AlZilla

Is that a very long strap, doubled over around the buckle to give you 2 layers? Very tedious work. The overlapped stitching isn't noticeable until you look for it. Very fine work!

Is that a clutch motor?

You'll be glad you did this repair. It's not nearly as difficult as it seems. I think your machine uses Allen screws, if I remember right. If it's slotted screws, you'll want good, hollow ground screw drivers in the right size. Let us know your it goes. Maybe you'll inspire the next person.

I wrestled a little with this post yesterday and decided not to respond further. To me, giving (whether a brand new car or answering a question like the OP presented) is done without expectation of any return or even a thank you. So, I wouldn't boot someone for not checking back in. An acknowledgment and thank you would certainly encourage more dialog, but people seem to be pretty self focused these days. Maybe he forgot where he posted the question ... It was really kind of a fragment of a question anyway, not really enough info to give a coherent, specific answer. I think Chuck nailed it - pretty much any information a person needs is somewhere here.

I'm pretty cavalier with the domestics, but the industrials I (usually) shut off. A good reminder,

Yep, that is a lot of work. Very nice work, too. You would be doing all of humanity a favor if you uploaded your images directly here. Unless you plan on leaving them on that 3rd party site for all of eternity and saddling your descendants with maintaining them in perpetuity, they'll disappear at some point in time. Imagine how disappointed someone is going to be 400 years from now, not knowing what that ancient belt looked like ...

Exactly. And people will spend long money for the latest and greatest. Thousand dollar cell phones when a $40 phone does the same thing, handgun optics that cost more than the handgun they're attached to, the list goes on. I believe what OP was saying is that they already have a 50 RPM start speed, so no need for a 5:1 gear reduction. I also think there's a language barrier involved. I don't know any more than the rest of you how sincere he is, but it's a worthwhile discussion. Definitely got me rethinking some of my choices. Wiz's comments above have made me wish I hand't turned my nose up at those outdated brushed servos! EDIT: Let's not forget leather stamps. Look how many people buy $50 big name stamps when a $7 Hobby Lobby stamp is pretty close.

I wouldn't get too wrapped up about price. Lots of people splurge on expensive stuff for their hobbies. Lots of people here drop thousands on a machine anyway, what's a couple hundred more for a cool motor? And bragging rights? I've never found easy availability of the HM-750 in the couple of years I've known about it. I don't even know what they retail for, so will we even be able to point and click the new wonder motor you guys are designing?

Looks like someone moved the hook saddle over, trying to disengage the left hook. You can see the extra gap between the needle plate and bobbin case. That lets the tab on the bobbin case hang up on the stops under the needle plate. Might be an easy fix. Whoever had it before was sewing single needle. Another tinker while I await the motor ...

Some follow up would be nice just to see how it actually worked out. But in the end if someone asks about XYZ sewing machine for a particular use and gets good advice, then it's here for the next person who comes along wondering the same thing. This place is pretty much Encyclopedia Britannica for leather sewing machines.

You never know if the person is visiting w/o logging in. It always does seem like they should at least acknowledge the responses. But, that's the world we live in now, I guess. Get off my lawn, too.

It does appear to have been used in a few different machines, lucky for me. I think this machine is the ancestor of the W&W D12, except the couple of pictures I can find of the D12 show a single bobbin serving both needles. This is by no means definitive, just me searching the net.

Thanks for taking the time to send this along. It's quite close, a good clear copy and has an Adjusters section, which I don't have. Very helpful!

Here's what the needle and foot area look like.

No, I guess I was unclear. OP needs to pull the chain for his foot lift. I'm suggesting he could engineer a pedal similar to what I'm doing to pull down the lever to control the servo motor on my project.

Just a nothing special bog standard servo from ebay: https://www.ebay.com/itm/356814829633 It says it's 750 watts but I bet when it gets here it's 550. It's got a 2 to 6 speed reducer already.

I think you're seeing the jump foot. I'll get some better pics of the needle area. I got a close enough manual here: https://www.universalsewing.com/parts-lists/singer . I got one for a 21W that has what I need. I had forgotten about that page. Sadly, all the downloads are randomly named so need to be "Save As"ed. I think I'm going to need parts for the left hook assembly but it looks like there are plenty on ebay for the 21W that should fit. It looks like in order to change the spacing of the needles (Gauge) it's going to require a presser foot and needle plate for each width! The good news of that is that very tight spacing between the needles and holes should contribute to a nice stitch. It's waiting for it's servo motor ... patiently.

Unless you're going to sit at that machine, I think a knee lift is out. I have a broken bass drum pedal I'm in the process of adapting to operate the servo motor on a sewing machine. The "beater" is broken off, so I'm just going to attach the pedal frame to the table legs and attach the servo motor arm to the pedal. Maybe this pic will inspire something. Edit: I just saw your stirrup idea. That might work, too, if you could keep it from swinging all over the place. Maybe a chain guide of some kind down low, limiting it's swing. Great idea.

Looks like a reverse lever half way up on the right hand side, to me. US shipping is listed a $123. Your tag for @RockyAussie didn't work right. Start with the "@" followed by the users name and select them from the drop down. I'll be interested in his thoughts, too.

It's really hard to tell what the specifications are. I'd lay that responsibility off on your dealer, since you have one. I saw someplace that it could handle thread size 20/3 ... whatever in the world that is! It should specify a range.

Well, here it is on Alibaba. I've never bought anything big from them: https://www.alibaba.com/product-detail/typical-tw3-341-heavydutysewing-machine-cylinder_1600595645634.html And here's a video that shows a clutch motor, Most will want a servo:

Easy peasy. Nice work.

When the Girl Scouts happen by to get some ideas for their next project, we don't need them blundering in to posts like the one in question. Just because worse is available elsewhere, doesn't mean they need a dose of it here while looking for key chain patterns. Even if that forum didn't appear in the All Activity or New Post streams, a person would then have to go looking for it. Maybe an "opt in" the first time a user accessed it. Verifying a users age is highly impractical for most cases.

I'd agree that neither of those machines seems ideal. Several members here have purchased machines from overseas (to their country). I wonder if that would be an option for you? I've never imported anything large and expensive, so I don't know.

I believe @Johanna can make that forum invisible to you.