Musical Instrument Tuner Using Elastic String

INTRO- In this instructable i will show you how to make an instrument tuner device.

It is constructed using simple, easy to get, parts .

It is useful when tuning a string instrument or when making one and needs to be tuned.

It is strictly mechanical -no battery needed.

I built it in one afternoon.

I am entering it in the Klutz Competition.

I make an sell plans for miniature string instruments such as Lyres and Modified Zithers. See my Web page for details on www.misticmodels81.com



































[[Video(akinst 2-4-22-9, {width:425, height:350})]]

Using the tuner see video.

The pictured view shows the general view of a plastic box and 3 elastic strings tied at one end to the bottom and at the other end to a tuning mechanism .A similar sized box is attached to the bottom and used as a resonator amplifier if more sound volume is needed.
The plastic box should be semi-rigid. A plastic pencil box is just right to work with .Use a square of stiff, white card-board for the notes printing surface.You will need to mark the notes as you press down to sound the note,I used my Casio to sound the notes. The first string is tuned to C below middle C. Second string tuned to middle C. Third string is tuned to C above Middle C. Use the thumb nail of left hand and press string to card-board,Hit the note ona casio or harmonica,etc.D mark, E mark, etc.Pluck string with your right hand. Repete with all strings. Tuner is now complete.

Tools can be a plier. saw, awl or pick,Hemostat {locking type}
I used gas pliers to close the open looped cup hook [tuner screw]. This is need to easily tie a knot at this end.Home Depot sells 5/8 hooks nickel plate steel with a collar.cost about 5 cents.
A Dremel can be used to drill 1/16 drill bit pilot holes for the three screws.Screw the hooks all the way down to the little collars on thescrew. For tuning you might need assistance in screwing the tuner clockwise farther when tightening the strings.

String- canbe a rubber band cut into a string. I found it will work but I note the rubber deteriorates over time. I found an elastic string, made by Pepperell Crafts called 1mm bead/jewelry cord,is more stable and they last at least 5 years. Buy a spool at most Craft stores for under $2.00

Anchors- The string is passed through the 1/16 in hole and anchored on the under side with a crimp bead [found in any craft store] cost about 5 cents ea.

My pencil box was 4 x 8 x 1 in. deep. The strings were 4.5 inches long inside but started with 7 in. long to easily tie a knot and stretch to tune to the C note.
I tied a knot at the closed cup hook rotated the string about3 times clock-wise around the collar and routed it down to the 1/16 hole and clamped it with my hemostat plier close to the hole.Then I strung a crimp bead of 1.3mm ID and crushed the bead with pliers close to the hole.This works better than tying a large knot that wont squeeze through the hole.
I pulled the string and plucked it to get it to sound slightly lower note than the C note I played on my Casio.Then I applied the crimp. Then I final tuned it to C with the tuner screw about 3 rotations or less.

Tune - Each string was separately tuned C lowest Octave, Middle C then High C..Use your thumbnail Start with note D then E, etc Pencil mark each note location where your thumb is holding the string down on the card board plate.The marked 7 notes per string should be located similarly across from each other.
After initial tuning let the finished tuner sit for 2 hours to stabilize then final tune only the 3 strings.
I made this one 3 years ago and had to re-tune it only once a month due to humidity, etc.
Standards rubber bands only were stable for a week.They also broke.
Anyone who knows music can even play a song on this device _{Have fun. Mistic}