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Floor pump question.

Unread postPosted: Thu Aug 16, 2007 3:25 am
Author: Mitchza89
Hey guys,

Just wondering, I'm looking to get a foot pump. All the ones I've seen are rated to 100psi, nothing higher.

Is there anyway I can turn it into a high pressure pump with some small modifications? When I say high pressure, I mean about 200psi.

Thanks alot,

Mitch.

Unread postPosted: Thu Aug 16, 2007 4:36 am
Author: Marco321
Shock pumps go up to 300psi so look in a bike shop maybe.

Unread postPosted: Thu Aug 16, 2007 4:37 am
Author: Mitchza89
Yeah I know that. I just need something thats got a large volume so I can get my marble gun up to 200psi. With a shock pump, it would take so long. Thanks alot.

Unread postPosted: Thu Aug 16, 2007 5:02 am
Author: shud_b_rite
I have a foot pump that is rated to 125 psi, a good quality one too. But after about six months of regular use it wont even make it to 80psi, it seams like there is too much dead space between the check valve and the piston. Maybe you could modify the have less dead space.

Unread postPosted: Thu Aug 16, 2007 5:06 am
Author: Mitchza89
Ah thats a bummer. I might just make my own high pressure pump out of copper and get a check valve myself.

Cheers.

Unread postPosted: Thu Aug 16, 2007 6:50 am
Author: Hotwired
I have a 160psi floor pump that I push over the gauge to get ~240psi

I know Chaos has a floor pump which reads to 230psi.

Unread postPosted: Thu Aug 16, 2007 4:19 pm
Author: Hawkeye
My instructions for making a high pressure copper pump are on here somewhere. You can easily make one of plumbing fittings and small check valve attached to your gun is also very simple to make.
You can go over 300 psi easily with a pump with a bore smaller than a regular floor pump and much faster pressure build up than a shock pump.

Unread postPosted: Thu Aug 16, 2007 6:18 pm
Author: Brian the brain
WARNING!!!
I made a stirrup pump that I got up to 65 bar ( yes that is almost 1000 psi)....
It worked extremely well ....

untill the( store bought!!) check valve gave out..essentially turning that into a burst disk, resulting in the push rod becoming a projectile.
THis would have been cool if my head would not have been in the way.
THe pump handle hit me in the mouth so hard it ripped the gums off my teeth, and nearly split my lip, the inside of wich looked like minced meat.My two front teeth were moved back a little, and were wobbly.Another tooth chipped..where the nut wich held the handle hit my face, I have a small scar where mustache used to be.My cheek and upper lip swelled up really bad and somehow I had a black eye, although that wasn't hit.
I remember I yelled out in shock, though I wasn't consiously doing so...very strange.
Oh well, that was two weeks ago and now I feel fine...Just my gums look scarred-up, that's all..
I replaced the check valve by a home made one, and have decided 40 bar is plenty.....
( what was I thinking???)

Be sure you use a ( or better yet , build!!) strong enough check valve..

Unread postPosted: Thu Aug 16, 2007 6:38 pm
Author: Fnord
untill the( store bought!!) check valve gave out..


I would have walked into the store the next day, looked at the guy and said "your check-valve failed".


Was it really rated that high? or did you just think "I wonder how high I can go..."
Anyway, that really must have sucked :(
I wonder where the piston would have landed had your head not been in the way...

Unread postPosted: Thu Aug 16, 2007 6:58 pm
Author: Brian the brain
The check valve was not rated to 65 bar...no...
I was indeed just pumping away, to see how high it could go...

THe last time I checked, I was at 65 bar, so It could have bursted way higher, since the only volume i had to fill was the bottom of the pump.

It went incredibly fast! At first I thought it had just exploded.If I would have shot a marble at that pressure it would have just been held back by the sound barrier.The force behind it was incredible!

I didn't even "feel" I was hit...I just found myself screaming, not knowing what had happened..
My face was numb for two days, THEN it started to hurt!!

Anyway, I have now built a safe version, wich I'll use to effortlessly pump up my cannon to 25 bar or so.( wich it is rated to)

Unread postPosted: Thu Aug 16, 2007 8:04 pm
Author: frankrede
Whoa Brian, scary story!
I wonder if using a few check valves in line with each other might work incase one fails?

Unread postPosted: Thu Aug 16, 2007 9:45 pm
Author: Hotwired
Nooo.... I don't think so frankrede....

What I think would happen is the first (unrated for 65bar) check valve would go (closest to the pump) and the shock would help the next one until inevitably you have a flying pump handle syndrome on your hands.

Just one check valve would do if you felt like finding the money for one rated to 65bar :wink:

Brian, that sounds incredibly painful, I always have that kind of image in my head when I'm squashing over-the-gauge pressure out of my floor pump and you've just coloured it in for me :shock:

Unread postPosted: Fri Aug 17, 2007 12:12 am
Author: f.c
you can get decent high pressure pumps that you use you're hands to manipulate for less that $60. there not to expensive you just have to look around more.