View Full Version : projectile motion

02-13-2007, 09:16 AM
i am new here.... i need help on a ball potting mechanism
the aim is to pott balls(tennis balls) in a basket using projectile motion.... the basket is 80cm high n the maximum length alowed for the robot arm(extension) is 65cm... so we have to give the ball a small projectile.... we were thinking about using rollers but as the robot size is limiting it has bcum difficult to install that mechanism.... please adivce wht would be most suitable... carapult or something with springs... or would we be able to work on the rollers... the maximum base area allowed for the robot is 1200 cm2 and the maximum weight allowed is 12kg.... please help

02-15-2007, 11:39 AM
Hey Robo,

Could you explain your project with a little more detail? I'm having a hard time visualizing it...

02-15-2007, 03:33 PM
I think anything which needs to shoot a ball like this usually uses spinning rollers to "throw" the ball. Think about a pitching machine at batting cages.

google "pitching machine" to see lots of examples

03-28-2007, 08:38 PM
In case he ever comes back...the base of the robot is approx. 30 cm x 40 cm... plenty of room for the spinning rollers...if is to be a repeater just use a piece of PVC pointing somewhat vertically for a magazine...or use air pressure with a servo operated valve. I doubt that you need to fire that tennis ball all that far but my kids and I once built a golf ball gun that used 125 lbs of air pressure. We never did get a reliable feed mechanism but we did manage a respectable 350 yards for our best effort.