The Form 3L has two lasers that must align well with each other in order to produce accurate printed parts with good surface quality, particularly along the line where the two lasers meet. The printer performs regular self-tests to correct for most misalignments, but certain types of laser misalignments require additional calibration.

Use this guide to print the Laser Alignment Print (LAP), interpret it, and calibrate your Form 3L.

Estimated time: 1.5–2 hours

Overview: Prepare the printer and a dust-free workspace for printing the Laser Alignment Print.

Step 1: Remove any previous prints

If the printer recently completed another print, remove the build platform and printed part and clean the printer as necessary.

Step 2: Insert consumables

Insert the resin tank, resin cartridge, and a clean build platform. Lower the cam handle to lock the build platform in place. Close the printer cover and press open the cartridge vent cap.

Overview: Print and wash the Laser Alignment Print before using it to calibrate your printer.

Step 1: Print the LAP

With the printer plugged in and powered on, tap the wrench icon to enter the Settings menu, then tap Maintenance > Calibration > Calibrate Laser Alignment > Print Test Part. Select your resin type and start the print job. It should take roughly one hour to finish printing.

Step 2: Wash the LAP

Wash the LAP in your solvent of choice and allow it to dry while still attached to the build platform.

Overview: After washing the Laser Alignment Print, examine the embossed bars on the printed part.

Step 1: Examine the X-axis bars

Locate the set of X-axis bars on the LAP. The X-axis bars are oriented perpendicular to the long axis of the LAP, directly next to the number markings. An embossed X is located at the left end of the set of X-axis bars.

Using a magnifying glass or other source of magnification, select the offset that best aligns the two halves of the bars. If two neighboring sets of bars look roughly equivalent to one another, the midpoint offset value should be considered the correct alignment. In the example below, the -60 μm offset shows the best alignment.

Record the offset that best aligns the bars.

Step 2: Examine the Y-axis bars

Locate the set of Y-axis bars on the LAP. The Y-axis bars are oriented parallel to the long axis of the LAP. An embossed Y is located at the left end of the set of Y-axis bars.

Using a magnifying glass or other source of magnification, select the offset that best aligns the two halves of the bars. If two neighboring sets of bars look roughly equivalent to one another, the midpoint offset value should be considered the correct alignment. In the example below, the -80 μm offset and -60 μm offset show equivalently good alignment. The proper offset would then be -70 μm.

Record the offset that best aligns the bars.

Overview: After determining the correct offsets using the LAP, input the offsets on the printer’s touchscreen.

Step 4: Complete the calibration

When both offset values are correct, tap Next to save them to the printer. Tap Done to complete the calibration procedure and return to the Maintenance screen.

Overview: After calibrating the printer, print a test print and perform final checks.

Step 1: Print a test print

Run a short test print of your choice. Note that any changes to the laser alignment do not apply to the LAP. Clean the printed parts and assess their accuracy and surface quality relative to parts printed before the calibration. Contact Formlabs Support or your authorized reseller if you have any additional questions.