Schrader threads to small?

Miniature guns are novelty custom, unique, and sometime downright crude! Common construction materials often include pill bottles or pens. Show us your work!
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Sun Apr 25, 2010 2:43 pm

I'm in the process of building the mini cannon for the mini challenge contest. It's actually a mini hybrid, the spark and schrader valve are epoxied to a male adapter, the problem I'm having is that the pump I have dosen't open the check valve on the schrader. I'm wondering if a different pump might solve this problem or will I have to redo the whole thing? I believe the problem is being caused by the lack of "area" for the schrader attachment to cling on?

Here are some pics to illustrate what I'm talking about. Thanks.
Attachments
Picture 3.JPG
Picture 3.JPG (33.45 KiB) Viewed 5057 times
Picture 2.JPG
Picture 2.JPG (31.58 KiB) Viewed 5057 times
Picture 1.JPG
Picture 1.JPG (23.64 KiB) Viewed 5057 times
Last edited by theBOOM on Sun Apr 25, 2010 10:01 pm, edited 1 time in total.
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Sun Apr 25, 2010 2:43 pm

It's probably the pump.
OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Sun Apr 25, 2010 2:45 pm

Bah, I hope it is, if not I'll go to my grandmas and see if it works with a compressor.
User avatar
qwerty
Corporal 2
Corporal 2
Posts: 678
Joined: Sun Apr 12, 2009 2:16 am

Sun Apr 25, 2010 2:45 pm

You could try glueing a small peice of wood or something like that to the pin that pushes the schrader down.
I visit occasionally to make unrelated posts.
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Sun Apr 25, 2010 2:46 pm

I could do that but I would probably make a mess beacause of the small area I have to work with.
User avatar
clemsonguy1125
Sergeant 5
Sergeant 5
Posts: 1485
Joined: Tue Jul 21, 2009 4:00 pm
Location: East Coast

Sun Apr 25, 2010 2:48 pm

Some bike pumps dont fit car tire valves, but most bells do, try taking it to a gas station and hooking it the compreser, if its not the pump this should loosin it up enough for it to work in the pump
That is all.
User avatar
Mr.Sandman
Corporal 3
Corporal 3
Posts: 762
Joined: Fri Mar 28, 2008 9:10 am
Contact:

Donating Members

Sun Apr 25, 2010 2:53 pm

Wow boom that looks really nice. Good job with the epoxy. If it isnt opening the schrader check valve then just keep pumping at it will let in the air. If not then there is something wrong with the schrader.
Yeah, it's that important.
User avatar
Gun Freak
Lieutenant 5
Lieutenant 5
Posts: 4971
Joined: Mon Jan 25, 2010 4:38 pm
Location: Florida
Been thanked: 7 times

Sun Apr 25, 2010 2:54 pm

I think the opening pressure of a schrader is 70 psi without pushing the button so yeah, just keep pumping.
OG Anti-Hybrid
One man's trash is a true Spudder's treasure!
Golf Ball Cannon "Superna"M16 BBMGPengunHammer Valve Airsoft SniperHigh Pressure .22 Coax
Holy Shat!
User avatar
clemsonguy1125
Sergeant 5
Sergeant 5
Posts: 1485
Joined: Tue Jul 21, 2009 4:00 pm
Location: East Coast

Sun Apr 25, 2010 3:02 pm

I think vhman's schrader check valve on his hp pump cracked at 75 psi
That is all.
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Sun Apr 25, 2010 3:03 pm

Okok thanks guys I'll try it again tonight, im going out to eat with my family... Thanks sandman :P
User avatar
saefroch
Staff Sergeant 2
Staff Sergeant 2
Posts: 1679
Joined: Mon Jun 08, 2009 8:47 am
Location: U.S.A.- See Map

Sun Apr 25, 2010 6:33 pm

The schrader valve will not open at all if the pump is not connected, the pin must be pushed down- at least I know this happens up to about 120 psi- and a great way to extend the pin if that's what needs to be done- put a drop of solder on the top of the pin... I've never tried it, but it should work on a small-scale apparatus like this if you've got a steady hand.
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Sun Apr 25, 2010 9:48 pm

Oh, I know that the pin has to be moved down for it to allow air in, the problem is that the hose dosen't reach the pin beacause of the lack of area for it to "cling" on.

What I'm going to try and do is move the "pin" up a bit with a schrader tool I bought some months ago, does anyone know if this will reduce its pressure rating or make it malfunction for some reason??
User avatar
Mr.Sandman
Corporal 3
Corporal 3
Posts: 762
Joined: Fri Mar 28, 2008 9:10 am
Contact:

Donating Members

Sun Apr 25, 2010 10:15 pm

theBOOM wrote:Oh, I know that the pin has to be moved down for it to allow air in, the problem is that the hose dosen't reach the pin beacause of the lack of area for it to "cling" on.

What I'm going to try and do is move the "pin" up a bit with a schrader tool I bought some months ago, does anyone know if this will reduce its pressure rating or make it malfunction for some reason??
First of all what pump are you using? If it threads onto the schrader then you are fine. But if its a quick release then you have a problem. Try oiling the valve stem and if that doesnt work then just use the valve tool.
Yeah, it's that important.
User avatar
theBOOM
Specialist 3
Specialist 3
Posts: 374
Joined: Wed Jun 03, 2009 10:49 pm
Location: San Antonio, TX

Sun Apr 25, 2010 10:35 pm

It's the stupid quick release type, and it's kind of old, so I think that might be the problem also the "rod" that presses on the schrader pin is too far back for it to reach the schrader. I actually lost the valve tool, I'll try and find it tonight before going to sleep.

The compressor in my house has some weird fitting on it, so tommorow I'll go out and buy an adapter so I can use it on the schrader valve.
User avatar
Mr.Sandman
Corporal 3
Corporal 3
Posts: 762
Joined: Fri Mar 28, 2008 9:10 am
Contact:

Donating Members

Sun Apr 25, 2010 11:11 pm

theBOOM wrote:It's the stupid quick release type, and it's kind of old, so I think that might be the problem also the "rod" that presses on the schrader pin is too far back for it to reach the schrader. I actually lost the valve tool, I'll try and find it tonight before going to sleep.

The compressor in my house has some weird fitting on it, so tommorow I'll go out and buy an adapter so I can use it on the schrader valve.
What you could do is take some thick walled metal tubing and tap it with some 7mm threads and you will have a quick functional adapter. If not, then loo around at hardware stores in the bins of random parts and see if you can fund something threaded that will fit the schrader.
Yeah, it's that important.
Post Reply