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Capstan and Backcheck Installation 2024-5

5/26/2024

 
This note is what I noticed during this recent capstan and backcheck installation. Skills and methods are to be improved. The installation videos and information can be found on WNG website. There are also PDF instructions available. This process took about five hours as of May 2024.
The capstan drill bit is a 4mm bit. The hole is drilled almost to the bottom of the key yet not drilling through. Think how ugly it looks from down under with a big black hole. Counter sink the entrance for the capstan to go in with ease. The wood will swell upward without the counter sink. Apply some wax to the capstans, we use WNG capstans. With an installer, twist the capstan down to the lowest and safest level without punching through the bottom of key, for the purpose of tapping, then unwind up to the designed height. The wood shim on the left of the third picture is the height gauge for this installation.
For backchecks, our Bridgeport milling machine has been doing the work. (She is our baby. To maintain, repair, and rebuild her, H&W MACHINE REPAIR AND REBUILDING is a good resource.) The backcheck is drilled and installed at about 21 degree angle. A deep punch mark is needed before hand, or the drill will slip and snap. Place the key in a vise, with a #35 drill bit, drill through the bottom of key. We tried not to drill through the key before. But some backchecks needed to be pressed very low. You can crack the wood on the bottom by not drilling through. 
We currently use WNG backchecks for their speed of catching and releasing the hammer tails. A special backcheck installer is used to hold and press down the backchecks. Press the backcheck all the way down to the bottom of key. They can be pulled upwards as needed during regulation process but will be hard to press down if installed too high. Dipping the backcheck wires in Teflon powder may  help the process to go smoothly without cracking the wood.

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