Learning how to manage mill radius
Having worked with milled parts for years, I can assure you that another common issue you will encounter is the wrong management of the mill radius.
To overcome this, you need to understand the following concept: milling processes cannot perform squared slots, and the mill radius will always be imprinted on the part.
In the following diagram, we can better understand the problem:
Figure 7.14: Mill radius
As you can see from the diagram, there is no way for our flute to leave a rectangular-shaped slot. If the mill cutter has a 20 mm diameter, we will always leave a 10 mm radius on corners. But what if we really need a squared slot? There are a few techniques that can help overcome this intrinsic behavior of milling machines:
- Reducing the mill radius
- Tweaking our part geometry
- Changing the milling direction
Let’s look at these three options in more detail.