Each Form 4 resin cartridge tracks the amount of resin remaining on the RFID sticker located near its bite valve. During a print, Form 4 generation printers regularly update this value based on PreForm’s initial estimate of the amount of resin required to print the current job.

Starting with firmware version 1.7, Form 4 generation printers use a load cell integrated into each cartridge floor to measure and update the amount of resin remaining in the cartridge.

This is more accurate than methods that rely on model sizes or resin tank fullness alone, but an incorrect measurement can lead to inaccurate cartridge fullness tracking. For example, the printer may report that the cartridge is low when it is not, or that the cartridge is fuller than it actually is.

If your Form 4 generation printer is reporting the wrong amount of resin in a resin cartridge:

1. Update PreForm and your printer’s firmware to version 1.17 or later so you have access to improvements to the resin tracking algorithms.
2. Avoid manually pouring resin into the resin tank, as this can make the fullness tracking inaccurate.
3. Recalibrate the cartridge floor load cell.
4. If your printer still fails to track cartridge fullness accurately, you may need to replace the cartridge floor. The Form 4 generation cartridge floor is available for purchase on the Formlabs Store.

If your printer continues to report incorrect resin cartridge fullness, upload the latest logs from the machine and then contact Formlabs Support or your authorized reseller.