The CNC router came about through a need to make more complex tooling for some new upgrades to the moth. As often happens the simple solution -to outsource all the milling to someone who knew what they were doing – was far too expensive for me. I decided to see how cheaply I could build my own CNC machine, knowing only vaguely what I was getting myself into.
The brief was to be able to handle a standard sheet of ply (1200 x 2400mm), but also to have 300mm of clearance under the gantry for making the large foam moulds needed for a sailing boat hull or a male surfboard blank. Stiffness over this area was a main concern, as was weight and demountability.
The design is based on two 6-meter-long painter’s trestles, which were the cheapest aluminium extrusion I could find that had sufficient structural depth and were of a satisfactory 6061 alloy. Electronics came as a kit and the moving parts I got at a good price through one very helpful supplier. The design was refined in rhino and the build was reasonably quick and painless, due to the ability to grab accurate dimensions for each part straight from the CAD model and print templates at 1:1. The machine ended up costing less than $3000 and has easily paid for its self with many hours of cutting tooling, joinery and architectural models.
Having a machine like this close by and learning how to use it has meant that the prototyping strategy is another element that can come into a design at an early stage. It has been a great experience to be able to create some really complex and exact parts that I otherwise could not have built and probably wouldn’t have designed.