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Stewmac Truss Rod Installation

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Well, just curious about Stewmacs hotrod truss rods. I have six, so I guess I should be more curious about installing them than most people ;-)

So, with the brass "blocks" at either end being near as damnit 15mm deep, and the rods 14-15mm from the top of the rout in "relaxed" state (thanks to that PVC wrap), what depth should I curve the truss rod rout to? My instinct tells me 15mm for the brass blocks with a curve dip of about 17mm in the centre of the rod. Now, how much wood should be left between the rout and the outside world here? 4mm would seem "stable" enough but that leaves a neck depth of 21mm plus the depth of the fretboard - one fecking fat nuck!! *cough*

I suspect I've already screwed up one awesomely made (for a first neck) mahogany and purpleheart neck with a truss rod install which has insufficient recess curve, so advice would be gratefully received. BTW - what happens when you have NO recess curve for the truss rod? *cough* Sorry, I must be coming down with a "cold" or something.

Your respects to the (potentially) deceased party please:


FYI, that mark is sweat from hard consciencious work. Wooha!

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If you dont want the neck to be so think you could try routhing a small slot in the fingerboard for the truss rod to fit in so that it is raised a little out of the neck, I dont think that would work with an angled head stock though. And for the space between the cavity and the out side of the of the neck that is use it about 1/8 inch (3.2mm).


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Oops! A bit too much red wine confuzzled my head last night. The depth of the brass blocks is 10.5mm (~7/8"). I actually depthed a neck to 15mm last night which is why I woke up this morning with a shot, thinking I'd be routing a channel right through it!! Oopsy.

TheGarehanMan: Thanks - that information reassures me that my first neck (the one pictured) should be recoverable :-) I actually wrapped the brass ends with greaseproof paper (fat-free, cookie paper etc.) to stop the glue from the ebony fingerboard seizing it. What would be the best way to check correct rod operation? I presume it would make more sense if the board was fretted and on the body?

Ooten2: Thanks for the info. I'm sure I have that information somewhere, so I guess I've scored myself some idiot points on my permanent record there....duh!! I think I've confused the issue in my head with other people talking about curved channels (especially in Mr Hiscock's guitar bible!) and presumed it was the same for Hotrods.

Vince D: I tend to design in small angles to my headstocks (4° for my Iceman set neck I'm working on for instance) whether it be scarfed or one-piece (both of these are one-piece for strength) so I don't think I want to jeopardise stability. Having double-checked my measurements, even if I was to rout a curve in the channels (which I don't seem to need with Hotrods) I could get away with a 14mm dip in the centre giving 3mm room play. It would still mean a 17mm deep neck, but that's no biggy. A thinner fingerboard would correct this. Given that the Hotrods don't seem to require a curved channel, the 11mm flat channel on a 15mm thick neck (minus fingerboard) leaves a comfortable 4mm before the rod bursts out from the rear of the neck a la Alien.#

Thanks for all the info guys, I feel a lot more confident in my rod installs now. For the record though, what thickness of wood are people confident with leaving from the back of the neck through to the rod channel? I presume this varies from wood to wood....

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Hotrods should be in a straight channel. Yes you can recess it just a little into the fretboard as long as you use a normal thick fretboard (1/4") not a thin fender board....

its a good idea to lube the threads of any truss rod with petroleum jelly (vaseline) to make sure the rod doesnt bind in the threads.

To keep glue from getting into the rod, cover the rod and channel with 3/4 inch masking tape when you spread the glue. After the glue has been spread, pull the tape, and clamp the fretboard on. The tape should stop glue from getting to the rod- unless you flood the crap out of it.....

There is no GOOD way to test the rod until the fretboard has been installed. If you place the rod in the channel without the fretboard and turn the nut, the rod will just pop out of the channel-

On another forum, people agree that 100/1000" (1/10") is a good minimum under the rod- I've gone down to 55/1000" with a wenge/zebra neck without issue, but wenge is a lot stronger than many other neckwoods.

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Excellent. I have plenty of margin for error now then. I've sanded back the neck almost to profile and I reckon I have a good 3mm-4mm of leeway in the mahogany. Good job we're not making basswood necks here!


This is what the neck looks like so far - I bound the fretboard with flamed maple and veneered the headstock with ebony (yet to be bound with shallower maple).


Another picture

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