Next, we need to make the blank perfectly square. Joint the best long edge until it’s perfectly straight. Then, place that jointed edge against the table saw fence, and cut the blank exactly 14 15/16” wide [379.4mm] (this is ¼” [6.35mm] narrower than we need in order to accommodate the ¼” thick [6.35mm] arcades that will be glued onto the front edge of the key blank). Next, trim about ½” [12.7mm] off of one short side, making certain that the trimmed side is exactly 90 degrees to the long sides. Then do the same to the remaining short side. You should end up with a blank 14 15/16” deep by about 29” wide [379.4mm x 736.6mm] – the width is not important now as long as it’s wider than the final width of the keyboard.
Laying out the keyboard
The entire keyboard must be accurately drawn onto the keyblank. In the 'templates' folder of your Harpsichord Project 5.1 directory, you will find a file named “1 octave keyboard.pdf”. Load this file into your pdf viewer and print it out using the finest quality setting. Make certain the width of the printed keyboard octave is exactly 6 1/2” wide [165.1mm], and the smaller template below it is 6 ¼” wide [158.75mm]. They should look like the illustrations below.
If you don't have the Acrobat PDF Reader installed on your computer, you can download it for free at this website.