The layout dimensions of an organ manual are something I've never found
in detail. Even the AGO console specifications that I have only give the dimensions to locate the
manuals but don't mention anything about their size except that the depth of touch is 5/16"-3/8"
scant and that the height of the sharps is 1/8" more than the depth of touch. I measured the keyboards
of two organs, a piano and an electronic piano but I got different measurements on all four.
I found the following dimensions in the Laukhuff catalog and decided to trust them to be correct:
- AGO Octave spacing = 164mm
- Length of sharps = 80mm
- Length of natural fronts = 45mm
- Width of sharps = 11mm
I decided to make the manuals with a nominal .050" gap between all surfaces. Using the measurements
I took from the four keyboards, I came up the following dimensions:
The length of the keys is 26.5 inches. With only an .050 gap between the keys, they needed to
be very straight. I didn't think I could make a single piece of wood that straight so I decided to make
each key out of two pieces of wood. For each key I oriented the pieces so that their curvatures
offset each other and glued them together against a straight edge. Here's a photo of the key body halves
and then four keys being glued up:
After letting the key bodies sit for several weeks, I measured the bow of each and marked it on
the key. Most had a bow of less than .040 but the worst was about .060. Then I arranged them in order of
least bow to most bow with all the bow in the same direction.
Here are two photos of the sharps having their angles cut. Notice the Ø.062 drill at the back
of the sharp in the first photo. The Laukhuff catalog specifies the sharps to be 1.5mm shorter at the rear.
Here's a photo of the natural and sharp coverings. The naturals are walnut and the sharps are maple:
I made the natural coverings out of three separate pieces of wood:
All the natural coverings started out the same. After gluing them to the key bodies, I used a flush
trimming router bit to trim them flush to the key bodies. I used a razor blade to later square up the
rounded corners from the router bit.
The key bodies are supported by a bed of pins. There is one pin at the center and one at the front of
each key. Here's the bed of pins:
The pins are captured by a small slotted piece of wood. The position of this slotted piece can be
adjusted to align the fronts of the keys:
I painted the inside of the slots with graphite paint:
Here's the completed manual: