When the Sunlu T3 first launched, it ran a customized fork of Marlin 2.0.x. It worked, but early adopters reported niggling issues: thermal runaway false positives, clunky mesh bed leveling, and a loud, inefficient stepper motor algorithm.

The consensus among reviewers and hobbyists is that while the Sunlu T3 (Terminator 3) hardware is solid for its price, its stock firmware is a significant bottleneck.

Custom Marlin builds include "Babystepping" (double-click the knob to adjust Z-height in real-time) and the M600 filament change workflow for easier maintenance.

: Firmware updates can optimize the printer's performance by refining the algorithms that control the movement of the print head, adjusting temperature controls for better stability, and improving the extrusion process. These enhancements can lead to higher quality prints, reduced print times, and less material waste.

That annoying high-pitched whine during slow circles (like on a vase mode print)? That’s the stepper drivers in "SpreadCycle" mode.