Hi all,
In Part 1 we built the keyboard blank and keyframe. In Part 2 we will cut the keys apart and fit the keys on their corresponding pins on the keyframe. Cutting the keys apart on a bandsaw is quite stressful in that the keys are not straight and the cuts must be made freehand. Any shaking will result in uneven gaps between the keys which may or may not effect the functioning of the key but will certainly effect the visual look of the keyboard. So let’s get calm and cut some keys.
The first photo is a picture of one octave of a keyboard. Notice that there are 7 “white keys” (labeled C to B) and five black keys (sharps). A little study of this picture should make it clear that the only place we can cut completely through from top to bottom is between the E and F keys and between the B and C keys. So we will begin cutting out the keys by cutting between all the E’s and F’s and between all the C’s and B’s. This is like taking a 4 x 8 sheet of plywood and drawing a cutting diagram onto it to make the most efficient cuts.
The next photo shows the keyblank on the bandsaw. The first cut is between key #24 (B)
and key #25 (C). This cut is made all the way from the back of the keyboard blank to the front and will divide the keyboard blank into 2 pieces.
The next photo shows the results of this first cut.
The next step is to cut between all the remaining B’s and C’s and all the remaining E’s and F’s. The next photo shows the results of these cuts.
The next step is to cut between all of the keys from the rear of the keyboard blank to the rear of the natural keys. The next photo shows one of these cuts being made.
Now we must separate the front ends of each key. This cut is shown in the next photo.
After all of these cuts are made, each group of keys look like the next photo.
All we need to do now is to separate the sharp keys from their neighbors. This is done on the scroll saw and the next 3 photos show this operation.
The next photo shows all of the keys. I think I mentioned in Part 1 that it was important to number the keys BEFORE cutting them apart. Now you will see why. I didn’t number them on the first keyboard I built 25 years ago and I learned that the keys are definately NOT interchangeable. For example, key #1 and key #13 are both C keys. They look the same to the eye but the holes we drilled into the keys in Part 1 WILL NOT line up if you switch the position of the two keys.
The next photo shows the keys in their proper order.
Here’s a closeup of several keys showing the eveness ( or lack thereof ) of the cuts. Not too bad for an old guy.
The next photo shows key #1 on its corresponding pins in the keyframe. Obviously, the holes in the key are too small and the pins will not go through. This makes sense because we used a drill bit several hundredths of an inch smaller than the pins when we drilled the holes in Part 1 so as to have nice, tight pins in the keyframe. So the next step is to enlarge the holes in the keys to allow the pins to go through them.
The next photo shows 2 keys and the tools used to enlarge and modify the holes. The top key shows the original 2 holes. The bottom key has been modified. Tool A is a little jig that has a pin in it and is used as a substitute for the keyframe pins. The balance rail hole (center hole) in the key must be elongated gradually from bottom to top to allow the key to pivot up and down. This is done by placing a homemade punch (B) onto the hole at the top of the key and banging it down until it bottoms out. The wood in the key is compressed and takes on the shape of the punch. Tool C is a hole enlarger that is used to slightly enlarge similar holes in the piano technology field. Tool D is a small round, tapered file which helps to enlarge the balance rail hole. Tool E is a small flat metal file covered with 220 grit sandpaper and is used to fine tune the size of the slot at the rear of the key. This rear slot is critical to the functioning of the key. If the slot is too big, the key will be free to move in the left-to-right direction at the front of the key. This is not good.
On the other hand, if the slot is too narrow the key will bind when you press it down or will not return to its rest position. This is fatal. What we need is the slot to be just one or two thousandths of an inch wider than the diameter of the pin. I don’t know of any way to measure this other than by feel. There should be no play at all between the slot and the pin but the key must slide without any resistance on the pin. The slot is cut on the bandsaw and is widened with the sandpaper file until the fit is perfect. This takes A LOT of time, patience, food, and a television set.
The next 2 photos show a closeup of the modified balance rail hole and the slot at the rear of the key.
The inside edges of the slot are eased to an angle to make it easier for the key to find its pin. (When servicing a harpsichord a key must sometimes be removed from the instrument. When it’s time to re-install it the service person will not be able to see the rear pin. Angling the end of the slot makes it easier to do this.) The next photo shows this angle.
The next photo shows the first 14 keys installed onto their rear pins.
The final photo shows the entire keyboard installed onto the keyframe. (The piece of pine laying on the rear end of the keyboard is there to keep the keys down in the back. The keys have not yet been balanced and need this weight in the back to keep them level for the purposes of this picture.)
The only thing left to do is to make some sharps and glue them onto the front ends of the sharp keys. We’ll do this in Part 3 (which will be a much smaller post than this one). Then we’ll put the keyboard aside for a while and start building the case of the instrument.
Till next time,
Ernie
Part 1 - The Keyboard Part 2 -Keyboard con't. Part 3 - Keyboard con't. Part 4 - The Case (Bentside) Part 5 - Case Bottom Part 6 - Case Sides Part 7 - The Lower Braces Part 8 - Case Finished Part 9 - Building the Registers Part 10 - The Stand Part 11 - Jackrail & Moldings
Part 12 - The Music Desk Part 13 - Building the Benchhttp://www.ncwoodworker.net/forums/f101/harpsichord-project-part-12-music-desk-18962/
In Part 1 we built the keyboard blank and keyframe. In Part 2 we will cut the keys apart and fit the keys on their corresponding pins on the keyframe. Cutting the keys apart on a bandsaw is quite stressful in that the keys are not straight and the cuts must be made freehand. Any shaking will result in uneven gaps between the keys which may or may not effect the functioning of the key but will certainly effect the visual look of the keyboard. So let’s get calm and cut some keys.
The first photo is a picture of one octave of a keyboard. Notice that there are 7 “white keys” (labeled C to B) and five black keys (sharps). A little study of this picture should make it clear that the only place we can cut completely through from top to bottom is between the E and F keys and between the B and C keys. So we will begin cutting out the keys by cutting between all the E’s and F’s and between all the C’s and B’s. This is like taking a 4 x 8 sheet of plywood and drawing a cutting diagram onto it to make the most efficient cuts.
The next photo shows the keyblank on the bandsaw. The first cut is between key #24 (B)
and key #25 (C). This cut is made all the way from the back of the keyboard blank to the front and will divide the keyboard blank into 2 pieces.
The next photo shows the results of this first cut.
The next step is to cut between all the remaining B’s and C’s and all the remaining E’s and F’s. The next photo shows the results of these cuts.
The next step is to cut between all of the keys from the rear of the keyboard blank to the rear of the natural keys. The next photo shows one of these cuts being made.
Now we must separate the front ends of each key. This cut is shown in the next photo.
After all of these cuts are made, each group of keys look like the next photo.
All we need to do now is to separate the sharp keys from their neighbors. This is done on the scroll saw and the next 3 photos show this operation.
The next photo shows all of the keys. I think I mentioned in Part 1 that it was important to number the keys BEFORE cutting them apart. Now you will see why. I didn’t number them on the first keyboard I built 25 years ago and I learned that the keys are definately NOT interchangeable. For example, key #1 and key #13 are both C keys. They look the same to the eye but the holes we drilled into the keys in Part 1 WILL NOT line up if you switch the position of the two keys.
The next photo shows the keys in their proper order.
Here’s a closeup of several keys showing the eveness ( or lack thereof ) of the cuts. Not too bad for an old guy.
The next photo shows key #1 on its corresponding pins in the keyframe. Obviously, the holes in the key are too small and the pins will not go through. This makes sense because we used a drill bit several hundredths of an inch smaller than the pins when we drilled the holes in Part 1 so as to have nice, tight pins in the keyframe. So the next step is to enlarge the holes in the keys to allow the pins to go through them.
The next photo shows 2 keys and the tools used to enlarge and modify the holes. The top key shows the original 2 holes. The bottom key has been modified. Tool A is a little jig that has a pin in it and is used as a substitute for the keyframe pins. The balance rail hole (center hole) in the key must be elongated gradually from bottom to top to allow the key to pivot up and down. This is done by placing a homemade punch (B) onto the hole at the top of the key and banging it down until it bottoms out. The wood in the key is compressed and takes on the shape of the punch. Tool C is a hole enlarger that is used to slightly enlarge similar holes in the piano technology field. Tool D is a small round, tapered file which helps to enlarge the balance rail hole. Tool E is a small flat metal file covered with 220 grit sandpaper and is used to fine tune the size of the slot at the rear of the key. This rear slot is critical to the functioning of the key. If the slot is too big, the key will be free to move in the left-to-right direction at the front of the key. This is not good.
On the other hand, if the slot is too narrow the key will bind when you press it down or will not return to its rest position. This is fatal. What we need is the slot to be just one or two thousandths of an inch wider than the diameter of the pin. I don’t know of any way to measure this other than by feel. There should be no play at all between the slot and the pin but the key must slide without any resistance on the pin. The slot is cut on the bandsaw and is widened with the sandpaper file until the fit is perfect. This takes A LOT of time, patience, food, and a television set.
The next 2 photos show a closeup of the modified balance rail hole and the slot at the rear of the key.
The inside edges of the slot are eased to an angle to make it easier for the key to find its pin. (When servicing a harpsichord a key must sometimes be removed from the instrument. When it’s time to re-install it the service person will not be able to see the rear pin. Angling the end of the slot makes it easier to do this.) The next photo shows this angle.
The next photo shows the first 14 keys installed onto their rear pins.
The final photo shows the entire keyboard installed onto the keyframe. (The piece of pine laying on the rear end of the keyboard is there to keep the keys down in the back. The keys have not yet been balanced and need this weight in the back to keep them level for the purposes of this picture.)
The only thing left to do is to make some sharps and glue them onto the front ends of the sharp keys. We’ll do this in Part 3 (which will be a much smaller post than this one). Then we’ll put the keyboard aside for a while and start building the case of the instrument.
Till next time,
Ernie
Part 1 - The Keyboard Part 2 -Keyboard con't. Part 3 - Keyboard con't. Part 4 - The Case (Bentside) Part 5 - Case Bottom Part 6 - Case Sides Part 7 - The Lower Braces Part 8 - Case Finished Part 9 - Building the Registers Part 10 - The Stand Part 11 - Jackrail & Moldings
Part 12 - The Music Desk Part 13 - Building the Benchhttp://www.ncwoodworker.net/forums/f101/harpsichord-project-part-12-music-desk-18962/
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