Wilborn Guitar Attempt

[scamp]

I decided that my next guitar would be something really different. Something more focused on science based acoustic design vs just the same old Martin X brace design. As a result, I read the Gore/Gilet books, which really helped my understanding of the guitar "science", I also looked at a lot of different alternative designs based on input from Professor Kasha like guitars from Klein and Kauffman. In the end, I decided that the current work being done by Ben Wilborn incorporated a lot of the acoustic design elements I thought made sense given my research and they also looked and sounded beautiful. Ben was also gracious enough to post an incredible amount of info on the web about how he builds his guitars which makes copying his designs feasible, I think. So..... I have decided to build a Nautilus type guitar as my next build and blog my progress. It may be a bridge too far but why not try.

My work started with generating full scale drawings of the guitar body so I could build molds, cauls etc. I used a tool called G Thang (free on the web) to generate the full scale body drawings by copying the radiuses of curvature from drawings of the guitar on the web. Nautilus body picture from the web on the right and G Thang drawing on the left.

Guitar Body Drawing 1.JPEG

Guitar Body on G Thang Design Tool.JPEG

Full Size Body Drawing.JPEG

G Thang is limited so the soundhole ( which looks like a comma ) could not be reproduced and the Florentine cutout curve ( which required two radiuses ) could not be done properly but the basic body came out fine.

[scamp]

Using the drawings I generated the body mold, top template and the Fox side bending form

Body Mold and Top Template.JPEG

Side Bending Mold for Fox Bender.JPEG

The sides of this guitar are three layer laminated sides. Ben uses a vacuum pump and a caul to do this. I looked into it but it's a lot of investment so I found a method used by Bogdanovich for laminating sides that doesn't require a vacuum pump. Basically use the left and right sides of the body mold bolted together to make a an outside caul and then use shaped hardboard with 3/4 inch blocks of MDF to make an inside caul. It turns out that the two side molds bolted together are not quite wide enough for the sides so I added another 3/4 inch section with dowels to align the two sides and increase the width of the caul.

Body Mold Halves and Center Alignment Layer for Laminated Side Caul.JPEG

Complete Side Laminated Caul Together.JPEG

Laminated Side Gluing Setup.JPEG

[jread]

Wow, that's really inspiring!

[scamp]

Needed to make a bending form for the cut away section. Decided to make the cut away form so it would work in my Fox Bender and also allow it to be used as the caul to make the laminated sides.

Side and Cutout Lamination Cauls.JPEG

Cutout Caul Set Up for Cutout Side Bending Mold.JPEG

Cutout Bending Mold.JPEG

Cutout Laminated Side Setup.JPEG

[scamp]

Had to generate a drawing of the bracing for the top so I scaled up a photo on the web of the Nautilus guitar ( made a matrix with dots on the ends of the braces ). Used published numbers of the guitar lower bout width to determine the scale.

Scaled up Drawing of Bracing .JPEG

Two of the major braces are curved braces made up of 6 laminations. Hence another caul needed to be built.

[scamp]

Building this guitar will be a stretch for me.

One detail that is a challenge and I have never done before is an arm bevel.
As a result, I decided to use some scrap wood, unused purfling and bindings from previous projects and do a practice arm bevel.

The arm bevel on this guitar is a "mini" bevel. It doesn't go very far into the sides. It only goes to the beginning of the side purfling ( about 0.22 inches into the sides) . This makes things easier. It also only about goes about 0.5 inches into the top. I used a 3/4 inch pine board to mock up a portion of the top and then routed binding channels and purflng channels as normal. I then made a template for the top arm bezel purfling channel and used a 0.5 inch diameter (1/8 inch deep) flush cut router bit and a small laminating router and widened the purfling channel already in the top so it went to the edge of the template.

Mini Arm Bevel 4.JPEG

I then glued the bindings and purfling in place and used a file and sharp scraper to create the bevel between the edge of the top purfling and the edge of the side purfling ( about a 30 degree angle ).

Mini Arm Bevel 8.JPEG

I then put tape over the bevel and trimmed it and then used it as a template to cut the black veneer that would be the surface of the bezel.



To glue this on i used a cool trick I saw on the web. I put a thin film of tite bond original on the bezel surface and the veneer.

Mini Arm Bevel 10.JPEG

Mini Arm Bevel 12.JPEG

I waited one hour and then ironed the veneer onto the bezel. Worked great! Trimmed down the veneer using sand paper and it worked well. I think I'm ready for the real thing.

Mini Arm Bezel 15.JPEG

[scamp]

On to making a multi-scale fret board.
Another first so decided to do a detailed drawing and possibly use it as a cutting template.
The end drawing would also be useful for determining the angle of the saddle on the guitar top.

Decided to use a Martin standard 24.9 short scale for the high E string and a Martin standard 25.34 scale for the low E string and make the inflexion point ( the point where the fret is perpendicular to the center line ) the 12th fret.
Struggled with how to accurately mark the fret locations and eventually came up with the idea of using the standard fret cutting jig I already had with calibrated templates for both scales to make marking templates out of 1/4 inch MDF. Cut fret slots in one inch wide MDF strips ( one for 24.9 and the other for 25.34 ) and then flipped them over and used the slots as guides to accurately make markings using a sharp pencil. Worked great.

Multiscale Cutting Templates.JPEG

Multiscale .JPEG

Here is the resulting completed drawing.

Multiscale Drawing.JPEG

Ordered the fret board and on to actually cutting it.

[scamp]

Been busy. After closer examination, the method of ironing on the bezel veneer didn't produce the results I wanted. You could still see the glue line and the bezel looked a bit flat which was necessary given the veneer is only 0.02 thick. So.... with input from some experts I contacted, I tried another method. I stripped the veneer off my first practice attempt to try this new method. This time, I used a thicker veneer. I had an old poor quality ebony headstock veneer which I sanded down to 0.04. I then cut the veneer into strips about .5 inches wide with the grain running perpendicular to the length. I then cut these 0.5 inch strips into tiles about 2 inches long with a slight bevel ( almost like I was going to use these pieces for sections of a rosette ) to follow the curvature of the bezel. I then butt joined these over the bezel area and taped them in place. I used CA glue and held them in place with my finger. I then used raps, files, scrapers, sandpaper etc. to shape it down. In the end it worked very well. No visible glue seam. Bezel looks more rounded and chunky. Any imperfections are easy to fix with some CA glue and ebony dust. Amazingly... no visible seam between tiles. Thought I would share this.

Bezel Again 7.JPEG

Bezel Again 3.JPEG

Bezel Again 4.JPEG

Bezel Again 6.JPEG

Bezel Again 56.JPEG

[Srick]

Great job! If it’s any consolation to you, Dale Fairbanks made a guitar for me with an arm rest. He never told me the whole story about it, but I suspect it was the first and last bezel he will ever do.

[scamp]

Well this took awhile. Tried to copy the bridge design that Ben Wilborn uses.
Used a wide 5 mm slot for a compensated saddle as suggested by Trevor Gore.
Unlike Trevor Gore... used ebony for the look ( even though it's dense and weighs more )
Came in at 27 grams. Not bad given most Martins are about 40 to 50 grams.
Hopefully it will hold together under stress.
We will find out....