HI! I am new to the forum. I hope I can help with and get some answers here!. Lets see. I am making my own POV Globe (Watch from min 5 to 7 please, I will talk about the big one not the small one) https://www.youtube.com/watch?v=CMt9ku1zJvQ Now, I managed to build the big one and design it with SolidWorks, but I didn't do any mechanical calculations (I know noob mistake). Well the thing is that in the first try the system was so unbalanced that it practically just tore of by itself. That was when I learned that I HAD to make calculations . But now that I've learned I have some questions about my design. I am feeling that 2 things happened: 1) The ring was off balance. How can I calculate where to put my electronics so that it balances perfectly? 2) The motor speed up too fast and too furious!. That is why I would like to know how I can calculate the HP or Watts that I will need. I know inertia has something to do with it but I really have no idea of how to calculate this. Also I used gears for this prototype but I am thinking of using belts for the next one, mainly because if someone has the brilliant idea to stick his arm in while the system is functioning. I hope someone can help me with this problem. Thank you so much in advance and if you have any questions please ask.