Page 2 of 2
Posted: Mon Nov 23, 2009 7:28 pm
by c11man
i dont understand the "revised" version i dont see a chamber
and all the c:b test you are using are not too much good for a pneumatic, those test are for a cumbustion, and those test gave the most efficency. for a pneumatic basicly the bigger chamber the better. but as you get above about 2:1 ratio the extra power is often not noticalbe
Posted: Mon Nov 23, 2009 7:56 pm
by julktyl
No worries, Techie.
c11man, thanks for pointing out that the tests were done with a combustion cannon, i didn't notice that.
Thanks also for the chamber info. As for the revised version, the chamber was the "stock" of the gun since i thought the chamber had to be that small.
I've redesigned... once again... because I was making it way more complex than it had to be. I threw out the idea of making a piston valve, started from scratch, and this is what I came up with. Thanks to c11man's info on the bigger the chamber, the better for pneumatics, I'll have to make a bigger chamber.
Let me know what you think, and remember, that isn't the final chamber.
Posted: Mon Nov 23, 2009 8:01 pm
by jackssmirkingrevenge
That's more like it, get yourself a shock pump and at 400 psi it should be pretty impressive for its size.
Posted: Mon Nov 23, 2009 8:15 pm
by POLAND_SPUD
Burnt Latke's Chamber to Barrel Ratio Tests
yeah c11man is right, it's for combustions
also he is right that you might have used a larger chamber... your first chamber was too large but this one could be slightly larger... you should be fine with a 3" length of 1/2" pipe... esspecially if you want to use a longer barrel
of course it's completely up to you and the source of air that you have
I have to admit that in the past I was a big fan of c:b ratios smaller than 1:1... normally they were lower than 0.5:1
but now that I have a fridge compressor with a tank I don't mind using ratios close to 2:1 especially on a small bore launchers that don't use much air anyway
Posted: Mon Nov 23, 2009 8:22 pm
by julktyl
As a matter of fact, I'm looking at shock pumps as we speak.
Trying to find one for decent price, will be pretty much just like the beto shock pump you bought. 400 psi here I come!
Posted: Mon Nov 23, 2009 8:24 pm
by jackssmirkingrevenge
julktyl wrote:Trying to find one for decent price, will be pretty much just like the beto shock pump you bought. 400 psi here I come!
Excellent, shouldn't be hard to find a good one for not much $$$. You might want to move to a longer barrel in future too, it will make a considerable difference in power.
Posted: Mon Nov 23, 2009 8:35 pm
by julktyl
POLAND_SPUD, I'll see if i can find something along those lines for a chamber.
jsr, brake line is very easy to customize lengths. Sometime in the future I might do some tests similar to Burnt Latke's to figure out the optimal c:b ratio for airsoft BBs.
Posted: Mon Nov 23, 2009 8:43 pm
by jackssmirkingrevenge
Or you could
download GGDT
Posted: Mon Nov 23, 2009 8:51 pm
by julktyl
Ha so that's what that is. I've seen it mentioned here before but never bothered to look it up. Thanks a lot
Posted: Tue Nov 24, 2009 5:57 pm
by Techie
I've redesigned... once again... because I was making it way more complex than it had to be. I threw out the idea of making a piston valve, started from scratch, and this is what I came up with. Thanks to c11man's info on the bigger the chamber, the better for pneumatics, I'll have to make a bigger chamber.
that's EXACTLY what i was thinking it could be made. due to my stupid lack of parts(pretty sad as its just a few connectors) i couldn't build it.