CNC cutting is rapidly becoming my drug of choice. The shear beauty of the finished pieces as they come off the machine is addictive. But getting here was a long and windy road.

This is the first in a series of articles that will explore the learning curve I went through in the hope it saves others some pain…

Disclaimer

I’m not a CNC expert! Anything I say in this article comes purely from my own experience, not from any official training or extensive apprenticeship.

Whilst everything I’ve written here is done so in good faith, you follow the advice and ideas at your own risk. If in doubt, ask an expert!

To CNC or not to CNC? That is the question.

2014-07-11 13.09.12I’d been thinking about purchasing some sort of equipment to produce high quality custom components for a while. Everyone was raving about the 3D printing revolution and the chaps at Flite Test were pumping out kits from their laser cutters at a rate of knots.

In the end it came down to accessibility and usability. 3D printers are great but the amount of time it takes to print even a small component is ridiculous. Laser cutters are also great but the cost and amount of support equipment (water pumps, spare parts etc.) was prohibitive.

A CNC cutter seemed the obvious choice. I could cut a variety of components from a variety of materials. They are fairly quick and relatively economical to run.

I started my search on eBay and quickly found what looked like a nice little machine. The price was more than I’d hoped to pay though and a quick search on the internet found the same model available direct from the manufacturer at a considerable saving to the premium charged by the eBay seller.

A short DHL shipping later and my CNC3040Z was unpacked and sat on the workbench.

Setup woes…

The first thing I have to say is that the machine is lovely. The quality is excellent and the fit and finish of the parts are really nice. A little bit of assembly is required to attach the stepper motors to the screw drives but that is about all I needed to do.

I was really excited to get started so it was frustrating to say the least that I then went through anything up to a month of fiddling and head-scratching to get the thing running.

bigstock-portrait-of-young-angry-man-52068682There are a number of modern CNC machines that are USB driven but these tend to be higher end kit. Most machines out there seem to be, like mine, driven by a serial connection. If you are considering going down the same route, here are a few things you need to bear in mind:

  • You will need to buy software to create your toolpaths and GCode as well as software to actually “drive” the machine.
  • You will need to be running a 32 bit version of Windows (not sure about Macs).
  • You will need a proper serial port to plug it into (USB to serial adapters don’t work).
  • It won’t run off a laptop, so you’ll need a desktop running all of the above.

So, as a result of all that I ended up buying a load of software that was recommended in the instructions for the machine. I also had to partition my desktop computer and install a second 32 bit version of Windows 7 as I use 64 bit for my work. I then spent a good day trying to work out how to configure the also newly installed serial port and software to drive my machine.

Finally, late in the afternoon one Monday the following happened…

I was overjoyed! So I quickly decided to get designing and produce some things to cut…

Other things you’ll need…

End MillsOf course, if you want to do any serious cutting you are going to need a good stock of router bits. The shape of these change depending on what you want to do with your machine but as I was only interested in cutting out patterns I went looking for an array of end mills.

I found a good supplier on eBay and ordered a range of carbide end mills. These are 4 flute designs with around a 10mm cutting edge length and 3mm shank. I ordered 1.0mm, 1.5mm, 2.0mm and 2.5mm sizes in packs of 10.

Just be sure you get the right size shank for your machine. I also ordered some that were 5mm shanks and had to sell them on!

Sacrifice board

If you are cutting “slots”, that is full thickness cuts to create something like a multirotor plate, than you will need to protect the bed of your machine. A sacrifice board is a level surface, preferably of softer material* than what you intend to cut, that can be clamped beneath your workpiece. I’ve tried a number of things but have found either foam board or simple MDF to be the best solution.

*The reason this board should be softer is because you will work out your feed rates based on your workpiece. You don’t want your end mill to hit a harder surface at the bottom of the cut and either deflect or break as a result.

Software Choices…

PM440

In the next article we’ll look in detail at the software I am using to run the whole show. What I will tell you in the meantime is what these are:

  • Sketchup 2014 – 3D modelling and blueprint design (with the Flattery plugin installed).
  • Adobe Illustrator – Tidying vectors and export in .ai format.
  • Vectric Cut2D – Toolpath layouts, generation and exporting G-Code.
  • Newfangled Solutions Mach3 – CNC controller software

I hope you’ve enjoyed this introduction to my CNC journey. I’ll try to get the next article out as soon as I can (but I’m a bit bust cutting more frames!)…