Keywell blocks

Since the keyboard is narrower than the space it fits into, the remaining space is taken up with a pair of keywell blocks plus a transposing block. The keywell blocks are shown below, glued up against the decorative front edges of the case:


In order to make sure the first and last keys don't rub against these blocks, 2 mm shims were glued to the left and right edges of the key frame:


The removable transposing block, shown below, allows the pitch of the instrument to be changed by shifting the keyboard sideways to fill the space left over when the block is removed. The block is held in place with two rare-earth magnets that are attracted to nail heads inside the keywell.


The keyboard shifts by one jack position, which allows a pitch of A=415 Hz when to the left and A=440 Hz when to the right.

Determining the proper thickness of the keywell blocks is an important part of making sure that the keyboard is properly aligned with the jacks: if not, the jacks could slip sideways off the key ends. I did this by progressively planing the blocks down and putting them in place, then sliding the keyboard left and right and observing how the jacks sat on the keys in both the left and right positions. When everything looked good, I glued the blocks in, then planed down the transposing block to fit the leftover space.