Albeit guitar manufacturing has come a long way in the past hundred years, there is a long history to show that you don't need much to make a guitar. All you need is a box to resonate the sound, a plank of would to act as the fretboard, a few screws, and some string. On account of its simplicity and instant reward factor, it is still pretty fun to build one of these traditional homemade guitars.
Yet, it would be a little silly to ignore all of the great things that have happened to guitars in the last hundred or so years. With this in mind, we are going to be bringing this cigar box into the modern era by amplifying it with a piezo contact pickup and a volume knob.
Step 1: Go Get Stuff
You will need:
- 10K-Ohm Audio Control Potentiometer with SPST Switch (Model: 271-215 | Catalog #: 271-215)
- 90dB Piezo Pulse (Model: 273-066 | Catalog #: 273-066)
- 1/4" Mono Panel-Mount Audio Jack (Model: 274-255 | Catalog #: 274-255)
- a cigar box
- 3 feet of 1x2
- 1-1/2" section of half round
- 3" section of half round
- (x3) 1/4" x 3" eye bolts
- (x3) 1/4" wing nuts
- (x3) 1/4" nuts
- (x3) 1/4" washers
- nylon guitar strings
- 5-minute epoxy
Step 2: Measure and Mark
Open up your cigar box. On each of the shorter edges, find the center point and then measure 3/4" in each direction from this point.
Note: This is assuming your 1 x 2 is 1-1/2" wide. Adjust these measurement for the exact length of your 1 x 2 if need be.
Step 3: Cut
Where you have made your marks, cut down until you have made two square holes that are flush with the top of the case that are the size of your 1x2.
Step 4: Measure and Mark
On one end of your 1 x 2 make 4 sets of lines that are an inch apart, starting half an inch from the edge.
On the first line, make a mark 3/8" from the right edge.
On the second line, make a mark 3/8" from the right edge and 3/4" from both edges.
On the third line, make a mark 3/8" from the left edge and 3/4" from both edges.
On the last (fourth) line, make a mark 3/8" from the left edge.
Step 5: Drill
Drill six 1/4" holes through the 1 x 2 where you had just marked.
Step 6: Measure and Mark Again
At the opposite end of the 1x2, make three marks that are 3/8" apart (at 0.375", 0.75" and 1.125"), and that are 1/2" from the edge of the beam.
Step 7: Drill Again
Drill through the 3 marks that you just made with an 1/8" drill bit.
Step 8: Piezo
Carefully pry off the back of your Radioshack buzzer.
Break apart the buzzer case without damaging or bending the piezo disc to free it.
You should be left with only the piezo disc with two wires attached.
Step 9: Audio
Attach a black wire to the ground lug of the audio jack and a red wire to the signal lug.
Step 10: Wire It Up
With the potentiometer knob facing upwards and the three side pins facing you, wire the black audio jack wire to both the pin on the left and the case of the potentiometer. Also wire the black wire from the piezo disc to this left pin.
Wire the red wire from the piezo disc to the right pin of the potentiometer.
Finally, wire the center pin on the side of the potentiometer, to the closest (front) pin on the bottom of the potentiometer. Wire the red wire from the audio jack to the furthest (back) pin of the potentiometer.
Step 11: Drill
Drill a 1/4" hole 1-1/2" from the bottom left corner of the cigar box for the potentiometer. I also drilled an 1/8" hold just to the left of this hole for the potentiometer's mounting tab (this helps the potentiometer lay flush with the case and prevents it from shifting).
Flip the cigar box on its edge so the clasp is facing upwards and drill a 3/8" hole for the audio jack near the potentiometer hole. Make sure not to put this hole too close to the top or bottom of the cigar box, or the audio jack won't be able to fit in.
Step 12: Glue
Epoxy your 1x2 to the inside-top part of the cigar box.
Make sure that the end of the 1x2 with the three small holes is sticking out about half an inch from the cigar box on the side with the potentiometer hole.
Step 13: Glue More
Once the epoxy from the last step has set and your guitar can be handled, close the case.
Mix up some more epoxy.
Glue your 3" section of half round to the front of the cigar box towards the edge with the potentiometer hole.
Glue the 1-1/2 section across the length of the top side of the 1x2 about an inch from the holes you drilled there.
Step 14: Tuners
Thread a nut all the way to the bottom of the eye bolt. Put a washer atop this nut. Pass the eye bolt from bottom to top of the single 1/4" hole closest to the edge of the beam. Place another washer onto the eye bolt and fasten it all in place with a wing nut.
Repeat this process on the center hole in the second line and the left-most hole in the third line.
In short, each bolt should have a hole directly in front of it once complete.
Step 15: Install
Insert the potentiometer into the cigar box and fasten it in place with its mounting nut.
Next, insert the audio jack and fasten this as well.
Finally, using standard two-sided tape (preferable), attach the flat side of the piezo element to the underside of the front of the cigar box guitar. Try to place this close to the 3" section of half round that is glued atop.
Step 16: Tie
Tie a guitar string to one of the small nuts.
Repeat the process with the remaining to hex nuts.
Keep track of which string is which. I highly recommend using the high E, B and G strings, as they will add the least amount of tension.
Step 17: String It Up
Pass the high E string up through the small hole nearest the potentiometer. Pass it along the length of the guitar and then down through the hole in front of the corresponding hardware tuner. Tie the end of the string to the eye bolt and twist it until the string is tensioned.
Repeat this in the center for the B string and then again for the G string.
Once all of the strings are tensioned, you can tune them to your liking.
Step 18: Finishing Touch
Fasten a knob to the potentiometer to make it look finished.