MIMF

Stewmac used to sell one, but no more. Anybody know where I can buy this type of rod? It uses one rod that can correct for both bow and backbow. The rod has both ends threaded: one forward and one reverse - and it turns in two blocks, one at each end. I used to make my own but am not setup to now.

These rods are a lot lighter weight than the hotrod type dual-rod setup, which is kind of a thing with me.

I've used the double action rods from Luthiers Mercantile International a couple of times and it might suit. Not sure about it being lightweight, though. It has right and left-hand threaded rod that can adjust both ways along with a flat metal that rides next to the fretboard. I think it requires a TR slot that isn't quite as deep as the StewMac hotrods.

The rod sold by Allied is the best one out there- have a look at that one.

+1 on the Allied rod. It doesn't require as much depth as the StewMac hotrod, but it's not really much lighter. It's a bar and a rod instead of two rods, saving some depth but not really any weight.
I suspect that the end anchoring would be a little tricky for a single rod providing dual adjustment.

Another +1 on the Allied rods.

I like my guitars to be as light as is practical. And on my personal guitars, I always put the strap button on the back of the neck around the 18th fret, SG style (they just play a lot better when put there). Needless to say, that makes the thing tend to be neck heavy.

Kinda looks like I might have to start making my own again. But I'll have a look at the Allied. I'm sure I've seen it before, but I've never used it.

Thanks, guys.

Anybody know anything about Bruce Johnson's trussrod? Apparently, there's something new/different/better about it. The pics on his website don't reveal much though. I imagine he would sell them. Maybe I'll email him.

Right after the LMI rod was mentioned, several people acknowledged their love of the Allied rod. They both appear to use the same type of construction. I have used the LMI rod with satisfaction but never tried the Allied rod. Can anyone who has used both provide a comparison?

You don't have to turn as hard to adjust the Allied rod. You have to turn it more than the LMI rod to achieve the same neck deflection--in other words, it gives a finer adjustment. I use them in most of my guitars.

Can someone advise on the Allied rod.... what's it weigh and what are the slot dimensions?

The 13" Allied rod that I use is 109g, .25" wide, and .353" deep.

thanks Bob

Bruce used to have a photo montage of how he makes his rods on his site I think. You can make one on a drill press with off the shelf parts. It's actually an old design and it works best in a curved slot. Why do you need a two way rod?

Not sure I want to answer that....

Okay, as often as not my necks come out slightly backbowed after gluing the fingerboard on. You'd think I would have solved that problem by now, after having done this off and on since ... 1976? Damn! So maybe I need to start a new thread on glue ups and backbow? lol. Ya think!

You know that comes from using water-based glue for the fingerboard/neck joint, right? The water in the glue expands the wood surface when it's wet, and it dries that way. If you use epoxy, that problem goes away.

Yeah, I know. But I've had too many bad experiences with (admittedly cheap) epoxy: not hardening properly, failed bonds, etc. I'm kind of scared of it at this point.

I have in mind to come up with a neck gluing jig that introduces a tiny bit of forward bow. I just never seem to get around to actually building it.

Just to see it, I ordered one of the Martin dual-action truss rods. It weighs 139 g. I have pulled off the shrink wrap and looked at it. It is threaded only on the adjustment end, welded on the other. So, it's a bit simpler than the Allied rod. It also requires more force to adjust than the Allied rod and one turn moves it more. The slot it requires is pretty much the same as the Allied rod with two exceptions: it can be rounded on the bottom and the adjustment end requires wider a 9mm slot. I would always install this one to adjust from the soundhole. I made a router slip on a nearly finished neck, which I had to discard, and was able to remove this rod by pulling it out of the slot without removing the fingerboard. I understand that Martin has been using these for about 5 years. With that many out there, it's probably pretty reliable. I plan to get some more and try them.

Regarding glue, I've built with Titebond, epoxy, and HHG joining the fingerboard to the neck. I always use HHG now and have for many years. Yes, it puts a bit of backbow in the neck. I wait a couple of weeks after I glue before I level and fret the neck. If the string tension doesn't bring it to perfect, and it usually does, the double action rod puts it where I want it. My necks usually require another adjustment about a month after I first string up the instrument. I abandoned the Titebond and the epoxy for that joint because of creep. When the weather changes, sometimes the joint between the fingerboard and the neck would become detectable with your fingers. HHG doesn't allow that. I don't use epoxy for anything anymore.

When the weather changes, sometimes the joint between the fingerboard and the neck would become detectable with your fingers. HHG doesn't allow that.

Yes Bob but I wonder about that. What happens if the wood of the neck and the fingerboard changes with the weather, or seasons, at different rates (which they do) and the glue will not allow that small bit of creep? The glue joint can break right off, or weaken and separate.

I have never had that problem. My guess is that the wood is able to accommodate that small amount. When it happened on my early guitars with the Titebond or epoxy, the edge wasn't visible but was feelable. Once, and only once, I had a customer who severely dried out his guitar--the fret ends were sticking out 1/16" on each side. The fingerboard on that guitar cracked in the middle. (All of the cracks closed after three months in my 40% room--that guitar was really dry).

gene downs wrote:Yeah, I know. But I've had too many bad experiences with (admittedly cheap) epoxy: not hardening properly, failed bonds, etc. I'm kind of scared of it at this point.

The obvious cure for that is to use a quality product. You owe it to yourself. I like West Systems epoxy and have never had it fail on me.