I like making new and interesting instruments and when I discovered this one I just couldn't resist the attempt. The Instrument comes from Sweden and is somewhat popular throughout Europe. I have never seen or played one in person so I'm going to be taking quite a few liberties with the design. So let's get started.
Step 1: The Design
This is a tenor nyckleharpa so it's tuned like a cello. I haven't put in any of the 12 sympathetic strings on this one for the sake of simplicity (nothing about this instrument is simple) I have also modified the key arrangement, instead of 4 rows of keys I only have 2 and I use each row for 2 strings (except in the case of the very top notes). The lower row of keys engage the 2nd and 4th strings and the top row engage the 1st and 3rd strings. As the bow can only play two strings at a time this seems to simplify the construction. We will have to see how this effects the play-ability of the completed instrument.
Step 2: The Body and Neck
I fist cut a template to help rough size the body stock for both the outline and interior cavity. I cut the neck so I would have the part to fit into the neck cavity. This way I could adjust the pocket to fit the neck perfectly and creat a very tight glue joint. I then rough cut the body stock to the template lines and hoged out as much of the interor as I could with the drill press and a 1" forsner bit. I then cnc cut the body and glued the neck in.
Step 3: The Top
My first attempt a making a carved top was a falure so I cut a new bass bar and then milled a top out of flat spruce, I the bent and glued this top to the back, side, neck assembly.
Step 4: Key Runners
I then began working on the parts that support all the keys, I call them key runners. There was some trial and error involved in finding a way to cut these without chip out. Eventually I found a way to cut them that worked out well.
Step 5: Keys
The process to cut the keys was the most difficult. Eventually I found that if I cut the parts and left a then piece of stock to mill of the back sides everything was well supported.
Step 6: Pins
I originally planned to cut the pins out of maple. This seemed extremely difficult so I tried making them from some stainless steel screws. I plan to cover them with something if the to e is to bright with the steel making contact with the the strings. I also made the bridge at this point it was petty straight forward milling a two sided part on the CNC.
Step 7: Setup and Adjustments
I had to make a few adjustments to the keys for clearance and I also have to put on the tuners and strings to set the position of the string notches on the bridge and tailpiece.
Step 8: Finishing: Ground
after finish sanding I begin ground coats with shellac with lots of sanding between coats. this will prepare the surface for the top coat of oil based polyurethane.
Step 9: Finishing: Top Coat
I thin down oil based polyurethane with mineral spirits and wipe on lots of thin coats to build final surface for wet sanding and buffing. I now have the instrument finished and assembled and its on to setup.
Step 10: Final Asembly
The setup process is very detailed for every instrument. String heights (action) has to be perfect and for this instrument there are may more small details to work out. the process often requires disassemble and reassembly as well as removal of stings and after adjustments are made re-stringing. If everything works out you get an easy to play instrument in the end.This instrument has been quite a challenge, I have learned a lot and found a lot better way to design all theses detailed functional parts for the next one. I'm currently learning how to play this thing so I can make a tone sample of it.