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On my first guitar I need to do a neck reset as I never got it 100%, and I wanted to give things time to move and settle, it's easy enough as its a bolt on mortice and tenon and I haven't glued the fretboard extension down. Anyway the question is my luthier friend emailed me this calc he uses



Now if I put my figures in I get

A=76mm
B=10mm
C=300mm

76mmx10mm/300mm=2.53mm

Now figure B imeasured from the top the the highest point on the bridge not including the saddle is this correct, and how many of you use this calc

many thanks

John

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Formerly JJH

I learn more from my mistakes than my successes

the only measurement that I use is the gap between the top of the bridge and the plane of the frets. with a straight edge run down the fretboard (with frets on) I like to see a gap of 1/32-1/16" or about 1mm between the top of the bridge and the bottom of the straight edge.

Just keep removing material from the back of the heel till you get it right. If you need to bring the neck forward (decreasing the gap) remove material from the fretboard end of the back of the heel. If you need to bring the neck back (increase the gap) remove material from the heal cap end of the back of the heel. Feather it out to give a nice gapless seam between the neck and the body.

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Your "B" spec is wrong. B should be the height from the top of the bridge + desired clearence to a straightedge running from the top of the frets. Not the top of the bridge to the soundboard.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I dont like to do the math, so i do things like Rod described- gradually removing material from the heel while constantly checking with a straightedge over the bridge. You are in luck that nothing is glued down!

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Jordan Aceto
Ithaca, NY

Ok if I substitute 11mm to get 1mm clearance it works out at 2.78mm

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Formerly JJH

I learn more from my mistakes than my successes

Somehow either something in my explanation, or my understanding of your measurements is getting lost. There's no way you need to remove 2.78mm from the end of the heel. Obviously specs are going to vary from guitar to guitar but here's my math, or at least my attempt to explain it. First, since the bridge is already installed the soundboard doesn't matter. You're working from the top of the bridge. I want a clearence of 3/32" (~2.4mm?) between the top of the bridge the straightedge placed on the fingerboard. If my straightedge has no clearence, and rest on the bridge then I need to change it by 2.4mm. This makes my "B" measurement 2.4mm. The "B" measurement is the amount you want to change the clearence at the bridge. Again, it might be me misunderstanding the question. I'll try to take a couple pics later today and see if we're on the same page.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Just to double what Woody B said, 2.78mm sounds like an extreme amount to remove, unless the neck set is waaay out. Like i said, i have never measured the amount removed, but i think it is typically less than 1mm for the majority of neck resets.(i could be off on that though, its just my "feeling")

I have seen some where a lot of material has been removed, and the heel starts to look funny when it gets smaller than normal.

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Jordan Aceto
Ithaca, NY

I do it by eye with a striaght edge .. slowly removing material and then seeing where everything lies, flossing sandaper to keep thiings tight at the jont. You have to do this eventually anyway. But, by seeing how much you need to change the lie, and some simple math you can get a feel for it, and remove some of the material with a chisel first.

Look at it this way

Your heel is about 3 inches (75mm)
The neck joint ot saddle is about 12 inches (300mm)

You have a 4:1 ratio there .... so for every 1mm of heel you remove, the height at the saddle changes 4mm. So if you need 3mm more height in the lie of the FB at the saddle, then about .75mm needs to be removed from the bottom of the heel.

In most situations, unless you have a really bad neck angle, removing more than 1mm is rarely required - because it makes a huge difference at the saddle.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I just use the 4:1 ratio like Tony. 12:3=4:1.

Pat

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formerly known around here as burbank
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