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How to make a double action truss rod

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I have investigated the double action rod really in my "building career". The conclusion was that I rather build guitars than weld truss rods. Here is the factory drawing for the Fender two way truss rod:


The Fender is made in a quite different way compared to the Stewmac version. Fender simply blocked the truss rod nut with a piece of wood, drilled so that you still can get an allen key though the hole into the truss rod nut. Stewmac use two threaded rods threaded into two brass blocks, with one of the rods threaded clock-wise in one end and counter-clock-wise in the other. They weld the nut to the rotating rod (top one is stationary)

I have used Stewmac trusses without any problem at all. I have however moved over to the type LMII sells, although I buy a slightly thinner version. Both works fine.

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Gibson does not make a straight channel truss rod situated directly under the fretboard. They use a curved channel just like Fender, however they install it from the top side of the neck, rather than the back like Fender. In this picture the wood between the trussrod and the fretboard can be seen.


In this picture you can almost see the curved channel


Gibson have mede their rods this way from mid 50's Gibson and onwards when they changed from a straight compression type truss rod embedded deep in the neck, close to the back of it, to todays curved rod.

BTW, I forgot that Stewmac has a new double action rod available. Read my prior answer in the light of me thinking of the old versions...

If you have would like to make a trussrod to learn or from a "do everything yourself" wish, then I could understand it. However if you think that making one truss rod will save you money I think you are wrong. You will need to invest in both tools and time. I didn't really understand were you are but I guess Spain or at least Europe (like me). My suggestion is to check for a lokal supplier. Check out Rockinger.com in germany. They have a double action rod priced at 10.90 euro. That cannot really be too expensive, can it?

I don't mean to put you you down, but if you cannot look at the picture of a double action rod and figure out how to fabricate one the task of doing one yourself is probably to hard. Look at this picture:


You have one square bar with a nut welded to it at each end. Then you have a rod that is threaded in each end. The thread is threaded counter clockwise at one end as is the specially fabricated nut. The rod is first threaded into the nuts, then the nuts are welded to the bar and finally an allen head is welded to one end of the threaded rod. To do this yourself you need to get a counter-threaded cut and die (I think thats the name), make the special nuts and have access to an arc-welding equipment. The raw material itself would probably more than the the cost of a ready made trusted. My suggestion is still to shell out with the 11 euro and get a fully functional rod from day one...

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OK, the pictures you linked to shows the Fender bi-flex trussrod. Thats the one I linked to in my first post. To do that type of trussrod the original way you rout a curved channel from the back of the neck. That doesn't seem to be what you want to do. I try to understand what it really is that you want to achieve. Do you want to use a straight channel, double action trussrod, placed directly under the fretboard, but have it look like the Fender bi-flex trussrod? If so this is the way I would do it:

- Use a lathe to turn walnut plugs with a hole in the center to match the Fender style plugs (or buy them ready made, they cost from 5$ plus shipping and import taxes but if you don't have access to a lathe you have no choice...)

- Rout the trussrod channel from the top of the neck blank. Stop before you reach the nut area (draw this out full scale for the actually measurements). Like this 105392d1323672833-installing-martin-1-way-truss-rod-flat-headstock-2011-12-12-17-02-07-jpg

- Cut the headstock to desired thickness but leave the fretboard end squared off, not like the smooth curve it will have when finished. This makes it easier to do the next step. Like this: 02-tr.jpg

- Drill a hole to match the plug you just made and make sure you have the center of the drill at exactly the same position that the adjustment nut of the trussrod have. quite similar to whats done here, altho at the head stock and without a already cut channel and with standard drill bits.

- Insert the plug and check alinement, fit etc, glue it in when you know the fit and placement is perfect and proceed with shaping the neck.

It can also be done without the plug, just drill a smaller hole, like this: trussrod_565.jpg

Now to the original question: How to make a double action trussrod. Are you seriously saying that getting the trussrod from here in Europe is to expensive? 10.90 from Rockinger, I see that Madinter in Spain have the Gotoh style straight trussrod (not my preferred version but I have used it over the years) for 9,31 and I know that there are more suppliers here in Europe (I get it locally for 15 Euro and I'm considering that a good price as I don't need to pay for shipping as I can pick it up by myself...). Shipping should be minimal if the one at Madinter is acceptable and a very small cost compared to ordering special metal working tools like the counter clockwise tap and die. I checked and here in Sweden the cost för a M5 counterclockwise die is around 60 Euro! And a matching tap is 30 Euro. So if you don't already have those (a cost of 90 Euro), or have access to tools like that, and on top of that cannot figure out how to make the trussrod from looking at the pictures; do yourself a favour and buy a ready made trussrod. It will save you a lot of time and money

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Thank you Swedish.I think your're right and it is possible it doesn't worth make it.Which one do you think is better in Madinter?



The length is differerent too.

Juan Carlos

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The links doesn't work... I would go for this:


You need to check that it works with your specific design. Draw everything out in ful scale and check.

I would hovered rather go with the rod from rocking as it is shallower and made of steel. But the Gotoh rod will work just fine. And possible make the neck a bit lighter too, and that is a good thing in my book.

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You can buy the blue two way rods all over the world, as they usually ship from china. Alternatively, there is PRS's way of making two way rods, which I want to try, but it will require a brazing setup, I think. They are a very elegant solution, low mass, and easy to make at home if you have a way to braze.

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Alternatively, there is PRS's way of making two way rods, which I want to try, but it will require a brazing setup, I think. They are a very elegant solution, low mass, and easy to make at home if you have a way to braze.

I made a search but couldn't find anything on that subject. Do you mind elaborate a bit? Very interested...

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  • 9 months later...

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