General information regarding the Fly RPFMex
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Fly-rpfmex board
Fly-rpfmex board


This page covers any general information for the Fly RPFMEX board.
Avaliable from the Mellow store on Aiexpress

In order to meet the customer for expanding Gemini, we made a 4-axis expansion board. The original Gemini 4-axis board can be expanded to 8-axis to meet the needs of more 3D printers. This expansion board would have limited functionality in a stand alone configuration as a 3D printer motherboard because it does not include heating and temperature measurement functions.


  • MCU: RPI RP2040
  • Communication: USB
  • 12/24V input
  • 2A 5V power supply
  • Drivers: 4 - TMC2209 onboard drivers
  • Sensorless Homing is not supported
  • Interfaces
  • 2 CNC Fans with replacable Fly MOS.
  • 1 Full power fan
  • RGB LED port
  • 3 Limit switch inputs


Fly-rpfmex board dimensions
Fly-rpfmex board dimensions


Fly-rpfmex BOM
Fly-rpfmex BOM
  • Fly RPFMEX Board
  • 4 heatinks for TMC2209 drivers
  • JST-XH connectors and crimp terminals
  • Fly MOS
  • USB C Cable