Hybrid QDV Design

[saefroch]

I've been thinking about how one could make a hybrid QDV... and I think this design will work, at least for low mixes. The spring will hamper the valve opening speed somewhat, but I don't think it will be much of an issue if the spring is for low mixes only, as it will only have to hold back a few pounds of force before firing, when the pressure should increase enough that it slides back cleanly.



No, as I attempted to show in the picture, the two o-rings and the pipes they seal against are NOT of the same diameter.

Good idea with an air spring... I could pressurize the area behind the piston precisely to work for different mixes... that could allow me to access higher mixes.

[c11man]

not a QDV its a piston hybrid with a oring sea on the front instead of a seat.

otherwise it would work if you got the correct math with the spring pressure and area differences

[saefroch]

Okay, so if this is just a normal piston hybrid, please explain to me how it is not a QDV hybrid.

[Hotwired]

He's right y'know.

It's a barrel sealing piston.

But instead of dropping the pilot pressure you're raising the chamber pressure to move the piston back.

[c11man]

QDV has both seals the same size, you have different sizes and a spring

[saefroch]

Ahhhhh so that's the definition of a QDV... it's totally balanced just by the pressure. I have another idea then though... I'll draw it up and you can tell me it's just another barrel-sealing piston hybrid.

[c11man]

most likely

[Hotwired]

Make it the way you want it then worry about definitions of what's inside after

[saefroch]

Yeah... all the possible designs I'm thinking of would require some precision machining... making a telescoping piston would be tough for somebody like me.

[Technician1002]

I have built that front seal for an air cannon once. You will need a new front o ring for each shot. They blow out of the groove and out the barrel in that configuration.

[ramses]

Does anyone know where my post went? You recognized the content, and no-one else posted that idea...

And the original post didn't' show an edit. Is this a new/double thread?

[jackssmirkingrevenge]

He's right y'know.

[saefroch]

Ramses, your original post is on the other thread. This is a new one, created for discussing the design.

I was thinking about the issue with the front o-ring blowing off... I might be able to attach the o-ring to inside of the gun itself, not the piston.

Yeeeeaaaahhhhhh.... even if it's not a hybrid QDV I think I'm going to go for this as the design for my eventual first hybrid.