Truss rod cavity - to curve or not to curve
Jonny Durango
truss rod cavity for single fender-style truss rods...i know JET does this
w/ a special jig that holds the neck in a backbow whilest it's being routed.
But natelson & cumpiano recommend a straight cavity w/o any curvature and
i've seen many solid bodies built the same way. So what's the deal? Is the
straight cavity just an accoustic thing? I've got a beautiful quartersawn
honduras mahogany neck built and I need to know how to approach the truss
rod design. Any and all help is greatly appreciated!
--
J. Durango
"Self-restraint enhances one's energy. Self-restraint is said to be sacred.
The man of self-restraint becomes sinless and fearless and wins great
results. One that is self-restrained sleeps happily and wakes happily. He
sojourns happily in the world and his mind always remains cheerful. Every
kind of excitement is quietly controlled by self-restraint. One that is not
self-restrained fails in a similar endeavour." - The Mahabharata, Santi
Parva
Skip Helms
strip about 7" long that tapers from 3/16" high to zero. You can run a rat tail
file along it if you like. Glue it in under the rod when you install the rod.
This gets a little harder when you are doing a one-piece neck since you have to
drill the hole through the headstock. Then you can add a slight hump in the
middle.
If you want to do it in a production format (I haven't done this but would if I
made a lot of them), make a jig out of a couple pieces of straight-edged wood
and glue a 3/8" spacer between them at either end. Beltsand a concave dip in
the middle. Then use your router with a pattern guide (the little bases with
the nipple that sticks out to register against the surface) to cut the slot.
Depending on the router you may need to fashion a base with a matching surface.
Skip Helms
Zia Guitars
MMGGUITARS
>file along it if you like. Glue it in under the rod when you install the
>rod.
The way I produce the half round in this type of rod cavity it to take the
waste from a 3/16" steel rod and file a 45 degree angle on the end.This makes a
nice scraper and will remove the wood so that the round bottom of the rod fits
into a rounded slot. This was a Charles Fox technique.
Marty
Jonny Durango
to go w/ the double expanding truss rod because i'll be using mahogany for
the neck and I don't want the single rod to compress and warp the neck with
time. N&C has very detailed instructions for making this truss rod for a
martin style SS, but not for a gibson/PRS style solid body. I would like the
rod to be adjustable from the headstock such as a PRS. Any pointers? Thanx
again!
--
J. Durango
"Self-restraint enhances one's energy. Self-restraint is said to be sacred.
The man of self-restraint becomes sinless and fearless and wins great
results. One that is self-restrained sleeps happily and wakes happily. He
sojourns happily in the world and his mind always remains cheerful. Every
kind of excitement is quietly controlled by self-restraint. One that is not
self-restrained fails in a similar endeavour." - The Mahabharata, Santi
Parva
"Skip Helms" <hjh...@attglobal.net> wrote in message
news:3CA46F8B...@attglobal.net...
Mike Dotson
Is this actually a problem?
Why not just buy the Hot Rod double action rod from Stew-Mac. It uses an easy
to cut straight channel and can be adjusted from the head or body end. They
work great.
Miker
easy
> to cut straight channel and can be adjusted from the head or body end.
They
> work great.
I used that one a year ago on my first neck and it was dead easy.
Jonny Durango
don't think it will be necessary to upbow the neck if it is built
properly....plus the hot rob is $15 and requires a slightly larger
cavity....I picked up a 3/16" steel rod today and I'm about to go bend
thread and wrap 'er up right about..............now!
--
J. Durango
"Self-restraint enhances one's energy. Self-restraint is said to be sacred.
The man of self-restraint becomes sinless and fearless and wins great
results. One that is self-restrained sleeps happily and wakes happily. He
sojourns happily in the world and his mind always remains cheerful. Every
kind of excitement is quietly controlled by self-restraint. One that is not
self-restrained fails in a similar endeavour." - The Mahabharata, Santi
Parva
"Miker" <mik...@mindNOTTHISspring.com> wrote in message
news:a83e41$tnt$1...@slb4.atl.mindspring.net...
Melvyn Hiscock
----------
In article <B19p8.158246$702.28248@sccrnsc02>, "Jonny Durango"
<jonnydura...@PLEASEattbi.com> wrote:
> Thanx for the advice. After doing some research on the subject I've decided
> to go w/ the double expanding truss rod because i'll be using mahogany for
> the neck and I don't want the single rod to compress and warp the neck with
> time.
