Contact Relation Triangle – Helps to Tune Machines

Triangle (ABC)
starts with point (A) being where the contact point touches the
front spring. Triangle (ABC) continues with point (B) being where
the rear spring is fastened to the deck. Triangle (ABC)’s last
point is point (C), a 90 degree angle going from the a-bar up to
point (A). Angle (ACB) will always be 90 degrees (or a right triangle).
This triangle will tell you a lot about how the machine will
run. Generally, when line (AB) is shortened, meaning the contact
is moved more toward the rear of the machine, the machine
will run faster. Machines with the contact point moved further to
the rear are sometimes referred to as cutback machines. Another
way to speed up a tattoo machine is to decrease the distance
of line (AC). Line (AC) can be decreased simply by turning
the contact screw lower toward the a-bar, or by increasing the
amount of contact screw that is exposed below the binding post
(usually turning the contact screw clockwise – depending on
the threading and setup of the machine). Additionally, another
adjustment can be made to the triangle to increase the speed
of the machine. The distance of line (CB) can be adjusted by
putting a shorter length rear spring on the a-bar assembly. The
shorter the length of line (CB), generally the faster it will cause
the machine to run. Because there is no right or wrong way to
configure any single machine, it is important to know what each
adjustment will do to the machine; the Contact Relation Triangle
is no exception. These are just general rules of thumb, and can
be applied in different fashions.