Originally Posted by Vridar

The following is from one of the Yahoo groups. Like Joe, I assume(d) the cams are(were) specific. Has anyone experimented?

"All slant needle Singers except the 301 and 404 use “fashion discs” to produce decorative and utility stitches. The 403 and 503 could sew nothing but a straight stitch without the use of a cam, the other ma- chines had a stack of cams built in and used the drop-in cams for additional stitches. A new machine usually came with 4 or 5 cams and 15 more were available. Unless you are into decorative embroidery, you don't need them for sewing, except for the fun of having them. The black plastic discs are called “top hat” cams by collectors because of their color and shape. The disks vary the stitch width to form the decorative stitch. The black top hat cams from the 401, 403, 500, 503, 600 and later Touch & Sew models are all interchangeable. The later Touch & Sews also utilized a two-layer cam to produce addi- tional stitches. One layer of the cam controlled stitch width while the second layer controlled forward/ reverse motion. These cams are a lighter color, usually beige and cannot be used in the earlier slant nee- dle machines. You can pick up Touch & Sew discs cheap because Touch & Sews are not collectible, then throw away the box and pop them into your 401. No one will know the difference."