Paper Punchings Archiac?

[Thomas D. Seay, III]

>Some new high end pianos sell in excess of $50,000. All that cash 
>and we still use paper punchings to level keys and set key dip. 
>Wouldn't someone eventually consider this to be archiac. Not really 
>saying it is, just asking the question.
>
>About 25 or 30 years ago a strange vertical piano was exhibited at 
>one of the trade shows. I seem to remember the name as a Thomas and 
>I believe it had all plastic componets. The keys on this piano could 
>be leveled and key dip set with a clever set of threaded key pins. 
>My memory of how this worked is faint but I'll try explain.
>
>Imagine an extra long balance rail pin as an axle with a small wheel 
>swedged about half way up the shaft. The lower end of the balance 
>rail pin is threaded and screwed into the keybed. So now place a 
>cloth balance rail punching on the round disc shaped (wheel) and 
>place the key over the pin like normal. The top end of the pin is 
>slotted so it can be turned with a screwdriver. Turning the top of 
>the balance rail pin either way raises the key up or down thus 
>eliminating the need for paper punchings.
>
>Setting the key dip was similar. Again the front rail pin had a disc 
>mounted about half way up the shaft. The lower part of the pin was 
>threaded and screwed into the keybed. This time the front rail pin 
>was slotted at the bottom end. The key dip was adjusted by inserting 
>a screw driver into the hole UNDER the keybed. A cloth front rail 
>punching is now on the disc (wheel). As the front pin is turned from 
>under the keybed the punching raises or lowers, thus eliminating the 
>need for paper punchings. With this system there probably would be 
>no need for a key frame.

This system sounds logical on the face of it, but you would encounter 
problems if you attempted to square the keys by slightly bending the 
balance rail side to side or tried spacing the key fronts by bending 
the front guide pin. It is critical that the pins remain absolutely 
square to the rail; otherwise, they will scribe an arc at their tops 
as they rotate. This would change the position of the part as the pin 
rotated. Once those pins get bent, I suspect it would be virtually 
impossible to get them squared up again.

If you never had to rebush, space or square the keys, it should work 
perfectly, at least in theory.

Tom



Tom Seay
School of Music
The University of Texas at Austin
mailto:t.seay@mail.utexas.edu