The keys are cut apart by starting with the lines between the B and C keys. The lines between the B and C keys and the E and F keys extend the full length of the key plank. A band saw is often used to make the cuts freehand. As an alternative, a Bosch jig saw with a 0.03 inch thick blade was guided using two pieces of straight edged hardwood to guide the saw. A scrap piece of lumber placed underneath the keyboard plank keeps the two halves in the same plane after the cut is finished.
The Bosch jig saw makes a thin, precise cut as seen in the following two images.
After cutting from front to rear on all the lines between B-C and E-F, the remaining cuts could not be made by clamping the straight-edged hardwood guides on both sides of the key. I had finished making an adapter for the jig saw to allow using the E-Z Smart guide system designed for circular saws. The following image shows the aluminum guide rail and the jig saw slipped into the base-plate. One virtue of the E-Z Smart guide is that a fraction of a key width is sufficient to provide enough clamping area to hold the work to the bottom of the guide. The threaded posts used in the clamps also serve as legs that hold the rail above the work table with the work clamped to the underside of the rail and enough clearance for the blade of the jig saw.
The next image show a close-up view of the blade cutting between G and A keys and the anti-chip edge of the guide.
After all the cuts are made the keys are still in groups of five and seven as shown in the following image. A line 3/8 inch beyond the top of the naturals is drawn to mark waste area. A hand scroll saw is used to cut the keys apart on a diagonal line between the existing cuts. The hand jig saw is used to square off the final cuts.
The following image shows the keys after being cut apart and loosely laid out on the workbench. The cut out between the sharps and the naturals will eventually be covered with the tops of the sharps.
A key lever mortise punch, a specially designed tool available at the Instrument Workshop, is used to enlarge the hole for the balance rail pins to allow the key to rock. The tool is basically a triangular wedge of hardened steel with a cylindrical tip the diameter of the balance rail pin. A little Caress bar soap rubbed on the punch makes it easy to pull out after being hammered into the wood. If this is your first time make sure you practice on some scrap stock. Also, be careful to align the punch to make a slot closely parallel to the long dimension of the key. Here are the keys after placing on the balance rail pins showing the slot made with the punch.
The hole drilled at the back of the keys is used as a guide for making a slot of the same diameter. The slot must be only a few thousands wider than the rear guide pin to prevent excessive sideways movement of the key without binding.
The final images show the keys after placing them on their pins in the key frame. A piece of scrap lumber is placed on the back of the keys to show them in their resting position. (The short focal length camera lens added some distortion to what are actually evenly spaced keys).
Next step is to add tops to the sharps and decorate the top surfaces with a veneer. I'm going to use solid Gaboon ebony for the tops of the sharps and boxwood to cover the naturals.
