Thumb Piano

Step 3 Front face

Measure and mark the two points to drill for the T-nuts, don't make the holes too large for the T-nuts or they will fall out easily. I drilled 5/32" holes for the T-nuts 2-1/2" apart and about 1-1/4 from the one end. Measure and mark the 1" hole centered about 4-1/2" from the same end.

I drilled the 1" hole part way through the back then turned it over and drilled the rest of the way from the front to avoid splitting either side of the plywood.

When I was done I found that 4-1/2" seems a bit too close to the T-nuts you could move it a half to an inch further down. Also I found out that a 1" hole seems to make the higher notes sound louder, epically the B key. A smaller hole would tend to shift the emphasis to the lower notes. Using a 1/2" drill gauge held over the 1" hole seemed to bring out the F note.

Drill the 3 holes and tap the T-nuts into place with a hammer.