pilot valve?? shrader?

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
User avatar
FORE!!!!
Specialist 2
Specialist 2
Posts: 277
Joined: Mon Jul 06, 2009 8:14 am

ive recently completed making a mini chamber sealing piston valve,using chrome mini cistern cock,3/4 copper for the chamber and 1/2 copper for the pilot volume which is actuated by a shrader

problem being that when i press the shrader the air just flows out of the end and not on the berrel side

what could the problem be???

is the chamber too small? ,does it need higher pressure to actuate??
Attachments
the piston chamber housing
the piston chamber housing
the piston
the piston
pilot volume ,shrader and piston in the back housing
pilot volume ,shrader and piston in the back housing
just a basic prototype to see if things work
just a basic prototype to see if things work
mini cistern cock
mini cistern cock
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Need a bigger pilot valve, try a 1/4" ball valve or blowgun.

Edit: Assuming your piston is a good fit inside the piston housing.
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26219
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 581 times
Been thanked: 347 times

When the air just escapes through the pilot valve, the problem is almost always that the piston is not tight enough, ie you have bigger flow around the piston than through the pilot.

Also, pilot volume is a tad excessive...
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Unless you o-ring that piston air tight and connect the schrader directly to the back of the tee/piston housing, a schrader valve will give you poor performance as a pilot valve. Even if you did do the above, a blowgun will give you far better performance.
User avatar
FORE!!!!
Specialist 2
Specialist 2
Posts: 277
Joined: Mon Jul 06, 2009 8:14 am

thanks for the responses i think ill go with a blow gun and see how it goes..

another question tottaly unrelated, how do i make a signature if ive already brought signature privliges???
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

FORE!!!! wrote:thanks for the responses i think ill go with a blow gun and see how it goes..

another question tottaly unrelated, how do i make a signature if ive already brought signature privliges???
I'd recommend making sure your piston is a nice fit too, that'll improve performance.

Scroll down here:
http://www.spudfiles.com/forums/profile ... ofile.html
User avatar
Willdebeers
Specialist 2
Specialist 2
Posts: 214
Joined: Tue Feb 03, 2009 1:18 pm

I agree with MrC, This is the mistake I made with all of my first piston guns. Try to reduce the pilot volume, use a better (bigger?) pilot and Make sure the piston is quite near to airtight.

WilldeBeers
Image
User avatar
FORE!!!!
Specialist 2
Specialist 2
Posts: 277
Joined: Mon Jul 06, 2009 8:14 am

well i tryed using a blowgun to no avail, would an excessive pilot volume stop the piston from hitting regardless of performance issues???

if not i guess my piston may have a sealing problem,altho it does fit near perfect to the housing considering its the brass shart from the valve it self?
al-xg wrote:
I've used various things like cutting oil, silicone lubricant, even butter

jsr wrote:
This collection of containers on your bedside table must look very intimidating to any visiting young ladies

...but hey, lube shows you care;)
User avatar
jmadden91
Specialist 2
Specialist 2
Posts: 246
Joined: Thu May 07, 2009 6:03 pm
Location: Queensland, Australia

Mine wouldnt actuate with the schrader or the blow gun and it is (as stated above) because of the piston not being a perfect fit. As I liked my Piston, i simply added a 1/4" QEV as the pilot, then the blow gun to pilot that.

Your an Aussie too right? If so check out bellpro, they have 40% off at the moment and cheap shipping.

http://www.bellpro.net/xcart_program/home.php?cat=268

A 1/4" one comes down to $21.53. Pretty good
User avatar
FORE!!!!
Specialist 2
Specialist 2
Posts: 277
Joined: Mon Jul 06, 2009 8:14 am

yeah dude im aussie,but i hate ordering shit of the internet,it kills me with anticipation,,not to worry tho cause i finally got it to work

it took exaclty one turn of teflon tape to to get it right and even then its a tight fit,hooray the first (to my knowledge)mini cistern cock chamber sealing piston gun
al-xg wrote:
I've used various things like cutting oil, silicone lubricant, even butter

jsr wrote:
This collection of containers on your bedside table must look very intimidating to any visiting young ladies

...but hey, lube shows you care;)
User avatar
jmadden91
Specialist 2
Specialist 2
Posts: 246
Joined: Thu May 07, 2009 6:03 pm
Location: Queensland, Australia

Nice one mate, congratulations. Oh and bellpro offers next day delivery hahah I sound like their bloody salesman haha
User avatar
FORE!!!!
Specialist 2
Specialist 2
Posts: 277
Joined: Mon Jul 06, 2009 8:14 am

next day delivery thats nice to know,and those are very sexy qev's
maybe for my next project,,,well if u were there sales man u definatly had me :wink:
al-xg wrote:
I've used various things like cutting oil, silicone lubricant, even butter

jsr wrote:
This collection of containers on your bedside table must look very intimidating to any visiting young ladies

...but hey, lube shows you care;)
Post Reply

Create an account or sign in to join the discussion

You need to be a member in order to post a reply

Create an account

Not a member? register to join our community
Members can start their own topics & subscribe to topics
It’s free and only takes a minute

Register

Sign in

  • Similar Topics
    Replies
    Views
    Last post