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Design Objectives

To build a guitar and then learn to play it.
As a young lad I always dreamed of bieng in a rock band, but when I grew up I realised that this was yet another career opportunity that had passed me by. Still I can't complain bieng an Engineer of course I still get all the drink, drugs and girls I can handle (At least that's what Careers Officer told me!)

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13/02/2016
Finally got back home and so had a chance to progress the guitar work. Today I concentrated on the "Gulf" Guitar. I set up my sander cylinder on my pillar drill and proceeded to square off the edges which I had cut roughly with the jigsaw. This all went well and I soon had both the body and the headstock looking much better. I then used a 10mm rad edge tool in the drill to roughly round the edges of the body for a more soft contour. This went less well as I was unable to set the height as I would have liked on the drill. In hindsight I should have used the hand held router, but not to worry I sanded the whole body by hand and adjusted the edges where needed. I was quite pleased with the outcome. I also added large grooved pockets between the switch recess and the pickups. I want to wire the complete guitar to the pick guard and then attach it as one to the guitar. This will give me the opportunity to easily change the configuration of pickups and switches for experimentation. many Fenders can be wired like this and I think this is a good idea. From this stage onward many people apply spray coats, but I believe a much quicker way would be to apply paint using a brush. Brushed layers are much thicker and therefore give more opportunity for heavier sanding. I used what I had on hand and that is  bondaglass voss rust paint! At least my wood won't corrode any time soon. I use this on my car restoration and I know it works well with build primer and car paint. There is still many weekends of work here, but I think I have made a good start.

 

10/02/2016
There has been lots of activity and as usual in all sorts of directions. Firstly The kit guitar has had some major modifications. I have hacked the rough shape of the body for the "Gulf" mods and cut out the headstock. Hopefully this weekend I will get a chance to do some sanding and maybe the first coat of primer. I have also replaced the tailstock with a fixed one with no tremelo and the plastic nut at the headstock has been replaced with a roller type. This required the first real piece of woodwork and some delicate sanding. I may be too high or too low I'm not sure, but either way it can be sorted when the guitar is together. i would prefer it too low at first so I can shim it up and experiment with the "Action" of the strings. I have also ordered a few tools such as a notched ruler so I can better setup the guitar and frets. I have been watching many videos online of how this is done.
I also havent mentioned that a couple of weekends ago when I was in London I spotted an unusual guitar on eBay. It didn't sell, but a quick message to the owner and I bought it privately for 40. I drove to Waltham Abbey in North London and picked it up on a Sunday morning. This is a Terminator Synsonic. It is a guitar from the 1980's which has quite a following in the USA and I think may be quite a collectors piece in the future due to ist unusual features.

As you can see by the image it is a Fender style guitar, but it has  an integrated amp and speaker! The two outputs are quite a mystery so this required further investigation. The on board amp is driven by two 9v batteries which are inserted at the rear of the guitar. Unfortunately the contacts in the box have been broken and some crude loose connections have been made. I will see If i can use some copper strip or similar to restore them, or if not there is a much better twin battery box available or I could use two single boxes. This would require modification to the body, but I may do this as it is a sympathetic modification and shouldn't detract from the appeal. The tuning pegs are also non original, but this is also OK as the standard ones were a real weak spot of this guitar. I might also add a 9v plug socket so it can be run off a "Wall wart" type power supply. If I keep any changes all nice and clean this should not detract from the value (Its only worth 40 anyhow!)
So the mystery of the two output jacks. I couldn't get the speaker to sound, so I took the electronics apart. Here is what the guitar looks like with the cover removed.
I removed the circuit board and spent an hour or so figuring out the PCB. The circuit is fairly straighforward. There is a conventional two pickup, volume and tone circuit that feeds to a amp circuit. The amplifier is a small in line KA2212 amp which is only 0.5 Watt and matches the speaker rating. The amp circuit is almost identical to the circuit in the datasheets for this amp. There is also a 1 Watt version available and also a drop in speaker....Hmm double the power sounds like fun! One jack plug can be used to take a signal straight from the pickup circuit so bypassing the amp. In this way you can use the guitar like a standard one without any electronics. The second jack when plugged into disconnects the speaker, but outputs after the amp. This could be used as a pre amp or to drive a small external speaker. I have noticed that one of the resistors on the board is burnt out so I think maybe some over voltage has been going on somewhere. In any case the circuit is quite simple and all the parts are available so I fancy having a go to fix it. I'm looking to get a small collection of guitars (No more than about 5) as I think they are just attractive items and this might be a nice low cost addition. My Switch guitar I bought about 4 years ago for 100 is now worth about 250, so this leads me to believe that this is not money wasted if I buy unusual looking or unusually made guitars.

