4 axis rotary

[magicniner]

If you're hand coding you need to start out understanding how the G-Code works, if you have a decent CAD/CAM package you just need to get the config right and the code comes out right.
There are so many ways to skin this cat, you can rough and finish a 4-Axis job in 3 Axes with manual 90 degree indexing, without using a 4th.

- Nick

[corkcnc]

As the guys said, you'll have an x,y,z and a axis. Best bet is to do all the roughing in 3 axis mode and just index 90 degrees each time, then do your finishing in 4 axis mode to optimise the surface finish. Solidcam has some nice features where you can finish parallel to a curve or to an axis or you can let your toolpath morph from the shape that defines one side of a face to that or the other. So if one end of the face was an arc and the other a straight line, your toolpath woud start as an arc and gradually change as it machines the face to straight lines. Nifty stuff.
Noel.