(Audio on step 6)

This electric skeleton violin uses a piezoelectric pickup. The body and neck are solid maple and the darker wood is mahogany.

I eventually finished it in November of last year after a two year build. It could have probably been done a lot quicker but exams and school got in the way. The body is made from a solid piece of maple. It was cut out using a band saw and a scroll saw, (I went through a fair few scroll saw blades!). The body was then shaped using a variety of hand tools. I aimed to try to use as few power tools as possible. The neck, fingerboard and pegs are explained further on.
The main book I used to make this was the Fiddlemaker's Worksheets by William K. Robertson. I highly recommend it to anyone wanting to make a violin, be it acoustic or electric. It has all the dimensions needed, the techniques for getting the correct finish and much more. The basic plan for this one came from tracing around a friends violin, (a very simple way to get started!).

Update: I have recently done a basic model of this in CAD. It is dimensionally accurate and is available to be downloaded in the following location https://gallery.autodesk.com/fusion360/projects/sk...

Step 1: Initial Drawings

As mentioned earlier. A simple way to get started is to trace around another violin. This, in combination with dimensions measured from the violin and from the worksheet book, can produce a simple starting template. Squared paper is extremely useful at this point!
The length of the body of the violin is 35cm and its width is about 21cm.

Step 2: Neck

I used computer software to model several parts of the violin. Any 3d imaging software is useful to produce accurate designs. I used Solidworks but there are plenty of free programs out there e.g. Google sketch up, Autodesk 123D, AutoCAD (30 Autodesk programs are available if you are student, http://students.autodesk.com/?nd=download_center). However, a very simple way of drawing 2D models accurately is using Microsoft Word and adjusting the lengths etc. in the properties section. This is really useful for producing accurate templates for cutting around.

This part of the violin is quite tricky to get right. I would recommend finding an old bit of wood to practice on. Harder wood is better as it is easier to carve without large 'chunks' coming off. Softer woods can split easily and this can make the carving process harder. When I did mine I did two practices before starting on the maple. It makes it a lot easier to figure out what order you need to do things in.

Here are the basic steps I followed:
1. Cut the side view out using a band saw (easiest option)
2. Drill out holes for the pegs, 5 mm diameter (a bench/pillar dill ensures the holes are aligned)
3. Cut the top view out
4. Chisel out the peg box
5. Using cabinet rasp begin to round the underside of the neck.
6. Using gouges and a rounded file begin to curve the underside of the head (image 2)

It is best to leave it fairly rough as there will be a fair amount of fiddling around getting the set-up right before actually attaching the neck. It just means you're less likely to mess up your nice smooth finish!

Step 3: Fingerboard

Sorry for the poor image quality. I thought it would come out better than that! All the dimensions you need for this part are on the photo.
For this part you need a hardwood otherwise you'll get lots of dents on the surface.
The image below includes the nut as well. The curvature of fingerboard is produced using a plane. The best way to test if you have the correct radius is to print of a template and run it across the surface.
For the final set-up on the fingerboard use a rule side on (shown in photo 2) and make sure that the surface of the board is slightly concave. This is best achieved using sandpaper as it easier to judge how much wood you're taking off. The final distance between the board surface and the rule should be about 0.5-1.0 mm.
This part of the violin is not varnished! it only requires oiling to bring out the colour.

Step 4: Pegs

The first picture below shows the basic dimensions for the pegs. Initially they need to be about 20mm longer than shown. This allows for easier fitting.
There are several tools you'll need/make in order to produce your pegs.

Reamer (photo 2)
This reamer is made from an old pair of scissors. An angle grinder was used to get the correct taper of 8.5 to 5.5mm (ish...) over a distance of 7.5 cm. I have to thank TimAnderson for his instructable on making this and the peg shaver (https://www.instructables.com/member/TimAnderson/)
This can then be used to make the peg shaver and getting the correct taper on the peg holes in the violin head.

Peg shaver (https://www.instructables.com/id/Cookie-Tin-Banjo-Part-2-Make-a-Tuning-Peg-Shaver/)
This tool can only be made once the reamer has been made. To make, simply drill a 5 mm hole in a piece of hardwood. Then, using your reamer, taper the hole. It is a good idea to mark on the reamer where the 8mm width ends. This insures that you only taper the hole that far. The next step is best achieved using a band-saw or mill but a 'bog standard' hand saw works too! You need to cut horizontally just above the hole. Then using a plane or a sander take the surface down until the full length of the hole is visible. Finally, clamp a plane blade above the hole to create a sharpener/shaver. Full photos on the link above.

Lathe
Simple pegs can be produced without a lathe, but I found that they were never quite true and were very difficult to get the detail I wanted. I found that a lathe was the easiest way to produce the shape of the peg in the image below. The head is done completely by eye but if you have a cutting jig available to you, the diameters below can be accurately achieved.

I used files and sandpaper to get the flats on either side of the peg head. I haven't really got any dimensions for this bit. It's really down to what you think looks good and feels right. After all it's your violin, it should be how you want it!
The final stage is to put the peg through the peg shaver to get the correct taper. They are now ready to be fitted to the violin!

If pegs seem like too much effort don't fear! Photo number 4 shows a ukulele machine head. These are the perfect size for a violin and allow quick and easy tuning. The only possible adjustment needed would be a hole half way down the peg, (shown in the photo).
REMEMBER: if you are drilling your own hole you will need to chamfer the edges with a larger drill bit otherwise your strings may snap.

Step 5: Electronics

For this section, there are many different ways to go. I went for a simple piezoelectric pickup from eBay and simply wired it straight to the 1/4" audio jack. This does require some form of pre-amplification but I didn't have enough space in the body to fit all of the electronics for an internal amplification unit.

There are several violin amplification kits available. They have everything you will need to amplify your instrument. Just remember to factor in the size of the device when designing the body!

Step 6: The Rest Is Up to You!

There are such a wide variety of designs that the rest of the violin is really up to you. The stages covered in this instructable are the basic stages which are fairly universal to most violin designs.

The chin rest and tail-piece both heavily depend on what design of violin you are going for. I'm currently working on one which won't have a tail-piece and the chin rest is separate from the body. I will hopefully get some instructions up for how to make a chin rest and tail piece at some point but exams are looming!

The body can be as interesting and wacky as you want! It's provides the most fun to be creative with and will be the main part that sets it apart from any other violin. The only main warning here is to keep the centre of the body strong, you don't want it snapping after all your hard work! If you find that the body is looking too weak it is possible to put a metal strengthener down the centre, hey it could be a feature! The only other thing to watch out for is that you keep enough room for the electronics.

The final finish is also very much down to your own taste. I used an amber oil varnish, which is traditionally used on acoustic violins, to finish this one. That along with a French polish (Colron French Polish sold at DIY shops) produced a lovely glassy finish. However, coloured dyes, sprays and oils can be used and hey, who even said it had to be made out of wood!

Hopefully, I've given you enough to get started on. Let me know if you have and questions.

Here is an audio/video of it being played by a friend.