Sunlu T3 Firmware May 2026
Change Filament (M600): A dedicated menu option. It will:
Because Sunlu’s official updates are sparse, the community has built:
Use these at your own risk – you will lose touchscreen support unless you port the DGUS LCD.
The stock touchscreen uses DGUS (DWIN) protocol. In _Statusscreen.h, disable legacy LCD and enable:
#define DGUS_LCD_UI_RELOAD
#define TOUCH_SCREEN
| Symptom | Likely Cause | Solution |
|---------|--------------|----------|
| Homing fails, probe does not deploy | Wrong probe type in firmware | Recompile with Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN disabled |
| Touchscreen shows no response | Firmware mismatch between mainboard and screen | Flash both mainboard and DWIN firmware |
| "TMC CONNECTION ERROR" | UART pins not configured | Update to post-2023 firmware, or manually define in Configuration_adv.h |
| Thermal runaway after 10 min | PID values incorrect | Run M303 E0 C8 S210 U1, then M500 |
| Extruder steps/mm wrong (default 140?) | Old firmware used 400 steps | Set M92 E140 (for T3’s standard extruder gear ratio) |
The T3 utilizes a modified version of a standard open-source UI, adapted for its specific knob-and-screen interface.
Sunlu does not maintain a public GitHub repository. Official firmware is distributed via: sunlu t3 firmware
⚠️ Warning: Never download T3 firmware from unverified third-party sites – corrupted firmware has been known to brick the touchscreen.
The Sunlu T3 is a workhorse, but it ships with a lethargic operating system. By upgrading from the stock firmware to a community build (or rolling your own), you unlock the printer's true potential.
Action plan for today:
Your first print after the upgrade will feel like a brand new machine. Whether you are chasing quality, speed, or reliability, the firmware is the key—and now you know exactly how to turn it.
Upgrading the firmware on your SUNLU T3 (Terminator 3) is one of the most effective ways to unlock higher print speeds, improve bed leveling accuracy, and resolve common bugs. Whether you are looking for the official stock version or a high-performance custom build, this guide covers everything you need to know about Why Update Your Change Filament (M600): A dedicated menu option
is a capable "Ender 3 clone" out of the box, the stock firmware often limits the hardware's potential. Updating can provide:
Improved Thermal Safety: Fixes issues where cooling fans might not activate properly during heating.
Advanced Bed Leveling: Custom firmware often expands the auto-leveling mesh (e.g., from 4x4 to 5x5) for better first-layer adhesion.
Faster Print Speeds: Unlocks the printer's advertised 250 mm/s potential through better acceleration management.
Additional Features: Adds "babystepping" for fine-tuning the Z-offset during a print and enables PID tuning menus for the bed and hotend. Official vs. Custom Firmware Because Sunlu’s official updates are sparse, the community
Depending on your technical comfort level, you have three main options: 1. Official SUNLU T3 Firmware
Best for users who want to keep the machine in its factory state. SUNLU provides the official 32-bit firmware on their official support site. Pros: Stable, factory-tested, includes "Fast Print" mode. Cons: Limited customization and slower bug fixes. 2. Custom Marlin Builds (Recommended)
Community-developed Marlin configurations, like those by Kaot93 on Printables or configurations found on GitHub, are highly popular.
Key Features: Higher hotend temperature limits (up to 285°C for all-metal hotends), jam detection, and manual bed tramming assistance. 3. Klipper Firmware
For power users, Klipper moves the heavy processing to a separate device like a Raspberry Pi. What is the difference between Marlin and Klipper firmware?
