Replacing the Form 4 cartridge floor

The cartridge floor includes the dispense arm mechanism and cartridge locating features. The cartridge floor mounts to Form 4 generation printers at the bottom of the cartridge cavity. A malfunctioning cartridge floor may prevent the printer from printing properly.

Use this guide to replace the cartridge floor.

Required Supplies:

Formlabs:

Cartridge floor
Zip tie
2.5 mm hex driver (included in the Form 4 tool caddy)

Third-party:

Nitrile gloves

Estimated time: 30 minutes

Preparing the workspace

Overview: Prepare the printer and a dust-free workspace for removing 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 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 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.

NOTICE:

Wear gloves and hold the resin tank by the tank grips on either side to avoid contamination or damage to the underside of the tank.

Step 4: Prepare the workspace

Clear a workspace around your printer. Ensure that the workspace is well-ventilated and free of dust. Prepare additional space for storing the back panel of the printer during maintenance.

Step 5: Clean the printer

WARNING:

Resin may cause skin irritation or an allergic skin reaction. Wear gloves when handling liquid resin or resin-coated surfaces. Wash skin with plenty of soap and water.

Open the printer cover and clean any resin pooled on and around the LPU with paper towels. Dampen the paper towels with isopropyl alcohol if necessary to fully remove the resin.

DANGER:

Fire hazard. IPA is flammable. Keep containers closed, and keep out of the reach of children.

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.

DANGER:

Performing maintenance on the printer while it is plugged in increases the risk of electric shock. Never remove the back panel of the printer while the printer is plugged in. Never reconnect the printer to power while the back panel is uninstalled.

Removing the back panel

Overview: Remove the back panel to access the cartridge floor.

Step 1: Remove the back panel screws

Use a 2.5 mm hex driver to remove the eight screws securing the back panel to the printer. Set the screws aside.

NOTICE:

Formlabs printers contain sensitive electronic components. Ground yourself before touching any electronics in the printer by using a grounding strap or touching a grounded piece of metal.

Step 2: Remove the back panel

Remove the back panel by sliding it down and away from the back of the printer. Set the back panel aside.

Removing the cartridge floor

Overview: Disconnect the cable connecting the dispense motor to the cartridge floor and remove the mounting screws to uninstall the cartridge floor.

Step 1: Locate the dispense motor and load cell

When facing the back of the printer, the cartridge floor is located on the left side of the machine. Locate the dispense motor and load cell, positioned underneath the cartridge floor.

Step 2: Disconnect the dispense motor and load cell cables

Press the plastic tab on the connectors to disconnect the cables running from the dispense motor and load cell. Once the plastic tab is pressed, the cable slides out of the connector. Do not pull on the wires.

Step 3: Remove the cartridge floor mounting screws

Use a 2.5 mm hex driver to remove the two screws that secure the cartridge floor and load cell to the printer. Set the screws aside.

Step 4: Remove the cartridge floor

Lift the cartridge floor out of the printer 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.

Installing the replacement 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, proceed to step 6. Otherwise, continue.

Step 3: Position zip tie

Move the motor wires so they lay along the body of the motor itself. Slide the included zip tie around the wires and the body of the motor.

Step 4: Secure zip tie

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

Step 5: Trim 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: Position the cartridge floor

Position the cartridge floor so that the screw holes in the load cell align with the threaded holes in the spacer. 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: Tighten the cartridge floor mounting screws

Thread a cartridge floor screw into the two screw holes. Use a 2.5 mm hex driver to tighten the screws and secure the cartridge floor to the printer.

Step 8: Connect the dispense motor and load cell cables

Connect the dispense motor and load cell cables. The cables only connect together in one orientation. The plastic tab should click into place to secure the connection.

Reinstalling the back panel

Overview: Reinstall and secure the back panel.

Step 1: Close the printer cover

Close the printer cover before reinstalling the back panel.

Step 2: Mount the back panel

Slide the top edge of the back panel under the cover bracket. Ensure that the eight screw holes in the back panel align with the corresponding holes in the printer and the back panel sits flush with the sides of the cover.

Step 3: Secure the back panel

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

Finalizing the repair

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

Make sure your firmware is updated to version 1.6.0 or later, 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.