How do I zero X, Y, and Z on my machine: touch plates, the paper method, and where to put the origin?

The concept

Your file has an origin (XY Datum + Z-Zero choice in Job Setup). Zeroing is telling the machine where that origin physically is on your material. Every wrong-position and wrong-depth problem traces back to this handshake. See the Z-zero mismatch and XY-position entries.

Zeroing Z

• Touch plate (best): a metal plate + alligator clip. The controller probes down until the bit touches, then applies the plate-thickness offset automatically. Fast, repeatable to a few thousandths. Verify the plate thickness setting in your control software once, because a wrong value offsets every job.
• Paper method (free): put a sheet of paper on the surface and lower the bit in small steps while sliding the paper. When the paper drags, you are about 0.003 to 0.004" high, so set Z0 (or step down that last bit). Slower, but fully adequate.
• Zero on the material top or the spoilboard to match the Job Setup Z Zero setting. Spoilboard zeroing is immune to thickness variation for through-cuts.

Zeroing X and Y

• Jog the bit to the chosen corner (or center) of the stock, eyeballing the bit center over the corner, and set X0 Y0. For most woodwork, eyeball accuracy (plus or minus 0.5 mm) is fine.
• Corner-finding touch plates (3-axis plates) probe X and Y edges too, which is worth it for repeat precision.
• Lower-left corner is the most common convention. Center suits round or centered designs.

Pro tips

• Re-zero Z after every tool change (see that entry). X and Y usually survive tool changes, so do not re-zero them mid-job or you risk shifting the origin.
• V-bits: zero on a scrap area or the spoilboard when possible, because the fragile tip is easy to chip on an aggressive probe.
• Write your shop convention down: datum corner, Z reference, plate thickness. Consistency prevents most setup errors.