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Semiautomatic tennisball gun

Posted: Tue Mar 17, 2009 5:35 pm
by colty-bear
I am currently working on a semiautomatic tennisball gun. I first got the idea watching Rob Dyrdeck's Fantasy Factory when i saw his. After that I did some research looking for valves that vould be able to fire semi automaticly. I knew or had an idea for the tank i would hook an air hose nipple straight to the tank and just leave the hose to the tank then after firing it would automaticly fill up again. But as for valves I was thinking of using a supah valve. Is it capable of firing over and over? I will use a 2.5 tee for loading and a 2.5 sch 40 pipe for barrel.
thx

Posted: Tue Mar 17, 2009 8:58 pm
by Lentamentalisk
There is next to nothing on this site that can't fire more than once. The problem is getting it to fire rapidly. Assuming you have a gargantuan compressor or air source, then you could probably fire a shot every 1-3 seconds, given a proper filling setup and all.

Posted: Tue Mar 17, 2009 9:00 pm
by colty-bear
So what your saying is if i put a supah valve hooked up to it then had a comressor always hooked up to it i could fire it every 3 seconds?

Posted: Tue Mar 17, 2009 9:36 pm
by spudtyrrant
joel has a semi tennis ball gun with the supah as the valve already http://www.spudtech.com/movies/asf/MOV00002.MPG

Posted: Wed Mar 18, 2009 12:02 am
by chrissilvermancs
...........

Posted: Wed Mar 18, 2009 12:29 pm
by SEAKING9006
They say that because there AREN'T that many semis. The GB Semi is one of the only ones we have. And the one Joel made isn't semi, it's bolt action and it fills kinda slow. You need HIGH flow into the chamber to get semi on a tennis ball level.

Posted: Mon Mar 23, 2009 2:40 pm
by colty-bear
Ok i got new news I was looking at supah valves and the newer models dont have springs on piston i was thinking the one with the spring is the one i need so i can have a constant air feed to the chamber... Anybody know where i can get a supah valve with a spring in it like this one?

Image

Posted: Mon Mar 23, 2009 5:26 pm
by SEAKING9006
No need for a spring. It fills as it is.

Posted: Mon Mar 23, 2009 7:03 pm
by colty-bear
so if i had a new supah model and a constant feed to the chamber it would shut itself off and let air compress into the chamber?

Posted: Mon Mar 23, 2009 7:09 pm
by daniel323
I first got the idea from Rob Dyrdeck's Fantasy Factory


I love that show

Posted: Wed Mar 25, 2009 8:51 pm
by colty-bear
UPDATE: I have a bad diagram here

Image


will it work?

p.s sorry if you cant see
they are labeled 2 1/2 pipe, 3 inch pipe, supah valve, tennisball feed, and air hose nipple for constant compressor feed.-you are all smart with this stuff so I think you can figure out where they all go together

It was this or i draw a picture and take a picture of it--HA!

Posted: Wed Mar 25, 2009 9:14 pm
by DonTheLegend
Sort of, probably. You're going to need an extremely large air source to fill this fast enough to allow you to fire again in 3 seconds. Also, you won't be able to leave it connected to air the entire time without some sort of modifications.

Once the valve opens, it will stay open until the chamber is empty and then it will reseal and you can start filling again. I'm not sure how the new supahs fill because the spring is what allowed the old ones to fill from the chamber side. Without it I would think it would have to fill from the pilot side? (Someone correct me if I'm wrong). If it fills from the pilot side, the small volume would mean it would make it virtually impossible to leave an air source connected the entire time and still fire the gun.

If you had a supah with a spring (or added it yourself) you would probably be able to leave the air source connected constantly to the chamber side. You would waste a lot of air, but you could probably make it work. Basically the valve would open until the spring could overcome the pressure flowing into the chamber and reseal. Then it would equalize normally until ready to fire again.

You would also have to figure out to feed ammunition. A bolt of some sort would probably be easiest. Overall though, 3 seconds is awfully fast to manually cycle a bolt and refill a chamber and shoot again. I think 10 seconds would be more realistic.

Posted: Wed Mar 25, 2009 9:20 pm
by colty-bear
Yes i see i wonder if any one would sell me a springed supah on here. But as for filling i will have a nipple with a hose directly on there and then it will fill automatically after firing. For the ammo drill a tennisball sized hole in the barrel then dremel out a tee glue on the barrel so the tee is lined up with the hole and have a spring fed tube of tennisballs.

Ill put up a wanted post now

Posted: Wed Mar 25, 2009 9:27 pm
by DonTheLegend
Would probably be easier to just add a spring to a new one... Most people here build their own valves, but you might find someone who has an old supah they're looking to sell.

How big of a chamber are you thinking of using? You say 3" diameter in the drawing but how long? You're going to have to make sure that your spring fed tube doesn't double feed or something similar before the valve reseats itself. This could probably be solved without too much trouble, but it's something to keep in mind.

Posted: Wed Mar 25, 2009 9:30 pm
by colty-bear
Yea, it would be an easy fix. I was going to use between 20-23 inches of 3 inch pvc piping