For the pressure you are talking about, there are several issues. 1 Air compresses. Sort of a no brainer, but hang on. 2 All piston pumps have some "dead" space between the piston and valves 3 Displacement at high pressure is high force. In regards to 1 and 2, if the output is 10X the input in absol...

May want to look at ones in my sig. Most expensive machine shop tool was purchased brand new for under $100. My ABS cannon and Mouse Musket didn't even use any power tools.

bravootome wrote: no, i will use GPL gas and as a valve i'll use one from my car ( it runs on GPL) ..

Are you dyslexic? GPL is a software license. LPG is a fuel.

You may want to revisit the 30 foot barrel design for a couple of reasons. 1 Flow drag. -- This increases with length 2 Acceleration distance -- How far does the projectile travel before it goes no faster 3 Depletion of source pressure -- Loss of chamber pressure combined with flow resistance may en...

You might be OK with the port piston O ring in the smaller diameters if you don't use a floating o ring.

My initial tests of a 2 inch floating o ring in that configuration resulted in loss of the ring on shots above ~60 PSI. Non floating ring designs tend to get stuck and fail to fire reliabily.

Vapor pressure will be a cold weather issue with a pump resulting in condensation, or low vapor pressure on delivery. Only a timed flow meter or low pressure venturi has no elevated vapor pressure in cold weather. A cold weather option is switching to higher vapor pressure fuel such as CNG. When wor...

The "Pump" is not needed at all. Your fuel and air are both supplied under pressure. The fuel and air can be "Metered" using either metering by flow meter and timed dose cycle, or with a pair of volumetric related traditional metering tubes, fuel and air can be metered in 2 metering volumes at the s...

The design works well but manufacturing the projectiles takes lots of effort for single use. An alternate design shoots a similar designed valve core to the rear for re-use, while permitting much larger selection of projectiles. Look in my sig for examples.

My only new braging rights are a new job, office and internet connection. DSL reports are showing ~650 Meg Down and 550 up.

They have zero traction. Whan not used on a superconducting surface, the use insane amounts of power. Google levating induction cooking for examples of the power used. It is in the multi KW range. The battery charge is good for a few minutes at most.

I was expecting it to not ignite as I calibrated them just off the gauge on my air compressor(hope to get them calibrated more accurately).

When working at elevated pressure, the combustability range expands.

mark.f wrote:Tech's still a buzzkill.

Sorry Less of a buzzkill than having an intentional release investigated. Freon is expensive. Sell it.

Word of advice, in many locations it is an offence to deliberately vent a small sealed system for disposal. In the US, look up the material online for the CFC certification. Fines are several thousand dollars. Some shops will recover and recycle the refrigerant for free because it is expensive. Disc...

Speaking of Nerf, I enjoyed the software game Nerf Blast Arena. It was built from Unreal Tournament. Many UT maps were converted, some with interesting glitches. Due to the larger player sizes, some passages became too small for some charactors. Like UT, it came with a map editor and there was an ac...

Interests change. Remember bell bottom jeans, mood rings, flower power? A thread on those would also be of limited interest. The only common interest here that I see on a consistant basis, is

MORE POWER
FASTER ROF

Nerf had it's run on making MORE POWER, but that has run it's course.