Hi,
I need to finish a mechanism to throw the ping-pong ball, or shoot the ball indoor (in the room), i.e. say for 5 meeter max in distance and 2 meter height max.
I googled for it but not much interesting results, so decided to ask here to point me to a good example
Thank you
look at the machine that throw tennis ball, the mechanism is quite simple
ironbot:
Hi,
I need to finish a mechanism to throw the ping-pong ball, or shoot the ball indoor (in the room), i.e. say for 5 meeter max in distance and 2 meter height max.
Any other constraints? Do you need to be able to aim it or control the speed? Is it single shot or does it need to be able to fire multiple balls? Any restrictions on size, weight, power supply etc?
PeterH:
Any other constraints? Do you need to be able to aim it or control the speed? Is it single shot or does it need to be able to fire multiple balls? Any restrictions on size, weight, power supply etc?
My need is very simple: to shoot once, then get reset manually, no need for automation. Shooting power of max 100gr is enough. My powr supply is LiPo, Mystery, 2800mah, 30C.
I have servo and 12v dc motors available, but don't have imagination for shooting 
no more constraints.
In that case I'd use a catapault with a servo acting as a release. It's mechanically simple, and you have ample scope to adjust it to get any range you want.
I googled catapult and found many examples of it. I finally implemented it not by a servo, but with ordinary dc motor, then in the path of throwing mechanism installed a bumper switch and connected it to int0 on digital pin 2, so that to some learn interrupting too.
It seems to work reasonably. Thank you and thanks to Lesto.
Look at putt return devices. It's just a solenoid that kicks the ball. You could put a solenoid in a piece of PVC pipe.
macegr:
Look at putt return devices. It's just a solenoid that kicks the ball. You could put a solenoid in a piece of PVC pipe.
any example link please? can't find it in google!
macegr:
Look at putt return devices. It's just a solenoid that kicks the ball. You could put a solenoid in a piece of PVC pipe.
To fire a ping-pong ball 5m it's going to need to be going darned fast and I think you'll struggle to get a solenoid to fire it that fast - and if you do manage it, I suspect you'll need a great deal of care to avoid breaking the ball in the process.
Well I already got the desired results by implementing catapult, just curious to know more of various shooting mechanisms. By the way, I've never did any project with solenoid, very interesting to do one
this is the basic idea. change the weel with an engine and you are done.
I wonder why this guy is wearing a helmet. Nowadays it seems important that anyone close to a bike carries a helmet. Seems that helmet marketing finally got it into a lot heads that bikes are inherently dangerous 
He's manning the launcher but otherwise defenseless, so it could be in case the tennis player returns one right home, but a face-mask isn't shouldn't be out of the question.
[The last thing you remember is hearing this Maria Sharapova-like shriek and then you're seeing stars.]
IMHO a face mask would be much more appropriate than a helmet. But this stresses my point. Obviously the "inherent danger" of the stationary bike appears larger than the danger of being hit by a tennis ball. This is marketing success.