30 replies to this topic

[InfernalDesigns]

it seems that the main complaint about safety is the use of a homemade pressure tank. What about if they used a commercial tank meant to take deal with compressed air? AndyMark.com has them for $14 http://www.andymark....t-p/am-2649.htm they are by no means the best or cheapest supplier, but they are easy to deal with. Toss an over pressure relief valve and gauge into the system and you will end up with a relatively safe set up for not much more than building everything out of PVC pipe.

[Langley]

The other safety concern is that the gun will be pumped up to ludicrous pressures allowing velocities way above what we would ordinarily allow. An over-pressure release valve or something similar makes a blaster safe from rupturing and also sets a ceiling for performance.

[InfernalDesigns]

Luckily OPRV's are cheap and readily available Mcmaster PN 9889K15 would seem to be a good candidate at $9.19 and a 50 psi blow off pressure. This is conjunction with a throttle valve than can be locked could mean a nice safe blaster with adjustable performance.

[Azrael0987]

If I ever build another one I may just use that air tank. It seems like it would work well. I havent touched either of them in a while, but since then have modded two titans with stock pumps and stock over pressure valves. The air cannons dont fire as hard as a singled titan tank, if that gives any reference. They have a much slower air release. I have yet to hook up a pressure guage to the outputs and test the pressure when the valve is opened. But due to the very large volume I expect they dont operate at a very high pressure.

[Nerf Gra]

But due to the very large volume I expect they dont operate at a very high pressure.

This has more to do with the surface area of the pump head than the size of the tank.


Smaller pump head, bigger pressure, less volume.

The fact that you're using a larger pump and a ball valve "trigger" probably cause them to not shoot as hard.

[Azrael0987]

I agree with the pump size meaning a lower pressure. But if I pumped the same amount of air from one pump stroke with the current pump into a tank half the size it would be roughly double the pressure. That's what I was trying to get at. Since it is much larger than any other air tank (excluding super soakers or hydro cannons) I dont think i'd be wrong in saying it would be less pressure. I'll try to get some real numbers up for pressure in the current setup soon.