I decided to attempt to make a 3-step zig-zag special disc for my Singer 411G. In my opinion the 4-step zig-zag that is built in just isn’t a substitute. I usually use a 3-step zig-zag when I’m sewing through elastic, and the fewer stitches you put through elastic, the better.
Time for a little analog computer programming. I carefully measured one of my existing special discs, deciphered the “code”, and drew up a 3-step zig-zag disc. I decided to draw up the design in Tinkercad, since it’s free and has a short learning curve. In Tinkercad you basically stack a bunch of geometric shapes together to make more complex shapes. I used Inkscape to draw the more complicated shapes that could be extruded, then imported the .svg files into Tinkercad. Hooray for free software.
After I finished the 3-step zig-zag disc, I decided to make a few more things while I still remembered how to use the software. The only Singer slant needle to standard snap-on foot adapter available is a simple plastic one, and it’s not that great, so I decided to try to improve the design a little. I also made some tension stud sprockets for my Singer 237, and the two missing template sizes that were never made for my buttonholers.
I had the parts printed by Shapeways. The only low-cost, high resolution option they offer is their “Strong and Flexible” plastic (nylon). I figured ABS would be better for strength and abrasion resistance, but I couldn’t find a 3D printing site with reasonable prices for high resolution ABS that would also allow me to sell the parts to other people. I figured after going to the trouble of making these parts, it would be nice to be able to make them available to other vintage sewing machine enthusiasts.
At least initially, nylon seems to be OK for these parts. The parts are thick enough that they are rigid, not flexible. They are very lightweight, but seem strong enough. Only time will tell how they hold up under use.
The 3-step zig-zag disc was a little tight. I had to file one of the holes a little larger to get it to go on my machine.
Here’s my 3-step zig-zag disc next to an original Singer special disc. These are for the Singer slant needle machines with model numbers in the 400’s, 500’s and 600’s that take the top-hat stitch pattern discs. (I’m not sure about model 690, which I think might take a later style of discs.)
The stitch quality is not perfect, but the disc works! I’m pretty sure the crooked stitches are due to minor math and drafting errors on my part, not a printing problem, since it looks like the stitches are shifted the same amount on each set of stitches. I showed the stitches to my husband, and he thought they looked straight, so maybe it’s not that noticeable. I think I’ll use this disc for a while, and if it doesn’t wear out too fast, I’ll correct the design and make it available for others to purchase. If it does wear out, I can try having it printed locally in ABS plastic for myself, at least.
Here’s the 3-step zig-zag compared to the 4-step. For the top two rows, I unthreaded my sewing machine and sewed on heavy paper.
The plastic snap-on slant needle adapter I previously purchased isn’t designed very well. The presser foot sits too far to the right, and it’s a bit crooked:
I designed my version so the foot would sit a little further to the left, but it ended up not being far enough. It’s kind of hard to measure what shape it should be. At least the foot is sitting straight now. This is my version:
I usually only use my slant shank snap-on adapter with my blind hem foot, which is wider than the feed dogs, so the foot being shifted over doesn’t really matter.
I can’t manage to make a manual buttonhole, and I have no interest in buying a modern machine that I’ll have to pay to get serviced, so I make my buttonholes with vintage buttonholers. I have one (OK maybe I actually have three) of the older style Singer buttonholers that don’t take templates and can make any size buttonhole, but you get skipped stitches with these buttonholers if you don’t stabilize your fabric really well, so I usually prefer to use the template type buttonholer. I’ve collected all of the template sizes that were made for the Singer/Greist buttonholers, but there were two possible sizes that were never made. Until now!
These templates actually came out just about how I intended, so I set up a shop on Shapeways so you can buy them too, if you like. Mine are a bit snug in the buttonholer, but still fit just fine. The 3D printing process seems to create products that vary in size a little, so if yours are too tight, you could sand the outer edges a little with fine grit sand paper.
The Singer buttonholers were made by Greist, so they take the same templates as Greist buttonholers. These templates are about 1 3/4″ long and 3/4″ wide, and will fit Singer buttonholers 160506, 160743, 489500, and 489510. Greist made buttonholers to fit many different brands of sewing machines. I don’t have the model numbers for the Greist buttonholers these templates will fit, but I think they should fit all of the Greist buttonholers that were designed to work with straight stitch machines (or zig-zag machines set on straight stitch). These templates will not fit in buttonholers that only work with zig-zag machines, such as the Singer Professional buttonholers and the Greist buttonholers with a “Z” at the end of the model number.
While looking up model numbers just now I learned there was an adjustable Singer buttonholer made in the UK, model 86718, that has a stripper foot (to prevent skipped stitches) like the template buttonholers do. Great, now I’m going to want one of those, too. At least buttonholers take up less room than sewing machines.
Now I can make perfectly sized buttonholes for those buttons that I bought a whole bag of at the thrift store!
As for those tension stud sprockets . . . they weren’t quite what I’d hoped, but I think they’ll work OK. The resolution on the 3D printer isn’t high enough for the inner diameter to come out exactly as designed. These sprockets are available for sale on various sites that sell vintage sewing machine parts (sometimes they call it a “gear”), but the hole on the inside is too small, so the parts have to be drilled or filed out. Well, mine had to be filed out too, but I happen to have a chain saw file that worked just fine to enlarge the hole. Next time I’ll just buy a sprocket instead of having it printed – it’s probably better quality plastic. Here are some pictures of me replacing the sprocket on a Singer 237:
The future is here! Pretty cool, right?