Emmo wrote:
look at tennis ball machines. Most use air...

wrote in message
oups.com...

The dog would play fetch all day if us humans
didn't get tired of throwing it.

I want to build an automatic thrower. Train
the dog to drop the ball in a 'hopper', the
machine waits 10 seconds, beeps, and throws
the ball.

I am looking for ideas on the mechanical
throwing mechanism.

Rich

Thebaseball throwers use two motor driven wheels about the size of
wheelbarrow wheels the wheels run all the time, the ball rolls down
little ramp into the gap between the wheels and whoosh!! away it goes..