Turn the Control Unit/SCU off for safety before starting any work.

Below are two methods, one from the factory manual, and the other from an actual tech.

 To adjust the X-axis leadscrew nut

• First remove the top metal cover.
  

• Rotate the X-axis leadscrew stepper motor coupling back and forth with two fingers (index and middle). A rule of thumb is that you should be able to rotate the metal coupling between the leadscrew and the stepper motor with two fingers, but not with a single finger. If there is practically no resistance to rotation (very easy to rotate with one finger) the pre- load is too low and the leadscrew nut needs to be tightened. If there is a heavy resistance to rotation (hard to rotate with two fingers), the pre-load is too high and the leadscrew nut needs to be loosened.
  

• Use a 7/64" wrench to tighten or loosen the socket head cap screw that is on the shoulder of the colored (usually blue or maroon) leadscrew nut. Adjust the screw in 5 to 15 degree increments and retest using your two fingers.

By adjusting the socket head screw on the leadscrew nut, you are varying the gap thus adjusting the tension between the nut and the leadscrew. Some new leadscrew nuts have two adjusting screws on each plastic leadscrew nut. If you have tightened the screw on the plastic nut where the gap is completely closed, it's time to replace the leadscrew nuts.

• Be sure and engrave a plate after you complete your maintenance.

Generally curved letters and slanted lines are affected by the leadscrew nuts and the carriage assembly. The upright shafts of T's and other upright straight lines are more affected by the ball slide.

To adjust the Y-axis leadscrew nut

• Remove the clip that holds the rubber boot in place and push it back to expose the leadscrew nut.
  

• Use a 7/64" wrench to adjust the exposed Y-axis leadscrew nut in the same manner as you adjusted the X-axis leadscrew nut above. Adjust as needed.
  

• Replace the Y-axis boot and clip, and the metal X-axis leadscrew cover.

 From The Techs

Symptoms of improperly adjusted leadscrew nuts include poor letter quality, excessive noise, and step loss. If you have one or more of these symptoms, leadscrew nut adjustment on your system should be checked. The following procedure explains how to do this, but first, a quick description of leadscrew nuts may be helpful background Information.

Movement of the spindle axis and engraving table axis is controlled by stepper motors, where the spindle is X and the table is Y. The stepper motors are coupled to, and turn the X and Y-axes leadscrews. The leadscrew is long, heavy, silver colored screw. The leadscrew nut is made of plastic. It is small and normally blue in color. Because the blue nut rides up and down the leadscrew for hundreds of hours, it is necessary to lubricate the leadscrew and adjust the leadscrew nut periodically. Both the leadscrew and the leadscrew nut are not usually in plain sight because they have to be protected from dust and debris. They may be covered with a rubber boot or metal cover. If you have a problem locating them, phone your local service enter for help.

With the control unit off, rotate the stepper motor/leadscrew coupling back and forth. If the coupling turns extremely free and there is no resistance, the leadscrew nut is too loose and should be adjusted.

If you have a problem with the engraving quality and the system is excessively noisy, pause the system in the middle of engraving. With the system paused, the stepper motors stop and remain in the locked position. Grab the engraving table at this time and lightly, but firmly, wiggle it back and forth. lf you feel any play, no matter how small, the leadscrew nut should be adjusted or replaced depending on how much adjustment is left. Do the same with the spindle axis.

To properly adjust the leadscrew nuts follow these steps:

• Lubricate the X and Y leadscrews
  You can't obtain a proper leadscrew nut adjustment with a dry leadscrew. You may want to engrave a few jobs or use X/Y GOTO to work in the lubrication.
  

• Locate the leadscrew nut
  You will notice a small allen screw on the end of the nut. Tightening the allen screw closes a slit manufactured in the nut to compensate for wear. If you find the slit to be fully closed, there is not adjustment left and the nut should be replaced.
  

• Using the proper size allen wrench, turn the adjustment screw about a 1/4 of a turn. Each time you adjust it 1/4 of a turn, rotate the coupling back and forth. The proper adjustment is when you have a fair amount of resistance when rotating the coupling. You do not want it to be too tight or too loose

In most cases, leadscrew nut adjustments will quiet down your system and improve the letter quality. If you continue to have problems with home position, letter quality or noise, you may want to contact Technical Support. It is very important to maintain proper lubrication of each leadscrew. Operating with a dry leadscrew will result in unnecessary wear and will eventually cause corrosion on certain areas of the leadscrew.