Trussrod Channel - How Tight Is Too Tight?

[TripleFan]

Hello,

my first post on this forum. Been reading some time now, but now I have to ask my first question.

OK, at the moment I´m doing two necks with scrap material to learn the proper steps.

Yesterday I routed the channels for the trussrods (Single-Action Double-Rod like this)

If I insert the rod in the channel it sits very tight. To give you the idea I have to lightly tap it with a hammer to get it in. I think this may be too tight? I guess it would be a better fit if I could sit the rod in its channel by simply pressing it down by hand?

I´ve tried the search and found a lot of measurements (mainly on the Stewmac HotRods) but I havn´t seen a description "how it should feel" to place the rod in the neck.

Any suggestions?

Thanx in advance

Ingo

[erikbojerik]

Yeah, my feeling is that you don't want it quite that tight, you risk splitting the grain in the neck over time if you really have to hammer it in. You want to be able to push it in with your fingers.

I would try to shave the channel ever so slightly (carefully) with a very sharp chisel, and only at the places where it is really binds (at the ends maybe?).

[TripleFan]

That´s what I thought, exactly.

Don´t know if I will revisit the channel on this one. It´s a test neck made of scrap after all.

The real deal I will route with a slight offset to achive a wider channel.

Thank you!

TripleFan

[docbass]

Well, I don't know about the accepted fit for a truss rod, but when I took the old one out of my 60s T-Bird, it was encased in glue that ran down from the maple strip on top of it and was about as tight as you could get. I had to chisel the glue away and still had to tug like crazy to get it out. I guess things have changed since that bass was built!

I had to use a new traditional rod and it went in with light pressure off my fingers. Hammering it in sounds too tight to me as well.

Edited May 14, 2007 by docbass

[Daniel Sorbera]

Hammering is dangerous and might split your neck. Plus the trussrod won't work very well with that much friction. It should slid in easily, but with little to no play on either side.

[doug]

If the main length of the truss rod fits fine and only the ends are tight, then slightly widen the ends with a chisel. You'll only have to remove a few thousandths to get it to go in nicely. I suspect that the fit issue is from the welds. I've seen this many times.

-Doug

[j. pierce]

I've had similar fit issues from the welds on the end of double-action LMI trussrods. I ended up taking a metal file and filing down the weld. Fit fine after that. I don't know I was asking for trouble doing this, but the truss rod has held up for a a couple of years with no problem.

[TripleFan]

Thanks for all the replies.

It´s not the welds alone that bind in the channel. The width of the rod is 6,2mm over it´s whole lenght but my router bit is only 6mm. Dumb me measured the rod before routing and didn´t think of offseting the router 1/10 to 2/10 at either side...

I didn´t think of splitting the wood. That´s something I will have to remember when going for the real necks. My main concern was about the rod still working when it sits that tight.

Thank you once more!

Ingo

[doug]

Maybe use the right bit on the "real" one? Just a thought...

-Doug