Duet 3 Expansion 3HC

Duet 3 Expansion 3HC

Adds more power to the Duet 3 Motherboard with CAN-FD bus connection, next-generation Trinamic 2160 stepper drivers, and more.


The Duet 3 Expansion board is a CAN-FD connected, high current, full-featured expansion board for the Duet 3 Mainboard. The Duet 3 family provides control for a wide range of machines, including 3D printers, CNCs, laser cutters, and more. It builds on Duet3D’s experience in developing the most configurable and expandable 3D printer control solutions. Duet 3 series aims to allow maximum machine design flexibility through highly capable mainboards, expansion boards, smart tool boards, and custom expansion modules.


  • Dedicated 32 Bit Processor (ARM Cortex M4F @120 Mhz)
  • CAN-FD bus connection to the Duet 3 allows for many expansion boards to be connected. The initial target is support for up to 8 x 3 channel expansion boards (another 24 stepper channels).
  • 3 next-generation Trinamic 2160 stepper drivers running at up to 4.45A RMS, 6.3A peak with firmware control of the complete feature set including up to 256 micro-stepping, StallGuard 2, and StealthChop 2
  • 9 PWM outputs of varying current capacities to support, for example, 3 extruders and 6 fans
  • 6 IO ports for end-stops, probes, filament monitors, and other sensors
  • 3 Thermistor/PT1000 inputs and support for 4 PT100/thermocouple inputs via the optional
  • Support for a wide range of Z probes, including DC42’s IR Z probe and the Duet3D Smart Effector for delta
  • DC42’s IR Z probe and the Duet3D Smart Effector for delta printers


The documentation for Duet 3 is available here: Duet 3 Expansion 3HC board