To adjust tension on the screw, first remove all Z-axis backlash in the conventional manner by
lifting the motor/speed control unit by hand while tightening the handwheel set screw on a
"fresh" quadrant of the leadscrew to avoid picking up any previous indentations. Once adjusted,
tighten the new center screw only until it is "finger tight". Use a very small amount of Loc-tite®
on the end of the screw to keep it in place. (Do not coat the threads or the screw may become
impossible to remove.) Overtightening the screw will cause the handwheel to become hard to
turn. The purpose of the screw is not to adjust backlash, but rather to keep it from increasing
once it is properly adjusted. Do not try to use the screw to pull out additional backlash. The small
5-40 threads are not strong enough for this task.
A few more tips
When in use, shield the unit from chips so they don't accumulate around the telephone jack
connections on the side. Do not use an air hose clean off the unit.
A metal stand is now included with your DRO so you can stand the unit up on your workbench.
This makes it easier to read while you work. If you wish to secure the box to the stand, a piece of
double-sided foam tape is a good method.
Reversing the direction of the reading on the X-axis
The X-axis readout is designed to read negative numbers when the handwheel is turned in the
clockwise direction and positive when turned counter-clockwise. Should you wish to change
your readout so that it uses a standard x-y plot, you can do so by switching two of the four wires
coming from the encoder for the X-axis.
To do so, unplug the X-axis cable from the readout box. Remove the four screws that secure the
lower housing to the upper housing and then remove the encoder halves from the handwheel. On
the bottom of the half with the encoder is a cover plate secured by three screws. Remove these
screws and the cover plate. This will expose the soldered connections for the four wires coming
from the encoder. To reverse the direction of the readout, unsolder the green and black wires.
Reverse their position and re-solder to the encoder leads. Reinstall in reverse order. The diagram
below shows the factory locations of the wires before the swap is made.
