The keyboard
Both Giangiulio and Wandel give a comprehensive description of their keyboards. I favoured Giangiulio although I felt that I would have to make certain things less complicated. On his web, under Opus 2, he has a schematic of a keyboard (one octave) with measurements in millimetres. I decided to use it, although the thought of having to work with a precision of a hundredth of a millimetre was quite scary at first. Some years ago, out of sheer interest in gadgets, I had bought a digital caliper, which now became my most imporant tool. Around this time I did another thing to improve precision in my carpentry work. I bought a pencil with 0.5 mm diameter lead and practised until I did not any more break it each time I drew a line on a piece of wood.
The sharps keys are all 10.5 mm wide and 80 mm in length. The naturals reach 45 mm further towards the player and are 21.43 mm wide at the front. The width of the naturals keystems varies. F and B are 11.11 mm, C and E are 12.64, G and A are 13 and D is 14.01 mm. Space between keys and keystems is 2 mm everywhere. It is not stated how long the keystems are in Giangiulio's design, but I thought, if a movement of about 10 mm in the keys is a fair value, then 20 cm each way of center was reasonable. For a practical reason I had to shorten the back end by 10 mm as the drill press I had access to for drilling the center holes had a span of 19 cm only. This, in fact, gives adequate lift in the pallets. To ensure precise drilling I clamp all the keys in place on the bottom plate and drill through.
I decided to use common building wood for the keystems, which was quite soft, and difficult to work with the required precision. It would have been better to use something more solid, like beech, for instance. But I kept on with the soft pine. To prevent bending I glued each stem together out of two halves. As the keystems were all glued and planed to measure, I put them side by side, with shims of 2 mm aluminium in between, and measured the total at 702 mm. The calculated number was 702.9 mm, and I was quite happy with an error of less than 0.02 mm pr. key.
For the naturals to reach the width of 21.43 mm, strips had to be glued, to one side in 4 cases, but both sides in 3 cases within the octave. These strips were 43 mm in length and planed, then sanded, to the correct thickness. In the case of the sharps, it was more simple. They are all alike, 10.5 mm wide, and 45 mm shorter than the naturals. As a bottom for the keyboard I used 12 mm plywood, measuring 34x84.5 cm. On it I glued two wooden strips about 10 mm high, one of them 19.5 mm from the front side, the other along the aft side of the bottom plate. To ensure the 2mm gap in front I attached to the front side a strip with a groove routed 2mm deep. Now I could line up the keystems, always with the aluminium shims in between, and clamp them firmly in place. The clamps were not removed until I had drilled the three sets of holes through the keystems and into the bottom plate, 4.2 mm in the middle for hinges, 2.5 mm near the ends for guide pins. The guide pins were made of 2.5 mm welding wire, cut to length and faired at the top end with a file. As hinges in the middle I used plastic covered curtain spring cut down to suitable length. In this way I got all the keys nicely in line, both vertically and horizontally. I had to elongate the guide pin holes in the keystems until they moved freely up and down.
It seemed to me that I would get a nice, balanced contrast in the keyboard by using the laminate beechwood from a circular table top, obtained at a thrift store, as cover for the naturals and the brown wood from my daughter's house for the sharps. I cut and planed 3.6 mm strips of the beechwood, 21.5 x 127 mm, glued them in place and removed the extra stuff by bandsawing, routing and sanding. The tops of the sharps are 10.5 mm wide and 12 mm high. The front end is cut to 10-15 degrees slant, but the sides are straight. The visble parts of the keys got 5 coats of varnish, which gives them a slightly glossy look. The last step in the making of the manual keys was to cut a groove into the far end and glue in there a pierced leather strap for attaching the tracker wire from the windchest.
