Contains option for circles of the following diameters (mm): 

• 2 to 11 (1mm step)
• 12 to 18 (2mm step)
• 15 to 40 (5mm step)
• 50, 60, 80, 100 (partial circle)

Designed to compensate for pen diameter (parameterized in freecad). Exported for:

• 0.8 mm (designed around a cheap 0,35mm lead click pen)
• 1.1mm (designed around Pentel GraphGear 1000; 0.7mm tip size)

I also exported 4 options for printer compensation (measurement in file name is given in µm, it is applied to the diameter so you can just print the “0” version and measure it)

Printing

I printed mine with semi transparent PLA (fillamentum crystal clear blue, purple and a manual color swap to generic black PLA for the last layer).

Designed for:

• 0.25mm layer height for first layer
• 0.2mm layer height for remaining layers
• 0.4mm nozzle (0.4mm line width)