Gerry Miller fired this volley in
:

You would need the heart shapd cam like on the old shuttle type sewing
machines - the one with the bottom thread wound on a small diameter
spool about an inch long (wide between end flanges).


Correct. And, FWIW, that book cover depicting the "universal coil
winder" does not have a cam shaped to control the reversing velocity.
It's (appears to be), just a circular cam with variable offset to limit
the throw, depending upon the length of the coil.

That's simple, but a bad choice in terms of preventing the piling we
discussed earlier.

Lloyd