DIYbanter - View Single Post - Need ideas about using bearings for a spinning device

Bob La Londe[_7_]

On 7/3/2020 9:53 AM, wrote:
Hi!

I am a teacher and I want to make a few of these gadgets for a project this fall. I'd like to make zoetrope/phenakistoscope boxes. My students will make the actual drawings, but I want to make some interactive display cases so they can show their work off to the rest of the school.

I'm not sure how to explain what I need - sort of like a lazy susan on a kitchen table, but that will spin for longer when spun by hand. I'd like kids to be able to run their hand around the outside rim of the wooden circular platform to get it spinning the right speed, then be able to just watch for maybe ten seconds without having to continue spinning it with their hand.

Ooh! Now I'm thinking of a roulette wheel. Those spin for a long time. I've also thought of skateboard and fidget spinner bearings, but not really sure what would be my best choice to make this work well and be cost-effective.

Extra, probably unnecessary info: I plan on encasing each one in a plexiglass upper casing with just the edge of the spinning platform sticking out one side so the kids can spin it. This would all be much easier if I could just trust middle school students not to destroy things!

Thanks for any thoughts!
Lori

Spin duration may be improved by mass. It takes more energy to
accelerate more mass, but it also takes longer for parasitic loads to
reduce velocity. This is only true up to a point. There will be a mass
threshold that will overcome the friction reduction of the bearings.
Balance is also an issue. If the load is well balanced the bearing will
work better up to its limits.