Diaphragm Piston

[frocksie]

I was thinking today about pistons and diaphragms, when I started thinking about combining the two, due to the popular belief that diaphragms open faster and pistons give better airflow. I came up with this design, with no idea how well it would work.

I'm wondering if this would give any appreciable advantage over a regular piston or diaphragm.

This drawing isn't to scale, although it may be close. Certain features may need tweaking, such as the thickness of the diaphragm, or the diameter of the diaphragm.

LEGEND

Seafoam Blue--4" Threaded Plug
Brown--Bumper
Yellow--Piston plug
Blue--3" endcap piston
Black--Diaphragm
Olive--Screws
Green--2" Sch. 80
Aqua--1.5" Sch. 21
Tan--Golf Ball

[elitesniper]

the only problem is that you need a washer behind that diaphram or it will blow tear or rip just like a burst disk, but looks like it will just perform the same.

[Hubb]

From looking, it appears as if the piston has to open, which will release the diaphragm, correct? If so, I don't see any advantages, just an extra step.

If that's not how it works, please explain it.

[ALIHISGREAT]

From looking, it appears as if the piston has to open, which will release the diaphragm, correct? If so, I don't see any advantages, just an extra step.

If that's not how it works, please explain it.

its a moving diaphgram, the piston has a hole in the the diaphgram can move back and as it is mounted on a piston when the piston moves back it gives extra flow.

why not just make a QEV style diaphgram piston?

[frocksie]

Hubb,
the way I saw it, when the pilot valve is opened, the diaphram will open, and then the piston.

[ALIHISGREAT]

Another point is that how much more power will you gain if any? because the extra pilot volume will make the diaphgram open slower.

[frocksie]

ALIHISGREAT,
The increase in pilot volume would be relatively small, less than 6 cubic inches. The only way to figure this out may be to make it.

[bigbob12345]

I would assume that the power increase wouldnt even be noticeable it just isnt worth all that extra work.And I think normal pistons open fast enough this is not needed.

[clide]

Unless you are using a very light projectile (much lighter than a golf ball) then you probably wouldn't even be able to measure the difference with a chrony.

[Hubb]

Hubb,
the way I saw it, when the pilot valve is opened, the diaphram will open, and then the piston.

I got ya. In order for the diaphragm to open first, the equalization hole in the piston will have to be large, which will basically make it useless. I see no advantage in the design. It's good, though, that the cogs are turning.