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Working on my first build which is a LMI parlor kit. I have the sides together with the tail block, heel block and kerfing installed. I have the top and back of the sides radiused to 28' top and 15' back.

I am just starting on the neck and have been researching the best way to address the heel block angle. I have the Robbie O'brian's "Building A Steel String Guitar" that came with the kit but he does not address what to do with the radius left on the heel block after sanding it it the radius dish.

When I sanded the radius on the top I went as lightly as I could on the upper bout because I know (from research) that area should be flat to accommodate the fretboard extension and to give me a proper neck angle.

I am curious what you all do in this area. I made this post because it was part of a very recent post where radiusing the top was discussed. Since I am at that point in my build I didn't want to hijack that thread.

Any help would be much appreciated.

Bob

You will get a lot of different answers to this one. For me, I radius the top rim, tail, heel and linings 25 ft. When I brace the top every part gets a 25 ft radius accept for 3" of the centre of the UTB which will remain flat. I use to cosistantly end up with more FB drop off than I liked. No more with this approach. I've used this on the last 5or 6 builds and it works great.

Next please.

It's also a good idea to bevel the heel bock down to no more than the thickness of the linings.

what you are after is a fretboard that lays flat on the soundboard when the neck angle is right , concept is not that hard executing can be , but doesn't have to be, if you are using radius dish's to build in the 28' top and sand the rims, that will set the neck angle real close if the heel is machined properly, what you want is to lay a flat edge on the neck, without the fretboard, flush with the body and have the straight edge lay flat across the neck and the upper bout while clearing the saddle, mark accurately , by about .098 to .118 at the saddle or 2.5 to 3mm..I use a jig to rout the upper tranverse brace to a 70' radius so the area is flat where the fretboard glues to...the attached pic is s similar jig used to make the 28' and 15' bracing. I find it easy to make templates in a cad program for the radius's and transfer to the jigs for cutting and sanding to shape. not real good pics, the caul is radiused to 70' as well and the UTB is glued using that caul after the other bracing is done in the radius dish on the go bar deck..

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MK5acoustics.com

Similar to last post story here with UTB radius, (accredited to Mr Stock) 'cept my jigging is a bit more antediluvian (pre-CNC)

I have a bit more of a problem (in a way) with the angle on top of the block at the neck, because I have been using an extension on this block under the FB to support the UTB.
After radiusing the top rim, I plane the top of this extention at an angle to line up with the UTB, (or to be exact, where it will be).

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

This will be interesting when i get there on my first build. We did nothing special when glueing the braces on my top. (viewtopic.php?f=10101&t=41876). All the braces were glued on in the radius dish. I am sure I will learn all about the various theories and methods when that moment arrives.

@Robert Lak Yes I am there now and as I stated in another post:



Thanks for your replies on this thread guys.

I was afraid you would not understand what I was asking but I guess I made myself clear enough. I do understand the geometry of setting the neck and I have reset a lot of necks in my time but this is the first time I have had to deal with trying to put a flat neck extension on a compound radius with the heel block and the UTB.

So if I am understanding it you can only make a compromise between the radius of the heel block and the UTB?

Am I wrong in assuming that this is the most critical glue joint on a guitar possibly only next to the neck joint? Since this is what ties the heel block into the top I would think we want as much glue surface on the top of the heel block as possible. By leaving that radius at 28' and the UTB flat or nearly flat (60'r or 70'r) the heel block will end up having some gaps in the joint or we will be distorting the top to conform to the compound radius. Now you have to glue a flat fretboard extension on it.

Am I just being too cautious about these angles and ending up with a loose glue joint?

This is actually funny because I have re-braced a few guitars in my day but have always removed the backs and worked from that side. I am of the mindset that you do not remove a top because you are then just building a new guitar from the inside out. I have turned away a couple of jobs because of that.

So this is all new territory for me.

Again, thanks for all your help and suggestions.

Bob

Just trying to clarify/respond.
Are you asking here about the
1) side to side radius or the
2) neck block to tail block radius?
In my previous post, I only referred the second, (gives an angle of about 1 1/2 - 2 degrees for my 25' radius
Any radius side to side after fitting the top I just sand flat.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

@Colin North, I am actually talking about the side to side radius AND the radius from the heel block to the sound hole. I understand how to properly set the neck angle (to the bridge).


@Todd Stock, So I am really fussing over angles so small that I shouldn't be worried about it? I do have a tendency to over think things sometimes. Much like if I am repairing a crack or something small, I use a photographers loupe and if I am happy with how it looks under extreme magnification then I know a client looking at it with a naked eye will be happy. I have yet to have someone complain or bring a repair back.