Introduction - Came for the sewing machines, stayed to learn about leather

[brongle]

Hey all,

Figured I'd introduce myself - I'm a self-employed machinist in upstate NY (capital region), and I've been working with metal for over half my life at this point. I have a couple bar fed, dual spindle CNC lathes in my shop and I make small parts for large steam turbines, nerf blasters, and hydrogen fuel cell systems. I also run a couple Formlabs Fuse series SLS printers. I've had a lifelong passion for making stuff that eventually turned into a passion for using, modifying, and maintaining industrial manufacturing equipment of all kinds. I found this forum when I got back into sewing about a year ago (mostly bags, some hats, and I'm now learning pattern drafting for garments) and quickly fell down the rabbit hole that is industrial sewing machines. This site has been an incredible resource for information about the range of sewing equipment that's out there! 

I started off with an 80s-era Brother Walmart-grade domestic machine, which was...frustrating, to say the least. The feed dogs were out of square with the presser foot and needle bar axis so it defaulted to sewing about a 6" radius curve to the left. Not great! I took it apart and remachined the mounting surface on the feed dog plate, which was out of parallel by somewhere around .020" across the ~1/2" wide mounting face 🫣

 

Didn't have a mill at the shop at the time, so it went in the lathe with a sketchy setup - tried turning that face initially, but the overhang was just too much and it chattered like crazy. Live tooling came to the rescue though, and I cleaned it up by jogging an endmill back and forth across the surface. Parallelism between the feed dog teeth and the mounting surface was greatly improved, on the order of .001-.002" as far as I could measure. The machine still pulled to the left a bit after that, though it was far more usable than before. By that point, it became clear that I needed something more capable, and I'd already started researching industrial machines. 

Within a month or so, I picked up a Durkopp-Adler class 272 needle feed machine with an Efka Variostop system on it, which I converted to 110V from 208V 3ph with a reverse fed transformer and VFD that I had laying on the shelf. That Efka system is incredibly cool from an engineering standpoint and is also much easier to convert to residential power because the motor runs continuously, using an electronic clutch and brake to drive the machine, rather than starting and stopping on demand like a modern servo would. 

Later last year, I grabbed a "Chansew" (Chandler) Model 100RB for a price that was too good to pass up, which is one of the various flavors of top/bottom feed machines imported under the Chandler, Consew, and Seiko names. Still working on putting together a table for it, and I'm debating how I wanna approach the drive system, since it came with an old clutch motor that I'm not very interested in using. The obvious route is a Chinese servo system, but I'm particularly interested in building my own out of some Clearpath servos I have leftover from an old project, with the eventual goal of adding a stitch programmer that I can set up for various repetitive tasks. 

 

 

All of my sewing so far has been fabric-oriented rather than leather, in part because it's more accessible, but also because it makes more sense for a lot of my applications so far. The 272 above is firmly a garment-class machine and could at best handle lighter leathers, but it's definitely not made for it. The Chandler is likely going to be my introduction into leather sewing after I get it set up, and I'm particularly interested in making leather bags with it. Currently lusting after a cylinder arm machine of some kind, ideally with a synchronized binder, as binding raw edges is currently one of my biggest struggles.

Some of my work is below:

Designed and made this tote bag yesterday! Needed a better bag for grocery-getting. This one's got two cargo pockets on the inside ends in addition to patch pockets near the handles and has a total volume of 16L.

One of my other interests is in making tactical gear for Nerf blasters, where bright colors are preferred over the camo and dark solid tones traditionally available in that space. I made a bandolier a few months ago for some 3D printed shotgun shells that hold a variety of soft ammo types in various quantities, and printed a little jig to handle sizing and spacing the loops so I didn't have to measure and mark out each seam location. It's sized for my centered zipper foot and worked extremely well for the ~50 loops on the sling. The elastic ended at exactly the right spot and the whole thing went together very quickly - a very satisfying evening project. 

 

 

 

 

 

 

Edited February 16 by brongle

[alfredleatherworks]

Welcome! I’m a sewing machine nerd and love seeing other people’s machines as well as what they’re doing with them. You’re making some cool stuff, and I love your 3D printed loop sewing guide. That’s pretty smart! I look forward to seeing what else you get up to! Especially if you do sewing machine modifications 😁

[friquant]

Cool push-button setup with the Durkopp-Adler 272. Is that always included with the Efka variostop system?

