Help with 'rocket launcher' design

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
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spudkilla
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Tue Dec 30, 2008 10:30 pm

RED FLAG

Did anyone notice the ASA going to the PVC Chamber without a regulator in between? That's 800-900 psi going into PVC. That is not a very good thing. AT ALL!

This is how your Air setup should look like:

ASA->Palmer's stabilizer->Chamber->Valves->Barrel

I'm trying to find the thread on warpig about the LAW exploding at a scenario. I guess it was before the servers crashed.
Why do I try to make a relevant post?
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judgment_arms
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Tue Dec 30, 2008 10:52 pm

spudkilla wrote: RED FLAG

Did anyone notice the ASA going to the PVC Chamber without a regulator in between? That's 800-900 psi going into PVC. That is not a very good thing. AT ALL!

This is how your Air setup should look like:

ASA->Palmer's stabilizer->Chamber->Valves->Barrel

I'm trying to find the thread on warpig about the LAW exploding at a scenario. I guess it was before the servers crashed.
I had assumed that the regulator would have been built into the remote like I do...

But, none the less, that is a very good thing to point out. :D
Call me "Judge", it's easier to type.

Spud gun safety rules
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Marlowe
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Wed Dec 31, 2008 12:57 am

Huh, I was wondering about that. I just kinda figured the air wouldn't go in all at once. Hmm... I thought about buying something from palmer a while back, and if I remember right they are quite expensive. Isn't there something else safe I could do to avoid that price tag? It'd more than double the price of my gun. Dang, that might be a problem. It can't be one shot, that is just a big no no. Hmph, if one of you could get back to me on the stabilizer deal, that'd be great. Also, while you're there, could you take a look at my plans for a paintball pistol on the previous page? I'd really appreciate the help.

EDIT: AHA! I think I just figured out a way to get the same safety of a stabilizer without it's lofty price. 4 words: Safety Pop Off Valve. I'll just hook it up to a male quick disconnect and then tap it into the resevoir using some sort of metal coupling. Now, do you think that this will work? Examine the revised diagram below, and make revisions as you see fit.
I think it'll kill two birds with one stone, fix the regulation on the launcher, and give me a valve that I can use to hook up the resevoir to the pistol's chamber, also pictured. Now, as far as I can tell, this is how the thing should be hooked up. If I'm incorrect, I'd love some one to let me know. Now, onto the pictures!

EDIT #2: Dang, well, just looking at this a little while after wards, I think I screwed up. Even if the pop off for the pistol where to work, (still no confirmation on that front) it would fill at the same time I shot, not giving any time for the valve to seal again for the next shot. So, I guess I just made a paintball sub machine gun. Not necesarily a bad thing, (I'll probably end up making something like it, but bigger, later on) just not what we were looking for. So, If anyone else has some ideas of a more delayed fill valve, that would be great. Just examine the pistol's diagram for an idea of what it'll look like. Thanks alot!
Attachments
The Pistol's diagram. I decided to replace all the 90* elbows with T joints to make it straighter.
The Pistol's diagram. I decided to replace all the 90* elbows with T joints to make it straighter.
The Launcher's Diagram
The Launcher's Diagram
Last edited by Marlowe on Sat Jan 03, 2009 9:46 pm, edited 1 time in total.
No bastard ever won a war by dying for his country. He won by making the other poor dumb bastard die for his country.
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Marlowe
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Thu Jan 01, 2009 6:57 pm

Wait, guys, just found something on a board about regulators. Here's the link: http://www.palmer-pursuit.com/cart/inde ... _id=189url . Just wondering if that was a schrader valve I saw under the Male hookup. Even if it wasn't, couldn't I make a shock pump that would thread on to the bottom, hook it up to a remote line, then hook the remote line to an HPA tank nipple, so I could half way fill a tank? Just wondering, cause I'd love to not have to go to dick's all the time to fill er' up. Also, if someone could take a look at the pistol again, and tell me if the new t-connector filled resevoir system is actually achievable, or should I go back to the original 90* elbow plan? Thanks for all the input so far guys, and I hope you can continue to help me as much as you have.

EDIT: Also, does anyone know off the top of their head what the pressure rating of brass or copper piping is? I've been looking around, but couldn't find it posted anywhere. If it was, then I was probably distracted by all the pretty pictures.
No bastard ever won a war by dying for his country. He won by making the other poor dumb bastard die for his country.
-George S. Patton
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Marlowe
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Wed Jan 07, 2009 10:26 pm

Well all, I just realized that my last idea for the pistol's pop off valve to work as a feed was pretty stupid. So, I'm thinking that either a check valve or a hammer valve would probably work, and would probably be better in the long run. Trouble is I don't really understand either. I know that the check is alot like a piston within a piston, but the hammer valve eludes me entirely. So, if anyone has found a good drawing of either, I'd love to hear about it. I've checked around the site and the wiki, but I haven't been able to find any sort of example or illustration about either. I'd love for some help on it, thanks in advance for any help you'd be able to give!
No bastard ever won a war by dying for his country. He won by making the other poor dumb bastard die for his country.
-George S. Patton
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Mateo
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Wed Jan 07, 2009 10:47 pm

hammer valves work quite well and are easy to make if you have the stuff. this should explain well and show you how to make one

http://www.instructables.com/id/Airgun- ... ase-Valve/

edit:he calls it an explosive air release valve but its the same thing
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Marlowe
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Mon Jan 12, 2009 7:50 pm

I had seen that, but I didn't watch the video, assuming that due to the incorrectly capitalized X, it would yield subpar results. Boy, how wrong I was. He explained everything so clearly, it was really great, talk about judging a book by it's cover! Well, now that that is settled, time to make a mock up. Sorry I haven't been on in a while, but you guys know how it is with exams coming up. So, I'll have to get the drawing to you later, probably around wednesday or some time near it. Also, I still have quite a large bit of sticker shock with the palmers pursuit merchandise, and was wondering if anyone had a more cost effective solution. Thanks a bunch guys, this is really shaping up nicely, and I have your input to thank for it.

EDIT: Does anyone know of a formula or something to get a desired amount of pressure into the resevoir, like per second or per pull or something like that? I'm not quite the one for math, just ask anyone who's seen my grades, and would love help with this subject.
No bastard ever won a war by dying for his country. He won by making the other poor dumb bastard die for his country.
-George S. Patton
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Marlowe
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Wed Jan 14, 2009 8:13 pm

Well, done with the drawings for the pistol. Sadly, still not semi-automatic, and I still don't want to have to go to an electronic trigger setup. I decided to go for a double trigger system that most paintball players would find familiar. So, here we have one of the final ideas for the pistol. Want to know what you guys thought of it, and if there is any room for improvement on the gun. While we're talking about it, I have a guilty little secret I'd ike to share. While being a super paintball nerd, and a rather geeky all around guy, I also play Warhammer 40,000. For those of you who don't know, it's a table top game where you pit races of alien origin against the future forces of mankind. So, the reason I share this is because I can't figure out what I should do to the pistol aesthetically. I was thinking about wrapping it in a body similar to this replica plasma pistol: Click Here to see.
Or I could just use pvc sheeting to cover the thing, and make it look pretty angular. So, it's up to you guys again; which path do I take for the body? I'm rather partial to the plasma pistol myself, though I have to admit that the angular PVC body would be quite elegant. Without further ado, here is the diagram! If you want to see how a hammer valve works, just look at Mateo's earlier post about the topic (by the way thanks for the help on that one).
Attachments
The diagram in it's most current form.
The diagram in it's most current form.
No bastard ever won a war by dying for his country. He won by making the other poor dumb bastard die for his country.
-George S. Patton
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