Official Luthiers Forum!

I am in process of building my first neck. I have made the 15 degree cut for the scarf joint and have a block ready for the heel. I plan on gluing these together after some final thicknessing of the headstock and plan to cut the truss rod slot after that.

My question is which truss rod is recommended for a 12 fret neck. Size and manufacturer, supplier etc.
And also how deep do I make the slot and how far up the neck. Want to adjust from inside the guitar I don’t like truss rod covers on acoustic guitars.

The Martin 12 fret rod is installed in a 0.360" deep by 0.250" wide slot...a 1/4" core box (round end) bit works well for this, or the slot can be cut on a tablesaw. The last 3" of the slot at the heel end of the neck needs to be widened and deepened for the adjuster assemble, which can be done with a router jig or hand tools. The UTB will need a 1/4" hole about 3/32" up from the bottom of the brace and centered - a 5mm hex long adjustment wrench will handle the adjustments with strings on or off.

There are other truss rods, but none we've found with this combination of price ($13), reliability (used on over a million Martin instruments since 2005 with no reported failures that we can find discussed by other repair shops, builders, or that Martin appears willing to attribute to the rod), and ease of installation (no filler strips).

https://www.martinguitar.com/1833-shop/12-fret-two-way-truss-rod/c-24/p-487

We make up 5mm wrenches from long T-handle hex wrenches (heat with torch, bend shaft 85 degrees while red-hot, then use shrink-wrap as desired), but they are also available from Martin and other vendors...get the long one.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)

Here's the best there is:
http://blanchardguitars.com/guitarpages ... _rods.html
Mr. Blanchard will make up any length you need, and there are some "standard" lengths he keeps in stock.

These from LMII are a similar design, and also work well:
https://www.lmii.com/482-truss-rods

I've never used the rod Woodie mentioned, but there are a lot of builders that use it. Can't argue with the price difference.

_________________
A man hears what he wants to hear, and disreguards the rest. Paul Simon

[quote="We make up 5mm wrenches from long T-handle hex wrenches (heat with torch, bend shaft 85 degrees while red-hot, then use shrink-wrap as desired), but they are also available from Martin and other vendors...get the long one.[/quote]


I'd love to see some photos of the wrenches you make.

Depends a little bit on your scale length but I have used LMII's TRSDA on 25.4 scale and TRSDS on 24.5 scale 12 fret necks. They give overall and acting length on their website. You have a bit of wiggle room at the nut end. Also the slot is 1/4 wide by 3/8 deep.

I'd love to see some photos of the wrenches you make.[/quote]

Nothing fancy...a shot of the shop-modified wrenches from last inventory.



Re: pricing: There are a large variety of truss rods offered, and at various pricing from less than $6 for an eBay sourced, Asian-made item to $40 for one of Mr. Blanchard's stainless truss rods. I would recommend avoiding the temptation to shop based on price, as the most expensive truss rod on the market is still just a fraction of what it will cost to replace a failed rod..and that ignores reputation damage for a commercial builder.

Re: fit: Keep in mind that some instruments (e.g., Size 5; baritone) will likely need a custom length rod, so either cut down a longer rod (we cut and reweld a standard Martin rod for Size 5 guitars or tenors and octave mandolins), or order a custom-fabricated truss rod from Mr. Blanchard or other source.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)

If you are not looking for a double acting rod and want to keep neck weight down you can make a "Gibson" style rod single acting rod and have it adjust from inside the guitar. Probably one of the cheapest options, and it can work reasonably well.

While I agree that these rods can work well, I no longer make them (unless I was making something experimental of a strange size). Good double action rods can be had for relatively little money. Making a rod cost me about 1/4 the money as the martin rods but it also took more time and didn't' have the double action. Plus I prefer the allen adjustment rather than the socket that I needed for the stew mac brass nut.

The martin rod costs $13 buck plus $10 shipping (to me). Ordering two at a time puts them at $18 each which is pretty reasonable for such an important component. I recently bought 4 of the new stew mac low profile rods. They are less similar to the Martin rod than I expected. I haven't used them yet. They are a little cheaper but don't seem as robust. I'll probably go back to the Martin rod next time.

_________________
Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

No need to mess around with inferior options when you make a strange sized instrument. Just order a custom rod from Blanchard or Allied. Blanchards may be better (I haven't tried them) but Allied makes a similar rod in custom lengths for $40. I had to replace a truss rod in a guitar I made - once, I don't want to do it again. It's just not worth going cheap and pay attention to depth of the rod slot in the neck too!

_________________
Steve Smith
"Music is what feelings sound like"

For anything shorter than standard 12 fret rods, a captive nut rod (non-rotating operating rod) can be cut and re-welded...we have a former aircraft welder in the shop, so pretty quick for us. If there is any question of having a skilled welder available, it certainly makes sense to order a custom rod already made to length.

_________________
We have become a civilization that elevates idiots, prostitutes, and clowns. Am I still to defend it? Yes, for its principles. Yes, for what it was. Yes, for what it still may be.

-Mark Helprin, The Oceans and the Stars: A Sea Story, A War Story, A Love Story (A Novel)

I just put a Blanchard rod in a 13 fret clear, 25.34" scale neck. Every rod is custom made so there is no upcharge for any size. I have limited experience, but the rod was very high quality and gave me confidence that it would never fail

Ed