I bought a CNC router, a Vertigo Tech M2 from down in Westport. Lead screws, 1200×600 bed, and a frame of pretty chunky aluminium extrusion. I thought about building one, but I’d rather buy it, plug it in, have it work, and put my time into building things with it.

Design shared from Fusion 360: Router Test Box 2

What I’ve learnt so far:

• Plywood rules the world.
• Up-cut bits give a really fluffy top edge. Straight bits are better, but compression bits ordered. Getting perfect edges on cuts isn’t easy.
• Making it quieter is needed if I’m going to run this at night in the suburbs, so cabinet being designed.
• Dust and chips go everywhere, so dust shoe on its way to me and the cabinet will help.
• Fusion 360’s integrated design (CAD) and manufacturing (CAM) is just plain awesome. Being able to draw something up, have it work out toolpaths, and then simulate the cutting used to be $100k-worth of software. Now it’s free.
• CAM is at least as hard as CAD, if you want to do it right.
• Cutting to just above the base board (onion skins) results in lots of time breaking out the uncut material and cleaning edges. A proper spoil board is needed so I can cut all the way through the ply to avoid this.
• Fusion 360 is great for generic CAD/CAM, but isn’t the best for a router. Nesting and layout you have to do manually and it barely does tabs for part holding (only for 2D contour toolpaths). It’s not VCarve Pro, but it’s also not NZ$1000.
• The machine will cut big chips with lots of noise or fine shavings with lots of dust. Finding a happy medium is going to take a bit of tweaking.
• If you cut interlocking ply parts 0.2 mm undersize, then all the pieces will slide together and hold without glue. If you cut at 0.1 mm oversize, you have to hammer the parts together. If you cut at 0.3 mm undersize, it all wobbles.
• There’s a heap of fancy joints you could do, but finger tenons are simple, easy to draw, easy to cut, self-aligning, can be hidden, and are strong enough with glue.
• T-track bolts need to be just the right size or they twist and stick.
• If you are drawing finger tenons, then you need to relieve the sharp internal corners. Casey Crogers’ dogbone plugin draws these automatically and makes this much faster.
• And if you want to do Voronoi patterns, coz you have a cnc router and you can, then Hans Kellner’s Voronoi sketch generator does the job.

Please ignore the plunge marks:

Tweaking feeds and speeds and checking accuracy like an old-school metal machinist: