The Spurlock article which was my beginning point is the March 1991 issue of the PTG Journal.

The key set I worked with for this first go was really in good shape. There were no warped keys. I would say that the left side of the key (in the photos — right side in the piano) is the reference edge, and that the jig makes a cut perpendicular to that edge. The loose plate adjacent to the lever has less bearing surface than the fixed block. To set the clamp, I provided a light down pressure for reference to the sled’s top, then clamped it tight against the block.

For this key set, the tail was relieved relative to the ivoried key length, so the back of the key was actually not in contact with the sled, but a millimeter or two above the sled. But I can see that an elevated contact points at the front and rear of the ivoried key length would eliminate problems for another key set. For this one, I judge my success by the uniformity of the rear profile of the cut.

The width between sides of the jig is 300 mm. The sled is 262 mm wide. Other dimensions are determined by the key. I’m giving you my working sketch here: http://www.flickr.com/photos/duanemcguire/4150416852/sizes/l/ Consider it to be my starting point. I know it is not an “as built” diagram, since I went direct from concept to finished product. In particular the sled and base are longer than indicated in the sketch. They were built to a more “comfortable” length.

The base and sled are made of melamine faced particle board for slipperiness. The inserted end of the sled has a pair of sliding closet door rollers on it for smooth use and to assure that particles on the floor of the jig do not interfere with the reference cut.

The plated hardware on the front of the slide are rollers sold as sliding door glides at the local Lowes hardware. The purpose is to make the cross cut smooth. Also by using the roller point above the floor of the jig, any chips/debris that the dust collection misses will not interfere with a true reference to complete the straight cut at the back of the key.

I found that the simple quick clamp was trouble free and solid for this key set. Another clamp at the rear of the ivoried section would provide additional security. I was going for for the min-max of hardware/accuracy. For this key set it was perfect. I expect it will evolve some with different key sets in the future.

Duane: Stieff Serial 28331 … bound for Syracuse Arts Academy.