This DIY Vat Heater Works with Any Resin 3D Printer

Like their filament-munching cousins, resin 3D printers have all kinds of quirks that can lead to print quality issues and outright failures. At lot of those issues are the result of the resin changing temperature in the vat, which is why some printer models include vat heaters. But if your printer doesn’t have a heater, there is no reason to panic. Instead of rushing out to buy a new printer, check out this DIY vat heater that you can add to virtually any resin 3D printer.

To get the best results with MSLA (Masked Stereolithography) 3D printing, you want the resin temperature to be about 25°C (about 77°F). But even more importantly, you want to prevent the resin from changing temperature too much during a print. The heat from the UV light and the curing reaction will naturally warm up the resin throughout the print job, which causes expansion and warping. To prevent that, you want to heat the resin before starting the job and then maintain a consistent temperature throughout. Resin cooling isn’t really a thing, but a vat heater can bring the resin up to a set temperature and keep it from falling.

This DIY option, designed by Dimitar, is universal and will almost certainly work with your printer model. It is a simple resistive heating system without two elements (either PCB or PTC) attached to the outside of the vat with strong double-sided tape. They warm up, which warms up the vat frame, which warms up the resin.

But though resistive heating is simple, Dimitar implemented sophisticated PID (proportional-integral-derivative) control to reach and maintain the set temperature. An ESP32 on a custom PCB controls power to the two heating elements through two independent channels and measures the temperature of each through a dedicated 14-bit ADC (analog-to-digital converter). That PCB accepts power through USB-PD, which is convenient.

The user interface is a nice full-color LCD paired with a set of buttons on the 3D-printed enclosure. Users can set the target temperature and view the current temperature of each channel. Dimitar programmed the firmware to take advantage of FreeRTOS in order to separate the tasks and maintain smooth performance. It also keeps Wi-Fi open as an option, which could be handy for additional features like starting heating from the same PC that sends print jobs to the printer.

It appears that Dimitar will offer this vat heater as a kit at some point. But for now, you can see the schematics on Hackaday and the firmware on GitHub.