Hi all and Happy New Year,
All of the major assemblies (except for the lid) have now been built. Now we have to return to many of these assemblies to make them functional. We’ll start with the pinblock which is the 1 ½” thick plank of red oak that the tuning pins will be embedded into. We built the pinblock in Part 8 – click here to review the pinblock construction. In this Part, we will add 1/8” thick spruce to the top surface of the pinblock to bring it up to level with the soundboard and to match the soundboard’s appearance. We will make the 4 bridges that we will need for this instrument. Then we will locate the positions of the 102 tuning pin holes we must drill into the pinblock – locate the positions of the two bridges that will be glued to the pinblock – and, finally, drill the tuning pin holes. Hey! Enough vacation – let’s get started.
The graphic above shows the working parts of a harpsichord similar to the one we’re building. What I call a pinblock the diagram calls the wrestplank. It shows two of the four bridges we need to make. When bridges are glued to the pinblock they are called the nuts – no doubt named after the inventors, Ima and Yura Nut. Regardless of what we call them, all bridges have the same profile but differ in size. The large bridge and matching nut tapers in height from ¾” to ½” and in width from ¾” to ½”. The small bridge and its matching nut tapers in height from ½” to ¼” and in width from ½” to ¼”. There are many ways to make these bridges. I’ve come up with a method that allows me to make bridges using only the tablesaw and bandsaw, with very little hand planing. While the bridges are fairly easy to make using this method, the process is very difficult to explain in words and pictures. So I’ll describe the process rather quickly and hope the explanation is clear enough. Here’s how I make the large bridge (called the 8 foot bridge).
First we’ll take a piece of ¾” maple and cut one long edge on the tablesaw to 35 degrees.Then we’ll cut the stock to its proper length which is 50 inches.
Next we’ll flip the stock upside down and make a pencil mark ¾” from the beveled side on one end of the stock and another mark ½” from the beveled side at the other end. Connect the two marks with a pencil line and cut on the bandsaw set to 90 degrees. This cut tapers the width of the bridge from ¾” to ½”.
Next we’ll draw a line on the beveled edge that tapers from ¾” to ½” end to end. This line is difficult to draw because the bridge is now quite thin and it’s difficult to place a long ruler onto it. Patience is rewarded however. Once this line is drawn, it’s cut on the bandsaw with the table set to 18 degrees. This cut tapers the height of the bridge from ¾” to ½” and cuts the top bevel at the same time. A little work with a small plane and some sandpaper files and the bridge is done. The next photo shows this line drawn onto the beveled edge of the bridge.
And here’s a photo of the finished bridges. The remaining bridges are made in the same manner with the dimensions changing as needed. The two bridges (shown on left) are put into the soaking bin to make them more pliable for bending. The two nuts (shown on right) will be glued to the pinblock and bend very little – so no soaking is needed.
Next we’ll turn our attention to capping the pinblock with spruce. We’ll prepare 6 pieces of 1/8” thick spruce – each 5 inches wide by 8 inches long. They’re edge glued together (using the same wedge clamping system we’ve used before) to make a spruce cap about 30” wide. Here’s the cap being edge glued.
After the glue sets we cut the length of the cap to about 28 ½”. This will leave about 1” of uncapped pinblock on each end. This is where the screws go that will secure the pinblock to the pinblock support brackets. After the pinblock is permanently glued and screwed down we’ll cut some spruce to cover the ends of the pinblock and, at the same time, hide the screws. Here’s the cap being glued onto the top surface of the pinblock.
After the glue has set the cap is trimmed flush and sanded with a random orbit sander until it’s level and smooth.
