It was only a matter of time before this happened – the player piano (original post) is a real workout to play manually. Since it works on vacuum, I had set aside the motor from an old vacuum cleaner for potential use in powering the piano. Tonight I built a small box to contain the vacuum motor and connect it to the piano. The box is made from MDF, partly because I had scrap that needed to be used, and partly because it’s very heavy & sound absorbing. I made the big fitting by cutting/milling a square from scrap, I then bored a hole in it on the lathe and welded it to a scrap of pipe.
One very large hose goes to the manifold powering all the key bellows, and another smaller hose powers the vacuum motor for the tracker/scroll mechanism. I didn’t notice the smaller connection at first, so I had to go back and tap a fitting into the connection for the large hose; there’s still enough room for both to connect though.
Overall it seems to work great, this effort was definitely a quick proof-of-concept though and I’ll need to go back and fix/test a few things:
#1 – Motor controller to slow down the vacuum motor. Currently it has way more vacuum than is actually needed and slowing down should reduce noise from the motor.
#2 – Ensure cooling is OK. Especially after slowing the motor down I need to test that air flow is good enough to keep the motor consistently cool.
#3 – Mount in piano base and complete further noise insulation.
#4 – Tee hoses (and potentially add check valves) so that manual operation still works.
Beyond that I do have plans to eventually (could be tomorrow, could be in 5yrs) automate the player mechanism using some small pneumatic solenoids I found on ebay. These would tee off of each line from the tracker bar and when they open it would simulate a hole in the paper passing by. With this it would then be computer controlled and able to play anything. By default these are off/closed, so the paper mechanism would still work fine, in computer-controlled mode I’d just need to block off the tracker bar holes with some tape.
