Guillotine

We have designed and made the electronics for our multi-filament drive.  It is in the form of an Arduino shield with DC H-bridge motor controllers, opto-sensors and an I2C interface.

The I2C means that it will be possible to drive the whole device from any RepRap controller that can drive a single extruder-drive stepper motor and that has firmware that supports the M260 and M261 G Codes.  The shield has been designed to be a single-sided PCB with a few jumpers, so it is easy to mill on a small CNC machine (which is how we made the prototype).  It needs a 12V supply for the motors, and so we may modify the design to add a 5V regulator to save having a separate wire to power the Arduino underneath.

The video above shows the device guillotining filament.  It takes a few seconds, but – as swapping colours or materials is a comparatively rare operation compared to moving and depositing material – it should not have a big impact on print times.

As always, all of the mechanical and electronic designs are on our Github repository along with all the software source code.