The Coordinator Rods
By John Fisher
(Jon Tirone)
A biologist tells how he watched an ant carrying
a piece of straw which seemed a big burden for it. The ant came to a crack in
the earth which was too wide for it to cross. It stood for a time as though
pondering the situation, then put the straw across the crack and walked over
upon it. Here is a lesson for all mankind! A man's burden can be made a bridge
for his progress.
The coordinator rods are 2
adjustable rods that go inside the banjo shell or wooden rim between the walls
of the rim. When first beginning this banjo projects, I wasn’t really sure what
they were even for. Thanks to Bill Palmer he helped me with a lot of
explanations. Remember, I didn’t even
have a banjo to look at and I didn’t have the coordinator rods. I found out
later that you can buy them from a supply house for about 20 or $25. Since I
would need to get them from the US somehow which was a bit inconvenient for me,
I decided to research the possibility of making them myself. I found out that
the main function of the coordinator rods is to maintain the banjo rim round in
spite of the pressure of the pull of the strings. If the rim became warped it
would also effect the tone ring if it was unduly pinched which could effect the
tone by not letting the tone ring move and resonate freely. This is at least
the way I understand it. I have seen some banjos with only one coordinator rod
but this one I built has 2 of them. I have also heard that some people actually
use the coordinator rods to bend the rim slightly to where it adjusts the angle
of the neck, which will adjust the action of the banjo. This is not a
recommended practice as it could damage some of the hardware like the tone ring
because of the stress plus it could kill the tone. The coordinator rods should
be just tight enough to maintain the wooded rim round.
Here is a picture of a
commercially made banjo showing the coordinator rods.
How the Coordinator Rods Work
The 2 rods are normally about 3/8" thick. The ends that are towards the heel have a hole drilled in them about 1" deep down the center of the rod that is threaded. The lag bolts that come out of the heel go through the wall of the wood rim and then screw to these rods. There are also washers between the coordinator rods and the rim wall. These rods are also what hold the neck on. On the other end where the tailpiece of the banjo is, the rod that is on the bottom or that is closest to the banjo top or skin goes into the banjo rim about ¼" deep. This end is also threaded and has a nut on it. The upper rod goes through the rim to the other side (also threaded) where it connects to the tail end piece. There is a nut and washer on the inside of the rim and a nut on the outside of the rim. The tailpiece bracket itself acts as a washer on the outside of the rim .
When you turn the nut on the bottom rod it will push against the rim wall. The top rod with the nut will do the same but the top rod also has the nut on the outside so that while the bottom rod can be adjusted to only push on the rim, the rod on the top can push and pull on the rim wall.
How I made my Own
It turned out to be very easy to make my own coordinator rods. I bought a 3/8" threaded rod from the hardware store that was plenty long to make the 2 rods. Because the threaded rod was already threaded throughout the whole length of the rod, I didn’t have to worry about getting the tools to thread a 3/8" rod. I then needed to drill a hole in one end of each of the rods and then thread the hole. I made the hole about 1" deep in each of the rods and then threaded the hole to receive the 3/16" threaded rods or lag bolts that go through the wall of the pot from the neck. I wanted to use a metal lathe to make these holes but I didn’t have access to one so I just did it freehand with an electric drill. It was not as perfect this way but it still worked out fine. This was easy, and for under $2 for all the parts including washers and nuts, I was able to make them in less then an hour.
Here is my version of the coordinator rods. You will notice 2 little 1/8" holes that are drilled in the middle of the rods. This is to be able to tighten the neck on to the banjo rim by inserting a large nail or something inside the hole and turning the rod.
Here is a crude attempt for
me to draw the details of the coordinator rods.
"Every great movement in the annals of history," said
Emerson, "is the triumph of enthusiasm."
It is derived, that magic name, from two Greek words: "en" meaning "in" & "theos" meaning "God." Enthusiasm is literally "God in us." The enthusiastic man is one who speaks as if he were possessed by God.
The Bridge