Summary

A larger anemometer arm. Print three, and weld them together with a soldering iron or heat gun.

Update: added some chamfering where the arm joins the cup, rotated to a better printing position.

https://youtu.be/T8JBusnESaY

The cap is NOT 3-D printed. Bearing is from a fidget spinner.

To do: models of the other components: hub, cap.