Saturday, February 17, 2018

A AU$200 CNC milling machine

When Peter, VK2EMU, showed an amazing CNC milling machine at the recent ARNSW Home Brew group show 'n tell meeting and then mentioned the price was just $200 I couldn't resist ordering one.

These are on eBay for AU$203.99 including postage.

You get a box of parts and a tiny CD-ROM which a bunch of files in Chinese and English including a word document that passes as instructions on how to put it together.

The instructions are terse.

Like other home constructors, I went down several false paths including using the wrong lengths of aluminium. It's all there but somehow not sequenced as clearly as it could be. The other frustration is the captive nuts that look like they should be able to be inserted sideways and then turn to lock in place. Perhaps it's poor manufacturing tolerance but I had to undo parts of the machine to slide in more at various times.

It took me about two hours to complete the job. Here's the components as they came.

The controller is a custom Arduino board with stepper motor drivers. The software on this board is GRBL 0.9 and to send commands to it (over the serial port) you need version 1.x of Candle available here.

So far I have confirmed that servos work and can send it instructions to draw a 1 inch circle. There is lots to learn.

For the money, it's a bargain. A beautiful machine. Some corners have been cut, there are 3D printed parts in there that probably reduce accuracy. Certainly this is a good way to have a tinker.

What I'd like to be able to do is have it etch the copper to make a prototype circuit board.


Unknown said...

Hey Peter, just wondering how you've gone with this machine. I'm considering picking up the same machine, or the next larger one, as a starter for dipping my toes into CNC milling.

Peter Marks said...

Hey Darryl, I haven't figured out the workflow for a circuit board yet but so far I can make it draw nice circles. I don't think it's going to be very accurate due to mechanical tolerances but it's certainly great value for the price. I will post more on the blog when I have some progress to report.