Can Transformer

I was thinking about the battery connections on my DIY digital watch and how tricky it was for me to create things out of thin metal. Either I cut it by hand, which always results in less than perfect parts, or I spend quite a while setting up my CNC3020 and cutting it on that. That gives better results but can be fiddly.

Then I made the link between the problem and the drinks cans that I melt down for raw material. Drinks cans are made of aluminium or steel and come in a nice uniform shape. So I decided to make a machine that can turn these cans into useful stuff. And the CanTran was born.

It's actually a sort of CNC lathe that is designed to chop up drinks cans, transforming them into useful things. Putting a can in the machine is a simple matter that takes just seconds, using a spring loaded tail holder and a 3D printed part that engages in the can top at the other end.
 
It's got three stepper motors and a Proxxon rotary tool to do the cutting. The controller is a Duet:

 

 
which has a nice web interface and accepts gcode. I've always had a problem finding a tool to generate gcode, so I created a small simple script to convert DXF files to gcode. This isn't too complicated a task as the CanTran has 3 axes, but in reality is a 2D machine. The script converts just lines and arcs from DXF (LibreCAD) into gcode with just 2 Z depths at the moment. Any tool that generates gcode should work.

I use a D bit cutter, the same type I use to mill PCBs.


There's a little tour of the prototype here:

This is the machine cutting some test slots into a can. This is sped up by a factor of 20:

You can make labels with it:

You can cut letters into the can and then illuminate  it:

Or, cut abstract patterns and do the same:

I've put the 3D files here:

https://www.thingiverse.com/thing:3570030

We'll have to see how useful it turns out to be...

And the there was what went wrong.

Casting Test

The first sand casting test is a simple one:

To hold it I have made a  box on the CNC using some custom  Gcode:

This box fits the casting really well (the peak of the cap had to have it's own cut out, this keys the box lid as well:

It's quite plain on the outside:

The box gcode was generated using a Tcl script, and I'm going to create a parametric top level script that drives the lower level gcode scripts so that I can generate boxes like this of any dimensions just by running the top level script.

Aluminium Melting

The latest piece of equipment has been fired up and the result is here:

These used to be food trays. There's a lot of dross with this process, maybe due to a large amount of oxide on the trays due to their high surface area. I'll try other sources of aluminium and see if I get better results.

Dragonfly Hairclip

 I've been working on this on and off for a while now. It's a dragonfly hairclip decoration made from acrylic and aluminium.

 The acrylic is turned and polished just like a pen would be, with two parts, one for the body and one for the head.

The wings are engraved aluminium sheet, each pair of wings took about two hours to engrave and cut out, admittedly this is mainly due to the resolution of the input file.

The parts are screwed together and then screwed to the hair clip.