Coffee Machine Update

Coffee Machine Update

The coffee machine works. It's good for single cups of coffee, as you don't have to stand there too long pouring water. The old coffee machine is definitely dying, it now takes about an hour to run a pot of water through it.

To investigate how easy it would be to automate the new machine, I set this up:

There's a peristaltic pump:

which pumps water from the kettle to the filter. The power supply is adjustable, which is important to ensure the water flow isn't too fast as it will overflow the filter. For the pump I have the suitable voltage seems to be around 4V, which is pretty low. Usefully the power supply seems to remember its setting when it's off so you don't have to set it up every time you turn it on. A simple voltage regulator circuit and a knob would be equally and probably more suitable.

This arrangement also means you can replace the peristaltic pump pipe if it is dirty or damaged. You can also clean the pipe. We've never cleaned the insides of the old machine.

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.

Coffee "Machine"

The old coffee machine that we use is probably going to fail soon, it's second hand and pretty old. I saw a simple Japanese design a while back and decided to have a go at something similar. My version uses cheap Chinese components sourced from Ebay and some recycled  bits and bobs.

There's a filter in a funnel that direct coffee into a jug below. The funnel, filter and jug are ebay items. The stand is made from part of an old chair frame and some wood from a tree we had taken down in the garden.

It makes pretty good coffee, but has the downside that you have to pour the water through the coffee over a few minutes, it's not very automatic. It does have the advantage that you can quickly make a single cup of coffee, probably quicker than the automatic machine can manage.

The filter is metal, I had to cut a handle off it so it had a circular outline and would fit in the funnel.