24/01/2016
I picked up the guitar kit on Friday from the Prof. house and on Saturday I had a good few hours building it up.

A couple of problems have arisen. Firstly the Bigsby style tremelo arm means that the strings need to be a bit longer than the ones supplied and one of the strings wasn't long enough. Luckily I have a few spare sets. The tremelo also means the guitar does not want to stay in tune (A common problem) so I think I will change it for a hard tail one such as one from a Gibson or Ibanez (Copies of these are available on eBay). The fifth string also has an unusual buzz which I think is coming from the nut at the top end of the guitar. It's only minor but I shall have to see what this is and sort it out. These kits need to be left for a while with the strings tensioned before any work is done, so I have left this at home and will do some mods in about two weeks time.
  Whilst down in London I have been doing some CAD design and this is what I have come up with.

I want to go for a bit of a 1950's sort of look so will modify the headstock shape and also reduce the body "Horns" down to something a bit more shapely. I have to be carefull as the top half of the body is hollow so can't really modify the rear top too much. I might get a scratch guard cut in steel. In addition I quite fancy an orange stripe somewhere and this colour combination was used extensively on racing cars sponsored by Gulf Oils. So from now on the guitar will be called the Gulf Guitar. I might even add on a Gulf sticker!

20/01/2016 - New projects.
It seems such a long time since I updated this post...It has been a long time! The initial MDF guitar body has really been abandoned. The main reason for this is the state of the headless neck. The nut location and height were really poor and there wasn't any easy way to fix that short of making a new metal end. I haven't really got the facilities to do that at the moment, so I needed a rethink. Unfortunately the MDF body had also been designed to take a headless type bridge and heel. I won't throw it away just yet, but I have decided on a new project.
  First in the pipeline is a new guitar kit off ebay. This is a more conventional Telecaster style guitar with a semi hollow body.

I have read that this kit isn't too bad and I was keen to have another go at something different. I am particularly keen to decorate the guitar with a sprayed finish, maybe Gulf racing colours (Sky blue and orange). The kit comes with a nice old style Rockabilly tremelo arm and some nice interesting neck inlay. I might also laser cut a new finger guard and switch plate in stainless. It depends how whether there is an laser cut order going in at the time of delivery. I will probably build this and then give it away to some lucky friend and won't be modifying it too much. I may even just build it and varnish it for a quick turn around. It depends how I feel about it when I get it.

  Second project is a 3d printed body design. I have looked around the net and there seems to be a few designs popping up. Here are two that I have downloaded and put into Catia V5

I like the one on the right best and apparently it is printed in 10 pieces. The one on the left is a is semi hollow design. I would love to do a design where the switches and pickups could be removed from the back so you could experiment with different configurations. One thing I also like is the "Westone Rail Bass" from 1985/1986. This is a period in guitar development where they were trying everything new and headless.

I'm not sure how rigid the body would be printed, but I could incorporate pockets for the rails in the back as I am used to this sort of thing having made lots of 3D printers. It could also keep the material volume of the print to acceptable limits. I could even fill it from the back with some infill material such as resin mixed with wood etc. to improve the acoustic performance of the body. I think it would be a welcome addition to the Reprap Orchestra!

23/05/2012 - Finishing.
Before finishing the main body I have produced a little test piece of MDF and plywood in order to test out various methods. I have tried acrylic stain, Danish (Tung) Oil and also
the Ronseal Diamond Hard Varnish from B&Q as used on the neck. The Danish Oil seems a little poor, but I will reserve judgement until I have a few more layers and polished it. The acrylic stain is OK on the plywood, but makes the MDF look rather muddy in appearance. So its going to be a natural wood finish in Hard Varnish unless the Danish oil improves. The test piece also gave me the chance to round the corners to see what they would look like. A large radius looks untidy as the cheap plywood isn't the best to sand, so I will stick to just a small rounding off before applying the finish coats.  

