help me design a pulse valve for a pneumag

[luke]

The second problem is that the o-rings aren't getting a good enough seal against the Plexiglas

Did you calculate your stretch, compression, groove and bore diameters?

[rawbutter]

Did you calculate your stretch, compression, groove and bore diameters?

Definitely not. I'm not sure I know what half those terms mean.

I know the o-rings are supposed to be 0.25 OD, and I bored out the trigger rod shaft with a drill bit that was 0.245. Then I rolled up some 600 grit sandpaper into a tube to smooth out the inside (mostly to remove the burrs left over when I drilled the air passages). I don't know anything else about the o-rings I'm using, though. They're basically the smallest o-rings I could find at my local hardware store.

[luke]

Did you calculate your stretch, compression, groove and bore diameters?

Definitely not. I'm not sure I know what half those terms mean.

They're the parameters that an o-ring needs to perform properly. Change one parameter and the others have to be adjusted. You have to stretch, compress and give an oring some place to go after its deformed in order for it to function properly.