How I made mine. And some few tips. I believe the string vibrating is what makes the sound. The faster you go the Inertia makes the string tighter for a higher pitch sound.
I have mainly Northwest European heritage and they have a form of these as well anciently. Spent most my childhood on big island, so thanks bradda for the demo 🤙
Naturaly, the wood acts like an airplane propeller, pitching one way to wind string up, then pitches opposite way to wind string up again the other way, then back the other way and so on.