This has been discussed a bit in the past, and is an FAQ: Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable
Big things:
- eye and hearing protection
- vacuum / dust collection and a dust shoe – list of designs at: Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable c.f.,
- Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable
- Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable
- clamps — I actually shift clamps back and forth between the two machines, though some of the SO3 clamps are large enough that they’ve never appeared on my Nomad: http://carbide3d.com/docs/tutorials/shapeoko-clamps/
- workholding surface — either T-track, threaded inserts, the awesome Carbide 3D threaded table, &c. — Shapeoko CNC Router, Rigid, Accurate, Reliable, and Affordable
- Measurement tools — presumably you already have some for the Nomad, but
- Level — precision has to start somewhere
- a good quality square
- a good set of calipers (if working on small scale parts, a micrometer)
- pinch sticks, a tape measure, a piece of string, or some other way to measure the machine on the diagonal
The machines are wonderfully complementary — hoping to have a project which takes advantage of both machines done soon. One thing to consider is you can use the Shapeoko to cut replacement MDF beds for the Nomad, and the Nomad to make clamps for the Shapeoko: