Fast flow extrusion test

This is a very quick test without the need for measuring tools.
The most important thing is to set the flow for each part.

Main part: 100%

If we want to check flow from 105 to 90:
1: 110%
2: 100%
3: 90%
4: 80%

If four fits best then we get best flow at 90.
This is the result of the mathematical operation (100+80)/2.