I Made a Basketball That Never Falls Off Your Finger....Almost 

I think you should have some holes in the spinning disc

Great video, keep up the good work! It looked like you were using the heat set inserts without holes already made. In the future you could consider modeling in holes. This way, the slicer puts several walls around the hole instead of putting the inserts into sparse infill. Additionally, many brands specify a size for the hole for the best engagement.For example, I have a set from CNC Kitchen that specifies a 5.6mm hole for an M4 insert. For the balance of the disk, you could consider printing a part with a concentric infill or at 100% infill. This way the weight would be evenly distributed. To reduce print time and add weight, you could put a circular pattern of nuts in, close to the outside edge. The tessellated edge of the disk should not matter as long as it is consistent. You could theoretically have a square plate and could still have it balanced, it is just more work for the motor because of the added air resistance. Hope this helps, keep up the great work!