Kenneth Michael Guitars LLC
|KMG "Success Kit" ™ Preparing the Bridge
Even though the contour on the top is very subtle, the fact still remains that the
surface is curved. The bridge clamp system provided with the “Success Kit” is
capable of applying a significant amount of compression force --- the top and bridge
could easily be crushed into submission and a matching shape. THAT WOULD BE A
MISTAKE!!! Not only would it distort the top contour, but also induce a harmful stress
component into the sound producing membrane.
Close examination of the bridge when lightly clamped will reveal the irregularities.
Another equally important consideration is the need for a perfect glue joint between
the top and the bridge. Many of the failures I have seen were the result of miss-
Matching the bottom of the bridge to the surface of the soundboard is relatively
simple. Using masking tape secure a full sheet of sandpaper (100 grit) to the guitar
in the general area of the bridge location.
It is then a matter of carefully moving the bridge back and forth near the bridge
location in the lengthwise direction. Note the two pieces of tape at the side to help
identify the bridge placement. As you progress steaks of sanding dust will appear on
the paper, the idea is to have a dust line the entire length of the bridge. When that is
accomplished there will be a perfect mating glue joint.
Now is the time to complete another important and often overlooked bridge
modification. The addition of individual chambered string ramps.
In the following, the upper illustration depicts the common practice of ONLY
chamfering the bridge pin holes and the net result. The string exits the bridge and
creates a pinch point and sharp angle. This is a potential breakage area for the
string. The path of the string continues at a relatively low angle over the saddle. Also,
note that even though the pins have a string groove they do not seat down
completely into the bridge. The net result of this set up is a loss of string leverage as
it passes over the saddle. In turn the vibrations from the strings do not excite the top
in an optimum manner.
The second illustration shows the set up and the results of adding chambered ramps.
The bridge pins can now be fully seated. Most importantly, the string attack angle
over the saddle is significantly increased. The breakage point is eliminated and the
string to bridge contact area has been greatly increased. All good things as they
relate to sound production.
Creating the ramps can be accomplished using several different approaches. The
best to use, is the electric Dremel type tool equipped with a fine burr or better yet a
dental burr. Swiss files work well but naturally the process is slower. Because the
commercial saws, supposedly made for this operation, are much too course I DO
NOT RECOMMEND THEM. It would be a simple matter to fabricate a small saw from a
20 TPI saber saw blade. Just cut a slit in the end of a 6” piece of ¼” dowel. Snap off
the end of the saber saw blade, insert the blade into the dowel, wrap with thread, and
smear on some glue.
The ramps need to be wide enough to accommodate the wrappings of each string
size, a little oversize is OK and actually good. The ramps should blend into the pin
holes in a gentle arch – remember we are trying to eliminate the sharp