QEV/Pop off hybrid?

[boom_o_matic_2.0]

I'm not entirely sure but I don't think any one has tried it but do you think a QEV/Pop off valve would work in firing a hybrid cannon? I would try it for myself but I"m kinda afraid of hybrids. lol. if you dont know what I'm talkin about just ask.

[Ragnarok]

Yes, it's been done. Or rather, something similar - what you suggest is not exactly the most practical way of going about it.

It's ore or less known as the "piston hybrid":
http://www.spudfiles.com/forums/fnords- ... t9589.html

[boom_o_matic_2.0]

Yea I looked at that one earlier and thought it was kind of what I was thinking of. I was just brainstorming cause I was considering building a hybrid eventually. I wanna weigh all my options before I do it cause I dont wanna blow myself up with one. lol

[mark.f]

The first ever hybrid cannon built in the spudding community used a sprinkler valve with a pop-off attached as a pilot, so yes, it will most probably work. Is it the most safe or practical way? Probably not.

[MountainousDew]

Sure, it may not be the most practical way, but it would ensure that you are getting about the same strength with every shot... But it would probably be a better gun if you make the piston, instead of using a QEV.

Then again, I know basically nothing about Hybrids, so...

[Moonbogg]

If you use a resistance based piston, won't there be post ignition chamber pressure that will need to be vented after every shot?

[boom_o_matic_2.0]

yea you'd probably have to vent it but atleast you wouldnt have to put a burst disk in it every time. thats the only thing I didnt like and I wanted one with a piston or maybe a QEV. if you had an adjustable pop off you could adjust the power of each shot.

[daccel]

Regarding venting, and the possibility of avoiding it, anyone have data on the relationship between pre and post ignition pressure, and opening pressure of the piston?

Just did a quick test fwiw, and I'm getting pre 75 psi, opening 80 psi, post 45 psi. Subsequent shots repressurized but not vented average the same.

There would be a power loss, though, I remember discussing that before.

[Moonbogg]

Regarding venting, and the possibility of avoiding it, anyone have data on the relationship between pre and post ignition pressure, and opening pressure of the piston?

Just did a quick test fwiw, and I'm getting pre 75 psi, opening 80 psi, post 45 psi. Subsequent shots repressurized but not vented average the same.

There would be a power loss, though, I remember discussing that before.

If you used O2 instead of air, you could compensate for that post ignition pressure by adding more o2. That 45psi of post pressure is useless gas, so add pure o2 to it to make it more like air. 16oz O2 tanks can be bought from mc master for $10.00 and it would last a long time i'm sure.
This is the problem with spring powered valves. You can try something different like a valve held by magnets. When the cannon fires the valve would blow off the magnets and the valve could ride along guide rails. Then just have a shaft attached and pull the disc back and it snaps into place against the magnets again. No post pressure at all.
Better yet, use electromagnets. This way, you can leave the magnets turned on for hybrid use, and then have a button attached that shuts it off when pressed. This way it can also be a true pneumatic cannon as well. 2 for one baby.

[boom_o_matic_2.0]

this is completely off topic but moonbogg you use alot of duke nukem quotes. lol. it makes me look up to you...alot.

[Moonbogg]

this is completely off topic but moonbogg you use alot of duke nukem quotes. lol. it makes me look up to you...alot.

I used them in the videos, but did I use them in my last post?

[boom_o_matic_2.0]

I could of swore "2 for 1 baby" was a nukem quote. hmm.

[Moonbogg]

I could of swore "2 for 1 baby" was a nukem quote. hmm.

Oh lol. I seriously didn't know. I guess I have some genuine Nukem in me.

[boom_o_matic_2.0]

dont worry. that IS something to brag about.