auto-piston prototype

[Sticky_Tape]

Why didn't you make somthing like this it would be alot simpler and you could hook up your blow forward brech if you make another one

[keep_it_real]

a blow forward breech connected to the piston is generally more reliable. The opening time (if there is one) in the valve above would be slower because it's refilling while the pop off is open.

[Sticky_Tape]

a blow forward breech connected to the piston is generally more reliable. The opening time (if there is one) in the valve above would be slower because it's refilling while the pop off is open.

The pop off would be open so the air would exit out the pop off and when the pressure gets low enough the pop off closes and there is also restricted flow. And JSR s attempt on the blow forward bolt was to get full auto but couldn't because the flow wasn't pulsed and this little device provides pulsed air and I think Jsr is also after slower rof that would sort of sound like pop... pop... pop... pop... pop... pop... pop... pop... pop... pop... as you see there wouldnt be too much ammo wasted un like a cloud that is like hiss bruuuuuuuuuup!!!
EDIT: I was thinking that there could also be a regulator to control the pressure into the pilot chamber and a valve after it the regulator would be to somewhat control the rate of fire that's probably be somthing that jsr fancys.

[Sticky_Tape]

I was thinking that there could also be a regulator to control the pressure into the pilot chamber and a valve after it the regulator would be to somewhat control the rate of fire that's probably be somthing that jsr fancys. sorry forgot not to dubble post I tried to delette this and edit the other post but this post wouldn't delette.

[jackssmirkingrevenge]

Just a heads up, I'm giving this concept another go, this time with an adjustable pop-off valve as a pilot. I found a female threaded section that fits the valve perfect, so it will be removable and allow me to adjust piston spring tension. The vertical brass tube will be connected to an air chamber (which in turn will be connected to an air supply) while the horizontal tube will feed into an as yet undecided reloading mechanism.

You also might recognise the breech and piston as being recycled from the failed marker project - to avoid the same fate as the latter, all will be comprehensively encased in epoxy

[ALIHISGREAT]

i hope it works, you deserve some sucess from your many efforts

[jackssmirkingrevenge]

i hope it works, you deserve some sucess from your many efforts

I'm quite confident it will, the pop-off pilot formula is a proven one, indeed my first prototype functioned in this manner. The advantage here is that not only do I have fine control over the pop-off pressure, but also I can make sure there's enough tension in the piston spring for the chamber to fill without exhausting through the "barrel" while also allowing the piston move when the pop-off actuates.

I'm hoping for a much more powerful blast of air that will give me the confidence to turn it into a properly completed mag-fed auto launcher, and a more relibable firing cycle than I got using just the pop-off.

[Brian the brain]

It's all starting to look familiar now..THe set up that is..not the actual parts.

This sleak design looks to be quite effective at high pressures.
THe pop-off is quite big compared to the main valve, wich should give you very good results...


Now finish the damn design buddy!
It looks to be a winner this time!

[jackssmirkingrevenge]

It's all starting to look familiar now..THe set up that is..not the actual parts.

Nothing original, I know, but I had to give it a go.

The pop-off is quite big compared to the main valve, wich should give you very good results...

This is one of the reasons why I'm confident, 1/4" pop-off pilot when I usually get great results with just a schrader testing in a couple of hours, fingers crossed

I gave it a quick go and it sounded extremely angry and promising, but started to leak so there'll be a bit longer to wait for full test results I'm afraid.

[jackssmirkingrevenge]

Update - no luck tweak as I might I just couldn't get the valve to pop. It either leaks slowly or seals completely. I'm guessing it's because a valve this size needs a bit of volume to force it open and in this case, the tiny pilot volume worked against me.

Bach to the drawing board, bigger piston this time.

[Brian the brain]

Darn-it!

Seems there is just no way of by-passing the hunger for gas of a full auto rig.

So maybe an autococker design ís the best way...

But that is not what we're after...

[jackssmirkingrevenge]

Seems there is just no way of by-passing the hunger for gas of a full auto rig.

We could always try a more efficient pop-off,take a look