How to Blind Hem on a Straight Stitch Machine (Just for Kicks)

I will acknowledge is that it is unlikely that anyone (myself included) will ever actually do this.  I usually either blind stitch by hand or on my ZZ machine.  But part of the fun of using vintage straight-stitch Singers is exploring the ingenious methods they had for doing tasks that require a zigzag.

There is an attachment made specifically for blind hemming on a straight stitcher, and as far as I know, it is only available for low-shank machines. (ETA:  I recently found out that this actually does come in a slant shank version for the 301 and 404 slant straight stitchers.)

Singer Blind Stitch Attachment for low shank straight stitch machines. 

Here it is blind stitching on my Featherweight.

Here's how it looks on the right side (with contrasting thread so you can see it.)

But just supposing I want to blind hem on one of my straight stitch slant shanks and I didn't have that attachment.  Then I'd reach for this:

This is a gadget Singer made to do zigzag and other decorative stitches on straight stitch machines.  Mostly those would have been low shank machines like the 15-91, 201, or 221.  The 301 and 404 are (as far as I'm aware) the only two straight stitch slant shanks, and there is a version of the Automatic Zigzagger for these machines which is harder to find, but not impossible.

This thing is HEAVY, it weighs almost a pound with the cam inserted!  This is the basic zigzag cam.

So getting ready to make my hem, the first thing I might do is finish the raw edge with a zigzag stitch.  This was done on that unwieldy gizmo shown above, and it did an acceptable job.

Now I'm ready to do the blind hem, and this is the cam that does it

Set it up to blind hem in the usual way.  I have adjusted the bight so that the zz will fall right on that left guideline on the foot.  I just keep the folded edge on that line while I'm stitching

Unlike a typical blind hem stitch that does several straight stitches followed by a left zigzag stitch, this one makes a half-circle between each zigzag.

And this is how it looks on the right side.

(same fabric, different lighting)

Yes, I have just made a blind hem on an old straight stitching sewing machine!  There is something kind of satisfying in knowing it can be done this way, even if you would never actually do it, right?