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My first Pneumatic w/ pictures!

Unread postPosted: Sun Oct 21, 2007 1:34 am
Author: tsb
Hello, this is my first pneumatic gun.

I have recently (yesterday) started the contstruction of the gun, its primary ammo is marbles but moose mighty beens have been tried and work fairly well. I am going to paint the PVC dark blue tonight and let it sit over night and tomorow...

At 80 psi i shot through a piece of plywood (im not sure how thick) and im 99% sure that it can withstand 250 psi. I'll try and get some dmg shots soon. :twisted:


50mm Pressure rated PVC Air tank; 44cm long
20mm poly barrel; 92cm long
20mm poly barrel; 60cm long
25mm Richdell modded sprinkler valve
Pilot; Blow gun handle
Inter-changable Barrels






Fixed leak in the valve.

Up-coming changes/additions:
Breech Loading System
Finish paint job

Smaller Air Tank


Unread postPosted: Sun Oct 21, 2007 3:12 am
Author: rna_duelers
When does it start leaking?When filled up with an air compressor?Or all the time?Does it leak from around the seal on the PVC or out of the actual valve threads?Just a few questions.

Painting the chamber black :thumbleft: .But use a very fine sand paper before you paint it and leave it to dry for atleast 4 days or so.Also buy a paint that is meant to stick to plastics,from a paintstore.I got one that is meant for Car bumpers etc and it works great much better then anything from Bunnings etc.

Fun shooting.

Unread postPosted: Sun Oct 21, 2007 3:21 am
Author: tsb
It leaks when i take the aircompressor off the valve, then it leaks out the end of it where the air compressor attached...


Unread postPosted: Sun Oct 21, 2007 3:31 am
Author: rna_duelers
Ohh rightio,well go get a new valve center.From any auto store nearly they are a spring and a seal that screws into the valve.If that fails then cut that one out and get a new one and wack it in.

They look like this.(the top one with the spring)


Unread postPosted: Sun Oct 21, 2007 3:47 am
Author: tsb
Ok thanks, But the only problem is that this one doesnt look like a normal one...

So im not sure if its made to do that sort of work.. Any help?

Oh, and btw do you like my first pneumatic? It still goes really well, like if i shoot it i can never see the bullet...


Unread postPosted: Sun Oct 21, 2007 5:17 am
Author: jrrdw
Make sure your valve core is screwed in snugly, alot of time assembly workers are in a hurry and don't get them in snugly. Moose mity beans??? Do they come in 1" diameter? And where do you get them? More importently, what are they? The name even sounds like fun! Fushion paint is used for plastic. Krylon seems to be the most popular brand that i know of, mainly primary colors i've seen in stores.

I voted YES, i like it!

Unread postPosted: Sun Oct 21, 2007 5:29 am
Author: Marco321
Nice gun, you can't beat simplicity

Unread postPosted: Sun Oct 21, 2007 5:40 am
Author: experament-u2
nice and simple good and clean good work chap
like jrrdw said for the leak get a pair of tweezers or something of the sort and tighten the valve core.

Unread postPosted: Sun Oct 21, 2007 5:53 am
Author: tsb
Ok thanks guys for the positive comments, moose mighty beens are just plastic shells with a ball bearing inside them so when u roll them down something they act partially like a slinky.. They do NOT come in 1" diameters, they are smaller then the actual barrel but it does not seem to effect how they work. But there expensive just to get like 10 or so..
I dont recomend them and i dont know if there available in the USA, i only know of AUS... And whats the valve core? Picture please.


Unread postPosted: Sun Oct 21, 2007 6:12 am
Author: jackssmirkingrevenge
lovely for a first effort, at over 100 psi the power should be impressive. You should have made it over-under though if you can get your hand on pressure rated elbow fittings - that way you can have a longer barrel without making it unweildy.

Unread postPosted: Sun Oct 21, 2007 8:42 am
Author: HaiThar
I would epoxy that shrader in, if I were you. It looks like one of those pop-in ones without any threads. That SHOULD take care of your leak problem...

Also, be sure to get the JB weld kind. It has a red and black container. The kind that is in a syringe doesnt seem to bond to plastics too well...

Unread postPosted: Sun Oct 21, 2007 11:31 am
Author: origin unknown
The tire valve on my 1st cannon is like that. To make it stop leaking, pull it forward while you fill your gun. When it gets to a higher pressure, it will stick to the wall and make a seal.

Unread postPosted: Sun Oct 21, 2007 3:05 pm
Author: tsb
Thanks guys, ill try try that origin when i get a chance.


PS: Wich one of you rated that you hated it? I am not getting up you for it because there are probably some major design faults or something, but please tell me what to do better next time, dont just say vote you hate it, tell me why.

Unread postPosted: Sun Oct 21, 2007 6:33 pm
Author: jrrdw
The valve core is the little part inside the shrader/tire valve. It screws in and out. rna_duelers posted 2 types of valve cores. If you are useing a long shrader/tire valve use the 1 he pointed to. If you have a shorter 1, use the short core valve. Sometimes they leak from brand new, if thats the case just use a new core. You can rob a core out of just about any kind of shrader, bike tube, old car tire, buy new off auto parts store shelf.

Unread postPosted: Sun Oct 21, 2007 11:58 pm
Author: mtronic
YAY you got it working, nice work mate :) That chamber is huuuuge, pump that bad boy to 150psi and let it rip at something.....then post a pic of what u just nailed :twisted:

you have used the same valve as me, pull it forward a bit so the bevel locks it into place.
Failing that pull it hard and then get some good strong epoxy/jb weld in under it a tad, let it go and then put some around the neck at the base of the valve. Let it dry over night.
The only thing I would change is next time stick the tyre valve in the end cap coz they are thicker, and you can seal them from the inside before you put the chamber together.

Good work man, looking forward to some sick dmg shots :D