Truss Rod Installation

[schnarf]

http://www.warmoth.com/common/supplies/trussrods.htm

I bought the GTR3 and TRN1. I'm having some trouble wrapping my mind around its installation. Yes, I know where it goes, but do both ends need to be anchored? If the nut end isn't held still, turning the nut won't alter the length of the rod whatsoever, it will just cause the nut to move up and down.

[Primal]

You've got it. You have to anchor both ends so that when you tighten the nut, it has something to push against, therefore applying force to bow the neck. I haven't worked with vintage truss rods because arched truss rod channels scare me.

Double expanding all the way IMO.

[schnarf]

Hmm, maybe I'll go with a double expanding truss rod. I probably should have done a bit of reading up before ordering my truss rod. Those are the flat-bottomed channels, right? Either way, how do I anchor the nut end?

Edit: Actually, if there's no downside to using this single-action truss rod, I'll probably use it. Anyway, my question still stands, how do I anchor it?

[Primal]

I don't know how to anchor it myself. Like I said, I am a double-expanding truss rod guy. I know that the truss rods that LMI sells use a flat bottomed channel, but I can't speak for all the different double-expanding truss rods out there. With double-expanding truss rods you don't have to anchor anything. As longs as the truss rods fits in snugly you won't have any trouble.

The reason I don't like single action truss rods is because you have to route an arched channel and then cut and shape a piece of wood to go in on top of the truss rod. I don't have the proper equipment or know-how so I opted for an easier solution.