Thought I’d try making some gears. The first one’s not so good – the mill bit’s first cut was too deep into the material, and the pressure was too much for it to follow the pattern closely. The next cuts were better but that first cut left a bit of a step on the edge of the teeth:
The next one was better. It’s better to start the mill well above the surface – “cutting air” – rather than risking the first cut being too deep:
Much cleaner.