//This tutorial is under construction... info displayed here is correct, but not yet complete.
In this tutorial you will find:
- Desriptions of the different parts of a bit
- The differnent types of bits
- Milling techniques
In CNC (computer numerical control) milling, there are many different techniques and tools. I wil discuss only the tools that are being used in the Fablab, and their possible implementations.
Let's first have a look at the different parts of a bit:
We discern the following parts:
Free length: The length of the part of the tool below the collet (where it is attached to the mill)
Shaft diameter: The diameter of the shaft of the tool
Flute length: The length of the part with the small diameter. This only applies to tools with multiple diameters.
Cutting length: The length of the part of the tool that actually cuts.
Cutting diameter (or flute diameter): The nominal diameter of the cutter.
Pay attention! As you can see in the image, the shaft diameter and the cutting diameter are equal for the 6mm tool, but not for the 3mm! This means that with the latter, the actual dept you can cut into your material is limited by the flute lenght.
As you can see in the picture below, the red areas are not machinable with the selected tool:
The free lenght of the cutter depends on how far you insert the tool into the mill, so this is not a constant but depends on your own action!
And last, in the lab we use two types of milling bits, flat tip and ball nose
