Currently a lot of makers are printing faceshields as "Makers vs Virus".
To cut the rounded edges easier, I have created a small helping tool.
The tool can be adjusted via OpenSCAD. The 80mm diameter variant is attached.
80mm diameter will create a 40mm radius etc.

You can use this tool to draw the cutting line on the faceshield foil or directly cut with a scalpel as seen on the pictures.

For me this tool made the cutting process a lot faster.

Print instructions

Can be printed without top and bottom layer.
The infill was set to 10% in my case to get more grip for more secure handling.