[flash319]

I am looking for the best method/tool for cutting convex or concave type surfaces? Does anyone have a good way to do this so that the finish is not to much work to sand down?

[mcphill]

A ballend mill cutting with a small stepover (like .001 - .005 inches).

[Phife]

Ball nose is your best bet, depending on the detail needed, I use a 1/8 and 1/4" ball nose for most of my 3d work.

You can get pretty good finish if you use a small stepover but the trade off is increased machine time.

[307startup]

Depending on the size of the work piece, cutting the surface with a fly cutter mounted in the spindle as the work piece rotates, will give you much better results than a ball mill ever will....and you can cut both convex and concave shapes with the same tool and slightly modified programming....inverting x or y, depending on which axis the 4th is mounted on