Making the Keyboard and Action

This page describes the process of making the keyboard.

The same wood material used for the soundboard is used for the keys, such as Sitka spruce or Japanese spruce, which are virtually free from warpage.

The action is fabricated in a separate process.

The action is a complex mechanism composed of wood, metallic pins, felt, and other materials. If the linkages between the parts are too tight, they will stick and movement will be poor. If the linkages are too weak, the parts will rattle and movement will be jerky. Hence, the action must be finely adjusted. Lubricant is applied to the red felt parts to ensure smooth movement.

The action is made almost entirely from wood, and the standard for precision in cutting and milling is 5/100 of a millimeter.

Next are the hammers, which are part of the action. First, white felt slabs made of pure wool are cut into triangular or trapezoidal shapes to match the model. The hammers gradually decrease in size as they move from the bass toward the treble range of the keyboard, and so the cross-sections are not uniform. They are left to rest for a short time to relax the fibers, then adhesive is applied and the felt is wrapped around a wooden core, completing the hammer.