What you are describing is called ‘rest machining’, and is available in CC PRO.
A trick that works in the free version is the ‘pocket / contour’ trick. Like rest machining, you use progressively smaller mills, but there is a limitation - at each step, the next smaller mill must be at least half the diameter of the previous.
So, you can go from 1/4" to 1/8", but not 1/4" to 1/16" inch. To get as small as 1/16", you need three steps - 1/4", 1/8", then 1/16". With real rest machining, you would be able to go directly from 1/4" to 1/16".
Here’s how the ‘pocket / contour’ trick works:
- Pocket as you would normally using the larger mill.
- Now, for each following bit, program a contour that follows the vector the same way the Pocket did. This will usually be an Inside Contour.
This will do more works that real rest machining, but it’s much faster than pocketing with the smallest bit.
Here’s three text blocks, each about 1.75"x1.25" (so pretty small) From top to bottom, we have here pocketing with 1/16", Pocket / Contour with 1/4":1/8":1/16", and finally Rest machining, 1/4":1/16". Notice you get the same result each time.
At this size though, the time savings are minimal.
As a ridiculous example, I scaled up this test by 9 times - Each text block is now about 16"x11". Now the estimated machining times are:
On larger areas, the Pocket / Contour trick can save a lot of time, and is competitive with true Rest machining.