So you just bought a 401 or 403 or 328 and you're wondering what the heck that little door in the top is for.
Maybe there's a thingamajig in there, or maybe it's just a gaping hole. Now you can't sleep at night...it's driving you crazy!
Fashion Disc compartment, Singer 328K
Have no fear! The Disc Doctor is here!
No, not really. But I can shed a little light on the subject.
From the 1950's into the early 1960's, Singer manufactured three basic kinds of machines: straight-stitch, semi-automatic zigzag, and fully automatic zigzag.
For example, the 400-series model lineup includes one of each type. The 404 is a straight-stitch model, the 403 is a semi-automatic zigzag, and the 401 is a fully automatic zigzag.
Zigzag stitching is produced when the needle bar is moved from side to side. The side-to-side motion is created when the internal mechanism is pushed by bumps on a revolving template. The template is called a cam, like the cams that drive pistons in a car engine.
If the cam is permanently built into the machine, then it's fully automatic. If the cam is removable or interchangable, then it's a semi-automatic. If there are no cams it's a straight-stitch only.
Side-by-side comparison of the inner workings of the 400-series slant needle machines:
401: fully automatic
404: straight-stitch only
If you purchased a semi-automatic machine you needed a set of insertable cams to create zigzag and decorative stitches. Singer called these cams "Fashion Discs" or "Special Discs."
Fashion Disc? Special Disc? What's the difference?
Singer produced two styles of discs. The first style is smaller, completely flat, and requires a screw cap to hold it in place. The second style is larger and has a raised center that looks a bit like a hat, which is why they are sometimes called “top hat” cams. This type of disc snaps into place without a screw cap.
Here they are, side by side:
Special Disc for Singer slant needle sewing machines
Fashion Disc for Singer vertical needle machines
Both discs are made from a hard, black “Bakelite” type plastic and both accomplish the same task. So why is one called a “Fashion”disc and the other a “Special” disc?
Strictly speaking, both types of discs are "Fashion”discs. But Singer typically referred to slant needle discs as "Special" discs. Therefore I refer to all slant needle discs as “Special Discs” and vertical needle discs as “Fashion Discs.”
But...the instruction book for my 403 instruction book says "Fashion Disc" not "Special Disc"...
You are right, Singer used both "Special" and "Fashion" when referring to the "top hat" style disc, and it's confusing because there's only one kind of disc for slant needle machines.
For example, the instructions for semi-automatic machines (403, 503, 603), use the term "Fashion Disc," while the instructions for fully automatic machines (401, 411, 500, 600) use the term "Special Disc."
The difference is that fully automatic machines had to have the stitch selector set to "Special" for the disc to work. However, the semi-automatic models don't have a "Special" setting, so the manual refers to "Fashion" discs.
However, the discs are identical, so it's simpler to call ALL slant needle discs "Special Discs" to distinguish them from the smaller flat disc used in vertical needle machines.
The 401, 411, 500, and 600 machines don't need Special Discs to produce decorative stitches, but their stitch variety is greatly enhanced by Special Discs.
Singer was not the only sewing machine manufacturer using interchangeable discs. Other brands used similar technology to produce zigzag and decorative stitches. Elna and Necchi were pioneers in using double- and triple-decker discs to produce complex stitches which required the machine to stitch forward and backwards, such as the Greek key pattern or buttonholes.
Elna Discs. Note the double-decker discs in the back row.
Necchi Supernova Discs. Individual discs could be combined into triple-decker units.
By comparison, Singer did not feature double-decker discs until the 700-series Touch & Sew machines.
If you haven't already experimented with your machine's discs, I highly recommend giving it a try. Whether your machine uses Special Discs or Fashion Discs, that little trapdoor is the gateway to a world of stitching variety!
Happy Sewing! Barbara OldSewinGear...dedicated to helping you get the most out of your old sewing gear.
OldSewinGear is the collaborative effort of retired repairman Gary and daughter Barbara. We love old sewing gear and enjoy sharing what we've learned in our vintage sewing machine adventures. We are located in Roseburg, Oregon.