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Sides braces and initial neck tenon fitting

Posted: Wed Sep 27, 2017 11:53 pm
by nkwak
I put in some side braces the other day. I made them from spruce bracing scrap.

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Then I had to cut away some space to admit the truss rod and took a little off the side of the tenon. Now it fits snug; not loose at all, but it's too early to do the full neck set obviously.

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I also have a case for it to live in when the RH starts falling, but it's been hot this week.

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Re: 2nd scratch build - Carpathian over EIR

Posted: Thu Sep 28, 2017 6:11 am
by Danl8
Very nice, clean work, Neil. Looks like this guitar will sing.

-d

Re: 2nd scratch build - Carpathian over EIR

Posted: Thu Sep 28, 2017 9:02 am
by johnnparchem
Looking really good.

Re: 2nd scratch build - Carpathian over EIR

Posted: Thu Sep 28, 2017 10:18 pm
by nkwak
Thanks.

I've decided that I'm going to make a sound port in the upper bout. I will be putting in a maple veneer (for decorative purposes) and a rosewood patch inside before routing it out. I'm hoping it turns out well.

Re: 2nd scratch build - Carpathian over EIR

Posted: Fri Nov 03, 2017 4:21 pm
by nkwak
I recently notches the rims and the fretboard extension to accept the braces for the top and back:

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In order to locate where to cut for the A Frame I used charcoal to scribe the position. Then I used hand tools to cut/chisel. I don't get along very well with power tools. They require a bit of finesse that I do not possess.

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Now all the pieces are roughly dry fit and can live inside the case together in anticipation of the RH dipping now that the northeast US heating season has begun:

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Re: 2nd scratch build - Carpathian over EIR

Posted: Fri Aug 03, 2018 12:03 pm
by nkwak
OK, I upgraded my go bar deck - and discovered that the rims are no as ready to accept the top as I'd hoped. I'm concerned that this would result in the dreaded "14th fret hump" so I'm trying to think of way to shaped the upper bout top geometry at the rims/neck block before gluing the top on:

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Re: 2nd scratch build - Carpathian over EIR

Posted: Fri Aug 03, 2018 2:06 pm
by Danl8
What exactly is the situation with the rims vs top?

Re: 2nd scratch build - Carpathian over EIR

Posted: Fri Aug 03, 2018 2:27 pm
by nkwak
I sanded a radius around the entire outline of the top side of the rims, even across the lateral axis of the upper bout. Meanwhile the underside of the upper transverse brace was left flat. The result is that the upper bout of the rims wants to have the radius but the top wants to be flat in that area. Doing a dry fit with the go bar deck the soundboard doesn't want to flex - nor should it IMO.

It's been so long that I've forgotten what I did on my first build but I remember doing something different with the UTB; I butted the ends against the sides with no taper and it appears that the upper bout is flat on the lateral axis. So I'm thinking that I'm going to have make a jig so that I can sand that axis on the rims flat with a 1.5 degree slop from the sound hole to the opening of the mortise.

This is probably pretty basic but like I said, it's been 5 years or more since I was at this point last time. Too long. Once I close the box and set the neck angle I need to make notes so that I don't get tripped up the next time around.

Re: 2nd scratch build - Carpathian over EIR

Posted: Sat Aug 04, 2018 10:28 am
by ruby@magpage.com
There are a number of ways to treat the upper bout so that you neck points in the right direction. Here is one by Hesh Breakstone that gets positive reviews every time it comes up. Hesh is no longer on the inner web as he has retired from guitar stuff:

http://www.luthiersforum.com/forum/view ... 17&t=25931

Ed

Hope it's not a problem ti cite another forum here

Nice looking box, by the way - very clean

Re: 2nd scratch build - Carpathian over EIR

Posted: Sat Aug 04, 2018 10:36 am
by nkwak
I’ve done a little searching around over at the OLF and think I know what to do thanks to post by Hesh that’s several years old. It’s actually a pretty simple solution;

- just mark a line across twhere the UTb will be,
- lay the rims in the mold top down on a flat surface with sticky back 120 grit sandpaper on the flat surface,
- place a 1/8” thick popsicle stick under the tail block,and
- (pressing down of course) pivot the rims just like if you were using a radius dish to “drive the bus” as John says.

I’m going to be overly careful of course but will report back on the results. I’ve got a LOT of sanding to do though so I may use my block plane to get started of course.