Sunlu T3 Firmware Update «PROVEN · PACK»

Upgrading the firmware on your (often marketed as the "Terminator") is a common way to unlock newer features, fix recurring bugs like "Jam Detection" false positives, or transition to a fully custom Marlin environment. The

is widely considered an Ender 3 Pro clone and utilizes a modified BTT SKR Mini E3 V2 Go to product viewer dialog for this item. motherboard with TMC2209 stepper drivers. Essential Pre-Update Checklist Before starting, ensure you have the following:

A backup of your original firmware files if possible, as official downloads can sometimes be hard to locate. Sunlu T3 Firmware Update

A FAT32-formatted microSD card (ideally 8GB or smaller for better compatibility). The correct firmware file, usually named firmware.bin. Official vs. Custom Firmware Options You have two primary paths when updating your T3: 1. Official Sunlu Firmware Custom Firmware for SUNLU T3 by Kaot93 - Printables.com

Phase A: Preparing the SD Card

Do not use the SD card you print from—it is likely fragmented or has bad sectors. Use a fresh 8GB or 16GB SD card formatted to FAT32 with a 4096-byte allocation unit size. Upgrading the firmware on your (often marketed as

Important: The T3 bootloader is picky. If the update fails, try a smaller card (2GB to 8GB works best).

Sunlu T3 Firmware Update — Complete Guide

Step-by-Step Experience (Typical User Report)

Download firmware from Sunlu’s website or Google Drive link (sketchy, often outdated).
Format SD card to FAT32, 4096 bytes. Copy firmware.bin.
Insert into printer, power cycle. Wait 30 seconds. Screen stays blue briefly.
If successful, file renames to firmware.CUR. If not, nothing changes.
For touch screen firmware: Remove screen cover, insert microSD into screen PCB. Harder.

What You Will Need

A microSD card (8GB or 16GB, formatted to FAT32, 4096-byte allocation unit).
A USB card reader for your computer.
The correct firmware file for your T3 version (.bin file).
The correct LCD screen firmware (optional – for touch/filament issues).

1. Set the E-Steps (Extruder Rotation Distance)

The direct drive on the T3 requires precise steps. Send G-code via Pronterface or USB: M92 E405 (Standard T3 direct drive value – verify with Sunlu's release notes). M500 (Save)

After the Update

Check firmware version again in settings – it should match the new one. Phase A: Preparing the SD Card Do not
Run initial setup
- Home all axes.
- Re‑level the bed (mesh data is often erased).
- Set Z‑offset again.
- Calibrate e‑steps if the update changed them.
Test print – A simple 20mm calibration cube is perfect.