Usually the extrusion heads in custom 3D printers have too many cables that need to be carried to the base plate, which makes it difficult to change the extruder through another working head.

I have designed this PCB for the extruder in order to reduce the extruder connections to just one. This would allow the extruder to be treated as a module so that it could be removed easily to be replaced by another working head such as a laser module or a drill.

1. The board allows the connection of a sensor of autolevel by means of servo motor and end switch or by sensors type BLTouch.
2. The currents required for each signal have been calculated for both 12V and 24V systems and the trace width has been adapted to operate normally.
3. The upper holes have a 31mm spacing to be screwed to NEMA 17 stepper motors.
4. It is designed to use connectors type XH and VH:

• Thermistor: XH 2pin connector.
• Fan for cooling de estruder: XH 2pin connector.
• Probe or limit switch for autolevel: XH 2pin connector.
• Servo motor for autolevel: XH 3pin connector.
• Stepper motor: XH 4pin connector.
• Heating tube: VH 2pin connector.
• PWM Laser/Layer fan: VH 2pin connector.
• Interface: 26pin ribbon connector.
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The system requires 2 of that boards, one for the extruder and other for interfacing the ribbon cable to separate cables to the 3d printer main board. Also can be put the necessary conectors at the end of the ribbon cable and use only one extruder PCB for the extruder.