SpudFiles

I just completed my last mod...a 2 1/2" barrel for tennis balls. After gluing the adapter on I test fitted a tennis ball down the barrel. It was a Penn not a cheap knockoff like whats at the flea market. I was quite surprised about the tight fit. Now, potatos will crumble if they get jammed but a tennis ball seems to compress and expand when there is a force behind it, like a rubber stopper. Has anyone had any problems with them? If the people who had problems are now dead were there any witnesses that seen problems with tennis balls???

No don't fire that cannon!
Tennis balls cannot be fired due to the nature of their flexibility
Especially Penn brand, because the are of higher quality and durability.


wowza

frankrede wrote:No don't fire that cannon!
Tennis balls cannot be fired due to the nature of their flexibility
Especially Penn brand, because the are of higher quality and durability.


wowza

Huh?

What I usually do with my tennis balls before I launch them is cut a hole in the side of them to let the air out of them, so it makes them a little smaller, creating a less-tight fit in the barrel.

How big? All the way through? Any other advice?

If everything is pressure rated you should be fine. I have not seen any problems.
Just to be safe you may want to try to find some tennis ball lube at your local sports store. You may have to ask be cause they often keep it in back.

wait, tennis ball lube?
i thought you just rammed them down a 2.5inch sch 40 and were done with it.

You have to use high quality tennis ball lube to prevent jamming in the barrel, low quality stuff can damage your balls.

@Hotwired: Um, I'm going to have to say it, or someone else will say worse...

...Eww!

Hmmmm olny thought that hard impacts caused damage to balls.

Sticky_Tape wrote:Hmmmm olny thought that hard impacts caused damage to balls.

Yup. Never hit your balls too hard, else they soften up and become useless.

Setting them on fire isn't recommended either, it burns all the hair off them, and it smells awful...

*shakes head* kids these days

ralphd wrote:How big? All the way through? Any other advice?

Just a hole about 3/4" long (I just stabbed it with a knife). The holes probably don't even need to be that big at all, just enough to let the air out of the tennis ball.

My barrel is probably a little bit different than yours, because I used 2.5" electrical conduit instead of sch. 40 PVC. (I'm not sure if there is a difference in size or not)

If you gun was properly built, and assuming it a 1X propane + air gun, a jammed shell in the barrel isn't a safety hazard. It is a PITA though since obviously you were trying to actually launch the ball.

A properly built combustion should have no problem with the ~120 PSIG peak pressure of a closed, 1X, propane+air combustion chamber.

You probably want to make sure nothing is behind the gun when you fire it. But that applies to all combustion launchers. If anything is going to fail it will probably be the cleanout since that isn't pressure rated.

Does it work? Yes it does and how. I was a little worried but I said what the hell and pushed the button. It was a little loud but I didn't realize that tennis balls prefer .7 to 1 instead of .8. I was able to reuse the same ball....cheaper than spuds and less mess so I will get a connector from Graingers and add the straw 6 inches.

So thanks for the advice from everyone especially those of you who emailed me directly. This Saturday I will go to the flea market for a sack-o-balls then shoot a few in the back yard. I think the neighbors won't mind harmless tennisballs from the sky.....for now.

So, I recommend this mod for everyone. I guess there is one more mod but there are draw backs....neighbors. PVC rockets will have to wait a while.

Hmmmm olny thought that hard impacts caused damage to balls.

You have to use high quality tennis ball lube to prevent jamming in the barrel, low quality stuff can damage your balls.

Setting them on fire isn't recommended either, it burns all the hair off them, and it smells awful...

this topic is getting a little wierd.

i have never heard of tennis ball lube. what is it for. i thought tennis balls fit perfectly in 2.5" pipe.