[Chak]

Originally Posted by Anupam Goli

What tread were you using on the plaction wheels? I'd avoid roughtop and go for a smoother tread.

Originally Posted by SenorZ

Who'd have thought having a fast moving rough piece of plastic pressed up against a thin plastic coating on a foam ball would do damage?!?

Originally Posted by Josho499#4613

Our team has found that the signature Vex "Colson Performa" (The smooth grey ones) wheels dont tear up the ball without sacrificing initial performance

Originally Posted by jwfoss

We've run a ball through a shooter prototype around 10-15 times with no damage at a few different compression setting. I strongly suggest using a wheel with a smooth surface (Colson, Stealth, etc) if working on a flywheel type shooter.

Thanks for the suggestions! We were prototyping on the second day and grabbed whatever 6'' wheels we had on hand to throw something together . Now that we've seen what plaction wheels can do to our ball, I think we'd be using Vexpro colsons or one of Andymark's colored stealth wheels, depending on how they perform in a later prototype.

Originally Posted by Ether

May I ask: were you commanding full voltage to those miniCIMs, or some fraction thereof?

We were running the motors as hard as we could. I think we can safely assume that the motors were getting full voltage.

Originally Posted by philso

Are you gently pushing the ball towards the spinning wheels and allowing them to grab the ball or are you vigorously pushing the ball into the space between the spinning wheels?

I wasn't the one putting it in, from from my perspective, we were not vigorously pushing the ball in, nor were we especially gentle. We just put it forward and watched it shoot.
Is that a significant factor in damaging/shooting the Boulder? After all, the robot would be pushing the ball into the shooter with some amount of force anyhow.

Originally Posted by Ginger Power

The GreenHorns' wheeled shooter is at the point where we aren't tearing up the ball anymore (initial tests were brutal on that ball!) Thanks to Andymark for the donated game piece!!! Now that it's tuned we're throwing about 15-20 feet and it's very accurate. Our current game piece is beat to heck and the flight path hasn't changed since all the little nicks and cuts developed. We have a new ball and an old ball and they fly the same.

Don't be afraid of wheeled shooters this year. The 1114 style articulating arm is going to be gold this year (it is almost every year...).

Originally Posted by Ginger Power

Smaller wheels, fine tuned compression, low gear ratios, and high rpm's. Those are the constraints I'd be designing my shooter around.

Thanks for the advice! We were going to use smaller wheels, but we had a scrap piece of 2x1 handy to fit a 6'' wheel shooter. Can you describe your "fine tuned compression"? I've always assumed that moving the 2 flywheels on the same shaft closer together would be enough to vary compression. Is that true?
What is the 1114 style articulating arm? A quick google search yields this thread.