Truss rod construction questions

[joel]

Hi all!

I'm considering constructing my own truss rods following the instructions in the excellent Design and Build books by Mr. Gore and Mr. Gillet. I have a few questions though before I take the plunge.

1. Single acting vs dual acting? How many of you steel string builders use a single acting rod? I have one or two LMI style dual acting rods left, but I've been thinking (dangerous I know). If I'm only building steel string acoustics and electrics is a dual acting truss rod really necessary? Counteracting steel string tension is a one-way job, seems to me I only need a single acting truss rod?

2. Does anyone know of suppliers of 3/16" steel rod, brass bar, and plain M8 * 25mm grub screws in the Brisbane area who don't want your first born as payment? My googling skills have so far been insufficient to the task.

3. I don't have any taps or dies, so I'll have to invest in some tooling for this, any hot tips in the tooling department? It appears that individual UNF button dies are rare as rocking horse poop, sets may be the way to go. As this design required both metrical and imperial, I've been considering an imperial set (the majority of which I'll never use) and individual M8 taps.

4. Anyone else building their own truss rods following the books? Any tips or tricks you'd care to share?

Once again, it's always a pleasure to discuss the fine art of wrangling wood into guitar shaped objects with you all.

[kiwigeo]

Hi all!

I'm considering constructing my own truss rods following the instructions in the excellent Design and Build books by Mr. Gore and Mr. Gillet. I have a few questions though before I take the plunge.

1. Single acting vs dual acting? How many of you steel string builders use a single acting rod? I have one or two LMI style dual acting rods left, but I've been thinking (dangerous I know). If I'm only building steel string acoustics and electrics is a dual acting truss rod really necessary? Counteracting steel string tension is a one-way job, seems to me I only need a single acting truss rod?

2. Does anyone know of suppliers of 3/16" steel rod, brass bar, and plain M8 * 25mm grub screws in the Brisbane area who don't want your first born as payment? My googling skills have so far been insufficient to the task.

3. I don't have any taps or dies, so I'll have to invest in some tooling for this, any hot tips in the tooling department? It appears that individual UNF button dies are rare as rocking horse poop, sets may be the way to go. As this design required both metrical and imperial, I've been considering an imperial set (the majority of which I'll never use) and individual M8 taps.

4. Anyone else building their own truss rods following the books? Any tips or tricks you'd care to share?

Once again, it's always a pleasure to discuss the fine art of wrangling wood into guitar shaped objects with you all.

Ive always installed double acting rods in my builds..steel strings and classicals.

I've managed to find individual dies and taps at Mitre10 and Bunnings.

Steel rod.....Im lucky in being a volunteer at a heritage railway so any metal requirements I use my contacts there to source same. I do recall sourcing some 3/16" steel rod from Mitre10 a few years back. Bunnings should have something

[joel]

Hi Martin,

"Bunnings should have something". Yeah, they should.... but they don't. At least not around here.

[Mike Thomas]

Hobby shops are a common source of steel wire and rod. K&S brand piano wire in 36" lengths comes in various diameters, including 3/16". It is a hard steel wire which would probably work well for a trust rod, although you might have to anneal the end for threading.

[Dave M]

Not really answering the question but... I crafted a few single action rods using the book which was quite interesting as an exercise. But I decided I am not really a metal worker and double action rods are fairly cheap and I would rather spend my effort on the more important aspects of producing a good sounding guitar. Not wishing to sound too negative.

[kiwigeo]

Pretty much my approach.

A few years back we did an ANZLF bulk buy from LMI and Ive still got a pile of rods sitting on my shelves.

Not really answering the question but... I crafted a few single action rods using the book which was quite interesting as an exercise. But I decided I am not really a metal worker and double action rods are fairly cheap and I would rather spend my effort on the more important aspects of producing a good sounding guitar. Not wishing to sound too negative.

[Trevor Gore]

I was hoping someone in the Brisbane area might have some local knowledge on this. The places to look for are steel stockists e.g. maybe these guys: https://earlybirdsteel.com.au/ . There may be some good offers going as they seem to be closing down soon, but there must be other similar suppliers in the Brisbane area. In Sydney I can source all the truss rod material from one supplier: Edcon steel in Brookvale, (https://www.edconsteel.com.au/steel-stores/ ) who also supply tools (taps and dies) - and fasteners.

Also, don't get hung up on the Imperial dimensions. 5mm rod (can also be stainless steel), and M5 taps and dies will work fine. The 10-32 UNF dimension was just to match typical existing USA parts.

It's not essential to have a double acting rod. I normally use single acting. However, with the BOBO neck design it is easy to pull the rod out and turn it over if you ever need to have it act the other way (a rare but not unheard off occurrence when humidity changes have had their way). It's usually a temporary issue, so if you do it, remember to turn it back the right way round!

The advantage to me of making my own truss rods is that I can make them any length I need, which is handy when building guitars with 12 and 14 fret neck joints and half a dozen or so scale lengths.

[Andos]

You should be able to get unf taps and dies from any 1/2 way decent engineering or machinists supply shop. It is not an uncommon thread size. I'm in NZ so things may be a little different on the other side of the ditch.
Buy high speed steel (hss) taps & dies. They are more expensive than carbon steel but stay sharp one hell of a lot longer.
I avoid using stainless. It is slightly heavier than mild steel and if you don't get all the oxide off and passivate the bend where you're heated it, it will rust if there is any moisture in the air. (80% RH on an average day where i live) Bend it cold and it will workharden and crack.

[joel]

Thanks for the replies gents,

Why? Why not? I'm a bit of a DIYer at heart so I want to give it a red hot go. Also, as Trevor suggests, I could make any custom length truss rod I desire.

Thanks Trevor for the tip on using 5mm instead of 3/16". That'll make buying the tools easier. One metric set of taps and dies will suit perfectly.

One question: do you re-harden the M8 25mm grub screw after working it? The instructions in the book don't say, but it seems like a reasonable thing to do given it's job.

[Andos]

No need to re-harden the grub screw. Even annealed they are tough wee buggers. You have a lot more thread up it than a normal nut and your rod will be softer anyway.
If you want to keep their hardness, you can drill and tap them in a lathe. Make sure your drills and taps are sharp, go slow with plenty of cutting oil and use all 3 taps in the set. Taper, intermediate and bottom and be very gentle on the end of the tap wrench. You can put a 0.1mm oversized tap drill through to make it a bit easier on your taps.
Easier and safer for your taps to do it Trev’s way but!

[Trevor Gore]

One question: do you re-harden the M8 25mm grub screw after working it?

If you let the grub screws just air cool after heating, they will harden up to more-or-less their original hardness, so remember to take the heat down slowly. I usually just put a tin can of grub screws in the wood burner at high heat of an evening and pull them out the morning after. Work them pretty well immediately as they will age harden and after a week or two will be back near their original hardness. Hence no need to re-harden.

[joel]

Thanks for the tips gents. I'm a complete metal working novice, so any help is greatly appreciated.

I now have the raw materials and tools to make a dozen or so double acting truss rods. I reckon this'll last me for years!