Thanks...if I'm careful, these tops always come off the lathe perfectly balanced. The only issue I've run into is where the wood's density (weight) varies from one side of the top to the other. So choosing the wood, followed by paying attention, is the most important thing...same as with turning yo-yos. You can see the density of this Red Palm wood change from sapwood to heartwood pretty easily. No amount of balancing was going to make this yoyo not wobble...
Wow, that Red Palm is gorgeous, Ed! Guessing that the black is the (vascular) sapwood? Is it more or less dense than the heartwood? It's fun to think about the sapwood as one 3D object embedded in another.
I don't envy your having to worry about material density variations, but I do envy the structural rigidities you can achieve. When it comes to wobble, LEGO tops present pretty much the opposite design problem: Mass balance is guaranteed for fully seated parts in rotationally symmetric arrangements. But wobble can come from structural oscillations alone, and some visual designs flex more than others -- especially when executed in LEGO.
The LEGO top below was all about the visual of that red 20-sided ring, and to keep the ring round, it could only have 2 spokes. You can imagine how spoke and ring flexures during spin-up might set up structural oscillations lasting well into spin-down despite perfect balance at rest.
https://www.youtube.com/watch?v=bcnKNU-OHhAI hate accepting wobble to get a certain look, and I can usually tinker my way out of it. But LEGO plastic just wasn't stiff enough here.