Here is how you can make new Wurlitzer-style valves. Use an automated punch machine and a "Pem" fastener machine; in fifteen minutes you are done.
The Pem fastener is the key to making the valves. In the past, restorers have had to use screws and then grind off the head of the screw. A Pem fastener (one source is McMaster-Carr) can easily be inserted on a drill press to make tooling. Many of today's piano rebuilders or home hobbyist would never run into Pem fasteners.
The firm that made them for me just happened to right size cutters in their CNC punch machine or it would have never happened. Once set up, these machines could make thousands of these valve discs in an hour. The machine time on this run, to make four hundred of the valve discs, was less than five minutes.
After they were made the manufacturer said "no more" -- they ran out of fiber material and I was lucky enough that they just happened to have the machine set up with the right sizes of dies the day I needed the machine. I would have never thought about the Pem fastener, which works perfectly.
Don Teach - Shreveport Music Co.
16 Aug 2004 10:21:54 -0500