Hollow Body Electric Violin With Bow

I had an old violin kicking about that was in pretty poor condition so I thought that I could reuse a lot of that violin to make an electric one. That though, didn't sound as much fun as making one from scratch though so I decided to make one using as little bought items as possible. In the end I ended up buying strings, fine tuners and components for a pickup, the rest was made from wood I already had in my workshop. Being quite small it was a good way to use a few nicer looking small scrap bits of wood that generally just pile up.

My original idea was to make a solid body violin but as I thought about amplification and using a piezo element, I came to the conclusion that a hollow body would vibrate/resonate more and give a better sound when amplified.

I have entered this violin in to the woodworking contest and if you find the Instructable interesting or useful please hit the vote button!

So here we go.....

I started off my looking at some images of electric violins on the internet which gave me a couple of ideas. Pretty much all of the ones I saw that didn't look like a traditional violin were solid body but they gave me a few thoughts about how I wanted my violin to look like.

I had some stripy brown oak already which had a very dark stripe with pale wood one side and darker on the other so I decided that the dark stripe would look good down the middle of the fingerboard and the body.

To sketch out the violin and get some dimensions I used a CAD package called Draftsight, I am not very quick with any 3D modelling software so I tend to stick with 2D and this package is free for individuals. One thing that can be useful is to copy images of things in to the software and scale the photo/image to a dimension you already know. In my case I knew the length of the fingerboard so scaled to a photo of a violin using that dimension. Your photo is then scaled correctly and you can then query dimensions of anything you need.

I have added the dwg. and a pdf. for anyone that is interested. It was mainly used to workout how to form the radius on the fingerboard but there is a general sketch and some dimensions (dims are in mm).

Materials

Wood for the fingerboard, body, pegs, nut, chin rest, tail piece and bridge.

Old guitar cable

Piezo element

Mono input jack socket

Tailpiece String Tail Gut

Violin String Fine Tuners

Violin strigs

Tools

Table saw

Band saw

Router

Plane

Chisel

Sanders (ROS, bobbin and belt)

Wood turning lathe

Fingerboard material - brown oak

I started off the fingerboard by building a jig to create a constant radius on the wood. A piece of wood would be attached to a pivoting central point and a router placed on the top to cut the radius and then move the router along the length until it is all cut.

I constructed an open top box measuring internally as 90mm x 90mm x 500mm (3.5" x 3.5" x 20") using some ply wood and screws. I then added a 70mm high x 480mm long bit of scrap wood and added an insert nut at 34mm from the top of the wood. With a 10mm thick board this would give me my desired radius. I then cut out a hole in the end to accommodate a bolt I could use to rotate the board. I then used a holder for my router I had built before to bring the whole jig together.

I cut an angle on the fingerboard to make it the correct dimensions as shown in the pdf using a scrap bit of wood I nailed to the fingerboard wood at an angle. This scrap wood was then referenced against the fence to obtain the right taper.

I then added another couple of insert nuts to the pivoting wood either end of the fingerboard so I could attach my wood to the jig. The narrow end of the wood needs to be higher than the wider end as the narrow end ends up thinner that the other end so need raising to make the top of the radius parallel with the underside.

Once it was radiused I cut it to length and sanded it by hand to 400 grit.

Neck material - spalted beech

Using my CAD drawing of the violin I drew the shape of the neck on the wood. I followed this by cutting the neck on my bandsaw and shaping it with a bench belt sander.

As the holes for the pegs are tapered I needed to make a tool. I had seen some previous violin tutorials that used some old scissors to create the taper. I therefore found an old pair and created a taper on the blade on the belt sander, followed by a cutting edge. Once a small hole was drilled I used the tapered blade to open up the hole.

I then marked out where I needed to hollow the peg box, used a pillar drill to remove the bulk of the waste and cleaned the hole up with a sharp chisel.

The fingerboard was then trimmed to the exact size and glued and clamped to the neck, using old sock and pants for protection!

Peg material - sapele

I cut some sapele to around 25mm x 25mm (1" x 1") and mounted it on a lathe between centres. I started by cutting the taper on the peg, using the holes in the peg box for reference, leaving a longer uncut section to the wider part of the peg. I then used a bolt sander to shape the peg head.

Body material - Oak sides and bottom and brown oak top

I had some 4mm thick long bits of oak already that I used for the sides. I wanted a nice curved look to the body so experimented some shapes by clamping the the thins bits of wood together with some different sized spaces.

I wanted to pre-curve the edge wood mainly to relive some stress so once I had the shape I wanted, I scribbed the shape on some mdf and cut it in two. I soaked the wood in some water for around an hour and then clamped them between the mdf and left to dry out. Once I unclamped it there was a bit of a curve to the wood so I think it did help a little.

One of the main parts of the body is where the neck attaches to it. I decided to use a nut insert in the neck that would bolt to block at the top of the body. This block is quite important to get right as it determines the angle of the neck/body and how high the bridge will need to be. By using some temporary clamping and a couple of tape measures I marked an angle on the block and sanded it to this line.

I then glued and clamped the block and some additional blocks to the body to create the curve.

