Official Luthiers Forum!

Most all my guitars are slot heads, so headstock adjustment is almost out of the question.
Are the Martin rods stainless? Are they welded or silver soldered?

The Allied rod works due to a thread differential. One end of the rod has 10-32 threads....the other end 10-24. Both threads are right turning. Turning the rod creates a tension or compression differential that articulates the rod. The Allied rod is made in China under license from Mark Blanchard...who owns the patent for that rod.

The LMI rod works also due to a thread differential but in this case the threads are opposite at each end of the rod.

The difference between them is that the Allied rod adjusts MUCH finer than the LMI rod. Although this finer adjustment is touted as a selling point, I find it cumbersome to have to make that many more turns to get the same adjustment as the LMI rod. In fact...it isn't much of a selling point for me. It may be to others.

I would like to point out that torquing a truss rod outside of its intended slot puts stresses on the welds that DO NOT otherwise occur. In other words....torquing the rod outside the slot incurs a strong possibility of cracking one or both of the welds. When mounted securely in its slot and actuated, the two way rods put a PURE shear load on the welds. It would be QUITE hard to crack a weld loaded in shear like this. "Testing" it outside the slot puts a concentrated tensile load on a point on the inside ends of the welds. I have found NUMEROUS cracked welds at this location upon receiving new rods. The habit of "testing" a rod outside its slot isn't a test at all....it's a recipe for rod failure. A proper micro-inspection at the factory, at the distributor, and by the luthier is the only practical non-destructive test that can be used to inspect a weld. Ultrasonic would be ideal...but that's never going to happen. I used a 10 power jewelers loop to find all these cracks....cracks that were, no doubt, produced by "testing" the rods.

I will note that the Allied rod, made in China, might be the most poorly produced rod I've seen on the market. The welded parts, apart from having numerous cracks in the welds, as described above, are often simply misaligned...crooked. The threaded blocks are CLEARLY welded to the rods without a proper jig. When informed of this, Allied was kind enough to offer replacements without me needing to return the bad rods...but they weren't discerning enough to replace them with good product. I received three replacement rods from an order of six and one of the rods was just as crooked as the worst one I had replaced. This was after a lengthy description and accompanying photos.

I'd also like to point out that the allen wrenches accompanying the Allied rod simply do not fit the recess in the ferrule. It was this issue that put me off using any of these rods. Strip out the ferrule and that's all she wrote. A welded truss rod should be rather easy to manufacture within reasonable tolerances.

Mark Blanchard will also make custom length stainless steel rods for you for $40 each. He uses the same thread differential action as the Allied rods. They are probably the finest rod available in this style of design. I can't say for sure because I haven't ordered one yet. I'm just certain of it due to the fact that it really only requires a modicum of skill and a conscience to make a good truss rod. After corresponding with Mark it is obvious that he has both.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

What about the Gotoh truss rod sold at LMI? I have a few and while they are good, they are very heavy. I had problems with them causing the guitar to be neck heavy.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

As an amateur builder, I've bought 3 Allied truss rods and rejected two of them (one of which was replaced by Allied). One had noticeable weld cracks and was replaced. One of two of the new style rods that I bought earlier this year, or perhaps late last year, was noticeably misaligned and I tossed it, but the weld quality had improved.. I liked the Allied rod because it requires a relatively shallow slot, but it's a hassle to have a 66% rejection rate. Thanks for the link to Mark Blanchard....

It's what happens when you outsource things to China

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

I have had good luck making my own. They are single action but they can be made to put a scoop on the neck by installing an d then tightening then sanding flat. That way when loosened again you get a scoop. Best of all these are light.


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Ken

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Ken

Have 3 Blanchard rods coming for my next 3 builds. Not concerned with weight, and have seen enough single action rods that bent necks on old instruments into an S curve by compression.
I think the really important part to remember is you don't want to crank on a T/R. It's there for minor adjustments only. The neck should be adjusted before it's fretted to compensate for string tension with the dual action T/R only just snug. You can't correct major neck problems with a T/R. That's why I level the F/B and fret after the instrument is finished (archtops excluded).

I switched to buying rods from Mark after one of the Allied rods rattled in the finished neck. I've been making Delrin spacers for the rest of the Allied rods so they won't do that. The Blanchard rods do seem to be much better made, as I'd expect from Mark.

I had that problem with both the LMI and Allied rods. Injecting rubber cement around the rod with a needle through a hole drilled in the fretboard fixed it. With my bolt-on necks I also snuck a longer needle around the tenon end of the rod into the channel with the neck off.

Somebody on some forum years ago recommended using the soft wax from a toilet seating ring around the rod in the channel during installation. That worked well and was what I did before switching to Mark's rod a couple of years ago.

Now with the Blanchard rod I just use the shim he recommends and nothing else and no rattles so far.

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

The S curve on old Gibson necks was a result of the idiosyncratic curved channel which Ted McHugh designed for the single action rod. A single action rod in a straight channel located as far underneath the neutral axis as possible will not generate an S shaped curve.

Noted, Murray, but have seen enough mangled T/R pockets and broken peghead veneers just above the T/R to NOT want to use those single compression rods. Granted, many of those old instruments had the T/R's and necks mistreated by cranking the T/R's to locked trying to straighten a neck that should have been planed and refretted.
I think a good dual action T/R is VG insurance against an instrument repair person that will try to go the cheap way to try to straighten a neck with a bad bow. Forty bucks for a T/R that works (I hope) is very worth it when you consider the amount of labor and materials you put in a guitar or mandolin. I've dug out a few T/R's in my time and it is no fun. Worst for me was an epoxied in Martin rod with the channel. Was a horrible experience. Put 18 hours into it and nearly broke the neck trying to get it out.
I see no one is able to compare the Martin dual action to the Allied...? John?

Anyone on the Martin dual action rod?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I just started using the Martin dual action rod instead of the Allied rod. I never had any problems with the Allied rod but some of the anecdotes, from what I think are reliable sources, made me a bit nervous about them. The primary reason I changed is that the Martin rod uses a shallower slot and doesn't require a filler piece so I like that. No long term experience so can't really speak to that.

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Steve Smith
"Music is what feelings sound like"

Just got the Blanchard rods...I'm sold.