Just starting out doing some very basic CNC engraving, perhaps just 2.5D, but thought I would list and explain the terminology as I learn.

Calibrating the CNC machine
Step 0: Collect All the Tools
Step 1: Level the Base
Step 2: Square the Bridge (X-Y Alignment)
Step 3: Square the Front-to-Back Backbone (Z-Y Alignment)
Step 4: Square the Side-to-Side Backbone (Z-X Alignment)
Step 5: Alignment of the 4th and 5th Axis
CNC – Computer Numerical Control, and commonly called CNC is the automated control of machining tools.
GCode – the script that tells the CNC machine what to do. So, turn the spindle on, what speed, what x, y, z position to go to, how fast to move etc.

Gear Design
There are some great online code generators for gears of all forms.
- Evolent Design free spur gear generator
Download the .SVG file and then drop it into Carbide Create to make the cutting path.

Squaring Stock
The process is primarily designed to square a piece of stock ready for the cnc. However, it could be used for general machining as well.

Tool Height Setter
Alan (Woody’s Workshop) has designed and made a hall effect tool height setter. Just a brief overview here, head over to Alan’s page where there are more details along with a PDF download that gives circuit design and full mechanical details – Hall Effect Based Tool Height Setter for use with PathPilot.