What accessories do I actually need on day one with a new CNC, and what can wait?

Buy on day one

1. Touch plate / probe (if not included): fast, repeatable Z-zero. The community line is that it "pays for itself in avoided crashes within the first week."
2. 1/8" collet (or reducing collet): most routers ship with only 1/4"; without the 1/8" you can't run small bits, and you'll want them immediately for detail work.
3. Cheap bit multipacks to learn on: snapping a $5 bit is education; snapping a $40 bit is a bad day. The proven starter five: 1/4" downcut, 1/8" downcut, 60° V-bit, 90° V-bit, 1" surfacing bit (see the bit-selection entry for when each earns its keep).
4. Digital calipers: material thickness, bit diameters, test-cut measuring. Used constantly, forever.
5. Hold-down clamps for your bed's T-track/inserts + blue painter's tape and CA glue (see the workholding entry).
6. Dust boot + hose for your vac/collector, for health and cut quality both (see the dust/safety entry).
7. Eye and ear protection.

Can wait

• Premium bit sets (buy good bits one at a time as specific work demands them)
• Vacuum tables, ATC dreams, 4th axis, laser attachments
• Exotic clamping systems: tape + CA and basic clamps carry you a long way
• A second spindle/upgrades of any kind: learn the machine stock first

Pro tips

• A cheap speed square and straightedge help you check stock and square the machine, and most shops already own them.
• Budget for spoilboard MDF and practice material in the first order, because people forget the boring wood.