The two resin tank latches on the Form 4 secure the resin tank to the printer. A malfunctioning resin tank latch may prevent the tank from properly securing to the printer.

Use this guide to replace one or both of the Form 4 resin tank latches.

Estimated time: 20 minutes

Overview: Prepare the Form 4 and workspace for replacing the resin tank latch.

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.

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

Open the printer cover and clean any resin pooled on and around the LPU with non-abrasive wipes. Dampen the wipes 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: Locate the retaining tab, remove the pin and spring, and remove the resin tank latch.

Step 1: Locate the retaining tab

The resin tank latch attaches to the printer with two metal pins held in place by a retaining tab. Lift the resin tank latch and locate the black retaining tab behind each pin.

Step 2: Remove the pin and spring

While pressing down on the retaining tab with the 2.5 mm hex driver, use the 2 mm ball-end hex driver to push the pin through the bracket. You may need to use a moderate amount of force to fully push the pin out of its bracket. Once the pin is removed, the spring separates from the bracket. Set the spring and pin aside for disposal.

Step 3: Remove the second pin

Repeat steps 1–2 to remove the second pin from the resin tank latch. Note that there is only one spring per latch. The pin with the spring is located closer to the front of the printer.

Overview: After removing the broken resin tank latch, assemble and install the replacement resin tank latch.

Step 1: Pre-assemble the resin tank latch

The resin tank latch needs to be partially assembled before installing it onto the printer. Slide the metal pins into the bracket from the inside of the latch. Insert the spring as shown with the shorter leg pressed against the latch. The pin threads through the spring. Leave space in the bracket for installation.

Repeat the previous step to thread the pin through the second bracket. Note that there is only one spring per latch, and the spring should be positioned such that it will be towards the front of the printer once the latch is installed.

Step 2: Align the resin tank latch with the printer

Align the resin tank latch with the pins and spring facing towards the LPU.

Step 3: Mount the resin tank latch

Lower the latch into place, ensuring that the longer spring leg sits in the small hole towards the front of the printer. The handle should fit easily with little force.

Step 4: Install the pin

Adjust the latch as needed so that the pins align with the metal tabs. Press down on the retaining tab with the 2.5 mm hex driver. Use the 2 mm ball-end hex driver to push the pin through the bracket. You may need to use moderate force to seat the pin. The pin is fully seated when the retaining tab clicks into place behind the pin.

Step 5: Install the second pin

Repeat the previous step to install the second pin in the resin tank latch. Note that there is only one spring per latch, located towards the front of the printer.

Overview: After installing the replacement resin tank latch, 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. Turn on the switch at the back of the printer. The printer initializes.

Step 2: Test the repair

Insert and secure a resin tank. Check that it latches in place and the printer identifies it properly. If you have multiple resin tanks available, test the printer with a variety of tanks. Contact Formlabs Support or your authorized reseller to share the results of the procedure.