Machine design

The machine is similar to the CNC V4 (which, in itself, is based on the cheap CNC machine I bought off Amazon).

Constraints

The only constraint my wife had was that it couldn't be any bigger than the 4th machine - which was okay as the largest I really wanted to cut was 4U panels (around 482x178mm). But you do also need to  hold the work down!

CAD design

The machine was modelled in DesignSpark Mechanical, and I used the CNC V4 trolley as the basis to give me the dimensions - plus it meant that when it was ready, it could sit on the trolley.

Parts

Where I worked, we were moving offices and there were a lot of parts that were being disposed of. I couldn't let the 700mm long 30120 extruded section aluminium go to waste! So they formed the main basis of the machine, with two cut down becoming the vertical pillars and two more the X-axis support - although due to a miss remembered measurement, I bought 800mm long rails...

I also wanted to have better stepper motors and drivers than the 4th machine (the ones in the 2nd machine were fantastic), so I opted for three NEMA 34 closed loop motors, bought from StepperOnline. Ball screws, linear rails and couplings for all three axes were bought from eBay, but I wanted to have a good CNC controller that could allow me upgrade possibilities. I went for the Root ISO Rev 3 controller - which supports 6 axes, and uses FluidNC as its back-end (which meant a broad GRBL compatibility).

The rest of it was made from various aluminium sheet and plate bought from Aluminium Warehouse (who I found out were just up the road from me), with some 3060 extruded aluminium as the bottom supports.

All of the items were colour coded, with the colours indicating what sort of material it was made from.

Most of the aluminium pieces were either:

• 1.5mm sheet, cut to size
• 5mm sheet, cut to size
• 10mm sheet, cut to size
• 50x10mm bar
• 50x15mm bar

Aluminium Warehouse cut all of the sheet to size - the bar I used my old chop saw (which needed a bit of a cleanup to get going again as it had not been used for over 12 years).