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pressure loss

Posted: Tue Sep 23, 2008 2:09 pm
by WEEMAN
Im currently working on a rifle sized spudgun with a nice big expansion chamber(1 1/2 foot to 2 foot) and a shoretr barrel(like 3 foot) but the only problem i can think of is loss of pressure....number 3.....
i want it to be like a shotty type gun but idk what to do do improve on the(REALLY) rough design.....


1-expansion chamber
2-4 to 2 inck bell reducer
3-2 90 degree elbows,interlocking kind
4-male adaptor for different sized barrels

so am i gonna lose pressure or not?

Posted: Tue Sep 23, 2008 3:02 pm
by Demon
You wont, because your propellant will fill the elbows too, so dont care about that.

Try making an pneumatic instead, more power, less sise :wink:

Posted: Tue Sep 23, 2008 3:11 pm
by SpudFarm
so i did draw the diagram i said on msn and since you left i can post here.

don't care to say that i did not write the right names on the fittings because i know that

Posted: Wed Sep 24, 2008 8:32 am
by WEEMAN
lol thanks!! ill try to make that :P

Posted: Wed Sep 24, 2008 8:51 am
by starman
You won't "lose pressure" but you should use a standard coupler and reducer bushing instead of that bell reducer. Also mount your BBQ ignitor and associated spark gap hardware with as few holes in the chamber as possible and through 2 layers of PVC (through a coupler and chamber) when you do.

This is a pretty standard configuration of an over and under combustion.
Also if you are shooting spuds, 1.5" is a better diameter and 2".

Posted: Thu Sep 25, 2008 11:10 am
by psycix
starman, its pneumatic