Semi Auto

[spudshot]

the trigger is right in front of the tee.

[clide]

Sorry for kicking this back up, but I just noticed the new questions.

jrrdw, somebody put the video up on Google videos when the story PCGUY posted it on digg. http://video.google.com/videoplay?docid ... 4370683540 hopefully that one will work for you.

dragon finder, are you talking about the check valve part of the piston? (the part that keeps air flowing backwards, light green in the animation).

If so http://www.spudfiles.com/forums/download.php?id=792& shows the parts of the piston. The left piece is the piston body of course, and the spring goes up in that large hole followed by the black part (a piece of rubber) and that is all held in by that gray piece below which is a snug fit in the piston and is held in by a small screw going into the piston body (the hole is not visible in that photo) and into that little indention you can see on the right side.

Also fklco has a good point, I think I've said it before, but it's worth saying again. A gun like this can be built fairly easily with a standard QEV and 3-way valve. The only hard part would be a loading mechanism, but with a little creativity it could probably be done without too much trouble.

Some of the older questions.

"how much did at cost total?"
Hard to say exactly, I went through quite a bit trial and error, so the actual cost for me was pretty high. But if I were to get it right on the first time, probably only $30 or so if you only count how much pipe was used and not the cost of a whole stick.

"how do u keep the paintball from moving down the barrel?"
In the one I actually built the ball moves all the way down to the bottom of the tee, so the lip of the barrel keeps the ball from moving forward and the bolt keeps it from moving back. If I were to build it like I should have, like is drawn in the picture I would probably use some sort of small piece of rubber that is able to bend down when the bolt passes over it, or a small wire bent in such a shape that the bolt can push it down and out of the way when the bolt moves forward. If you need I can elaborate and/or draw a picture if you are really interested.

Thanks for fielding some of the questions for me spudshot.

Too tired to proofread, sorry if the post is full of errors.

[ZealousAlcoholic]

It would be super cool if you tapped it for a paintball barrel... Barrel Taps

Expensive, but cool.

[davo925]

hey i have all the tools to make the paintball gun but i need more of a discription on how to make it

looks awsome

[Velocity]

generally on these spudgun forums, people do not like to give out plans.

If you are unable to create one yourself from just looking at the diagrams and information provided by clide, you probably shouldn't be making one. Bear in mind that machined parts can be dangerous if not made properly.

Also bear in mind that your replication of this cannon does not need to use the same exact parts as the original

While Im at it, try not to post in dead topics if you dont have anything significant to say

[NUKEWARHEADSCIENTIST]

this is pritty much exactly what i have been working on lately. i just havnt been able to get it semi auto its just been spray and shoot. spray and shoot. spray and shoot. but even that hasnt worked yet

[killagorrila99]

this is pritty much exactly what i have been working on lately. i just havnt been able to get it semi auto its just been spray and shoot. spray and shoot. spray and shoot. but even that hasnt worked yet

No Offence Man but start building clouds. Much cooler then "compressor" guns that you build...

[Jolly Roger]

Is very easy to use pneumatic Quik exhaust valve made by Aignep Italy
http://www.aignep.it/article/articleview/59/1/54/
And
Slide valve
http://www.aignep.it/article/articleview/60/1/54/

Best to use Quik exaust valve size 3/4
and slide valve 1/8 or 1/4

I tray with 1/4 quiq exaust valve and work very nice but look to be small size.

Sorry for my english

Hey by the way thanks for th video link clide, I probably dont need to say it but that is a sick gun.. Oh yeah fklco, those valves, you plan on using them in conjunction with a larger piston valve am I right? If so good idea with the slide valve but how exactly does the exhaust valve work? I don't see how you can drop the pressure in the supply line... Also just wondering about paintball slide check valves. They are just normal slide valves (dont know why they call them check valves..) but they handle higher pressures. Does anyone know if they would be suitable for a gun similar to clides, not sure about the flow rate thats all...

[Jolly Roger]

EDIT

[clide]

They should work fine, a picture or link to the valve you are talking about would make it easier to verify. Although I haven't seen one in person, I wouldn't be surprised if a 1/8" slide valve had more flow than most blowguns.

The exhaust valve is just like a piston or diaphragm valve.

[Jolly Roger]

Yeah heres a link the valve http://www.sakworldpaintball.com/slidchecval.html I opted for a paintball valve over a normal slide valve as the cannon will be operating at around 250-300psi. They are fairly small ports - 1/8 normally I think. I was thinking either that or I could machine one out of alloy. That would mean the o-rings would have to be really thick and tightthats all. You think it would be worthwhile making one or using one of the smaller paintball ones?

[clide]

Yeah, that seems like any other slide valve. What size of gun are you looking on using it with.

[SpudStuff]

You dont need thick o-rings. all you need is the right groove dimentions for the ring you are using. The groove needs to be 90% of the O-ring thickness and 100% of the ring wide. these can hold 100's if not 1000's of psi.

[Jolly Roger]

Thanks spud, so the groove width is horizontal in reference to the valve being horizontal? Yeah clide I'll put in a ggdt pic that shows the stats. I was planning on running the slide valve to a remote trigger using a brake line (wire) or pneumatic actuating ram. Unless of course there is some easier setup of course - just want to be able to set the trigger to about two - two and a half pounds. Well heres the pic (ggdt's optimizing methods dont work for some reason - they give me worse figures then what i started with so i manually configured the size of the resevoir to give the best and most ecconomical performance in response to the fixed barrel dimensions.

[lonegijoe]

hey guys. I don't believe this to be a dead topic but there is a site that will help a few of you to understand how paintball guns or basically any projectile gun works. ONce you have a better understanding of how it works not only does it help you to be more safe but it will help you to understand what you need to make your gun design work the best it can. Help troubleshoot,etc. I think a lot of people try to build stuff before they actually understand it. That can be very dangerous,especially if you leave out a necessary component that you need to safely shoot the object out of the device. Don/'t need stuff blowing up, etc.

http://entertainment.howstuffworks.com/paintball1.htm