dikman

Looks good, very neat work.

Well done, nice restoration and a serious bit of modding!

A good point, the external-mix siphon-feed are better suited to what you want to do as they generally have a wider spray pattern than a double-action internal mix - plus they are cheaper, easier to use and simpler to clean.

Yep, that is their primary function, but the fact you can vary the speed is what makes them so useful. It is very difficult to make a single phase AC motor variable speed - grinders, lathes, drill presses etc - but by replacing the single phase motor with a 3-phase and adding a VFD you can adjust the speed on-the-fly with a simple potentiometer. My belt grinder, lathe and drill press have all been so modified, much better than changing belts to adjust the speed. I haven't, however, bothered with using such a setup on any of my sewing machines as the ubiquitous servo is perfectly adequate (and a lot simpler to set up).

There have been quite a few posts on here regarding using VFD's and yes, it can be done, along with using DC motors and gearboxes. There is, of course, quite a bit more involved than simply installing a servo but it can be done.

My thoughts - if you got the machines at good prices then I'd keep both, set the Singer for #69 thread and the Seiko for #138. If you only want to keep one I'd keep the Seiko then look around for a heavier machine BUT finding a used heavy duty machine isn't going to be easy (unless you're very lucky).

A big one! Airbrushes aren't intended for covering large areas. A normal spraygun will be overkill for that but you can get small sprayguns which are used for detail work.

Nice! The angled basket weave is very well done.

I can understand that! I often do/make things because "it seemed like a good idea at the time" or it was just a challenge to do it. I suspect it will end up being more complex than you think but best of luck.

Beefy, it will be an interesting project for you and while you may be able to design/build something to do what you want it is likely to be specific to your setup. On a personal level my first servo had a needle positioner, I bought it because it sounded like a good idea and I had no idea what I was doing! I tried it and didn't like it. I find for sewing leather a slow, controllable speed is all I need and an NP is of little value.

First photo it's level with the needle plate, just needs a washer or two to keep it there. Or am I missing something else that I can't see?

A couple of washers under the edge guide to level it maybe?

Sounds like your blade is sharp, I reckon it's got too much moisture in it. I had a similar thing when I wanted to try something in a hurry, I dunked the leather in a bucket of water and started cutting not long after and had a similar result. I think the excess moisture makes it too soft and causes the leather to "grab" on the blade.

Very impressive! Looks like a lot of work, I'm sure he'll love it.

I cut the fingers off an old pair of leather gloves and slip one on my finger. I cut off the end so my finger pokes out. Sewn quite a few holsters and gunbelts, Works for me.