DUE TO SIZE LIMITATIONS THIS POST HAS BEEN DIVIDED INTO TWO PARTS. PLEASE SEE PART 15B TO READ THE EXCITING CONCLUSION. :rotflm::rotflm:
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 Bench Part 14 - Building the Soundboard Part 15A - Pinblock & "Nuts"
All of the major assemblies (except for the lid) have now been built. Now we have to return to many of these assemblies to make them functional. We’ll start with the pinblock which is the 1 ½” thick plank of red oak that the tuning pins will be embedded into. We built the pinblock in Part 8 – click here to review the pinblock construction. In this Part, we will add 1/8” thick spruce to the top surface of the pinblock to bring it up to level with the soundboard and to match the soundboard’s appearance. We will make the 4 bridges that we will need for this instrument. Then we will locate the positions of the 102 tuning pin holes we must drill into the pinblock – locate the positions of the two bridges that will be glued to the pinblock – and, finally, drill the tuning pin holes. Hey! Enough vacation – let’s get started.
The graphic above shows the working parts of a harpsichord similar to the one we’re building. What I call a pinblock the diagram calls the wrestplank. It shows two of the four bridges we need to make. When bridges are glued to the pinblock they are called the nuts – no doubt named after the inventors, Ima and Yura Nut. Regardless of what we call them, all bridges have the same profile but differ in size. The large bridge and matching nut tapers in height from ¾” to ½” and in width from ¾” to ½”. The small bridge and its matching nut tapers in height from ½” to ¼” and in width from ½” to ¼”. There are many ways to make these bridges. I’ve come up with a method that allows me to make bridges using only the tablesaw and bandsaw, with very little hand planing. While the bridges are fairly easy to make using this method, the process is very difficult to explain in words and pictures. So I’ll describe the process rather quickly and hope the explanation is clear enough. Here’s how I make the large bridge (called the 8 foot bridge).
First we’ll take a piece of ¾” maple and cut one long edge on the tablesaw to 35 degrees.Then we’ll cut the stock to its proper length which is 50 inches.
Next we’ll flip the stock upside down and make a pencil mark ¾” from the beveled side on one end of the stock and another mark ½” from the beveled side at the other end. Connect the two marks with a pencil line and cut on the bandsaw set to 90 degrees. This cut tapers the width of the bridge from ¾” to ½”.
Next we’ll draw a line on the beveled edge that tapers from ¾” to ½” end to end. This line is difficult to draw because the bridge is now quite thin and it’s difficult to place a long ruler onto it. Patience is rewarded however. Once this line is drawn, it’s cut on the bandsaw with the table set to 18 degrees. This cut tapers the height of the bridge from ¾” to ½” and cuts the top bevel at the same time. A little work with a small plane and some sandpaper files and the bridge is done. The next photo shows this line drawn onto the beveled edge of the bridge.
And here’s a photo of the finished bridges. The remaining bridges are made in the same manner with the dimensions changing as needed. The two bridges (shown on left) are put into the soaking bin to make them more pliable for bending. The two nuts (shown on right) will be glued to the pinblock and bend very little – so no soaking is needed.
Next we’ll turn our attention to capping the pinblock with spruce. We’ll prepare 6 pieces of 1/8” thick spruce – each 5 inches wide by 8 inches long. They’re edge glued together (using the same wedge clamping system we’ve used before) to make a spruce cap about 30” wide. Here’s the cap being edge glued.
After the glue sets we cut the length of the cap to about 28 ½”. This will leave about 1” of uncapped pinblock on each end. This is where the screws go that will secure the pinblock to the pinblock support brackets. After the pinblock is permanently glued and screwed down we’ll cut some spruce to cover the ends of the pinblock and, at the same time, hide the screws. Here’s the cap being glued onto the top surface of the pinblock.
After the glue has set the cap is trimmed flush and sanded with a random orbit sander until it’s level and smooth.
DUE TO SIZE LIMITATIONS THIS POST HAS BEEN DIVIDED INTO TWO PARTS. PLEASE SEE PART 15B TO READ THE EXCITING CONCLUSION. :rotflm::rotflm:
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 Bench Part 14 - Building the Soundboard Part 15A - Pinblock & "Nuts"
Last edited:
