Fittingproblem!!

A place for general potato gun questions and discussions.
igiigi
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Sat Sep 26, 2009 5:48 pm

we have here in town one big shop for plumbingstuff but they have only metal parts! and with the bit pvc they have u can´t make a chamber! :/

6 euro is alot i think!

maybe i try to get (make) a huge pipe and make a chamber of it?!
it must be big enough for a small fan! and the barrel i would connect with a elbo?!

hmm... becoase i better will build one of metal than of the gray pvc :)
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MrCrowley
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Sat Sep 26, 2009 6:35 pm

we have here in town one big shop for plumbingstuff but they have only metal parts! and with the bit pvc they have u can´t make a chamber! :/
You should make a high pressure cannon out of metal then. Unless you want a big bore cannon, then you will need to use PVC really.
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POLAND_SPUD
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Sat Sep 26, 2009 7:09 pm

mrcrowley is right IMO....
metal is superior to PVC in many ways... sure it's heavier but since it has higher pressure ratings you can achieve more power by using higher pressures..

also thx to threaded fittings you can reuse all the parts you buy...
so, for example, you build your first gun you need a length of pipe, ball valve, quick connect fittings for filling, and a couple of other fittings to put everything together... then you can replace the BV with a QEV (or build your own piston valve) and use the BV to pilot the QEV....

some say that PVC is cheap but once it becomes a part of a gun you can't really reuse it and you can never trust old PVC parts...
so contrary to what you might think, using threaded metal fittings is a good way of saving money

some of the parts were on most of my guns and then I used them on my fridge compressor
(consider building one yourself)
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Brian the brain
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Sun Sep 27, 2009 1:10 am

how much cost those pvc chamber in holland?
wich one??

The cannon I showed that my brother built cost around 500 euro's in total.
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
igiigi
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Sun Sep 27, 2009 5:25 am

holly shit it´s a lot!!!

ya, i mean metal is rly save and powerfull, but heavy...
pvc is light and u can better work with them....

but it should by work by propan injection!

i´ll watch out for good (pvcor/metal) fittings. of coarse i´ll show u than the finished work! :)
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Technician1002
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Sun Sep 27, 2009 1:33 pm

I found the opposite to be true regarding chambers in metal vs PVC. I have 2 cannons with about the same chamber size. My dragon is a couple feet of 6 inch sched 40 PVC with a 2.5 inch coaxial barrel. The breech reducer is schedule 80 to reduce to 4 inch then reduce again with a 3 inch female adapter with a short length of 3 inch pipe for the 3 inch piston. It is immensely heavy.

If I used sched 40 Iron pipe and duplicated it, I agree that it would have been very heavy. On the other hand my 2 inch cannon uses a very thin disposable freon tank for the chamber. The pressure rating for both is nearly the same, but the 3 gallon cannon is much lighter and not nearly as brittle.

The steel one was less expensive to build. I used mostly recycled materials and a free disposable tank.
Attachments
This metal tank cannon is much lighter.
This metal tank cannon is much lighter.
6 inch tank on the Dragon Cannon.  This is a 2.5 inch coaxial piston cannon.  It is heavy and difficult to hold.
6 inch tank on the Dragon Cannon. This is a 2.5 inch coaxial piston cannon. It is heavy and difficult to hold.
Dragon Tank.jpg (33.29 KiB) Viewed 2164 times
igiigi
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Sun Sep 27, 2009 3:19 pm

fantastic!!! but its pressure cannon right?

i would like to make this here, i´m pretty sure it would be works if i would find a way to make out of pipe a good a chamber.

Image Image

what u guy´s think, coult it work with only one ignitor (and a fan)?

i mean this metal fittings.
Image
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POLAND_SPUD
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Sun Sep 27, 2009 4:50 pm

uhmm... you can build combustions but metal parts work the best with pneumatics (or hybrids)

lol PUI
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igiigi
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Sun Sep 27, 2009 4:53 pm

"lol pui"????????????????????????????????????????????
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theBOOM
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Sun Sep 27, 2009 5:19 pm

So basically your looking for an over under combustion cannon... What size chambers do you think would fit your design?
If your going for a big combustion gun I wouldn't invest in steel or other metal parts beacause it will make the gun heavy, but if your going for a small compact gun 1 inch chamber or so.. then metal parts would be good and provide safety...
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MrCrowley
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Sun Sep 27, 2009 5:27 pm

Posting Under the Influence (he's drunk ;))

If you want to make a combustion out of metal parts, make a hybrid. If you want to fire big projectiles up to 2", a hybrid like this will be fine:
http://www.spudfiles.com/forums/the-m48 ... 17599.html

All you would have to do is probably make the chamber 2" in diameter, and use a 1" or 1.5" union. My chamber is only 1 1/4" with a 3/4" union, but if I used a 1" union, I could shoot golfballs about 800 feet per second.


If you want a really big hybrid, try asking your local fire department for oxygen tanks that they're going to chuck out. Most of the time they're still in pretty good condition, but for some reason wont pass safety or are too old.

On your curretn design above, the chamber is far too big. Halve it, and you'll be fine.
igiigi
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Sun Sep 27, 2009 5:39 pm

ah thank^^ its sunday why is he drunk??

i even won´t shoot golfballs i have good plumb from fishing^^
i wanna try to make that not heavy i think 10 kg = 20 pf. would be OK`!
and the barrel maybe 1.2 meter = ca. 4 feet long.
i´m not sure about the chamber, i have to looking for the right parts...
would be nice if i could find a chamber like 80 cm long and 6 cm radius!
and it must be work by propan injection, coase i have no way to feel the chamber with air! :/

and, oh jeah ur spudgun is very nice!! this is that what i´ll try to find tomorrow!!
thanks for link! i can´t belive that the small chamber has so much power!!!! oO

tomorrow i´ll check out our shop for metal pipe with fastening (i hope thats the right word) try to combine the elbo´s with the big pipe and check out the smaller pipes (as barrel)

if i´ll find some good stuff i´ll post here as soon as possible!
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POLAND_SPUD
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Mon Sep 28, 2009 12:22 am

@igiigi uhmmm sorry... that must have been confusing... and since I managed to correct all the spelling mistakes before posting I shouldn't have added that
:wink:

If you are mainly interested in combustion guns (not pneumatics) then you should build a hybrid... metal can handle higher pressures than PVC so you can get more power from a smaller metal hybrid than from a large basic PVC combustion...

of course you can also build powerful pneumatics with metal... they are generally easier to operate and simpler but they require a source of air, such as: compressor, fridge compressor or a track pump....
metal pipe with fastening
(uhmm, you mean 'gewinde' right??) :wink:

they are called 'threads'... threaded pipes/fittings, and so on
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jackssmirkingrevenge
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Mon Sep 28, 2009 1:25 am

igiigi wrote:ah thank^^ its sunday why is he drunk??
He's Polish, he doesn't need a special day or occasion :D
igiigi
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Mon Sep 28, 2009 5:23 am

jeah, polskas drink only on day´s wich ends with "day" ;)

"tak jest kurva" :) hope u understand!

ok, if build a Hybrid Cannon with small chamber, i put some gas in and I need put air in right? without air it doesn´t works (becoase the chamber is to small)?

hmm can I put air with a bicycle pump in? and gas with tank injection?
if jes, how should the ratio of air/gas be?
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