Official Luthiers Forum!

for those of you that use the LMI fret slotting templates, what do you make of this note in the instructions sent with the template and blade?

"a note about the index pin:

the non-tapered end measures .075" and the template slot measures .100" .
.100 - .075 = .025

.025 / 2 = .0125

use the non-tapered end to set the nut slot .0125" towards the bridge. do this because the strings should meet the fulcrum of the nut ("the breakaway point") .0125" behind the face of the nut. the face of the nut being the surface nearest the bridge.

please not that there are some differing opinions about where the breakaway point should be. some seat that point a few thousandths closer to the bridge for intonation reasons. we cannot advise you about these intonation ideas, but you can probably get some info at one of the luthier's forums on-line."

i also read their article on intonation on-line and found this:

"Luthier Lance McCollum has noted that for those who order pre-slotted fingerboards (such as the ones sold by LMI); there is usually a fret slot to mark the nut position. The slot width is .023 or .025 wide. If you cut the board, as most do, right at the slot and position your nut there, then you have automatically introduced this compensation, as the prescribed amount (.012) is incidentally half the width of the slot!"

so should i just cut a slot at the zero fret position and then cut the board off there? according to LMI this will give me the .0125" nut compensation i need. i just dont get why using the non-tapered end of the index pin is any different than using the tapered end. both ends just center the slot. it doesnt matter what the diameter of the registration pin is as long as it fits in the appropriate registration slot, right? should i just do away with the nut compensation all together? help me out please.

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sweat the small stuff.

I don't use the registration pin that came with my LMI fret templates. When I was making my fret slotting sled, the pin just didn't seem like a good way to register the template. I made a little piece of bone out of scrap from a saddle blank, fitted perfectly to the slots in the template, and installed that in the fence on my sled instead of the pin. Works perfectly.

To locate the nut, I cut a slot at the nut position, then cut the board off a smidge shorter than that. I like a little more nut compensation than you'd get by cutting off the board exactly where the template will slot for the nut.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

I have the Stewmac steel templates, and simpy dont use the nut slot on them at all. I use a 1mm nut comp, and as such simply cut the end of the FB at the required spot after detaching from the template.

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

The way to use the LMII pin to give you a little nut compensation is to use the non-tapered end when registering for the nut location like the direction say. And to move the template towards the headstock. The non-tapered end is smaller in diameter than the slot is wide so there is some slop. When you move the template and fretboard towards the headstock, the side of the slot will bump up against the pin and then you have that 12 thousandths of compensation.

That would get you .024" compensation, adding half the width of the kerf that the blade cuts. Or, you could go the opposite way with the slop and be .001" reverse compensated, which is pretty close to right on scale. What I do is cut every slot with the tapered pin, and add about another .020" compensation after sawing through the zero slot and cleaning off the wood on the bottom of the cut up to the edge of the kerf. That way I get about 1/32" compensation.

I have always ignored the straight end of the pin, assuming it was for a different template system without tapered slots, or that the pins just came that way from the manufacturer. But it is annoying to have it push into your finger when you push in the pin, so I stuck a little block of wood on it.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

The difference between .024 and 1/32" is about seven thousandths of an inch. Not enough to probably hear.

thanks guys. if you slide the non-tapered end of the index pin all the way into the template slot it will center the fret slot the same as the tapered end. if you just slide the narrow end in without it fully engaging, it allows for some slop. that makes a lot more sense so thanks for clarifying that for me.

so of the handful of you that responded, you are using anywhere from .012 to .040". that seems like a wide range to me. im still trying to figure out compensation in general so i think i will do a bit more research. thanks for your time guys.

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sweat the small stuff.

Huh. On mine (about 7-8 years old) the non-tapered pin will not fit snug even if pushed in all the way. I haven't measured, but it looks like the .024" that Barry mentioned.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I've always just used the tapered pin and cut the 0 slot as the nut. I always assumed that it gave about .0115-.012 relief (half the width of the fret slot) Where does the .024 figure come from?
At any rate whatever relief it gives seems to be OK for intonation on my instruments.
TJK

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It's not what you don't know that hurts you, it's what you do know that's wrong.

yeah, i dont know. maybe ill just give LMI a ring and see what they say about it. i just measured the pin and template and the non-tapered end is .077" and the slot in the template tapers from about .090" to .060" . thats a little different than what the paperwork says. anyways, ill make it work. im not sure how much compensation im going to use yet, so maybe ill just skip the zero fret slot and cut that end off later. thanks again.

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sweat the small stuff.

ok, so i was a little embarrassed to ask any compensation questions until i felt i had done sufficient reading to at least say that i tried. maybe this is a different thread all together, but i guess i dont really need to start two compensation threads. so here goes. i think i basically understand why we compensate guitars, im just having a little trouble with what that looks like practically. if you chop off some material from the first fret to compensate the nut, that moves the fretboard that distance towards the nut, right? do you then move the neck/body joint back closer to the bridge, or does that defeat the purpose? im really confused now!

would anyone be willing to discuss this over the phone? the keyboard just isnt cutting for me right now. maybe send me a PM if you have a few minutes to better explain this to me. id be glad to make the call so no one gets charged for it. (does anyone actually pay long distance anymore?)

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sweat the small stuff.

I know, it does get somewhat confusing, Heath. Anyway, where the neck joins the body doesn't really have anything to do with it. Presumably you will want that joint to line up with either the 12th or 14th fret regardless of anything you're doing with compensation. Position your bridge by measuring half the theoretical scale length from the 12th fret, then add the amount of compensation to the saddle location that you want to add. That determines the bridge/saddle location, and you would not change that no matter how much you have or haven't compensated the nut. Ultimately, the break over point on the saddle for each string should be determined by intonating each individual string, using a strobe tuner, with the goal being that, when the open strings are tuned perfectly to pitch, as many of the fretted notes as possible are also as close as possible to perfectly on pitch (using equal tempered tuning); I'd suggest starting with the 12th fret and getting that in tune, and then check other frets above and below that. When I do this, the top of the saddle is flat at that point, and I'm using a short length of unwound string, bent into a little "L", tucked under the individual string I'm working on, on top of the saddle. I can move that forward or back to find the best intonation for that string, then pencil mark that spot on the saddle, and that's where I'll shape the saddle's crown for that individual string. I learned that trick here on the OLF.

There was a discussion on nut compensation here quite recently that may help answer your questions. I don't remember what the title of that thread was, but you should be able to find it if you search. In that thread, someone linked to Mike Doolin's explanation of intonation/compensation, which is about as good as any that I know of.

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/