First attempt at an arrow notch. STL export from OpenScad.

Configured for 1/4" arrow shaft diameter, 1" of arrow shaft coverage by the notch. Notch extends another 1/2" past shaft.

Thickness of the notch walls is 1/16".

notch_1_16th_string.stl is set for strings with 1/16 inch diam.
notch_1_32nd_string.stl is set for stirngs with 1/32 inch diam.

Note, design is in-progress. Have not printed nor tested these yet.

Model was drafted in OpenScad, configurable for different parameters. Files uploaded at STL exports. Will upload the OpenScad design once I've cleaned it up a bit.