dikman

Handstitched, that is a brilliant idea!

Yep, they are a tinkerer's delight.

Many have used treadmill motors to drive small lathes and they appear to work well but Don makes a good point about why it might be problematical on a sewing machine. Given that servos are relatively inexpensive and are a simple plug-and-play it seems like the logical way to go.

Joe, most of these inexpensive/basic wood lathes have a threaded headstock, not morse taper. The simplest way will be to get a piece of suitable wood to make your burnisher from, drill a hole that is slightly undersize for the headstock thread and force screw it on. Then you can spin it up and turn it down to suit your needs. I just made a burnisher on the lathe and force screwed it onto my grinder. Runs at 2800 rpm but works fine, I haven't had any need for a variable speed burnisher.

I know exactly what you mean, it's nice slowly driving that big needle and heavy thread through thick leather. It feels like a real man's machine.

Same here. I spent a lot of time experimenting with extending the clutch arm, made a small speed reducer, fitted a larger pulley to the handwheel and in the end fitted a servo and reducer.

Chris, why not just post the file in the 3D section? Then it's there for anyone who wants it.

Congratulations! There's something satisfying knowing that you have a machine that can punch through almost anything!! All you need now is an ubiquitous 3/8" upholstery-class machine for lighter duties and you'll be set.

My thought too.

Another advantage of a home-made reducer is you can tinker with the ratios by changing pulley sizes.

That's neat, Don. I would imagine the only reason it hasn't been offered is cost? Plus, of course the bog standard servo is a straight swap for either a clutch or another servo motor, no messing around.

IF it uses an optical sensor. It appears that most, if not all, of the generic servos use Hall-effect sensors, not optical now.

You may find this site useful here in Oz if you don't have any sources close to you. https://www.vardhman.com.au/

Should be more than enough, I use a 550w (well, so they say, who knows what it actually is ) Lishui Skyrit on my Seiko and it goes through whatever I put under it with #138 thread. Of course, I do have a speed reducer fitted too.

"spinny thing"......

My Skyrit's are from Lishui and I've been happy with them.

Spyros, I reckon that's pretty good for the money, and if I didn't already have a large wet-wheel grinder I'd buy one. Here's a thought, if you've got access to a lathe you could turn a wood wheel to replace one of the wheels and use it as a burnisher.

My thoughts too. It would be an interesting exercise - but only if someone gave me the motor, I wouldn't buy one just to see if it would fit!

A direct drive sounds good but a "normal" servo is perfectly adequate for my needs, simple to fit and can be fitted above or below the table. If it needs to be replaced virtually any servo can be slotted in. It also allows a speed reducer to be fitted, which will give slower speed with increased torque, something you can't do with a direct drive. My servos can also be easily swapped amongst my machines, if needed, something I couldn't do with a DD. A DD certainly looks neat but adapting one to older machines could be a bit of a pain and from my perspective not worth the trouble. It would be an interesting exercise to try setting one up but I'm happy with my setup(s) so I'm not about to try. For a garment machine they may very well be a great solution but I'm not convinced about their suitability for leatherwork. Just my thoughts on the subject.

The "generic" push-button servos work well with a small motor pulley and either a reducer or large pulley to replace the handwheel. I know you said you don't want to fit a reducer, Chris, but you may not have any choice in order to achieve what you want.

That's a LOT of stamping!!!!

Brooks, they are beautiful! In answer to the OP's question, no reason you can't use a Dremel, but make sure it's a variable speed as the fixed speed version would be too fast. I normally do my burnishing on a bench unit but I use a Dremel for small and odd-shaped areas. I made a couple of wooden attachments for this.

Bargain!!

As far as I know there is no .stl file freely available for that gear ring. The chap who made it sells the kit so is not going to give out the file.

Here's a copy of the user manual to start with - https://www.manualslib.com/manual/1005412/Singer-Class-31k.html If it works with a domestic needle then it's likely that the needle bar has been re-adjusted and will need to be reset. You need to check the adjustments and timing of the needle and hook. As JJN said if you can set it to work with 135 needles then it will make life easier as they are a very common type. And in my opinion get rid of the old motor, it belongs in a museum as given its age the wiring insulation is likely to be brittle and cracking so potentially dangerous. A servo motor will make sewing much easier. There are guys on here who sew the sort of stuff you're talking about and hopefully they will chime in.