Customized version of https://www.thingiverse.com/thing:4776109

Created with Customizer! https://www.thingiverse.com/apps/customizer/run?thing_id=4776109

Using the following options:

print_view = 1
height = 6
inner_radius = 8
outer_radius = 21
edge_radius = 0.5
ball_radius = 2
ball_edge_radius = 0.3
space_ball_rings = 0.2
min_space_between_balls = 0.25
ball_height_space = 0
guide_size_ratio = 0.5
ball_guide_height = 0.8