times, went clunk and it all stopped. Turned it off, tried again and this time tripped the cct. breaker in the shed plus the bigger one feeding the shed itself!! (That one had me worried). The display showed an E5 error message, which indicated a needle positioner fault. I reset the breakers, disabled the positioner and tried again and this time it worked. It was about this time that I recalled this posting...... I have a choice - needle positioner and whatever speed setting I can get from the servo or no positioner + speed reducer + whatever setting I can get from the servo. I have another pulley coming that will give me a 2.7:1 reduction, so I'm thinking that I will be better off with the reducer and the reduced low speed and increased torque it will give. (Plus I put too much effort into making the reducer to not use it.....).

What they said. From my limited experience the cylinder arm has greater overall versatility.

Also, that one is set up as an edge binder. Unless the other parts are included you may have to buy extra feet, needle plate etc.

Very neat! A lot neater than mine, but then my machine has been well used, so what I made suits it .

Clamp the awl blade in a vice, between lead sheeting to protect the blade, and carefully use two screwdrivers, one either side, to lever the handle away. It's a pretty safe bet that the blade is only driven in to the handle as a friction fit.

Another great idea! I didn't think of using the buffing wheel cone!

Ferg, in my case it is a reverse thread - one end of the grinder shaft is a right-hand thread, the other is left-hand so anything screwed onto the threads will tighten with the rotation (this appears to be normal, as all my grinders are like this). I made a couple of these burnishers and haven't had any problems with them. They don't need to be ultra-tight, so the thread in the wood doesn't have to be deep.

Eric, that's a mind-boggling array of......things.

Thanks Eric, good enough reason to not waste time on it.

No idea about the increasing the bobbin size, sorry. (Although maybe I should look into it...one day). As to the belt, that could change depending what size pulley you use on the motor. I found the best way was to use a piece of rope around the pulleys, tied off on the overlap with a couple of cable ties, and then took that to a car accessory place and got them to measure it and found a belt that was the same size (or very close). If you do this set the motor adjustment rod about midway first. Also, take the old belt in to get the correct width (although slightly wider will still work).

I turned my own wooden burnisher on my lathe, and while it was mounted in the lathe I bored the hole slightly undersize and then turned it by hand onto the threaded end of the grinder shaft, effectively cutting the thread into the wood.

Yep, your drawing looks identical to the Pfaff.

While the Pfaff has the "synchronizer mechanism" fitted as part of the machine, besides the plate you listed you also need a fitting that screws on the end of the plate to actually turn/fold the binding tape, different shaped inner/outer feet, different needle plate and a different feed dog.

With all those shiny bits it looks a bit like a retro coffee machine/coffee grinder....

Nice choice of pulleys, unfortunately for me the price of shipping ($85!!!) is a minor problem. The largest I found out of China is a 120mm (free shipping), so I figured mounting that on a shaft with a 45 mm should give me some speed reduction and coupled with a servo with another 45 mm on it will give the Singer a bit more low end grunt. It's not too bad now, but it won't do any harm to fit the reducer.

The beauty of this is that there's no hassles trying to mount a speed reducer and line up the belts. The servo motor's pulley is less than 2", so this combo gives me lots of low end grunt. So far the Pfaff seems to love it. I figure if it's good enough for some of the bigger machines to have a large pulley, it's good enough for the little Pfaff! All it cost me was $12 for a bigger belt. I just wish I could do the same to the Singer 166, but I can't, so I'm in the process of making a speed reducer (I'm scratching my head trying to figure out how to mount it).

I was going to suggest the same thing. I have a small gas torch (happens to be a Dremel, but there are plenty of others out there) that gives a pencil thin flame. That will let you get it exactly where you want it, without flame splashing around everywhere. As Wiz said, heat it up, tap it a bit, let it cool and see if you can wriggle the screw back and forth (just work it slowly). If you have any of that "cold in a can" freezing spray you could try heating it and then zapping it with the cold straight away, sometimes that can help break the seal. A bit rough, but you could also try holding the screwdriver in place, twisting and tapping that with a hammer. While not as effective as an impact driver, it may help to start it moving (might not do the screwdriver much good, though).

The pulley is from one of my "bits and pieces" boxes - the one for pulleys and bearings. As to where it originally came from, I've got no idea! It's fairly heavy cast steel, so gives a bit of a flywheel effect. When I removed the existing pulley/handwheel it left a 1/2" shaft, which just happened to be the size of this pulley (I have a nice alloy one that I intended to use - same size - but it has a large centre hole and I would have to make a sleeve for it. This seemed easier). Might look a bit odd, but it works. As for pushing the limits size-wise with the leather, yep, I'm under no illusions about what I'll be able to do with the machine. It's more a matter of experimenting to find its limits. It has no problems pushing a needle through the thick stuff, but actually sewing a stitch may be a different matter. If I can use 138 thread through slightly thinner stuff then I'll be happy with that.

I'm with Uwe. If you didn't release the linkages first they would have bent when the table was dropped, and if you did release them then they need to be re-aligned to reduce the rather acute angles showing on the first photo. The linkages look pretty simple.