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Posted: Fri Sep 10, 2010 7:18 pm
by POLAND_SPUD
Well, I prefer the polish version of that joke. Everything there is pretty much the same, but instead of drunk Irish twins we have a drunk father and son...

So when I saw your posts I thought "OMG saefroch is Gippetto's son!!" :wink:

@saefroch
It is a cool idea but probably a more traditional design would be better.
For a chamber volume of 5.7 cubic inches
hmm then what about a HPA tank and a fridge compressor feed with pressurised air? :wink:

Posted: Sat Sep 11, 2010 6:44 am
by saefroch
Well how far can one normally push a fridgy? Or a good-sized HPA tank?

Posted: Sat Sep 11, 2010 6:53 am
by POLAND_SPUD
Let me quote al-xg as as he has done it, not me
(lol I hope he doesn't mind it)
It's hard to work out exactly what happens, but the max pressure achieved with that second compressor on it's own was ~44bar (on a small volume, maybe it just took longer on large volumes, ie paitnball tank 0.6/1.1L, but that seemed to make it struggle more just to reach 40bar).
Putting just 2bar input pressure raised the max pressure to ~70bar and also increases the fill speed.
However, that 70bar max pressure is when the compressor cuts out (not stalling), overheat protection/overcurrent protection ? I have a separate component from the relay, most relay diagrams show a winding protection switch.
This happens with small and large volumes alike. (hot compressor and cold compressor alike)

Increasing the pressure speeds up compression, (at first the motor seems to run faster) but the compressor seems to struggle if more pressure is added. Extra pressure on the inlet does not seem to help max pressure.
70 bar = ~1015 psi

Posted: Sat Sep 11, 2010 7:17 am
by Crna Legija
i have taken my fridgy to 800psi :twisted: , i think i could take it to a 1000psi but i don't want to break it. i might be getting a 7kw air condition compressor soon :D.

Posted: Sat Sep 11, 2010 7:18 am
by saefroch
Hmph. Guess I'll be looking into a fridgy as well... success is doubtful though. And has anyone ever gotten one battery-powered?

Posted: Sat Sep 11, 2010 7:19 am
by inonickname
saefroch wrote:Hmph. Guess I'll be looking into a fridgy as well... success is doubtful though. And has anyone ever gotten one battery-powered?
Not to my immediate knowledge, and the draw will be pretty goddamn high.

Posted: Sat Sep 11, 2010 7:42 am
by Crna Legija
you could use a power inverter and battery to power it, it would heavy and probably not last long, not to mention expensive

Posted: Sat Sep 11, 2010 7:47 am
by saefroch
That's what I thought. And that's why I would prefer a human-powered device.

Posted: Sat Sep 11, 2010 7:54 am
by Crna Legija
how much do PCP pumps go for? they get a couple thousand psi.


edit: they are expensive and have crap all flow

Posted: Sat Sep 11, 2010 8:07 am
by inonickname
-_- wrote:how much do PCP pumps go for? they get a couple thousand psi.
Around $200 US will yield you a decent 3 stage pump. They aren't suitable for large chambers, as they need to cool down after 10 minutes of operation. They are good for topping up PCP tanks or filling pony bottles.

You need to keep your chamber fairly small.

Also, before you order one contact customs and check the legality and if required get a permit. They seized my airsoft bb's because the seller was too lazy to mark them as slingshot ammo.

Posted: Sat Sep 11, 2010 9:05 am
by Crna Legija
i don't want one i sugested to saefroch, but my brothers got his gun license so i could most probably get it if i wanted one.

sad about you bbs, i got a 300mw green laz0r from ebay passed them cunts. At lest we have a PM now did you vote for the ranga this time?
if the election was two days later i would have been able to vote :lol: