Woodruff Key in Player Piano Transmission
By Jon Page
I'm trying to get a Sterling upright working. It was restored well
but the reroll failed. At first I thought it was the retrofit reroll
pneumatic not getting enough vacuum but I discovered the problem in
The take-up spoon brake also doubles as the roll drive clutch. It
slides along the shaft on a metal insert. The insert is ~2 mm square
stock. The piece that caused the jamming is 'L' shaped, 15 mm by 5 mm.
The short arm fits into a hole in the shaft and it rotated in the hole
to cause the jam.
I suspect there was another 5 mm arm on the other end to stabilize it
on the shaft. It sits on the shaft and not in a slot. I'll have to
take it apart to see if there is a corresponding hole on the shaft
under the brake (the long end of the slide looks like a brake).
(Message sent Thu 11 Jun 2015, 16:33:32 GMT, from time zone GMT-0700.)