# 18 Bluesmaster

[Jim.S]

A couple of things caught my interest so far in your build, The approach to edge thinning on the inside rather than the outside, do you still leave 2mm soundboard thickness on the edges? Also your CF layup approach on the falcates, two pieces rather than one on the main falcates and that you apply to the brace first rather than the soundboard, another way to skin that cat.

[weslewis]

I use a spreadsheet out of "the book" to determine top thickness, in this case its .113, the pockets were milled before final thickness to .040 depth, then both sides are sanded to the final thickness sanding the inside till the pockets are .020 thick, with the idea of the edges being .020 thinner. Rebating the braces for the carbon tow makes for a neater layup as opposed to painting them on. IMO

[Jim.S]

Okay I am a little confused and can't get a close enough look at your photos to see what you mean by "rebating the braces". Have you made a small rebate in the bottom of the brace for the CF tow to sit in? I had considered this at first but in the end find I get very tidy results without any squeeze out anyway.

EDIT. Okay, yep. I see now you are staying above the recommended minimum edge thickness. When I convert those imperial measurements in my head I tend to over do them so this time I looked with a calculator.

[weslewis]

EDIT. Okay, yep. I see now you are staying above the recommended minimum edge thickness. When I convert those imperial measurements in my head I tend to over do them so this time I looked with a calculator.[/QUOTE]

You can imagine the fun I had converting from SI units!!!!!

yes small channels cut top and bottom appoximately .015 to .020 deep, main idea was to keep the tow from fraying hopefully making for a stiffer brace.

[Jim.S]

Ha! Nice. So are you getting robot to cut those rebates for you if so I assume it is a square rebate, I was just going to gouge a round rebate but thought I may as well just give it go Trevor's way in the end. It does seem that the way the CF tow is laid up will get you more or less stiffness.

My last one was a 2.55mm(0.1") sinker redwood with 6.4mm (1/4") high braces but I still only manage a 1.6 degree bridge rotation and 15 thingamajigs for monopole mobility measurement. That is with a 13" lower bout so as I don't want to go any lower on the braces my next step is to drop the number used for ƒ in the top thickness formula. I keep my tow very tidy and assume that's why I still come up quite stiff, that and the small bout.

I also want to add that I am very happy with the guitars I am building now and still have room to improve.

[weslewis]

I use a 1/16 bit , square tip, in a dremel mounted in stew mac router base on a home made mine router table, in second posts of pictures, to cut channel. I find this little router table very useful!! my last falcate , a medium size , also had a bridge rotation of around 1.5 to 1.7 degrees of rotation , the main braces were .320 or 8.01 mm tall, the resonance freq came in at 172.8

[weslewis]

Another thing I like about this type of bracing is the epoxied CF when cured locks in the top radius, in this case 28ft , the Upper transverse brace has a 70ft radius and is glued in a separate jig to flatten the upper bout.

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[weslewis]

some neck block detail, I prefer to build the mortise into my neck blocks, then use Cumpiano's table saw method for cutting the tenon.

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[weslewis]

This one is getting solid linings top and bottom, I thought I would dress up the inside using some zebrawood linings. The strips are cut and bent on the mold then the rim is used for laminating the strips to shape. The linings are then shaped,sanded, and installed on the rim.

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[weslewis]

Finally made some progress on the rims ..

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[vintageparlors]

weslewis is making all the right moves.

[weslewis]

UTB is glued on using a 70' radius form, final carbon tow glued to top of braces.
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[Jim.S]

Looking good Wes. No CF on those braces above the soundhole to the UTB? I would love to see a larger shot of that CF layup with the rebates if it is possible.

[weslewis]

It has been slow going lately, got the top braced and glued to rim, I glue the back on first using the dishes only reversed so I can clean up the insides. I will get some preliminary freq charts soon.
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[weslewis]

sorry about the lack of good pictures Jim, other than what I have posted, I use a 1/16 bit and cut about .020 deep, It is certainly easier to keep the carbon tow on top and in the center of the braces using this method , at least for me.