Official Luthiers Forum!

Is there any difference between the double action truss rods offered by Allied Lutherie and LMI?

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

I believe the Allied truss rods are based on the design by Mark Blanchard. They use 'differential threading' which reduces the change in length of the rod per turn of the wrench. Essentially, it's 'geared'; it's much easier to turn the wrench, but it takes more turns to effect a given adjustment.

Thanks Alan,
The LMI rod picture on their website looks pretty much just like the Allied rod. I wondered if they were constructed the same. I have used the Allied rod and like it. I have not purchased the LMI rod. Just wondering if the LMI rod is the same design...

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

I have both, figuring they were similar. I was wrong. I won't use the LMI rod -- 'nuff said. Got 6 I'll let go cheap.


Sent from my iPhone using Tapatalk

My opinion is that the Stew-Mac AL channel one way rod is a much superior type of rod that can be epoxied into it's channel thus adding stiffness to the neck. That given I know some folks like to have the advantage of a two way rod. I built for years using a non-adjustable rod so a switch to one way rod was easy. Just my opinion of course.
Tom

_________________
A person who has never made a mistake has never made anything!!!

Does anyone have the info on that T/R similar to the Allied, but better? Was around $35. per as I recall.

Mark Blanchard makes custom two way rods Hans. Allied copied his design. I started using them after an Allied rod broke in a new guitar and 50% of my remaining rods broke when stressed. This was 5 or 6 years ago and I think Allied addressed the problem.

The Blanchard is the Cadillac of two way rods. I have been very happy with them.

http://www.blanchardguitars.com/guitarp ... _rods.html

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

Thanks Terry.
I've been pretty satisfied with Allied's, but lately, seems as though the allen wrench supplied doesn't fit too well, and this last one I have from a batch of six I ordered a year ago, is pretty stiff, even after I greased it up and ran the rod both ways in a vise.
Think I will try a few. Guess 40 bucks is worth it if they work...

I probably should have been a little more informative about why I dissed the LMI rod (I was posting on my iPhone). On the LMI, the threads are the same pitch, but one end is left hand and the other right, as you find on a turnbuckle. On the Allied (and Blanchard) rod, the threads are both right hand, but they are different pitch -- coarse at one end, fine at the other. This results in rod movement using more turns -- i.e., much finer adjustment. Very clever!

I have heard of quality control issues resulting in some breaking Allied rods some years ago. I didn't suffer any problems like that, but I do test the crap out of them. I've had a couple in last year that were very stiff -- they were replaced by Allied without hesitation.

BTW: Allied has switched in the last year to all stainless construction. Not as pretty as the previous chromed rods, but I'd rather have no rust than chrome no one can see.

The Blanchard rod has a 4mm socket. Nice and snug.

Regarding testing- I always stuck one end in a vise and torqued them each way. I did that to the one that later broke in a guitar.

Allied has plans for a testing jig on their site. Just a slotted piece of wood with another clamped over it to hold the rod.

When I made one of those and tested the remainder of my Allied rods 50% of them broke at a weld. Like I said this was a while back, a bad batch, and they addressed the problem

I think the jig is probably a better way to test than the vise.

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

Most of my problems with them is hard to get the allen all the way in, and dang hard to get some of them out again. I had one customer call me and ask how to get the wrench out! While I was talking to him, he got it out.

Ahhh, the difference between 4.0mm and 5/32". It doesn't matter until it matters....

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Care to be a little less cryptic?
Are you saying that Allied ships a wrong wrench with their T/R's?

FWIW the current LMI rods seem to be very robust. I tested mine to semi ridiculous lengths in a vise before installing.

It does sound like the dual-pitch Blanchard design would offer finer adjustment, but the LMI rod is fine enough for me.

The aluminum channel rods concern me just a tiny bit because of the less favorable thermal expansion coefficient of aluminum. Steel is really ideal because it's the same as the strings, though of course it doesn't matter if it's just sitting in a pocket and has room to slip.

Has anyone noticed any difference in holding tuning in practice with the glued in aluminum channel type T/R?

Some makers of the wrenches (strangely, the more up-market ones IME) don't distinguish between the two sizes, because the difference is so small (4.00mm vs 3.96875mm) and then there is the manufacturing tolerance of both the wrench and the screw socket. So whilst most of the time the two wrenches can be used interchangeably, and mostly 4mm wrenches will fit 5/32 sockets, sometimes they won't. I have a set of cheapo Chinese wrenches that I bought in Seattle when I needed a wrench in a hurry, where the wrench sizes are exact and the 4.00mm wrench won't fit a 5/32" socket (not even a tight fit), whereas I have no problems with my "much better quality" workshop sets. But I usually use ball end wrenches because they are easier to engage and the ball ends tend to have more clearance anyway.

I have no idea whether Allied ships the wrong wrench or even ships a wrench at all because I make my own T/Rs, which happen to have 4mm sockets. That's why I know about the problem. I suspect US fasteners will be imperial sized, but the wrenches might not be, despite what might be stamped on them, depending on where they were sourced. If owners use their own wrenches rather than the one (maybe) supplied, who knows??

_________________
Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Everything in Seattle is better. That's just the way we do things.

_________________
George :-)

Thanks for clarifying.
Yes, Allied provides wrenches with the T/R's...I'll have to check to see what the size is.

The Allied wrench is 9/64", and is a bit of a sloppy fit with the rods that I received. It works but there is a bit of play in the socket.
I've since gone to Martin 2-way rods, good robust rod with a 5mm socket, simple installation, whats not to like?
Cal

_________________
Remember, there are no stupid questions, only stupid answers!

Me too

_________________
Steve Smith
"Music is what feelings sound like"

Sorry to put a bend in the thread, but are you guys getting the Martin rods direct from Martin?

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker

I got my last ones from John at BluesCreek Guitars. You can also get them directly from Martin.

Cal

_________________
Remember, there are no stupid questions, only stupid answers!

I grabbed a bunch while I was at their store up there. I just used the last one so will have to order some soon from John.

_________________
Steve Smith
"Music is what feelings sound like"

Do you guys ever use the Martin rod as a headstock adjustable rod ?

The enlarged area for the nut would worry me.

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

I don't.

_________________
Steve Smith
"Music is what feelings sound like"

I have used the Martin rod with headstock adjustment. No problems from what I've seen. It is a good adjustable rod.

Overall, I prefer not to have headstock adjustments, just because it messes up a nice canvas for inlay designs. But it's still awfully convenient, and the Martin rod works well from my experience.

Dave