How to build a ballista to launch a golf ball 25 meters

[carlos_isaias]

I need some help on building a simple ballista that could launch a golf ball 25 meters away. If you have any ideas of designs please post them. Thanks.

 

[The Bob]

What sort of ideas do you have? Are you thinking of using elastic bands and wood or a spoon and a mechanised launcher?

Please throw us a bone on what you have to go with.

The Bob (2004 ©)

 

[cscott]

What sort of ideas do you have? Are you thinking of using elastic bands and wood or a spoon and a mechanised launcher?
Please throw us a bone on what you have to go with.
The Bob (2004 ©)

AFAIK ballista's are large crossbows.

 

[Danger]

Is this a private endeavour, or a class assignment? If an assignment, are there any specific restrictions on material, technique, etc.?

 

[carlos_isaias]

It is a class assignment. Compressed gas, slingshots and electrical components can't be used. The projectile launcher has to be mechanical. Other than that there are no restrictions.

 

[Danger]

Okay then. You'll have to think up some designs of your own and we'll critique/advise. We can't do your work for you. I would recommend that you start by Googling the device and see what's been done in the past.

 

[agusta]

Does it have to be accurate? A simple but effective method is to use the old school tennis ball launcher type design. You know the one where you have two wheels spinning in opposite directions and you roll a ball down a shoot between the two wheels and it launches out. If you make them well enough where the speed of the wheels can be adjusted independently you can make them fire extremely accurately. When you say it has to be mechanical what exactly do you mean? Does it have to throw the ball with an arm or a sling or could you use compressed air?