Neck truss rod jig

[Chris Richards]

Hi

Love making jigs especially when they work has planned! The pictures are pretty self explanatory. This one lines up everything for a vintage truss rod installation, the steel guide blocks are angled for the adjustment nut and the anchor point and the sleeve insert for the adjustment nut ensures a centred hole for the truss rod..

[Mark Swanson]

Good job...so this is for a trussrod under the fingerboard, and not "skunk stripe" type? can you show the trussrods and how you are making them, and anchoring them in the neck?

[Bob Francis]

That is a nice piece of work Chris!
Very clever.

[Hans Bezemer]

That's a very nice jig. Good work.

[Chris Richards]

Yep this is for an under fretboard truss rod, I use the Stewmac anchor "barrel" and X nut and thread a 3/16th length of mild steel. Also I use the curved guide in the jig to mark the filler strip so it's a tight fit over the truss rod. I've had a few problems in the past with rods not working, this jig ensures that everything lines up.

The anchor barrel once threaded on the rod, I peen the end over then lightly wipe the rod with thin oil and slide drinking straws over it before fitting it.

[Chris Richards]

Ummm.... Sorry the pictures are in reverse order, you'll notice that my tap wrench is, errr... somewhat "Heath Robinson" as we say in the UK, I think you say "MacGyver!

[Mark Swanson]

That's good! I used rods like that for a while but things were inconsistent for me, and sometimes they would work, and sometimes they did not. So I switched to a double-acting rod from Allied. I could never figure out why they worked sometimes and did not work sometimes.

[Chris Richards]

Hi Mark.... Yes I agree, in the past I've had this type of rod do nothing no matter how hard I've tightened them up and then sometimes they work fine? In my frustration I've tightened the nut so hard it has started to pull the anchor point through the wood! and still nothing. I've also tried bending the neck then tightening the rod and still no luck, so I'm hoping that this jig will make the rod operation more consistent, it seems to so far...Cross fingers.

I've only ever tried a double acting rod once, mainly because the neck was very slim but because of this the whole thing wasn't rigid enough and it needed constant adjustment so that one ended up on the firewood pile ?

[David King]

Hi Chris,
I'm coming up with a similar system and wonder how deep your channel deflects in the center. I've been told that the deflection should be at least one rod diameter i.e. .188" for the thing to work but it still needs to be as close to the back of the neck as possible. I'm doing bass necks which are considerably longer so perhaps more deflection is in order. I use a flat disc anchor that's 5/8" dia x 1/4" tall. I don't see that pulling through the wood very often.

I'm always amazed at how easily the surviving pre-CBS truss rods work. I've always wanted to saw one open up to see exactly where the low point lies to get such a good playing surface after so many decades. There are so many bad necks out there that I see all the time I have to wonder if it's all just in the piece of wood.

[Chris Richards]

Here's a picture of some Fender necks sliced down the middle... This is what I used to design my jig, basically the curve is quite drastic! Well to my eye anyway. I also have experience of Gibson necks, which use the same type of truss rod and these go very close to the back of the neck, a customer had shaved the neck down by only very little and broken through to the truss rod cavity the only thing I could do was veneer the whole neck and paint it..

[Chris Richards]

The other point is that I've used channel type truss rods which are easy to fit and very good and they rely on just a shim (that's no more than a 1/16th) under the centre of the rod in the u-channel. I'm assuming straight rods work since if the neck curves the rod curves as well and hence tightening the rod will pull it straight and hence bend the neck.

[Jim McConkey]

Chris, did you take that picture? If not, you may post a link to the picture, but not the picture itself, due to copyright laws.

[David King]

What that photo shows is that the rod deflects about 1.5 times the rod diameter. More than 1/4", closer to 5/16".

[Chris Richards]

Apologies, No I didn't take the picture, I couldn't bring myself to saw through a couple of vintage Fender necks! They're pictures I found somewhere on the 'net, I can't remember where so please feel free to remove them.