I redesigned the pulley for the double action birdcage pull that I made yesterday. The main difference is that it’s slightly larger and the hole on the non pulley side has been moved 90 degrees.
Here’s a side by side comparison with the one that I made yesterday. The old one is on the left and the new design is on the right with the strings on it.
I foreseeing possibly making it wider with the ends flaring out, so that it doesn’t roll inside the jacket and twist the line. We’ll see if that actually ends up being a problem, or if tension alone will straighten out or keep the lines straight. I’ll play with it a bit and see what happens.
If you’re curious about this style of pull, I think I first read about it in Jim Steinmeyer‘s book The Magic of Alan Wakeling. In that book it’s used to vanish a fan, however I think using a pulley on a wrist to wrist pull is much older than Wakeling using it.