pump help!!!

[mouz]

need...... high capacity..........pump........soon..........ahhhhhhh.    my arm is sick of using the shock pump. i want to have my shock pump screw on to it and use that as the pressure gauge. it needs to attach to a schrader. where should i attach the shock pump? can i use the schrader as a one way valve and just not have a pin holding it open so that the air will just open it and then it will close at the end of the stroke? if so what pressure does a schrader open at?

[FighterAce]

Dont relay on that shock pump for pressure readings... it failed me miserably and it could fail you too... just get a decent pressure gauge.
You could give a machinist to machine a replica of the one way valve on the shock pump.. it works pretty well. If you want to use a schrader as a one way valve, remove the spring from it because they open at around 5-7 bar.

You're not going to reach 400 psi with a 3/4 copper pipe as pump cylinder. You gotta use the one with 13mm ID and thats not a lot more volume. 3 times the volume of your shock pump max. But depends on your height rly.... I've seen you dont have 2m so...  gonna be bout 3 times more volume.

[mouz]

well i have about 20 feet of 3/4 inch, and i need to buy the 1/2 inch (13 mm.). and i also want a big chamber. why couldn't i get 400 psi with 3/4 inch copper?

[boar]

for a pump with a 3/4 bore you would need to put 176.625 lbs of force on it with a 1/2 bore you would only need 78.5 lbs the 3/4 is not undoable but the 1/2 is more manageable

Boar

[FighterAce]

for a pump with a 3/4 bore you would need to put 176.625 lbs of force on it with a 1/2 bore you would only need 78.5 lbs the 3/4 is not undoable but the 1/2 is more manageable
Boar

For 176.625ibs and 22mm ID you get 351.37 psi. To reach 400 psi you need 202.26ibs. To make things clear I used 0.50265 sq inch for the area. You've been calculating it for 350 psi Boar, I think mouz wants to reach 400 

Now, by jumping down on the pump, the average human can double or even triple their weight effecting on the pump but I think 200 ibs is just too much for someone who doesnt have 200 ibs... Go with the 13mm ID and you'll need 113 ibs to reach 400 psi and again... with a little jumping  600 psi with 170 ibs.

No offense but thats WAY more manageable if you're not a fatty

[boar]

i calculasted for 3/4" bore a area of 0.4415625 sq inches

Boar

[mouz]

OH.............. kaBonk.... that was my head. i get it. thank you for saving me from me. yes, if i tried to push down 200 pounds i would go up, saying as i only weigh 106.....   but the 13mm. is WAY bigger than my shock pump, now, does that figure you go there change if my pump gets longer?  cause i'm planing for at least two feet.  

[boar]

longer is good just increases the volume and the length of the stroke

Boar

[mouz]

ok.

[mouz]

could i use a presta as a one way valve?  because if i could i could just have a tube with a plunger and one end that threads on to a presta. if not i will make a cross bow. 

[mouz]

oh and i REALLY need a pump now because my shock pump is gone.

[boar]

ive got mine working now i gave up on finding that washer and just made a delrin plunger for the valve it works pretty well but doesnt seal good till 200 psi im gonna make another one a little bit diffrent shape also gonna make a larger pump git it up to as much pressure as i can then switch to the smaller one

Boar

[FighterAce]

oh and i REALLY need a pump now because my shock pump is gone.

Me too 

The machinist managed to make me a copy of the plastic part on the pump head from Al and a 3/8 MPT thread on the bottom instead of the original one. Now I just need to find the hose and a decent pressure gauge.

I find that one way valve on the shock pump very good because its so easy to take apart and if you go with metal parts, nothing can fail you on it... besides the O ring...
If you have a lathe or know a machinist that could help.. give him the one way valve parts of your shock pump and tell him to make a copy out of aluminum or brass... if you dont know the machinist then better go for aluminum because its easier to work with and there for cheaper 

I used a schrader valve as a one way valve until my shocky broke... it worked pretty good up to 400 psi. But if you dont remove the spring, you're gonna go through those cores pretty quick. I dunno about presta.. I never used them

[mouz]

i was going to machine myself a new body for my pump out of aluminum, and get a new pressure gauge and make it have a longer stroke, but still use the schrader connection and one way(which are metal), but my shock pump isn't dead its gone. i accidentally left it on the bumper of a car, and now a don't even have the pieces from it     a presta valve works a lot like a schrader valve, but instead of a spring closing it the air pressure from inside closes it.

[FighterAce]

Thats nice! I see some fine calculations and a very customized cylinder ID commin your way