I have never known a standard curve rod compress a neck and warp it. I have
seen necks with curved rods that have warped all on their own from other
factors, but there is not enough pressure exerted on a curved rod with
normal light strings to cause that much compression. Think about the curved
rod, as you tighten it tries to straighten so it is not a compression but a
bending. (OK there is a little compression but this is my point - NOT MUCH)
A straight single rod in a channel RELYING on compression can cause problems
and I have known few that actually work.
The twin adjustable rods, such as the Hot Rod, work well but do sound
different to a curved "Ted McHugh" rod. Instructions on fitting these, that
will also work on acoustic guitars, are in a book written by a guy called
Hiscock.
Hope this helps,
Melvyn Hiscock
Sheldon Dingwall - Dingwall Guitars
You bring up an interesting point on the tone of different truss rod
designs.
We've never used a single curved rod (for our own reasons - I'm not trying
to bash them).
How would you describe the difference in tone between them and a double
expanding style?
Sheldon Dingwall
"Melvyn Hiscock" <mel...@globalnet.co.uk> wrote in message
news:ub6ruas...@corp.supernews.com...
Melvyn Hiscock
Sorry this took a while to answer as I managed to throw Outlook Express in
the trash!
I am not sure I want to make any definite statements about how different
they sound as I have not used too many double rods and there are so many
factors influencing the sound of a guitar that it is too easy to get into
generalizations. (This happens a hell of a lot!)
Unless I make two identical guitars each with the different rods but with
all else the same, I am going to keep this as a private theory. My own
opinion (and it is nothing else) is that the aluminium channel rods sound
flat in comparison to 'real' (ie Ted McHugh) rods. I sort of feel that
possibly, with the wind in the right direction and the price of cheese being
stable, that the double rods fall somewhere in between although nearer to
the bent rod in tone. How non-commital can you get?
But, I know of many people who use and love double rods and I am a great
believer of 'If it works, DO IT'
Hope that isn't too confusing.
Melvyn
in article 7xDt8.18440$Kq4.8...@news2.calgary.shaw.ca, Sheldon Dingwall -
Dingwall Guitars at she...@dingwallnospamguitars.com wrote on 12/4/02 5:01
pm:
Chris Johnson
a curve into it via a curved filler spline.
How can a straight, unbent rod work? All it can do is apply tension to the
neck. By applying pressure against a curved surface, it will attempt to correct
a back bow.
If a straight conventional rod works, it's practically a miracle. It has no
mechanism to actually correct a bow.
CJ
Miker
no
> mechanism to actually correct a bow.
Imagine a line running down the exact center of the neck... in the middle
both horizontally and vertically.
Install a straight rod behind that line, 'opposite' the fretboard.
Using the rod to compress that side of the neck will tend to curve the other
side back, correcting a bow.
That's how I understand it. I would think I'd prefer the curve as well, tho.
Carol Goulden
"Miker" <mik...@mindNOTTHISspring.com> wrote in message
> > If a straight conventional rod works, it's practically a miracle. It
has
> no
> > mechanism to actually correct a bow.
>
> Imagine a line running down the exact center of the neck... in the middle
> both horizontally and vertically.
>
> Install a straight rod behind that line, 'opposite' the fretboard.
>
> Using the rod to compress that side of the neck will tend to curve the
other
> side back, correcting a bow.
Fine in theory. Total pants in practice. It presumes the wood will compress
easily for one thing and that you can get enough pressure to do the job.
This was my point earlier, a curved rod is not under that much compression,
it is just bending (no doubt someone will come up with some math that tells
me exactly how much compression is happening but it is not important!). The
rod behind the centre theory also assumes the compression only happens along
the length of the rod, in the rear section of a neck but since all the
fibres are joined, it must also compress the other half to some degree.
>
> That's how I understand it. I would think I'd prefer the curve as well,
tho.
>
It is so much more satisfying to sit down with your brandy (or mine)
afterwards and think of a job well jobbed.
Melv
>
Miker
> afterwards and think of a job well jobbed.
Lets just hire it done! I'll buy this time. :)
miker