16/05/2012 - Body Sanding.
After completing the body construction and fitting the neck pocket it was on to sanding. I read in a guitar magazine that using a drum sander
was the way to go for the edge of the body. I ordered one of these and it arrived today. I modified my pillar drill as a sanding table using a piece of 18mm MDF drilled in the right places and bolted to the table. The picture shows a 50mm diameter drum sander, but I also ordered a 25mm diameter one should I require it later.
It works incredibly well and the edges are starting to look really nice. A few more evenings work and I should be able to make a decision as to whether a simple Danish Oil (Tung Oil) finish will be OK or I will need filler and paint. I really want to avoid this as it's lots of work and the guitar doesn't really justify such effort. I have also made another decision in that the pick guard will not be plastic, but steel or aluminium sheet. I don't really have the facilities at the moment to bevel a 3mm thick laminated sheet for a nice edge, but I think I can manage a sheet metal one. I'll do this first and see how it looks. I can always upgrade in the future when I get a little more confident.


13/05/2012 - Build Phase Started.
I have been busy cutting MDF and plywood for the new body. As I only have a A4 printer I couldn't print the paper templates out full size in one piece, but as luck would have it there is a tiling facility on the print output, so with a little cutting and tape I had a set of full size templates. All the parts were marked and cut out with a hand held jigsaw. Not too accurate, but a good sanding and reshaping should have this sorted. After gluing the centre 3 MDF layers together I will sand the inside features to make them presentable before attaching the front and rear. I can't help thinking that if this was made from 8 layers of 6mm ply it would look fantastic, particularly if laser cut so it was accurate and required minimal finishing. I'll log that as a future idea. The body feels quite light, but is already very rigid.


11/05/2012 - CAD work nearly Complete.
The past few days have been spent refining the design. All the parts have now arrived which means they can be CAD modelled and added. I ordered a new neck which I was hoping to fit, but I have now decided that the current one will be better if fitted with a "nut" at the head end. Internally the body has two struts between the neck and the bridge, hopefully this will make the body rigid so it stays in tune, but this may reduce the acoustic volume as the front sound board will also be rigid. This isn't a problem as I want a very quiet guitar, but hopefully a little more tone than an unplugged electric. I have also altered the design so there is no need for a rear removable cover. All electrics can be done by removing the pick guard. I have also left room for a neck and bridge pickup should I wish to add one later. As for finish I have decided to keep it natural if possible, plywood front and rear and MDF centre, just sealed with Tung oil. This wont be the best looking guitar, but at least when people see it they will know its hand made! If I do have problems with edge splintering when cutting the board, I will just have to resort to filler and paint.



06/05/2012 - Phase 2 Development.
A CAD investigation is now underway to see if the guitar can be improved. It would be nice to have a guitar that has a little more volume when unplugged and with this in mind I am designing a semi acoustic box with an ergonomic shape. I also intend to use only one pickup and keep the wiring simple. The picture below shows a humbucker, but I will probably use a lipstick type pickup. In any case the pickup and wiring will be attached to the back of the pick guard (shown in dark grey), similar to a Fender Stratocaster and hopefully can be removed and changed as one piece so I can experiment. I'm hoping that mods to the pickup are possible without removing the strings. I have also kept the front and back flat so its easier to make in MDF.


04/05/2012 - CAD Modelling Complete.
All the CAD modelling is now finished. This means that if I want to do any modifications to the guitar it will be much easier to work out the design before manufacture. Click image below for a larger version.

Further investigation on the net has revealed that MDF has been used successfully for guitar bodies. In fact they work quite well. A company called Lindert made guitars this way between 1986 - 2002. Contrary to expectation they are highly sought after and are renown for their strong build and good sound quality! It seems that this may be the way to go for this guitar. Some MDF guitars are covered with epoxy to give them a hard finish. I have some fibreglass gel coat in the garage, so this may be ideal and wont cost anything. I have ordered a Tune-o-matic bridge and I may also add a single "Lipstick" pickup. I'll start the CAD work as soon as I can so I can get a feel for how it might look.

03/05/2012 - Build Complete.
Today saw the completion of the headless guitar kit. As there weren't any instructions with the kit I was short of the wiring diagram.

After searching the net, as usual in the guitar world, there were so many different ways suggested, I was a little confused, so in the end I chose the simplest I could find.

