The X-axis motor assembly consists of the X-axis lead screw, anti-backlash (ABL) nut, and X-axis stepper motor. When the printer is operating normally, the Light Processing Unit (LPU) travels along the X-axis lead screw, driven by the stepper motor. A malfunctioning X-axis motor assembly prevents the LPU from traveling along the X-axis and from printing properly.

Use this guide to remove and replace the Form 3 X-axis motor assembly.

Estimated time: 30 minutes

Overview: Prepare the Form 3 and a dust-free workspace for replacing the X-axis motor assembly.

Step 1: Remove the build platform

Remove the build platform first to avoid dripping resin into the printer cavity.

Step 2: Remove the resin cartridge

Remove the resin cartridge and close the vent cap to prevent resin from dripping off of the bite valve and into the printer.

Step 3: Remove and store the resin tank

Remove the resin tank, place it in the resin tank case, and cover it with its lid. Set the case and tank aside on a clean, flat surface.

Step 4: Prepare the workspace

Clear a workspace around your printer. Ensure that the workspace is well-ventilated and free of dust.

Step 5: Clean the printer cavity

Open the printer cover. Clean any resin pooled on the printer floor, inside the printer cavity, with paper towels. Dampen the paper towels with isopropyl alcohol if necessary to fully remove the resin.

Step 6: Unplug the printer

Disconnect the power cable before continuing with maintenance. Do not perform maintenance on the printer while it is connected to power. Wait five minutes after disconnecting the printer from power before proceeding.

Overview: Remove the rear shell of the printer to access the X-axis motor assembly.

Step 3: Remove the rear shell

Gently flex the sides of the rear shell outwards to unclip it from the printer frame. Pull the rear shell directly away from the printer to remove it. Set the rear shell aside.

Locate—but do not remove—the two nuts, retained in the lower shell, that previously secured the external rear shell screws. Ensure that they did not come loose while removing the rear shell.

Overview: Remove the left side shell of the printer to access the X-axis motor assembly.

Step 1: Unscrew the screws on the bottom of the left side shell

Lay the printer gently on its back. Remove the two screws holding the left side shell onto the printer with a 2.5 mm hex key. Set the screws aside.

Overview: Remove the X-axis motor assembly.

Step 1: Unscrew the X-axis motor assembly

Open the cover and locate the four screws securing the ABL nut to the LPU housing. The LPU housing is in the LPU garage, on the right side of the printer cavity. Remove the screws using a 2.5 mm hex driver. Set the screws aside.

Use a 3 mm hex driver to unscrew the two leftmost screws securing the X-axis linear rail to the printer frame. Set the screws aside.

Step 2: Remove the X-axis motor assembly

Locate the stepper motor on the left rear side of the printer. Grip the stepper motor cable connector by its plastic housing and unplug the cable from the back of the stepper motor.

Grasp the square stepper motor and gently pull the X-axis motor assembly out of the left side of the printer. Dispose of the used X-axis motor assembly as electronic waste according to local regulations.

Overview: After removing the old X-axis motor assembly, install and secure the new X-axis motor assembly.

Step 1: Adjust the ABL nut

Remove the replacement X-axis motor assembly from its packaging. Rotate the ABL nut on the lead screw until it is approximately centered on the lead screw.

Step 2: Insert the new X-axis motor assembly

Gently slide the new X-axis motor assembly through the opening in the left-hand side of the printer.

Step 3: Secure the X-axis motor assembly to the linear rail

Align the X-axis motor assembly screw holes with the two leftmost screw holes in the linear rail. Thread one 3 mm hex screw into both of the screw holes. Use a 3 mm hex driver to tighten until snug.

Step 4: Secure the ABL nut to the LPU housing

Slide the LPU housing to the left until it reaches the ABL nut. Ensure that the ABL nut fits securely into the indentation in the LPU housing.

Thread one 2.5 mm hex screw into each of the four screw holes in the ABL nut. Use a 2.5 mm hex driver to tighten until snug.

Step 5: Plug in the stepper motor

Plug the stepper motor cable into the new X-axis stepper motor. The cable will only enter the connector in the correct orientation. Be careful not to bend the pins in the connector.

Overview: After installing the new X-axis motor assembly, reinstall and secure the shells

Step 2: Secure the side shell

Using a 2.5 mm hex driver, screw the two 2.5 mm hex screws into the side shell of the printer.

Step 3: Replace the rear shell

Place the rear shell back onto the printer. Press it towards the front of the printer to ensure that it fully seats in place. There should be no gaps between the rear shell and the side or bottom shells.

Overview: After replacing the printer’s X-axis motor assembly, power on the printer and perform final checks.

Step 1: Power on the printer

Close the printer cover and connect the power cable to the printer and the power supply. The printer initializes and the LPU moves across the printer cavity. Ensure that the LPU moves smoothly and reverses direction when it reaches the left side of the printer without any unusual noises or error messages.

Step 2: Test the repair

Start a print. Contact Formlabs Support or your certified service provider to share the results of the procedure.