Most of the time when people ask about variostop, they are asking how to get rid of it because they lack 3-phase power, or because it's broken. I think you said you are using VFD to supply the 3-phase.

I'm intrigued by needle-feed systems. Haven't seen one come up for sale around here.

[brongle]

On 2/22/2026 at 2:04 PM, alfredleatherworks said:

Welcome! I’m a sewing machine nerd and love seeing other people’s machines as well as what they’re doing with them. You’re making some cool stuff, and I love your 3D printed loop sewing guide. That’s pretty smart! I look forward to seeing what else you get up to! Especially if you do sewing machine modifications 😁

Thank you! It seems like this is where all of the sewing machine nerds congregate the most, so I'm excited to join in. 

 

5 hours ago, friquant said:

Cool push-button setup with the Durkopp-Adler 272. Is that always included with the Efka variostop system?

Most of the time when people ask about variostop, they are asking how to get rid of it because they lack 3-phase power, or because it's broken. I think you said you are using VFD to supply the 3-phase.

Based on a manual that I apparently only have on my shop PC right now, it appears they offered both two and four button setups! I don't think they were sold without those buttons, but I'm not positive about that. IIRC, Uwe shared a 272 that had the 4 button option a while back. There was also an optional stitch programmer panel that expanded the programmability of the drive, and I believe you could configure the buttons on the machine head to select different modes in the stitch programmer. The manual I have lists the pinouts of all the connectors and some signal timing diagrams for the various accessory ports, and I think it'd be pretty cool to hook up a microcontroller to duplicate that functionality, and possibly add more of my own. I wish those buttons were a little bit clickier, because the one next to the step/reverse function enables and disables auto backtack, and it's very easy to accidentally bump it without realizing.

That's what I've seen in my searches too - it's a shame, really, because they're very cool drives, and they're actually much easier to convert to single phase or 110V than almost anything newer. I do have 3ph power at my shop, so I tested the machine on that before the conversion. The speed control isn't quite as stepless as a modern servo, and mine has a bit of a jump in speed at the very top end, but there are adjustments for that and I haven't played with them yet. I have yet to see an aftermarket servo system that can auto backtack, and I really like that feature. Plus, keeping the thread cutter functional would be considerably more difficult with a generic servo.

The VFD I used is a 220V 1ph input unit from Hitachi that I had on the shelf, and it's quite oversized for the application with a 2.2kW max output. A 110V 1ph input/208V 3ph output VFD would've been even cleaner here, but I didn't have one on hand and was able to snag a 1kVA 110-220V transformer off eBay for about 40 bucks shipped, which I wired in reverse. No problems so far with that setup. I think that the significantly higher inrush current you see when reverse feeding a transformer is still small enough to avoid tripping breakers with a transformer that small, and I've now tried that setup in two different houses without issue. The only reason this works is because the variostop motor runs continuously, and the electronics take a single phase input that is normally tapped off the motor connections. To prevent the noisy VFD output from messing with the electronics, I pulled power for them directly from the transformer, although I suspect that the motor could act as enough of a filter to make that unnecessary. This has the funny side effect of powering up the drive before the motor starts, so some of the machine functions still operate with the motor off (namely foot lift). 

I have seen the motors available separately from the control boxes, and they did offer 110V and 220V single phase options, so I'd imagine the motor could be swapped if another one with the appropriate voltage came up for sale. Then it'd just be a matter of swapping out the internal transformer in the electronics for a lower voltage one, or maybe even just rewiring it for 110V, depending on the taps that are broken out on it. As far as I understand, performing a similar operation on any modern servo system ranges from challenging to essentially impossible, because the 3 phase units will throw a fit if they aren't seeing clean 3 phase power at the input. Seems really silly to me, given that these motors draw next to no power and it all gets rectified into DC before going back through an internal VFD anyway. I really don't know why they wouldn't just design one drive that can take a wider range of power options. 

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I'm intrigued by needle-feed systems. Haven't seen one come up for sale around here.

I love the needle feed! It's so nimble and fun to sew with, and it's come in quite handy in situations where a drop feed machine wouldn't be able to keep fabric from slipping, particularly around curves. That's a double-edged sword though if you're making garments that need certain seams eased together, like when setting sleeves. I think I'll probably end up grabbing a cheap drop feed machine one of these days for that purpose.