Anycubic Mega S

The Anycubic Mega S is a cheap 3D printer. I bought this printer for about $280 CAD with shipping.

Configuration

Serial talks at 250,000 baud.

The print area is 210x210x205 (width, depth, height).

Anycubic suggests that the following slicer settings:

• bottom layer speed not exceed 20mm/s
• top/bottom speed 30mm/s
• outer shell speed 30mm/s
• retraction speed at 60mm/s at 6mm or for flexible filament at 91mm/s at 6.4mm

Firmware

For an updated firmware, see:

• https://github.com/knutwurst/Marlin-2-0-x-Anycubic-i3-MEGA-S

The stock firmware can be found on Anycubic's website, near the bottom of the page.

• https://www.anycubic.com/products/anycubic-i3-mega-s?variant=32094219305091

Use the OctoPrint Firmware Updater plugin. Configure it by setting:

• Flash method: avrdude
• AVR MCU: ATmega2560
• Path to avrdude: /usr/bin/avrdude
• AVR Programmer Type: wiring
• Baud Rate: auto

Note that the TFT display will look identical. This is because the display is driven by a separate STM32F103 microcontroller and only interacts with the printer via serial. More information on the displays at https://github.com/knutwurst/Marlin-2-0-x-Anycubic-i3-MEGA-S/wiki/Types-of-Anycubic-Touchscreens

Knutwurst's firmware issues and some notes:

• Still has startup / connection sounds. Disable by editing Marlin/Configuration.h and ensure STARTUP_CHIME is not defined.
• Filament sensor needs to be closed or else it shows an error on the display when the machine is powered on. The special menu to disable the filament sensor is only temporary and reverts on a reset. You will need to undefine the ANYCUBIC_FILAMENT_RUNOUT_SENSOR in Configuration.h to disable this completely. The screen nags you of the filament because this firmware will send J15 to it on startup to the display if FILAMENT_RUNOUT_PIN is high.
• Since Knutwurst made it easy to configure for a specific device with configuration flags (eg. KNUTWURST_MEGA_S, KNUTWURST_TMC), recompiling for a specific model is very convenient. Review the first 100 lines of Configuration.h and uncomment whatever applies. You may want to uncomment line 287 so that #define MOTHERBOARD BOARD_TRIGORILLA_14 is defined.
• Bed size is changed from 210x210 to 225x220 (width, depth). The slicer needs to be updated accordingly.

Mods

• Filament Holder - https://www.thingiverse.com/thing:2841440
• TMC2208 V2 driver. I bought 5 TMC2208 V2 modules. Follow the guide at: https://github.com/knutwurst/Marlin-2-0-x-Anycubic-i3-MEGA-S/wiki/Swap-stepper-motor-driver-for-TMC2xxx
• Y Belt Tensioner - https://www.thingiverse.com/thing:2789837

See Also

• https://www.thingiverse.com/thing:2901190 - Goes over mods for the Anycubic i3 Mega. Some of the slicer settings may be of interest.