I haven’t seen your design, but it would depend on how fast your flywheel is actually spinning. If you have too much friction in the flywheel bearings then you are pushing your motors into the high load, slow speed area (to the right on the graph).
You, really, want to be on the left, around 1.5 in-lbs torque and 85% nominal speed while launching the balls. There could be excursions into above 90% speeds when idling and below 85% when motors are recovering flywheel speed. The more kinetic energy flywheel could store the narrower that band could be. However, you don’t want flywheel to be too heavy because, at some point, it won’t be practical and it will take forever to bring it up to speed.
Here are jpearman’s torque-speed curve for 393 motor:
So your 8:1 and 32:1 ratios look about right and, if the motors rotate at ~85% of their nominal speed, then you want to look at the “good” friction. In order for flywheel to transfer some of its kinetic energy and angular momentum to the ball, there needs to be a good grip between them. That’s why we put rubber bands there and spent extra time making sure they are evenly distributed.
Also, there has to be just the right amount of ball compression. If compression is too small, grip will be weak and the balls will not fly far, even if the flywheel rotates fast enough. If the compression is too large then a lot of energy will be wasted compressing the balls.
Michael, I am sure you know this already, because I’ve seen 6210z robot’s reveal and it handles balls pretty well. My main concern would be how to compress balls of varying densities. We haven’t experimented with backplate design much yet - in the video we we just ramming the balls through with the excessive force.
But the next area of our research would be to try to design backplate in a such way that a softer material will handle a lot of the compression and, therefore, provide more predictable compression and ball-to-flywheel gripping force, regardless of the ball density.