Once that was dry I added a 5mm thick length of brown oak to the top, glued, clamped and then trimmed with a router bit.

Chin rest material - English walnut

I had some nice Walnut my boss gave to me a few years ago after felling a tree in his garden so decided to use a bit of this for the chin rest.

I used an existing chin rest to trace the shape on the walnut and cut the shape on a bandsaw. I used a chisel to create a dished shape to the upper side followed by a lot of sanding. I then shaped the underside of the chin rest using a belt sander.

Up until now I hadn't thought of how I was going to attach it to my violin so looked at a few designs and decided that I was going to use a bow shaped bit of wood to attach to the chin rest which would then bolt to the violin body. I drew a shape out on some oak, cut with a bandsaw and shaped with the belt sander. I then made an L shaped bit of wood to screw the chin rest to the bowed oak.

Tail piece material - english walnut

I used another bit of walnut to make the tailpiece. I cut a triangular section of wood and then sanded the tailpiece to a shape I found pleasing. I then drilled four holes in the tail piece to fit the fine adjusters to.

I then need to drill a couple of holes through the narrow end of the piece and cut a channel in the back, using a chisel, so I could use a tail gut to attach it to the violin body.

Nut material - sapele

This definitely looked liked the easiest part to make but I did have to make a second one once I had finished the violin as it was too high, they weren't spaced quite right and some of my strings were buzzing.

I used a small piece of sapele cut to the length of the fingerboard width, with a height so it was a millimeter or so above the fingerboard. I then shaped the back end of the nut with some sanding and added some string grooves using a set of small files. I then added some glue to the bottom and clamped it with a spring clamp.

I had looked at pickups a little previously when I built an electric upright bass, although I ended up using a second hand bridge pickup I had already bought some cheap piezo elements. I bought a jack input off eBay and had some guitar lead wire already too.

The piezo elements had some very thin wire attached to them and didn't look particularly robust so I removed these and replaced them with a small section of guitar lead that I had stripped to each end. My soldering technique is fairly poor so any hints or tips welcome.

I then covered the top end of the piezo with some hot glue and used the same glue to fix it to the inside of the body. I positioned it so it was underneath the bridge. I then used some more glue to stop the lead from moving around.

Bridge material - steamed beech

I got the main dimensions of the bridge from an existing violin bridge and drew a rough shape of a thin bit of beech. I then cut the main lines out with a bandsaw and added a taper on the belt sander. My bridge ended up being 4mm (5/32") thick at the bottom and 2mm (1/16") thick at the top. The taper should only be added to one side of the bridge so the other side is square to the feet. I then added a few cut outs with an oscillating bobbin sander and drilled a few holes to the main body of the bridge.

I I left the grooves in the bridge until the whole violin was complete so I got them just in the right place.

Now I had a the bits and the pickup was installed all I needed to was to add the back. Once the back is installed there is no way to get to the electronics so I had to be happy they were as good as they could be. If in the future I need to get back in I could always cut a hole and screw a cover back on once I'd finished, but hopefully I wouldn't need to!

I cut a 5mm thick piece of oak to the rough shape of the body then glued and clamped it to the bottom using a lot of clamps and some socks etc. to protect the body from any clamp marks.

Once the glue was dry I used a pattern bit on the router to clean up the bottom of the body. I then sanded all the unsanded parts to 400 grit, followed by adding a coat of hard wax oil.

Bow material - sapele, spalted beech and horse hair

As I had made much of the violin I decided to make a bow as well. I have made a bow before for a double bass so i had a hank of horse hair left over so was able to use that, if I remember correctly I bought it off eBay.

I followed this tutorial to make a simple baroque style bow.

I made the main stick from sapele and shaped it on a belt sander to get the tapers on the bow about correct. I followed that by making a frog by shaping a small piece of wood and cutting a groove in the top. With a hole drilled in the wide end and a hole and slot in the other end I would put the hair through the wide end first. I wrapped some cotton around the end of the hair and secured with super glue so the hair didn't some thought the hole. I then determined where I wanted the end to be tied. Once it was all dry I bent the bow in order to secure the other end.

Finally I installed the frog and added some rosin to the bow ready for playing.

All that was left once it was all put together was to tune the strings and plug the violin in to an amplifier. Luckily everything still worked and the sound was actually a lot better than I thought it would be!! It sounded as good as an amplified acoustic violin. When not plugged in, due to the hollow body, it was fairly audible and would be an excellent practice violin for anyone who needs to keep it quiet. My 9 year old son is learning violin at the moment but isn't on to a full size violin yet.....I'm sure he'll use it more when he does.

Also being an electric violin means that I can use it with guitar pedal effects and with my loop pedal I have to create mad sounding loops.

All in all I'm very please with the outcome of the violin, I just wish I could play it with any kind of skill. Oh well!

I have added a couple of sound recordings of the violin. The first one is played my my partner Jo, who apologises for the bits out of tune but she is very rusty! The second is me with it connected to a loop pedal just messing about....this is also out of tune but it at least shows you the tone I can get from the violin.

Thanks for reading