jor2daje wrote:I dont think going down in calibre would be a very good idea, because the surface area and force go down exponentially, so you would need very high mixes, and a pretty finicky detent/seal. I would find a easily and cheaply available material, maybe 1/2" copper pipe, and base cartridges on that. Although ofcourse as you get bigger cartridges you need bigger "syringes" or suitable replacement.
Fair points, but the appeal of a smaller calibre is that I get to keep the cartridges "firearm sized", indeed at the moment there's a 7.62 NATO cartridge on my desk which I had drilled out as a coaxial body that's looking quite tempting
Perhaps you could devise a sort of 2 stage pump for pressurizing premixed fuel, because you wouldnt want to store it at high mixes in large volumes.
The beauty of the syringe method is that you're only storing the mix in the cartridge - while it's in the syringe it's only a 1x mix and only gets pressurised when you fill the cartridge, I see no current need for a pre-pressurised chamber.
SpudFarm wrote:My tip is still to have a "large" chamber that is premixed at 10x.
After you connect it to the chamber you pump oil in the bottom of the premixed chamber to displace the mix into the gun. Then just drain the oil to drop the pressure.
I fear something like that would be liable to blow up, it seems to make more sense to me to have something like the alternative filler presented in
this diagram, where a pneumatic piston compresses a 1x mix while filling the cartridge - slowly of course, we don't want a single use diesel engine
JDP12 wrote:Help me out here to make sure I'm understanding-- the basic idea is that you insert a bb into the cartridge, then insert the syringe from the front, push mix in, and that forces the bb back into the seal? Not sure why I'm not comprehending this all the way but SPG's diagram just wasn't working itself out in my head.
Pretty much, once you pull out the syringe the pressurised mix tries to flow out but this forces the BB into the seal and plugs the hole.
POLAND[size=42]ialwaysknoweverythinginretrospect[/size]SPUD wrote:damn I was expecting it.
Typical
Now you can either use higher mixes or build a new one with an adjustable detent.
Forget the latter option, as to the first I need to modify a 50 (actually 60
) mL syringe as the nozzle doesn't match the seal.
well wouldn't it be a better idea to use higher mixes ?? lol who said you can not use 6X or more ??
Keeping the cartridge volume small and upping the mix would certainly also be an option, let's imagine you have 1mL cartridge volume 0.5mL of dead space and a 60mL syringe. You could technically reach a 40x mix or so, though the force needed to push down the syringe would be around 590 lbs
Say with a 5mL syringe, this works out to about 12x mix (but with 5 times the volume) and a more reasonable 170 or so lbs on the syringe...
something like this:
