Hi all,
It’s been 10 days since we started the Harpsichord Project (it seems longer than that to me and probably to you too). I’m trying to keep my posts current with the work so that my mind is still able to remember what I do well enough to attempt to describe it (no guarantees here, for sure). If you’ve ever had a house built you know that the progress seems to go very fast in the beginning and then slows to a crawl. Same thing with building a harpsichord. Pretty soon, the interval between posts will get longer as the real detail work begins.
In this post we will add the case sides to the Bottom and, finally, we’ll end up with a HSO (harpsichord shaped object). Let’s do it!
We will be using screws to clamp the sides to the bottom (and to each other) so the first step is to drill holes around the perimeter of the Bottom. Since the sides are ½” thick we’ll draw a line ¼” in from the outside edges of the Bottom. The first photo shows this.
The next step is to assemble the entire case without glue. This allows us to get precise measurements for each side as slight differences from the blueprint are inevitable. The joints are simple butt joints (miter joints were more often used in the originals but I’ve never been comfortable with them and they’re difficult to cut on the bentside). The next photo shows the spine clamped to the Bottom. The clamps are adjusted until the spine is 90 degrees to the Bottom and then a few screws are driven through the holes we drilled in the last step into the spine to hold it in place.
In the next photo we clamp, square, and screw the bentside to the bottom but we’ll leave the length oversized for now.
Next we install the cheek, mark it for length, and cut it to its proper length.
Next we install the tail.
Now that all of the parts are installed onto the Bottom, we’ll mark the bentside for length, cut it to size (actually, we’ll live it slightly too long and sand it flush after it is installed with glue), and re-install it onto the Bottom.
Here’s a view from the rear.
Next we’ll drill pilot holes in the bottom edge of all sides drilling through the holes we previously drilled in the Bottom. Then we’ll take the whole thing apart to make some necessary dados, rabbets, and other fun stuff. The next photo shows a ½” wide rabbet routed into the front inside edge of the spine and cheek. In the 17th century these instruments had a front panel which closed in the instrument. It fit into these 2 rabbets. In modern building, this front panel is almost never used but the rabbets remain as a decorative element.
Next a dado is cut into the spine and cheek which will accept the nameboard.
Now we will re-install all of the sides (this time with glue). The next photo shows the cheek being glued in. Care is taken to get the sides perpendicular to the bottom especially the front ends of the spine and cheek. Any out of squareness here will be visually apparant when the keyboard end blocks are installed in a much later step. As I said before, screws are used to clamp the parts together while the glue dries. Similarly, the butt joints between adjacent case sides are clamped with screws. Yellow glue is used between the Bottom and the bottom surfaces of the sides. I do use epoxy for the butt joints (although I’ve been convinced for years that this isn’t necessary). In 25 years I’ve never had a problem with joint separation regardless of the type of glue used. After the cheek, the bentside, tail, and spine are similarly glued in. I won’t show photos of this as it would be too repetitive.
After all the sides have been glued in, the nameboard is glued into the dados we previously cut into the spine and cheek. The next photo shows this.
The next photo shows 3 of the four slots that were cut into the nameboard and spine. Brass control levers will ultimately pass through the slots in the nameboard which are 3/16” high. The larger slot in the spine is an escape window which will allow the removal of the registers (more on those later) without having to remove the strings first. These slots were cut the old-fashioned way – a series of holes drilled into the wood and a lot of hand work with chisels, files and sandpaper.
Finally, the screws used as clamps are removed, the holes filled, and the case is rough sanded. The final 3 photos of this Part shows the finished case shell with the keyboard.
The case, as it is now, is far too weak to withstand the 6000 pounds of tension it will be subjected to once the strings are installed and tuned up to pitch. A lot of interior bracing is needed to make the case stiff enough to withstand this tension. Any flex in the case will cause the instrument to go out of tune. Let’s face it – if it won’t hold a tuning it’s useless as a musical instrument. In Part 7 we will add the interior case braces and a few pieces of decorative molding.
Thanks for sticking with me. See you 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/
It’s been 10 days since we started the Harpsichord Project (it seems longer than that to me and probably to you too). I’m trying to keep my posts current with the work so that my mind is still able to remember what I do well enough to attempt to describe it (no guarantees here, for sure). If you’ve ever had a house built you know that the progress seems to go very fast in the beginning and then slows to a crawl. Same thing with building a harpsichord. Pretty soon, the interval between posts will get longer as the real detail work begins.
In this post we will add the case sides to the Bottom and, finally, we’ll end up with a HSO (harpsichord shaped object). Let’s do it!
We will be using screws to clamp the sides to the bottom (and to each other) so the first step is to drill holes around the perimeter of the Bottom. Since the sides are ½” thick we’ll draw a line ¼” in from the outside edges of the Bottom. The first photo shows this.
The next step is to assemble the entire case without glue. This allows us to get precise measurements for each side as slight differences from the blueprint are inevitable. The joints are simple butt joints (miter joints were more often used in the originals but I’ve never been comfortable with them and they’re difficult to cut on the bentside). The next photo shows the spine clamped to the Bottom. The clamps are adjusted until the spine is 90 degrees to the Bottom and then a few screws are driven through the holes we drilled in the last step into the spine to hold it in place.
In the next photo we clamp, square, and screw the bentside to the bottom but we’ll leave the length oversized for now.
Next we install the cheek, mark it for length, and cut it to its proper length.
Next we install the tail.
Now that all of the parts are installed onto the Bottom, we’ll mark the bentside for length, cut it to size (actually, we’ll live it slightly too long and sand it flush after it is installed with glue), and re-install it onto the Bottom.
Here’s a view from the rear.
Next we’ll drill pilot holes in the bottom edge of all sides drilling through the holes we previously drilled in the Bottom. Then we’ll take the whole thing apart to make some necessary dados, rabbets, and other fun stuff. The next photo shows a ½” wide rabbet routed into the front inside edge of the spine and cheek. In the 17th century these instruments had a front panel which closed in the instrument. It fit into these 2 rabbets. In modern building, this front panel is almost never used but the rabbets remain as a decorative element.
Next a dado is cut into the spine and cheek which will accept the nameboard.
Now we will re-install all of the sides (this time with glue). The next photo shows the cheek being glued in. Care is taken to get the sides perpendicular to the bottom especially the front ends of the spine and cheek. Any out of squareness here will be visually apparant when the keyboard end blocks are installed in a much later step. As I said before, screws are used to clamp the parts together while the glue dries. Similarly, the butt joints between adjacent case sides are clamped with screws. Yellow glue is used between the Bottom and the bottom surfaces of the sides. I do use epoxy for the butt joints (although I’ve been convinced for years that this isn’t necessary). In 25 years I’ve never had a problem with joint separation regardless of the type of glue used. After the cheek, the bentside, tail, and spine are similarly glued in. I won’t show photos of this as it would be too repetitive.
After all the sides have been glued in, the nameboard is glued into the dados we previously cut into the spine and cheek. The next photo shows this.
The next photo shows 3 of the four slots that were cut into the nameboard and spine. Brass control levers will ultimately pass through the slots in the nameboard which are 3/16” high. The larger slot in the spine is an escape window which will allow the removal of the registers (more on those later) without having to remove the strings first. These slots were cut the old-fashioned way – a series of holes drilled into the wood and a lot of hand work with chisels, files and sandpaper.
Finally, the screws used as clamps are removed, the holes filled, and the case is rough sanded. The final 3 photos of this Part shows the finished case shell with the keyboard.
The case, as it is now, is far too weak to withstand the 6000 pounds of tension it will be subjected to once the strings are installed and tuned up to pitch. A lot of interior bracing is needed to make the case stiff enough to withstand this tension. Any flex in the case will cause the instrument to go out of tune. Let’s face it – if it won’t hold a tuning it’s useless as a musical instrument. In Part 7 we will add the interior case braces and a few pieces of decorative molding.
Thanks for sticking with me. See you 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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Different pianos can have different tones, but how about the harpsichord? For example, the bentside. I was surprised that the bend didn't need to be a little more precise. How different can the shape of the basic case construction be before you lose the sound you want? 
