Post 34: Thinking of a headless and fretless bass

   I would like to use that wonderful piece of canari wood to try my hand at making a more traditional wooden bass. I want it to be special in some way.

   I considered using 5 single tuners to make it a 5 strings long-scale bass using extra long strings, possibly pushing the scale to 38". But then I ran across a really nice set of tuners and string locking nut on Amazon for only $35.99... I was not expecting much, but it turned out really nice and solid, and I decided to use it and go for only 4 strings. 

    On top of that, the way the individual bridges are designed, I could with minor modifications place a piezo pickup right under them. All I had to do was to cut 2 slots on the sides to accommodate the width of the piezo and one underneath for the wire:

   I had first made a rough mockup in Photoshop:

So I more or less reproduced it full scale on a large piece of poster board, straightening the original slanted design

     I will be refined as I look at it over a few days and fiddle with the shape, probably shrinking the body some.

    The length of the neck will be determined by the length of the strings, and I want big strings, so I ordered a set of 5 D'Addario Xtra Long flat-wound bass strings,  of which I will only use the 4 bigger ones .65, .80, .100 , and .132.

Post 33: Ready for further tests

  I took the instruments completely apart to bend the end of the neck back, and then reassembled it and restrung it with a new set of flat wound strings in diameters .26, .36, .46, .59, .70, .85, and .105.

  The tuners ended up being too hard to adjust by hand, I will need to change the thread of the screws to a smaller one, probably using M4 metric screws fitted to the knurled knobs.

  I gave it to my friend LaDonna to play with and test for a while.

Post 32; Stringing the guitar

  After the first full springing test, I realized that both the nut and the bridge were too high, the frets to quite level, and that the neck was not as stiff as I thought.  I needed to add a pair of truss rods to counter the pull of the strings. 

   I cut two brass half-moons that I attached at the neck and at the bridge with 3 large screws. 

        Two M4 stainless steel rods connect them and long nuts at the end of the neck allow adjustment

      Once these were installed and loosened, I put the guitar back together. The fingerboard was attached with double-stick tape. I gave up the idea of a bridge with adjustment for intonation and instead cut and shaped a slim piece of bone. The ebony was shaved to be level with the brass holders in order to lower the bridge as much as possible. A groove was cut in it and the bone strip was attached with epoxy. 

      

     The brass nut was cut down and attached to the neck with two small screws. The two side strings were installed, the position of the grooves for these two strings marked on both the bridge and the neck, ans shallow grooves cut. 

   I tightened the truss rod some, and then some more as the rest of the strings were installed and roughly tuned. The spacing of the strings was marked and grooves cut for the rest of them. They were still too high both at the bridge and the neck and the grooves were progressively deepened till I was happy with the action.  I will fine tune it later. notice the 1/8" aluminum at the end of the neck is pulled up by the tension of the strings. I will need to bend it back some to make it stiffer and compensate.

        A test showed that both the piezo pickup at the bridge and the magnetic pickup work fine with an acoustic guitar preamp.  However, the bridge pick up is very sensitive and picks up taps on the body and finger sliding noise on the round wound test strings. So I ordered a set of flat wound guitar strings and a set of bass strings in graduated sizes.

        Instead of a switch between pickups, I decided to use two pots to control the mix progressively before running the signal through the preamp, which is attached to notched pieces of aluminum glued with cyanocrilate.