Post 28: STARTING A NEW INSTRUMENT

    I have not quite finished the last post and will update it later with pictures of the finished instrument.

    But I want to share the new project first.

   I have been wanting for a while to build a smaller instrument for a change. The violin is a little too high-pitched for my taste, so I thought I would design a 5 or 6 strings viola with the additional strings on the low side. I started thinking about a unique design using of course aluminum and brass and sketching in my notebook. After a few attempts I did not like, I finally came up with a simple design I liked a lot. This is the rough sketch of the concept:

   The structural part is a 1/4" thick curvy aluminum spine to which is attached a split wooden fingerboard(1/2 on each side of the spine). The strings are stretched and roughly tuned using dulcimer pins tuners at the neck, and there are slightly larger brass versions of the standard cello fine tuners on the tailpiece. The bridge is triangular with a slot that fits on the spine and a built-in piezo stick like the new cello bridge.

I started a scale drawing with tentative shapes, geometry, and dimension:

After a few days mulling, it evolved into this:

  

       I am particularly pleased with the spine design, the holes being both decorative and purposeful,  the final weight being a big concern. I had to make the instrument as light as possible without compromising the rigidity. Here are some details of the tailpiece, bridge and neck:

  After a while, the blueprint got messy and I needed to make minor changes, so I started a new one with corrections:

         It's time to start building this thing. First, I had to carve out a small space in my cramped studio:

       First, I cut the basic spine shape out of a piece of 1/4" aluminum:

        Then I used Forstner bits to drill the holes. 

       Next, I made a sample fine tuner out of alu and brass:

     The tailpiece was cut out of the same piece of 5/16" thick 2" aluminum tubing I made the neck of the 12 strings bass lap of. I had a hard time flattening it to the proper curvature and drilling the hole. I also made more fine tuners. 

      Next, I roughly cut the two wooden sides out of Guatemalan caoba, a lightweight mahogany. The wood not being thick enough, I had to glue a piece on each side to accomodate the wider part of the fingerboard:

         I cut them in a wedge shape on the bandsaw and used two threaded rods to attach them to the aluminum spine:

    I cut the large slot for the preamp and started shaping the wood on the belt sander. I cut a separate piece for the fingerboard and roughly shaped its curve too. I will take measurements of †he neck of LaDonna's viola when she comes by with it and figure out how to modify it to accomodate 6 strings instead of 4: