SpudFiles

Good idea of selling a pre-made piston valve to anyone who can't make their own. Personally i don't like buying pre-made stuff even if i can't get something to work the first time. Just getting to build it is half the fun for me.
PS: check out my name and make sure your parts aren't DWV!!!

Because of the parts avalible and the design it has to have 1.5" porting. But what about MrCrowley's piston valve? That was 50mm- 40mm.

MKII is here!

The valve turned out better than expected, and I should have damage shots as soon as I can get a good chamber and barrel.

wow, that looks pretty good. I can see you spent time actually finding the right parts.

Get some test shots and make a few more prototypes, and then we'll see how good it really is.

yeah, the first one was just to see if the concept works. I'm having a bit of a problem though, The piston only can slide back 1/4". the porting is 1.5", so is this enough? Is it to restricting?

Well for a piston that large I might recommend a little bit more. 0.5-0.75 inches would be more than enough. 0.25 inch will be fine though.

If you do find it overly restricting, then you know what to do for the next prototype

Jogumpie wrote:yeah, the first one was just to see if the concept works. I'm having a bit of a problem though, The piston only can slide back 1/4". the porting is 1.5", so is this enough? Is it to restricting?

It is restricting. The minimum is about 1/4 the diameter of the port. In the 1.5 port a .375 is minimum. Can you adjust the length of the piston?

To prevent a double restriction of the piston opening and valve seat, I aim for the opening to be about 1/2 the seat diameter so the seat is the only real restriction.

Those measurement only apply to valves where the air is able to enter from all sides. Ones built inside a T where 3/4 of the sides of the piston are not a port, the distance needs to be larger so the area is not restricted to the valve seat. It is why I like coaxial designs. The less distance a piston has to move out of the way, the faster it is all the way open.

Well I modified the piston and it now opens 3/4".

By the way, I have never dealed with 16bar pipe before, its really thick.

Wow, sounds really good. Very nice and neat too! How are you arranging the pilot setup?

Its basically the same as Sean's setup. (QEV, Blowgun, quick disconnect etc...)

I still havent decided the final price though.


EDIT: Btw biopyro, is your QDV done yet?

oh yeah, here are some moar pics:

Piston open:


Piston closed:


Parts needed to build it:


Enjoy!

Very nice and neat!

Not quite. I'm finding the piston verrry tight still. Just need to make the vent ports reeeally smooth. What size were the o-rings on it btw? I cut one of them a little, and I think it needs replacing. I've bought the shock pump for it, should be here by next week.

13mm. They were quite strechy though. Try smaller ones. It should work better.

EDIT: MKII went to a photoshoot today! Here are some pics. These will be used in the promotional.





Enjoy!

Oops! Ignore this.

Damage pics will be a crucial seller! Where are they? Looks really nice though, I can't wait to see how it performs!

Finally got some damage pics! I'll upload them in a sec. Just need to find that cord...

By the way, this thing is way more powerful than I thought it would be, decimating 3/4" particle board.