Transposer and Music Desk

I recently spent some time looking at and copying pictures from the Ruckers book for the moulding profile used in the period instrument I’m building and discussing it with my mentor. In the end I decided to seek out miniature bits (¼ inch shank) and purchase them rather than to have a custom bit made. I found a site called which had 4 bits from Amana Tool that I thought might work. I purchased the following bits:

After trying all the bits out in both poplar and mahogany I decided that the Miniature Classical had the nicest profile and that’s the one I used to cut the first set of mouldings for the Transposer.


The Transposer is a set of three blocks of wood, 2 which are fixed to the sides of the keyframe and one which is removed and moved to either far side of the key well to shift the pitch of the instrument. Normally music from the early period is played at A415 (A = 415 Hertz) and when you play with more modern instruments you need to shift the transponder so that you’re now at A440.

Although making the Transposer at this time is a bit out of order according to the ‘book’, I decided to go ahead and complete the Transposer parts and much to my horror when I put all the parts in to test the fit I discovered that the keyframe was slightly out of square. Hmmm, what to do. Well, I never liked the way the stiles on the keyframe looked anyway, they were made from poplar and didn’t really look that good. So, I made two new stiles (out of curly maple no less, because it’s all I had laying around that was the right size – a leftover piece from another project), removed the old ones and replaced them. They look much better now, and they’re very square. I put it all back together and what a difference. Then for the Transposer I installed the mouldings and drilled the holes for the Transposer parts and mounted them to the sides of the keyframe. Width-wise they fit very well, but on the bass side the height is a bit skewed. I’m still trying to figure that out, but by placing a 3/32” shim under the transposer area on the bass side levels things very well. Here are the Transposer parts before installation:


and after (keys removed from the keyframe):


I finished prepping all the parts and worked on completing the Music Desk. The basic pieces had been cut already, and so I cut all the lap joints and glued up the desk. The joints were reasonable, but not as tight as I had hoped, so I ended up filling a few and then ran the desk through the drum sander. Installed the music shelf after routing the profile on the lower front part. Since it will be painted, filling the few joints is really not a problem as they will not show and now they’re smooth as silk. I installed the music desk to the base with the decorative hinges. After considering ways to prop the desk up, ended up using small pieces of the moulding as stops.

About npcarey

Amateur Luthier, woodworker, music enthusiast, software enthusiast
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