|
By: Michael Granger
Some guitars will just NOT adjust properly with the standard
methods available like the bridge saddles, nut filing
adjustments and the ability to set the bow (or lack thereof) of
the neck itself. Adding shims to the bolt on neck may be
necessary to get the guitar to play properly at all locations up
and down the neck. A nut shim acts as a spacer between the nut and neck raising and
lowering the distance between all of the strings at the lower
end of the guitar, starting at fret 1 and moving towards the
body of the guitar. A neck pocket shim acts as a spacer between the neck and body,
changing the angle from which the neck protrudes out away from
the body. Try to imagine the strings of your guitar as a flat plane and
the fret board as a parallel plane running underneath them. The
angle of the top plane which contains the strings is controlled
by the position of the tremolo and the nut. The angle of the
lower plane which is the fret board is controlled by the neck
pocket of the body. If your setup is perfect these two planes will have an equal
distance between them at any point. If your guitar doesn't look
this way try adjusting the height of the tremolo itself first.
This will usually take care of the problem unless you find your
action becoming too high or to low equally across the length of
the fret board. If adjusting the height of the tremolo corrects
the problem but leaves you with too high or low of an action
(distance between the strings and fret board) then you will need
to resort to using a shim. You may want to "block" the tremolo
before you start the shimming operation. Shims can be found and used in two different areas of the neck.
One is under the nut and the other is directly under the heel in
the neck pocket of the body. Nut shims are usually made out of one or more thin sheets of
brass. Shims located in the neck pocket are usually made out of
a thin piece of wood. In either case you can produce your own
shim if needed by using a sheet of heavy stock paper such as a
business card. For shims in the neck pocket you might need to
fold the paper stock 3-4 times to get the required thickness
needed, then trim to fit properly. First determine if the distance between the strings and fret
board is to close right up against the nut itself. If this is
the case then add a shim under the nut and raise the tremolo by
adjusting the tremolo posts until the strings are an equal
distance from the fret board down the entire length of the neck.
If the distance between the strings and the fret board located
right up against the nut is OK then you will have to place a
shim in the neck pocket to correct your problem as directed
below. If your strings are higher on the Low E side, place the shim in
the neck pocket under the heel of the neck and parallel with the
length of the neck on the Low E side, which raises the entire
neck down the Low E side when it is bolted on. Before doing this
check the angle of the tremolo to make sure it is flat against
the body and not floating at an angle. If your strings are higher on the High E side do the opposite,
as explained above, by placing the shim parallel to the neck on
the High E side in the neck pocket. Again before doing this
check the angle of the tremolo to make sure it is flat against
the body and not floating at an angle. If your strings become higher the closer they are to the body
place the shim across the neck pocket in the end closest to the
neck pickup. This will turn the other end of the neck pocket
into a fulcrum point and move the head stock towards the back of
the body lowering the strings over the high end frets. If your strings become lower across the high end frets place the
shim across the end of the neck pocket furthest away from the
neck pickup. This will raise the headstock away from the back of
the body, raising the strings up from the end of the fret board,
closest to the body. In some instances you might find that you need the shim to raise
only one corner of the two planes as described above. In these
rare cases, make a smaller shim and place it in the appropriate
area of the neck pocket. Of course upon removing the nut from
the neck or the neck from the body, if you find a shim already
there determine what action it was doing in the first place then
make the necessary corrections. Shimming a guitar neck is definitely an ART. However, if you
look at it scientifically, as angles against a plane, you can
understand the "how and why" of adjusting a guitar neck this
way. About the author:
Michael Grainger is a music studio owner and has vast experience
setting up guitars for his customers. See more information at Instruments Now
People searching for the term "Learn To Play Guitar" found this page helpful.
| 
