Home made PVC air gun (6mm plastic BB)

[kumaran]

Hi guys,

I don't know much about air gun. I got this interest to own air gun few weeks ago. After search through internet and found out that factory made air gun is illegal in Malaysia. I have contacted few under ground suppliers but they sell too expensive (due to illegal item like drugs).

This leaves me with no other option rather that build/make the air gun on my own (hobby). After search through internet, I grab some information and started to make my own air gun using pvc fittings. After two weeks, I taught I've made it but the bb just rolling out of barrel after open the controlled air from cannister.

I realized that I need to let the pressurized air out fast enough (aka brute force) to make huge impact to push bb out of barrel. Again search through internet and watched few videos ON YouTube and found out hammer valve mechanism is the way to go. I'm still finding best way on how to make hammer valve trigger for this design.

PVC fittings: 3/4 inch
Barrel : 1/4 inch
BB : 6mm

Please guide me with links on how to make good hammer valve trigger system using 3/4 inch PVC fittings.

[jackssmirkingrevenge]

So many chambers note that those drinks bottles are not good for high pressures.

This is as good a how-to as you'll find for a home made hammer valve with limited resources: http://www.spudfiles.com/forums/hammer- ... 23202.html

A hammer valve is not the only option for powerful pneumatic semi-auto though, you might also want to consider a quick exhaust valve and slide valve setup, especially if you're limited to low pressures: http://www.spudfiles.com/forums/semi-au ... 23626.html

[kumaran]

Hi Jack,

Thanks for your feed back, I appreciate it. I taught the metal bottle can with stand higher pressure. Its made of aluminium. which bottle do you suggest to change? There bottles just to cater for more storage. Ball valve to allow some pressurised air and not all for single shot. Another valve at trigger but just not quick enough to release. The two links you gave me is very useful. Qev and slide valve will do the trick right?

[jakethebeast]

I say change all the bottles. I bet you have seen some French people using them, but the aluminium is quite thin on those bottles. So if you want to play it safe, i would suggest changing them to stronger bottles. Small propane bottles are quite good, but they need modification to use.

Other than that, it looks very good, nice build!

[kumaran]

Hi Jake,

I say change all the bottles. I bet you have seen some French people using them, but the aluminium is quite thin on those bottles. So if you want to play it safe, i would suggest changing them to stronger bottles. Small propane bottles are quite good, but they need modification to use.

Other than that, it looks very good, nice build!

Thanks for your advice, I appreciate it. I definitely will change the bottles once the concept works.

I checked QEV but that requires 2 air inlet. Why? I understand how hammer valve system works and still thinking how to make using PVC pipe and fittings. Are there any references for those made air gun using PVC hammer valve system? Please share. TQ.

[jackssmirkingrevenge]

some information on how the slide valve works:

http://www.spudfiles.com/forums/viewtop ... tml#345975

you will need to have two chambers, a main pressure chamber feeding into the slide valve, and a smaller firing chamber attached to the QEV.