Formlabs SLA printers (starting with the Form 2) automatically heat resin to a set temperature before starting a print. Once the ideal temperature for the inserted consumable is met, the print begins. The printer may periodically pause to sense the resin temperature and adjust it accordingly.

Form 2

The Form 2 has a metal tank carrier below the resin tank that heats the resin. An infrared sensor behind the tank senses the resin temperature.

Form 3/Form 3B

The Form 3 has an air intake vent at the rear of the unit. The printer heats the air and blows it across the resin tank to heat the resin. A thermal sensor in the heater duct senses the air temperature.

Form 3L/3BL

The Form 3L/Form 3BL print chamber is heated by hot air blown from the right side of the printer, next to the resin cartridges. The warm air in the print chamber heats the resin, and the air temperature is measured by a thermal sensor at the air intake.

Form 4/Form 4L generation

Form 4 and Form 4L generation printers heat resin with resistive heaters located beneath the resin tank. An infrared sensor below the tank (built into the LPU 4) senses the resin temperature.

Confirming a print causes the printer to enter the Preparing to Print status as pre-heats the resin to a target temperature. The target temperature may vary depending on the material used. Ensure the printer’s cover remains closed to continue pre-heating.

The build platform lowers when the printer reaches the automatic start temperature, which is around 30 °C. Tapping the Start Now button on the printer’s touchscreen at the minimum start temperature, which is around 20–30 °C, may cause adherence issues.

While printing, the printer continues heating the resin to maintain the target temperature, which is around 35 °C. After completing a print, the printer holds the target temperature for 30 minutes to allow another print job to start immediately. Heating stops if there is no interaction for 30 minutes. After heating stops, it is normal for the resin tank to remain warm.