The cartridge floor includes the dispense arm mechanism and cartridge locating features. The Form 4L contains two cartridge floors located in the cavity on the right side of the printer. A malfunctioning cartridge floor may prevent the printer from printing properly.

Use this guide to replace the Form 4L cartridge floor.

Estimated time: 30 minutes

Overview: Prepare the Form 4L and a dust-free workspace for replacing the cartridge floor.

Step 1: Remove the build platform

Remove the build platform first to avoid dripping resin onto the Light Processing Unit (LPU).

Step 2: Remove the resin cartridges

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

Step 3: Remove and store the resin tank and mixer

Unlatch the mixer and resin tank. Remove the resin tank and cover it with its lid. Set the tank aside on a clean, flat surface.

Step 4: Prepare the workspace

Step 5: Clean the printer

Open the printer door and clean any resin pooled around the LPU 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 from the printer 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 right side panels to access the cartridge floor.

Step 1: Remove the mesh filter

Remove the mesh filter from the right side of the printer. Set the filter aside.

Step 2: Remove the lower right panel

Use a 2.5 mm hex driver to remove the four screws securing the lower right panel to the printer. Remove the screws and the panel and set them aside.

Step 3: Remove the LPU fan filter

Disengage the fan retainer by pulling downwards and swinging the wire arm towards you. Remove the LPU fan filter by pulling straight down on the filter’s body. Set the filter aside.

Step 5: Remove the upper right panel screws

Use a 2.5 mm hex driver to remove the eight screws securing the upper right panel to the printer: three screws on the top of the panel, two screws on the bottom of the panel, and three on the front edge of the panel inside the printer.

Step 6: Separate the upper right panel from the printer

With the help of a second person, push the upper right panel straight up to release the studs on the panel from the slots in the printer frame. Carefully rotate the top of the panel down and away from the printer.

Overview: Uninstall the cartridge floor from the upper right panel.

Step 1: Locate the cartridge floor cables

Both cartridge floors have a cable for the dispense motor (having two wires) and the load cell (having three wires). There are also two cables for the cartridge RFID boards. Locate the dispense motor and load cell cables for the cartridge floor you plan to replace. For your reference, the panel is labeled F and R for the front and rear cartridge slots, respectively. Similarly, the front cartridge floor wires are labeled 0 and the rear cartridge floor wires are labeled 1.

Step 2: Disconnect the cartridge floor cables

While continuing to support the upper right panel, unplug the dispense motor and load cell cables connecting the cartridge floor you are replacing to the printer. Gently squeeze the plastic tabs to unplug the cables. Do not pull on the individual wires.

Temporarily mount the panel back on the printer so you can access the cartridge floor. Take care not to pinch any of the loose cables.

Step 3: Remove the cartridge floor mounting screws

Use a 2.5 mm hex driver to fully loosen the two screws that secure the cartridge floor to the upper right panel.

Step 3: Remove the cartridge floor

Lift the cartridge floor out of the panel and set it aside for disposal. There is a small spacer that sits underneath the cartridge floor. Ensure that it does not fall into the printer as you remove the cartridge floor.

Overview: Connect and install the replacement cartridge floor.

Step 1: Mount the cartridge floor spacer

Place the spacer beneath the cartridge floor on the metal tab. Ensure that the screw holes in the spacer align with those on the tab.

Step 2: Check the cartridge floor dispense motor wires

Remove the replacement cartridge floor from its packaging. Depending on when the replacement cartridge floor was assembled and packaged, there may be a zip tie around the dispense motor. If that is the case, cut and remove the zip tie.

Step 3: Position the zip tie

Slide the included zip tie between the motor body and the plastic clip surrounding the motor. If your cartridge floor kit did not include a zip tie, use a suitably-sized third-party zip tie.

Step 4: Secure the zip tie

Carefully close the zip tie around the motor wires and the plastic clip. Position the head of the zip tie to the side.

Step 5: Trim the zip tie

Trim the zip tie so it will not interfere with installing the cartridge floor. Omitting the zip tie will not impact performance but increases the likelihood of damaging the dispense motor during installation.

Step 6: Mount the replacement cartridge floor

Mount the cartridge floor on its seat in the upper right panel, aligning the screw holes in the cartridge floor with those in the panel. Pass the dispense motor and load cell cables through the gap between the cartridge floor mount and the upper right panel. Take care not to pull on the dispense motor cable, especially if you did not install the zip tie in the previous step.

Step 7: Secure the replacement cartridge floor

Thread the two mounting screws into the screw holes in the cartridge floor. Use a 2.5 mm hex driver to tighten until snug.

Step 8: Connect the cartridge floor cables

With the help of a second person, position the upper right panel next to the ride side of the printer. While supporting the panel, connect the cables. Make sure to connect the cables correctly according to the labeled stickers. As noted above, both cartridge floors have a cable for the dispense motor (with two wires) and the load cell (with three wires). There are also two cables for the cartridge RFID boards. The panel is labeled F and R for the front and rear cartridge slots, respectively. The front cartridge floor wires are labeled 0 and the rear cartridge floor wires are labeled 1.

Step 9: Replace the other cartridge floor (if necessary)

If you are replacing both cartridge floors, repeat the uninstallation and replacement steps for the other cartridge floor.

Overview: Reinstall and secure the right side panels.

Step 1: Mount the upper right panel

Once all cables are connected, rotate the panel upwards until it rests against the side of the printer. Check that the studs on the panel are aligned with the key slots in the printer frame, then slide the panel straight down. Ensure that the eight screw holes in the panel align with the corresponding holes in the printer.

Step 2: Secure the upper right panel

Thread one mounting screw into each of the eight screw holes in the upper right panel. Use a 2.5 mm hex driver to tighten until snug.

Step 4: Install the LPU fan filter

Slide the fan filter under the wire filter retainer and push upwards until fully seated. Pull downwards on the filter retainer and swing it beneath the filter to secure the filter in place.

Step 5: Mount and secure the lower right panel

Align the screw holes in the lower right panel with those in the printer frame. Thread one mounting screw into each of the four screw holes. Use a 2.5 mm hex driver to tighten until snug.

Step 6: Reinstall the mesh filter

Place the mesh filter over the grate on the right side of the printer.

Overview: After replacing the cartridge floor, power on the printer and perform final checks.

Step 1: Power on the printer

Connect the power cable to the printer and the power supply. The printer initializes. Check that the printer initializes normally and does not display any error messages.

Step 2: Calibrate the load cell

Tap Settings > Tools > Calibration > Cartridge load cell, and follow the instructions on the screen.

Step 3: Run a test print

Insert any missing consumables and upload and start a print. Check that the print starts normally, resin dispenses from the resin cartridge, and the parts print successfully. Contact Formlabs Support or your authorized reseller to share the results of the procedure.