Now its together I must say the kit is a little basic and doesn't go together well. The neck was misaligned and I had to bolt it on with an extra plate and also I couldn't avoid fret buzz when setting it up. There seems to be no "nut" at the head end and this meant fret 1 buzzed terribly. In the finish I had to put a piece of copper wire under the strings to lift it a little and also had to space the bridge up with some washers. Having said that it does look quite cool and is quite playable even though the action is quite high. Quite an enjoyable project on the whole. The only thing left to do is update the CAD model with all the extras and then have a think about whether I want to build another one or strip it down for parts. Things that would make it better are:-

1) Use a conventional nut at the head end.
2) Use a separate bridge assembly such as a Tune-o-matic
and a string adjuster. Eliminate the tremelo spring and arm as I dont like these anyhow.
3) Use a single pickup and simple wiring circuit. Just use less but better quality kit.
4) Change the body shape for something a little more ergonomic. I do like how light it is though.
5) Do a better paint job.

30/04/2012 - One step forward two steps back.
Over the past week or so I have assembled and strung the guitar, but unfortunately the neck seems to be a little misaligned. As the neck pocket and the bridge pocket
was pre machined, this leaves little room for manoeuvre. I have now stripped it back down to have a think what to do. I'll probably widen the neck pocket and shim it a little. In the mean time a nice guitar came up on the net. As it was only 100 I bought it and picked it up yesterday.

There are many reasons why I felt this was a good purchase. 1) It gives me a good guitar to take measurements from. 2)I can start learning to play 3)Its a composite guitar made in one piece from a patented material called "Vibracell". As I am not a Carpenter I thought that this might be an easier way to make a guitar as it would be closer to the skills that I have. It deserved closer inspection.
   I looked up the patent and it is a polyurethane foam with wood and silica mixed. The Switch guitar company are now no longer trading, so this may mean that in the future this may gain in value. The model is a "Switch Stein 3 in Red Fireburst" and is in mint condition. It sounds really nice and hasn't needed retuning yet, which leads me to believe this material is very stable. I really like this one. Thanks Brian.


06/04/2012 - Finding your own solution.
Having read up on the way to paint finish a guitar I became more confused as to all the different methods. There is so much contradicting advice that I thought I would find my own way. I tried staining the body by diluting the stain to 10%, but it was so weak it didn't do anything. I applied it neat and it was too dark, so I rubbed it down until the grain showed through then spray coated it with acrylic lacquer. I am absolutely useless at spraying and I got a few runs, but I have sanded them out and the the finish is OK. I give myself about 7/10. I really need to spend some more time sanding the initial wood. The neck was easier and I just used Ronseal Diamond Hard Varnish from B&Q. A bit of wire wool and some pledge made it came out OK. I varnished the fretboard also and this looks presentable. I will probably apply some wax later.

The neck mounting plate and screws arrived and I had to shorten the screws a little to make it work. I still need to cut off the rear two with a Dremel so I can mount the top humbucker pickup.

03/04/2012 - I know nothing about guitars or how to play one.
First thing was to buy a kit and see how it was done. I want to build an acoustic guitar and I always liked resonator (Dobro) guitars, but an acoustic is quite complex, so as a first step maybe an electic would be easier.

I always liked the look of a headless guitars and as luck would have it I found a kit on a Canadian website. Unfortunately the postage costs were very high (around 60 to the UK) and also I could get stung for import duty. A further search located the same kit in Germany at the ML Factory, so after translating the website I ordered one. The cost was 149.90 Euro + 12 postage (about 137 total). This a bit expensive as you an get a Fender kit for about 50, but its the style I wanted and headless kits are made in smaller quantities.



It's a loose copy of a Steinberger guitar popular in the 1980's and is a bit cheap in places, but nothing that a bit of rework cannot fix. As I am hoping to learn how this is done, the first thing was to reverse engineer it and that means duplicating the parts in CAD. This is nearly complete and so now I will be able to redesign any parts and be sure they fit. After doing a bit of research, I want to bolt the neck on so it can be removed, so I ordered a bolt plate off ebay and also some wood stain and spray varnish from www.rothkoandfrost.co.uk
The only nice colour they had was an "Ink" blue, so this is what I am going to have a go at. Tonight I put three coats of clear varnish on the neck, tomorrow I might have a go at staining the main body. The ink is cellulose based and needs to be diluted 10:1. Fortunately B&Q sell hammerite thinners which is a cellulose thinner.