Official Luthiers Forum!

Hi all.

I routed out the channel in the neck for the truss rod and I think it's a little deeper than it should be.
With the truss rod in place, the gap from the truss rod to the neck is about 1/8" (.125). Is this an acceptable dimension?

I have cut the "shim" (Not sure what the correct terminology for the piece of wood that fills the area between the truss rod and the finger board is), and I've got it flush, but am wondering if I should possibly shim underneath the truss rod and above it or just leave it as is (with the .125 "shim").

If pictures are needed, I can provide them once I get home.

Any advice on this would be greatly appreciated.

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

Blain;
I'd put the shim under the rod -make it of the same wood as the neck -just in case you carve into it .
Better to hit wood then rod!
Mike Collins

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Mike Collins

Thanks Mike.

What would you say would be an appropriate distance from the truss rod to the fingerboard surface of the neck? About .0625" or so?

I'm thinking I could basically make another shim about .0625" thick and then make the one that I currently have about .0625" as well.

So .0625" shim at the bottom of the truss rod channel, truss rod, and then another .0625" shim on top of the truss rod that is flush with the neck surface that the fingerboard glues to.

Does this sound ok or would you go another route?

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

Blain,
I would leave at least a 1/16" between the bottom of the truss rod and outside of the neck. If you are too close, then when you tighten the truss rod, it could crack through the back(or worse carve through like Mike stated). Another option is to slice the neck down the middle and remove the truss rod pocket all together, then glue in some laminates as the same thickness as the truss rod slot, then re-route the channel. Not sure if that makes sense, but let me know. Good luck!
Tracy

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Tracy
http://www.luthiersuppliers.com

Tracy is right on with his suggestion!
How thin will this neck be carved?
That will determine what you do with the fill strips.
I carve my steels to 13/16th at the nut and 7/8th at the 10th or 11th fret !

Mike Collins

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Mike Collins

Thanks Tracy and Mike,

I haven't finished carving the neck completly yet so I can leave it a little thicker if need be.

Is there a standard depth that the truss rod channel should be (My guess is that it would depend on the truss rod).

I'll measure the depth of the channel and take a measurement off of a neck that I'm referencing for carving and see what it's at. It could be that I've got plenty of "meat" there since I would think it would be around the measurements that you specified Mike. And the depth of the truss rod isn't any deeper than .625" I don't think. So if I add the .0625" shim under the truss rod, that would bring the depth down to about .5625" deep. That would leave me at least .25" minimum at the nut.

Thanks for brining up the point about it possibly cracking through the back or me possibly carving through it Tracy. I hadn't thought about that. At first I was only concerned about it being farther down from the top of the guitar than usual, but I'm glad you mentioned this before I ended up accidentally scrapping a guitar neck.

Thanks guys for all the help.

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

Blain,

If I understand your original concern, the fingerboard can sit right on top of the truss rod. Thats the way I do it. Make the truss rod slot just deep enough so the top of the rod is flush with the surface of the neck.

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53% of all statistics are made up on the spot
http://driftwoodguitars.blogspot.com/

Hey Blain;
I visited Allied Lutherie's site last night & read their new truss rod installation instructions. They are now recommending cutting the channel 1/8" deeper than the rod & epoxying a wood strip over the rod.
Sounds like you did just the right thing!

I would fill the channel as some have said.Use the same wood as the neck and get a nice tight fit then re-rout the channel to the correct depth. Good luck with it.

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Anderson Guitars
Clearwater,Fl. 33755

Thanks Todd;
I was working from (faulty old) memory when I wrote the note above. The info on Allied's site is a departure from the past instructions. It'd be a good idea for anyone using their rods to check it out.
By the way... Allied's improved truss rods are well worth the increased price. Instead of the left hand / right hand thread arrangement, they are now using a right hand thread on both ends. One coarse thread & one fine. Makes for a very smooth acting rod with a much more gradual adjustment.

Thanks everyone.

I measured everything last night and if my memory serves correctly the actual truss rod is .375 high.
The depth that I routed was about .5625" Deep.
So the wooden shim that I have on top of the truss rod is about .1875" thick.

I'm thinking that I will maybe stick the shim throught the drum sander a few more times to get it a little thinner and then glue it in under the truss rod and then make another shim whatever thickness I need to put on top of the truss rod to be flush with the neck where the fingerboard mounts to.


I'll check out the instruction on Allied Lutherie's site now to see what they say.

Thanks again for the help.

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

I'm trying to add photos and having trouble, so if they don't come in I'll try again...

The above are pictures of what I have for the truss rod channel.

the total depth of the channel is .534" and the shim shown on top is .157"

I still haven't corrected the problem yet, but thought I would post pictures before I head out to the shop to work on it.

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

This looks like a martin style truss rod with metal on 3 sides. With this style, should the open side (with the fiber tape on it) face down into the neck or up into the FB?
Thanks.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

to me looks a bit too deep.... it will work for sure but you'll have to make sure the neck won't be too thin and ending up exposing the chanel/truss rod.

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Yes it is a Martin style truss rod. The open side with the tape will be face down into the neck.

I am still going to take a little off of the shim and place it at the bottom of the channel and then place a much thinner shim on top of the truss rod and be careful to still not cut through it when shaping the ncek.

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

I just wondered if there was an orientation that was considered more correct with that truss rod...metal side up or down.
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

I'm not 100% sure since I'm still new to this, but in the Frank Finocchio videos he said to put the metal side up ("tape" side down) so I just assume that's the way to go. In the video he didn't give any explaniation (that I remember) as to why it should be that way.

He did specify that no glue should be applied to the tape side so maybe that's the reason since it wouldn't be possible to glue the shim on top without gluing over the tape...

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

Thanks everyone.

I've sanded off about 1/16" from the original shim that will now go under the rod and created a 1/16" filler strip to go on top of the rod. Hopefully this will work ok.

The "V" neck idea is a good idea Hesh. I might have to try that as well.

Thanks again everyone!

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

Here's a couple of pictures of the "fix" that I did on the truss rod channel. I basically made the bottom shim .0945" thick and the top shim .0625" thick. I of course need to cut the shims off at the end of the neck, but now I'm wondering if any of you would recommend that I leave the top shim as long as the truss rod so that it can glue to the fingerboard (just seems to make sense to me).

Todd, I'm not sure I understand what you mean by "popsicle". Could you clarify please?

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."

Blain,
   If it's a Martin rod, it must be installed with the tape down in order to
function properly. It is a one way adjustable rod. Martin has chosen to
continue using these one way rods for some reason, but they do work
well when installed in a very stable neck.

    Be sure that you leave at least .100" of neck material behnd that rod
slot...even with the shim under it. If you don't, you'll run the risk of the
rod pushing through the back of the neck when string tension is applied
and any adjustment is made. The highest area of risk in this case will be
toward the headstock since the ends of the rod will be forced back as you
adjust against string tension and any forward bow created by it.

    Don't make the mistake of underestimating the force applied on the
bottom of that slot as well as on the back of the fingerboard as tension is
present.

     I've seen it happen in a number of guitars with those rods installed
and I've replaced many of those single action rods with dual action rods.

All the best,
Kevin Gallagher/Omega Guitars

Thanks Kevin,

Is it too late for me to switch to a dual action truss rod?
I'm wondering what the dimensional difference is?

Well, this is my first guitar and I think I'll leave plenty of meat behing the truss rod. I just went out and did some "almost final shaping" of the neck and I'll have just over .30" between the bottom of the truss rod channel and the outside of the neck (not including the shim at the bottom).

_________________
Thanks,
Blain

http://www.ullrichguitar.com

"89.67% of all statistics are made up on the spot."