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Re: Be afraid... Be VERY Afraid
Okay, I have a bit more time now that I'm not at work and can list some of the questions I have about how this would work and what the benefits are.
Years ago, I was able to receive a lot of fantastic feedback from engineers on this site, so there's definitely merit to posting ideas and soliciting feedback. That should continue, but a bit of humility goes a long way.
Questions/Concerns --
0. What problems were you trying to solve when making this design? What were the criteria you used to guide your decision making process and how did each of this model's elements satisfy that criteria?
1. Do you intend for the sphere to slip sideways against either driving roller? If not, no part of the sphere that isn't touched by a roller will ever contact the ground, so why use a sphere at all? If yes, the maximum possible force of friction between the sphere and the driving rollers must be less than the maximum force of friction between the roller and the carpet; this sacrifices available pushing force, putting your robot at a disadvantage in pushing matches.
2. The sphere is driven by a roller using friction. The available force of friction will be determined by the pneumatic cylinder pushing the roller against the sphere. You can use leverage here to make a smaller cylinder provide force that nears or exceeds your practical maximum possible friction force as determined by the coefficient of friction between your roller and sphere/sphere and carpet, but in all cases, the maximum friction force the robot can exert on the ground will be dictated by the sphere/carpet interaction.
3. When a roller is being pressed onto the surface of the sphere, because there is currently nothing shown to retain the ball from moving away from the drive rollers and ball casters, your mechanism will push the robot away from the sphere, unseating it from within the four ball casters. You will now be riding only on the thin interface between your drive roller and the sphere.
Driving forward or backward will cause the sphere to shift in the opposite direction. Any sideways motion will cause the sphere to slide sideways off the driven roller and, for lack of a better explanation, wedge itself into place between the drive rollers and two of the ball casters. You may not be able to recover from this condition except by going to a middle position that removes both rollers. The condition will repeat anytime you try to drive, however. You absolutely have to capture the sphere so that it cannot move vertically independently of the rest of the module for this to have ANY shot at working at all.
There are a lot of problems here and I think that, if you worked through them, you'd end up at a swerve module.
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--Madison--
...down at the Ozdust!
Like a grand and miraculous spaceship, our planet has sailed through the universe of time. And for a brief moment, we have been among its many passengers.
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