DIY PROJECT TO MAKE A PLAYABLE MINI-BANJO 2 STRING 2 OCTAVES FOR KIDS.
This two day project is very similar to but not identical to the Instructable "Mini-Uk 1-14-2010.
You can use the Ukkulele information for stringing and tuning ,etc.
Step 1: MATERIALS
Same type materials and tools as shown in the Ukulele Instructable; You can substitute other wood for the neck . I used Oak found in the Decorative timber of Home Depot. It is already to use.
The frets were split wood coffee stirrers .05 inches thick. Some people use no frets at all.
Resonator chamber happened to be a dog food container but any round case could be used.The material is aluminum and esy to use. See figure Construction for details.
Amplifier- Dollar store earphones 1 in. diameter 32 ohms are very sensitive and save a bundle of money.. Feed into Radio Shack pre-amplifier/speaker [about $12.00] This can feed into your major amplifier or a i-pod stereo amplifer now sold for under $5.00 in some stores.
Step 2: CONSTRUCTION
Attaching the neck wood to the case; Mark off the location where the neck meets the case at the top. Punch 6 holes with an awl in the case . This will give double the strength when the glue [Goop ] is added here . Let the two parts cure for at least 4 hours
. String feed - Use an awl to punch two small holes in the top where the Polymeric elastic strings will feed through. The strings will be notes B and D just below and above Piano middle C. Pull strings through the holes and twange them untill they sound close to but lower than the final desired note.
Final tuning is done with the screw eyes at the neck top. Then add a bead crimp and use long nose plier to squeeze bead closed to the metal case inside of the case.
Step 3: TESTING
After completion of the instrument-
Frets may be used . If so - you can use fret location the mathematical way or my way which I find easier. Use a tuning devise or in my case a cheap Casio type 3 octave keyboard..
Tune B note then next hit Cmiddle note and place a finger on the string and find the C note sounding like the casio. Mark with a pencil for fret one. Continue like this with all naturals and sharps.[Kids may not like to use sharps so you could leave out sharp frets.
Repeat for the next string D note. D# , etc. till you cover at least two octaves for the banjo.
Sit the unit aside for 2 Hours- The note B and D will drift down to a lower note- Retune each string to B and D. This drift effect will occur for at least 3 tune-ups in 6 hours.Drift is under a half -note so your player will note practically no noticable drift. After a couple of retunes you can then disregard the minor drift.
Step 4: AMPLIFICATION
Amplification can be used as stated above. I used some old earphones of the dynamic type 8 to 32 ohms and with stereo cord attached.Dollar stores have these for a buck and work as good as the high-priced microphones now on the market. Ear bud phones work too. Feed into a 1mvolt sensitivity pre-amplifier and then into your stereo system or any old amplifier. I use an old PC speaker /amplifier system with a powerful two- watts output. See figure.
Glue the ear phones to the inside of the case or outside and inside if you wish to use both ear pieces. Use silicone rubber tub seal adhesive in case you need to remove later.
The pre-amp is Mono-input so use a stereo to mono adaptor here[Dollar store $1.00].Same for output.