How to find information about ball throwing machines

[burak]

I wonder that are there anyone who have an idea about ball throwing machines(tennis ball throwing machine, volleyball throwing machine etc.) How can i get information about this subject?
(i am sorry of my bad english, i wish i could explain what i want to learn )

 

[hitssquad]

anyone who have an idea about ball throwing machines (tennis ball

These things?
http://images.google.com/images?q=tennis ball machine

Are you trying to figure out how to make one?

 

[burak]

These things?
http://images.google.com/images?q=tennis ball machine

Are you trying to figure out how to make one?

thank you for your help.
yes i was trying to figure out that.
i am trying to project a volleyball throwing machine and getting knowledges about that. i need any different ideas. the two thing is to keep in mind that the ball will not rotate on its own center as much as possible and the trajectory is determined (specified)

 

[Madsunz]

Not sure if you are trying to construct something for yourself or manufacture something, but if you are looking to make a simple ball hurling machine, do a Google search for Trebuchet. It is a simple style machine that you could use to hurl any type of object.

 

[burak]

thank you everyone who helped me, i get many informations about the machine. i have only one problem that;
how can i do velocity control to a motor, in other words, by using what kind of motor, i can control the velocity of the motor?