Another teacher and I at my school received a grant to work this summer on creating a variety of musical instruments from scratch to help explain how instruments work and the physics of sound to students. We created laser cut djembe drums (see another Instructable for this), a laser cut tenor ukulele (see another Instructable for this), and a laser cut electric guitar (Les Paul style) along with some other instruments including flutes and trombones.
For this project the goal was to create the body and neck of the electric guitar from scratch using plywood and a laser cutter. The final result will not replace my current Les Paul guitar, but some more work on the design, especially the neck and tuning pegs, could make the design work well enough. The final guitar produced is shown here along with a picture of my original Les Paul style guitar that I used to fine tune measurements. The other two pictures are for the laser cut djembe. This is my first attempt at writing an Instructable so I will be adding more pictures, videos, etc. as time permits. I tried to take pictures as I went, but looking back a few more close up pictures would be helpful. If I have time to make a second one, I will be sure to add some more pictures. I have also included the Inkscape *.svg files for the body and neck.
Step 1: Create Body
I used images of Les Paul guitars from the internet and measurements from my guitar to create an Inkscape template to cut out the body using a laser cutter. The body consists of 1/2" thick back plate, two 1/2" thick middle plates with etched grooves to run the wires for the pick-ups, and an 1/8" thick front plate. The plates were first cut out of cardboard to allow for fine tuning the dimensions before using the wood. The laser cutter was set at a lower power for the grooves to run the wires in the middle body sections. This requires some fine tuning depending on the power and speed of the laser cutter. The holes for the screws for the bridge need to be adjusted to a larger size and the position needs to be slightly adjusted. I also need to add another hole for the switch. The jack for the electric guitar chord was placed in the same compartment as the other electronics. If I make this guitar again, I will move the jack into a more traditional spot in the bottom of the body which will require some redesign.
Step 2: Create Neck
The neck was also created using plywood and the laser cutter. The side silhouette was used to create 5 1/2" thick pieces that were glued together. The wood was also cut at the same time to create supports to hold the neck horizontal once glued. This was used to hold the neck level under the laser cutter to cut the shape of the neck from a top view. This required multiple passes and caused excessive scorching but did give the shape. Using a band saw for this step in the future may yield better results. Grooves were also cut in the side of a couple of the sections to allow a truss rod to be run up through the neck. For this iteration a 3/8" threaded rod was used for the truss rod which makes the neck more rigid, but it still bends under the tension of the strings. A real truss rod may be used in the future. One can also buy a pre-finished neck with frets, etc. which may also be worth it in the future depending on the use of the guitar. Pieces for the silhouette and top view were also cut out of cardboard ahead of time to fine tune the dimensions. Larger grooves were cut into each silhouette for the frets, but they ended up being too large for the fret wire. Larger wire segments were used instead.
Step 3: Mount Neck, Drill Holes for Tuning Pegs, and Add Frets
The plate was used to line up the holes to mount the neck and it was screwed in place. The truss rod runs through the neck. No nuts were attached to it yet since it would require carving away some of the wood and may not improve the slight bending of the neck caused by the string tension. The frets were created from soft wire that was lying around (probably aluminum) and hot glued in place. More permanent glue will be used in the future if this form of fret seems to work. The hot glue does dampen the vibration of the strings if it extends too far away from the fret.
Step 4: Add Hardware (and Additional Holes)
A prewired "harness" was used for this so only the pick-ups needed to be added. Numerous wiring diagrams are available on the internet if you want to do it yourself. The wiring harness may need to be rewired since the connection with the amp through the cord and the switch do not give consistent results. An extra hole needed to be drilled for the switch since the wire harness purchased had one more tone knob than my original guitar. Also a hole was placed for the input jack in the same location as the switch and tone knob instead of the traditional position at the bottom which can be fixed by cutting a hole in one of the middle panels in the future.
Step 5: Things to Fix
1) Redo electronics
The switch and chord connection seem to drop out.
2) Reinforce neck
There is too much flex to the neck which makes it hard to push strings down and changes tuning.
3) Add hole for additional switch to design file and reposition hole for bridge slightly
4) Make holes for bridge, etc. the right size to prevent additional drilling.
5) Add better hole for cable to attach.
6) Smooth out neck more.
7) Fix or replace strings and tuning pegs since guitar does not seem to stay in tune well.
Make a Strat. I have the parts to make a Strat, but this time I'll be using a pre-made neck.