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PostPosted: Fri Jul 01, 2005 1:38 pm
by BigBang
Hey Gang,

Here is my first pneumatic. I had been wanting to build a smaller cannon that I could shoot easily in my back yard. After watching the threads on GGDT 4 I got interested in making a pneumatic. What I came up with was this muzzleloading paintball rifle. One of my friends said the paint job was the same color scheme as a big bruise - thus its name. The entire rifle is double walled, and while it is difficult to see in this image, the bipod is made of a 1.5" t-fitting that I opened up a bit. As a result, the rifle can freely swing and rotate on the bipod in all directions.

<img src="http://www.spudfiles.com/uploader/uploadFiles/PaintballRifle.jpg">

The barrel is made from 0.75" CTS CPVC. I sleaved this into 1" CTS CPVC and held it all together with Gorilla glue. The barrel is quite rigid, and is of course a perfect fit for paintballs. The barrel length is 36", and the overall length of the rifle is 56". You can also see the safety pressure release valve in this image.

<img src="http://www.spudfiles.com/uploader/uploadFiles/Muzzle.jpg">

Here is a close-up of the action. I used a Deltrol QEV that I bought from McMaster Carr. I polished it up with the wire wheel on my grinder and was surprised at how well it turned out. I also put a ball valve safety in there and situated it so that I could actuate it with my thumb while aiming. The trigger is a little push button valve I also bought at McMaster Carr (part #62475K11). Also, for reference, to keep the pilot volume low I plugged the butt stock of the rifle with plumbers epoxy just to the left of the both the push button trigger and the ball valve safety.

<img src="http://www.spudfiles.com/uploader/uploadFiles/Action.jpg">

Here is the "filling station." I got the idea from D_Hall's website. I bought the low pressure "Palmer Tire Stabilizer" from Air Soldier Products for $95. Whew, that was expensive, but I wanted something portable other than a bicycle pump.

<img src="http://www.spudfiles.com/uploader/uploadFiles/FillingStation.jpg">

As for performance, I just about blew a hole in my garage door the other night at only 80psi. The QEV is rated to 125psi. At this max pressure GGDT says I'll get a little over 600fps. That is, of course, if I did my GGDT model right. At this point I have just modeled the QEV as a generic valve. Does anyone know how to model the valve more exactly? It didn't dawn on me to take the valve apart and do the proper measurements till it was all assembled. Doh!

Note to PCGuy: Feel free to use these images at SpudFiles if you wish.

Happy 4th of July

PostPosted: Fri Jul 01, 2005 2:16 pm
by spudman029
WOW! Nice RIFLE!

EDIT-Is that really your first pneumatic? Mine was no way near as good.

PostPosted: Fri Jul 01, 2005 2:19 pm
by Freefall
If you can still unscrew the screws that are holding the valve together, it shouldn't matter that it's assembled already.

That's a slick looking gun. Great job!

PostPosted: Fri Jul 01, 2005 2:59 pm
by sonicst0rm
What's GGDT? Link?

PostPosted: Fri Jul 01, 2005 3:01 pm
by jasonsmithmyer
Someone had told me that you aren't supposed to use a PVC chamber when filling with CO2 because of the temperature shock that the cold CO2 has on the PVC. It makes it brittle or something. Am I Just crazy or is that true. The reason I ask on this post is cause he's using a CO2 canister to fill his Gun.

Awesome gun, I love to see cannons and the like that are actually made to look like real guns.

What is the pressure rating on that valve?

PostPosted: Fri Jul 01, 2005 3:23 pm
by Krazy_K
Nice gun man, that thing is beautiful, especially for a first. Jason, CO2 is fine to use, you should just make sure that you have the bottle upright so you don't get any liquid and dry ice forming and you should be ok.

PostPosted: Fri Jul 01, 2005 3:46 pm
by greeneyedboy5
tHAT LOOKS REALLy NICE. great jOB. i LIKE THE C02 FILLER UPPER.

PostPosted: Fri Jul 01, 2005 3:55 pm
by Freefall
<blockquote id="quote"><font size="1" face="tahoma,verdana,arial" id="quote">quote:<hr height="1" noshade id="quote">What's GGDT? Link?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
I'd suggest trying the search button, but I know you'd find hundreds of results, far too many to search through.

Or you could try Google. But again, the first few pages have links that mention it, but don't say where to get it.

So: here you go:
http://www1.iwvisp.com/thehalls/ggdt/index.html

You need a couple files that you may or may not already have. These files are linked on the installation page so if you get errors because you didn't follow instructions, go back and read them again.

GGDT is a powerful tool, and as such, has a bit of a learning curve. Fortunately, it's not very steep, and the "usage" and FAQ" links on the GGDT homepage should answer most of your questions.

PostPosted: Fri Jul 01, 2005 3:59 pm
by Mr.Plow
Whoo wee!

Do you use Krylon Fusion for the paint? I can't get over how NICE that looks!

Excellent cannon, I LOVE the design!

PostPosted: Fri Jul 01, 2005 4:27 pm
by BillyBobJoe
WOW! NICE! Very professional looking! I love the Palmer Stab. Setup. Did the 3/4" fit nicely into the 1" CPVC? Thats a good idea . . .:D