This sounds a lot like what we're planning on doing. We used the 8" andymark traction wheels to shoot it up, with what I'm thinking is about 1 inch or so of compression. We're driving it with a 32 teeth drive sprocket and the sprockets on the wheels are whatever they come standard with. The gearbox is a banebots 4:1 planetary. I'm are trying to get a bigger (more teeth) drive sprocket, but I haven't found anything yet. I don't even know where we got these 32 tooth ones. We haven't tried shooting them up a chute yet, as we don't have material yet to prototype that. We got to shoot it vertically about 8 feet or so. Seems to be fairly consistent. Hopefully we can find something to prototype the chute with Saturday, because I'm worried about being able to actually get the ball out of the chute. I don't think we have quite enough power yet behind the launcher.
BTW, we also direct drove them from the cim motors. Don't do that. The speed is ridiculous, and it could probably throw the orbit ball a long way, but I bet the ball would get destroyed in the process. It already looks pretty battered.
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Originally Posted by EricH
No, you don't. 1 will do just fine, if you have a back plate to compress against. 2006 showed that. Contact time has little or nothing to do with it.
I was thinking a bit (dangerous, I know), and had a thought: What if most of the chute didn't rotate, but just the top part did and had the launching wheels close to it? You could run a belt up to the top and have a slower launch speed because you no longer have to fight gravity for the full distance. You also have the ball moving when it comes in, so there is less motor speed loss, and you can shoot faster.
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I was thinking about this as well, but mounting the motors and getting it all situated seems like it would be somewhat more complicated. If you just use the chute to direct the orbit balls, it can be extremely light, make of thin aluminum that could save you a decent amount of weight compared to mounting it on top of the chute, which would have to be made out of much stronger material.