To build the jig, I took a block of wood and a small piece of 1/2" dowel. I drilled a 3/32" hole through the dowel, inserted a balance pin through it, and then nailed it into the block of wood. The keys balance on the pin so I can play with the weights and key action apart from the instrument.
These weights and the jig are somehow used to determine the amount of weight needed to cause the keys to return properly after being played with consistent action. To achieve this, weight is either removed from the keys by drilling out some mass on the underside of the key head (or doing some fancy half-moon-type carving on the front of the key) or is added by inserting lead wire (which looks a lot like the spooled solder I've used on stained glass panels), presumably further back near the tail of the key.
The manual indicates that keys one through nine need a weight of nine grams - the equivalent of one quarter and one dime, which I taped together. Keys 10 through 19 need eight grams, or a nickel and a penny; keys 20 through 29 need seven grams, or three dimes; keys 30 through 39 need six grams, or a dime and a penny; and keys 40 through 45 need five grams, which is equal to two dimes. I made up a set of those combos and labeled them each with their gram weight.
Great! But now what? How does this little jig and weights relate to the keys? In other words, how do I use this nifty little tool? The manual is incredibly short on explanation and offers zero pictures aside from a drilled out key bottom. I've been all over the Internet and YouTube looking for help. I'm soooo tired of writing to the guy who wrote the manual to ask him to explain things further. A picture of this gizmo in action would be helpful.
So, if anyone out there has built a KoS clavichord and can help me, please drop me a message! In the meantime, I will read the manual for the 20th or so time and see if a light bulb goes on.
