Saturday, August 15, 2020

Post 7: Cigar Box Guitar with wound wire frets, Piezo Zither tests

    I marked the fret positions, filed rounded notches on the sides of the yardstick, and wrapped the half-round brass wire around it, and it did work fine. So I used big head 1" roofing copper nails in predrilled holes to attach it to the neck:

   

    I received yesterday a Pre-Amp I had ordered from Amazon for $13:

     I thought I would just try plugging in it the single piezo bar pickup I had slid under the bridge of the zither and then plugging the preamp in my amp. Once again, I was amazed by the strength and tone of the sound that came out. I could hear all the strings, even those that were not above the piezo. I will try to slip a second piezo under the other end of the bridge to even the tone.

    In order to test the hurly-burly wheel idea, I took some disks I had already cut for a past project. Two of them,  7" and 8", were cut out of high-quality fine-grain 5/8" pressboard. One is just made of very thin 1/8" hard masonite tileboard. I fitted all three of them with a shaft and a little crank made up of brass lamp parts left over from yet another past project. I rubbed a piece of rosin hard all around them for a while, and then burnished and smoothed it out with a spoon. 

    All three worked, even the very thin one, with the zither, but also with the cigar box guitar and the high string of the bass. But it was obviously very hard to apply just the right amount of pressure and control the speed of the wheel while just handholding the thing.  The next step will be to test the wheels mounted in a fixed frame, and with an electric motor with variable speed. I found one with a rotation speed of 100RPM:


      I also want to test other strings of varying gauge and length: violin, viola, guitar, cello, etc... I bought a bag of 50 harpsichord tuning pins,  and a selection of cheap strings. I also got a roll of .029" and a roll of .051" piano wire to test longer strings. I happened to have a prepared panel 18" x18" that will make a fine frame and sounding board for violin strings. In fact, it is the perfect size for violin strings. 

     I mounted one of the wheels on the shaft of the geared electric motor and connected it to a dimmer connected to a little 12volts DC  power supply. I mounted an aluminum strip to anchor the strings on one end, and two rows of tuning pins on the other end, some on top for the shorter strings, others on the edge for the longer ones. I stretched one set of 6 guitar strings, and a set of 4 violin strings, using a threaded 1/4" brass rod as a bridge against the pins. The idea is to group the strings and tune each set for a particular chord that can be sounded by the handheld motorized rosined wheel. An ebony strip serves as the main bridge, which I angled so the chords would get higher going from one set of strings to the next.

       The concept definitely can work, but I have to improve the quality of the sound. I find the tuning pins difficult to adjust on such short strings, making it hard to tune the chords. Also, the sets of strings will have to use separate concave bridges with the same curvature as the wheel, so the 4 strings touch the wheel and sound together without having to apply pressure to push the two middle strings down.

       The other little gismo in the picture is a Joyo Infinite Sustainer.  This is a budget Chinese rip off of the original eBow. These have been around since the 70's, but are not used very much. It basically creates a feedback loop when it is placed close to a string and makes it vibrate continuously. It does work well on my guitar and produces interesting sounds on the new longer string test zither. But it doesn't work so well with the shorter strings of the first test zither, nor on the long strings of the bass. I will need to test it some more before I decide whether to keep it or not. 

       I do hope it will work on the electric cello I am just starting to think up, because that would really be the sweet spot soundwise. I just started a rough mockup, and have an ebony fingerboard ordered. It was cheaper to order one from Amazon than to buy a strip of ebony to carve one from scratch! I have a wooden cello bridge to use as a model to make my own with a built in electric pickup out of a 1" thick chunk of aluminum left over from the Motorcycle Bobbing Project. I want to use that strange aluminum spiral as the scroll that ends the neck. I will more or less preserve the angles and measurements of a classic cello, and started to make an aluminum saddle by partly flattening and shaping a leftover section of 1/8" thick extruded 2"x 2" angle molding. I am not sure yet how it will be attached.



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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 ...