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Step 8Drilling the keyplank
In order to drill them the marked up keyplank and keys have to be kept aligned together the same way that the keys would be on the keyframe. Blüthner suggested nailing them using wire nails.
Most drill presses will reach the front pins, but the sides and back of the keyplank and keyframe will stick out a lot and there won't be much support. You can fasten them to a stationary table drill by hand or use a small drill press placed on top of the keyplank with the head lowered almost to the base. I used a homemade drill press that has a relatively long reach and clamped the keys and keyframe together to a table that can slide in front of it. It makes it much easier drilling in lines and at compound angles.
I drilled each hole from above, and in three passes - first a tight driving fit through the keyplank into the keyframe rails with a bit about 90% of the pin diameter, then a running fit just through the keys and then a hole large enough for clearance as the key rocks. A special step drill bit like Audsley described would be more efficient.
Since the rails aren't parallel I drilled it in two settings, starting with the balance rail first so I could bevel it up to the centers of the pin holes before driving in a pin in the top and bottom holes to re-index the keyplank on the keyframe for drilling the front pins. I put a shim under the front so the holes through the keyplank would be straight and clean. Bluthner suggested drilling out the waste behind the natural heads, too, but I did this after sawing, and only a hole large enough to turn a fret saw blade. I also used the drill to make the angled holes for the backchecks, which required repositioning several more times to get the compound angles right.
The front mortises have to be made oblong with perfectly parallel sides, and Bluthner suggested using a broach but didn't describe it. I made one that works like a couple of stuck together knives I learned was based on an old one discovered in France, but I used one that is shaped like a double sided metalworking broach. I chucked it in a benchtop drill press and kept the mortises aligned by using a fence and locking the spindle. It leaves the narrow sides kind of rough depending on the type of wood, but it looks like the mortises in old piano keys.
I routed a shallow groove around the row of natural front holes and glued a strip of scrap from the keyplank into it so the holes don't show through the keytops. It had to be really thin so the tops of the front pins don't hit it when the keys are pressed down.
Most drill presses will reach the front pins, but the sides and back of the keyplank and keyframe will stick out a lot and there won't be much support. You can fasten them to a stationary table drill by hand or use a small drill press placed on top of the keyplank with the head lowered almost to the base. I used a homemade drill press that has a relatively long reach and clamped the keys and keyframe together to a table that can slide in front of it. It makes it much easier drilling in lines and at compound angles.
I drilled each hole from above, and in three passes - first a tight driving fit through the keyplank into the keyframe rails with a bit about 90% of the pin diameter, then a running fit just through the keys and then a hole large enough for clearance as the key rocks. A special step drill bit like Audsley described would be more efficient.
Since the rails aren't parallel I drilled it in two settings, starting with the balance rail first so I could bevel it up to the centers of the pin holes before driving in a pin in the top and bottom holes to re-index the keyplank on the keyframe for drilling the front pins. I put a shim under the front so the holes through the keyplank would be straight and clean. Bluthner suggested drilling out the waste behind the natural heads, too, but I did this after sawing, and only a hole large enough to turn a fret saw blade. I also used the drill to make the angled holes for the backchecks, which required repositioning several more times to get the compound angles right.
The front mortises have to be made oblong with perfectly parallel sides, and Bluthner suggested using a broach but didn't describe it. I made one that works like a couple of stuck together knives I learned was based on an old one discovered in France, but I used one that is shaped like a double sided metalworking broach. I chucked it in a benchtop drill press and kept the mortises aligned by using a fence and locking the spindle. It leaves the narrow sides kind of rough depending on the type of wood, but it looks like the mortises in old piano keys.
I routed a shallow groove around the row of natural front holes and glued a strip of scrap from the keyplank into it so the holes don't show through the keytops. It had to be really thin so the tops of the front pins don't hit it when the keys are pressed down.
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