Printed two hubs, and cut 30 pieces of 80mm long string trimmer line.

Put them in.

Now, if I only had a robot to try them on.  Anyone?

The line tended to curl as I was cutting it, which made getting 30 equal lengths a possible challenge.  It also didn't help that this particular line literally came from my string trimmer as I changed out the line for some new stuff.

To solve the cutting a bunch of equal length sections problem, I came up with a simple solution of putting it inside a balloon handle (tube) bent over at the correct length, and then cutting them.

Worked well.