How should I figure out what motors I need to rotate this ball?

Question

I have a machine with 3 wheels 120 degrees apart from eachother, basically making an equilateral triangle. when this machine runs you put a baseall on top of these 3 wheels, and the wheels spin in certain ways to make the ball rotate in 3 different directions. Right now I have 3 very strong motors connected to these wheels that spin the ball. I am now trying to make a prototype that will be economical and need to figure out how strong these motors need to be at minimum. How should I figure this out. Is there some calculations I can do or, is it just going to be trial and error?

Answer 1

Trial and error may be the easiest way. Otherwise you go through analyses of weight, friction, ball contour (especially seam height), etc. Not knowing what speeds you want and what, if any, gearing you're using, it's hard for me to say anything about actual power, but when you say "very strong" I assume you're talking more than tenths of a watt, which is the range I envision your final system using. If your current motors are way too large you probably can't get useful info on loading, but if you can measure the electric power they use compared to no-load running at about the same speed, you just might get some useful data.