It is impossible to use a cylindrical cutter (milling cutter have flat end) for 3d machining.
The cutter can not create concave and convex surface toward the Z axis (ZX plane and ZY), the result of stair steps to places of curves.
The ball cutter create small waves at first, but those will disappear during the finishing phase.
What need to know :
- 3d sculpture is much longer than the 2D machining but have tips to reduce the total machining time.
- A special tool with a rounded shape at the end is required.
- All software for creating gcode CNC machining do not support 3D machining
- To prepare your machine you need for like for 3D printing have STL format file
- No it is not necessary to make a post treatment after machining, no need to sand after you have properly set up your machine with a finishing phase..
Warning : make sure that your tool is long enough to machine your 3D object to the bottom.
Your 3D object should not have forms with a negative rake angle if your CNC milling machine is a milling machine 3 axis.