Filter thread adapter to attach large filters to small lenses. Parametric to create an afapter to fit any lens and filter you want.

See https://en.wikipedia.org/wiki/Photographic_filter#Filter_sizes_and_mountings for a list of filter thread diameters and their corresponding pitch.

Adjust variables i_d, i_p, o_d, o_p, and n_knurls in SCAD to given dimensions.