FrankenCNC

This is a small CNC made from E-waste, built to be a pen plotter.

Print instructions

Category: DIY Summary

This is more of a showcase than something you can build from the files.

The goal was to make a CNC plotter using e-waste. It started when I disassembled some printers/scanners and found the motion systems. I immediately knew I wanted to build something out of it.

The electronics are very simple, an arduino running GRBL, a CNC shield and two stepper drivers. I use Inkscape to generate the G-code and Universal G-code Sender to stream it.

The parts you can see of the bed of the machine are all the iterations and failed prints created during this project.

How I Designed This

Construction

I had two axes, one driven by a worm gear and the other driven by a belt. I needed to find a way to mount one on the other.

I used some spacers to align and level the X axis on top of the Y axis. I then designed some brackets based on the hole patterns already present on the sheet metal construction. The brackets are needed to increase rigidity and prevent misalignment.
The X axis is braced on the underside to prevent flexing.

The other side of the Y axis is made from a glass fiber rod recycled from a tent frame. A 3D printed bushing ensures smooth motion.

The X carriage was the most complex part to design. At first I tried a simple design, which was simply placed on the rails but this carriage was lifting and not staying level. I then added foots which lock the carriage on the rails, but theses needed supports.
The top of the X carriage is pierced to enable easy toolchange.

Operation

The first toolholder was a fixed pen holder with a screw. This posed some problems as the wooden board is not perfectly flat and the pen was binding and jittering.

This was fixed with a second design which featured a sliding pen, this enabled height correction during plotting.

Future developements

The next step is pretty obvious, making a toolholder with a servo to eliminate travel marks on the drawings.