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Posted: Tue May 22, 2012 11:10 am
by jackssmirkingrevenge
Pretty impressive stuff, hopefully projects like these will inspire more youngsters out there to save up for some proper machine tools :)

As to the pump, you should definitely make provision for cooling, and if you're going for direct drive a smaller diameter piston with a longer stroke is a good idea.

Posted: Tue May 22, 2012 11:36 am
by wyz2285
hopefully projects like these will inspire more youngsters out there to save up for some proper machine tools
Not that I don´t want to, but the only lathe I could find is 700 euro, a mill is not even sold around here. You can´t buy one online neither, first most of them do not do cross country shipping, even they do, the shipping price is equivalent as the own lathe :evil:

Posted: Wed May 23, 2012 2:57 am
by Desmo
That sucks man, have you looked on ebay for little c2 sieg lathes and such? Someone might import them. Maybe check out machinery auctions, Portugal had some pretty serious lathe makers in the day from what i read (at least 3 of them).

Anyway back to work. Spent an hour on this QDV prototype. If it works ill make a proper one :)

The piston was made from the last little scrap of delrin. It wasnt thick enough so i turned it sideways and made the piston that way :P The diameter of it is 14mm.

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The complete piston with the valve body. Its a 30mm steel axle. A bit overkill but its all i could dumpster dive today :P The holes bored out to 14.2mm roughly for the piston to sit in.

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The inlet hole is 10mm diameter. The inside has to get re-bored after its drilled to smooth it out again.

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A chunk of galvanised pipe with a 3/4" NPT thread on the end is used to join to the existing plumbing. So thats fish mouthed out with a grinder and welded up.

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The major bits. As you can tell i'm still learning how to TIG :P

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The valve mounts to the T piece with a 180psi cap thats drilled and tapped to fit. If it works ill weld a bung into the galvanised tube so it's much neater :P The pullrod is the last bit that has to be made. Hopefully thats done tommorow ready for a trial!

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Posted: Wed May 23, 2012 3:06 am
by MrCrowley
Damn, nice work! Looking forward to seeing it in action.

Posted: Wed May 23, 2012 4:05 am
by Crna Legija
fark mate you got all the tool, i wanna decked out shop like that one day.

Posted: Wed May 23, 2012 5:31 am
by pneumaticcannons
Not that I don´t want to, but the only lathe I could find is 700 euro, a mill is not even sold around here. You can´t buy one online neither, first most of them do not do cross country shipping, even they do, the shipping price is equivalent as the own lathe
welcome to my world. Except I can't even order small stuff. Unless it's really small and cheap. The cheapest lathe I found over here was $1000 and my dad just wasn't prepared to pay that amount :evil:

Sorry for partially Hi-jacking your thread desmo. I think the cannon's awesome. Don't think I've ever seen a QDV used as a pilot. Man, I'd kill to have a shop like yours.

Posted: Wed May 23, 2012 5:51 am
by Desmo
Cheers :) The tools the cannon was made with are certainly not out of the realms of most people. The lathe was $1200 aud and the welder was $400 off ebay. A little c2 lathe is only around $500 out this way and that would do most of you just fine. All was paid for by my first job making $10 an hour full time :P just gotta do a little bit saving is all. Its a worthy investment :wink: !

Check out if you have "hack spaces" around your areas too, they usually have mills, lathes, laser cutters etc for a $20-40 a month membership. Pretty good deal if you can find one!

Anyway the valve works now. Pulling the qdv open fires the gun instantly more or less vs 3 seconds of the previous setup. the qdv body has to be honed out properly because its extremely tight. I'm not sure if its opening itself or whether I'm just yanking it open manually at the moment. Then this puppy can get tested at a full 130psi :shock:

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Posted: Wed May 23, 2012 7:02 am
by Crna Legija
Did you buy one of the Chinese tig mig plasma cutter things? i was thinking about it but didn't wanna take the risk, that lots of cash on a apprentice wage.

Posted: Wed May 23, 2012 7:29 am
by Desmo
Yeah i have one of the ebay HF tig/plasma cutter deals. It goes just as good as the old lincoln invertec touch tig, maybe even better cause of the High frequency start in all honesty. The plasma cutter is wicked handy too. Definitely recommend one (the model i got at least haha, you never know with the chinese)

Posted: Wed May 23, 2012 8:06 am
by Crna Legija
what one did you get? you need argon for it right?

Posted: Wed May 23, 2012 8:28 am
by Desmo
Ill try find it on ebay tommorow for you. And yeah you do if you want to use the TIG. The bottle costs $300 outright or its about $90 rental per year then its $90 to fill roughly. A fill goes for about a year with the amount of stuff i do. , the plasma needs a compressor to go with it.

Posted: Wed May 23, 2012 9:32 am
by mattyzip77
Wow man I am speechless! Instead of taking the easy way out and getting a qev, a ball valve, or a sprinkler valve you made a smaller better pilot. You definatly got some skill and I cant wait to see more advanced cannons from you. I would add a 120 psi pop off valve to the chamber along with a pressure gauge. As far as a paint job I would do a light, flat camo green color. Did I mention I love your tools!!! :wav:

Posted: Wed May 23, 2012 9:57 am
by wyz2285
Check out if you have "hack spaces" around your areas too, they usually have mills, lathes, laser cutters etc for a $20-40 a month membership. Pretty good deal if you can find one!
Things doesn´t work like that around here, most of people only likes beer and football :roll:
But well... I have a family member that owns a big factory :) sadly in the other side of the globe :(
Nice work, with your tools, pvc is a wast of time, go hybrid or HPA.

Posted: Wed May 23, 2012 2:19 pm
by MrCrowley
wyz2285 wrote:But well... I have a family member that owns a big factory :) sadly in the other side of the globe :(
Parts of New Zealand are antipodal to Portugal so does that mean they own a big factory over here? :D

Posted: Wed May 23, 2012 2:38 pm
by jackssmirkingrevenge
wyz2285 wrote:Nice work, with your tools, pvc is a wast of time, go hybrid or HPA.
Seconded, you have the facilities to aspire far beyond a "standard" single shot muzzle loaded PVC spudgun ;)