Page 2 of 3

Posted: Tue Nov 13, 2007 4:11 pm
by Brian the brain
I was being sarcastic guys...

Posted: Tue Nov 13, 2007 4:22 pm
by DYI
Sarcasm doesn't always translate well in text. The 900 psi bit did seem kind of strange though.

Posted: Tue Nov 13, 2007 4:38 pm
by Brian the brain
the actual story is true, including the injuries.I used a 15 mm pipe with a 12 mm inside diameter.Pushing down with all my weight, I could easily compress it.The volume however was tiny.
When it blew I didn't even realise it, I just heard myself screaming, like it was somebody else..
An dthen I saw the blood..
I have been a bouncer for 8 years, and in all this time nobody has ever succesfully punched me in the face.No that I've quit I nearly klill myself...how ironic


I was just being sarcastic about the blueprint part.
.
That thing was too frickin dangerous, it could have killed me, you think I'll give you blueprints??

Posted: Tue Nov 13, 2007 4:48 pm
by DYI
Oh, sorry, I didn't realise what you were being sarcastic about. That must have been painful. What exactly was it that failed?

Posted: Tue Nov 13, 2007 4:51 pm
by ALIHISGREAT
Brian the brain wrote:the actual story is true, including the injuries.I used a 15 mm pipe with a 12 mm inside diameter.Pushing down with all my weight, I could easily compress it.The volume however was tiny.
When it blew I didn't even realise it, I just heard myself screaming, like it was somebody else..
An dthen I saw the blood..
I have been a bouncer for 8 years, and in all this time nobody has ever succesfully punched me in the face.No that I've quit I nearly klill myself...how ironic


I was just being sarcastic about the blueprint part.
.
That thing was too frickin dangerous, it could have killed me, you think I'll give you blueprints??
sounds like i t hurt... alot.

and i would like plans because i want to make a high pressure pump but only like 300psi so i would use a bigger diameter pipe etc. but i haven't got a clue about the rest :lol:

Posted: Tue Nov 13, 2007 5:11 pm
by iknowmy3tables
well sounds like the rod wasn't locked in, looks like that one must have for this, also a bumper usually a spring to cushion the top and bottom part of the strokes thats a feature on most real higher pressure pumps
and definatly don't be cheap on your check valves, I belive your check valves used free motion balls in them right, well make sure they're spring loaded check valves

I had an interesting idea about a telescoping pump locking diffrent cylinders to adjust volume but with Brian's story I wouldn't make one for pressures high

hey don't forget that you can buy bike shock pumps that can go to 500psi

Posted: Wed Nov 14, 2007 12:04 am
by Brian the brain
The checkvalve blew..if that helps...so definately make your own, sure to withstand any kind of force...

Posted: Wed Nov 14, 2007 12:27 am
by nz_cannons
You can buy hand pumps for pumping up PCP air rifle cylinders.
They can go up to 4000psi some of them.
Might need to make some sort of custom fitting for connecting to a gun though.

Posted: Wed Nov 14, 2007 6:57 am
by Hawkeye
Follow any of the instructions on here!

The key to preventing accidents is to have a small spindle check valve with an o-ring that can't be accidentally displaced into the chamber while pumping. You just want to unseat it a little and allow air to hiss past it.

The pump rod doesn't have to actually pop out of the gun totally to hurt you if the check fails. It only needs to rapidly extend.

Posted: Wed Nov 14, 2007 8:03 pm
by iknowmy3tables
what the heck Hawkeye your comment was posted five minutes into the future wow is my clock messed up
edit: oh omg I forgot the fact that its am lol

brian can't you get a extreme presure check valve for fairly cheap, what were your checks rated to
mcmaster part: 7775K12

Posted: Thu Nov 15, 2007 1:14 pm
by Brian the brain
Here is the basic idea.Make sure no part of the checkvalve can get blown out, because indeed, it was the rapid extension of the handle that got me.

THe idea is to use a long piece of threaded rod.Two nuts make up the piston head.You will need to "lathe"them using a bolt ( to hold them on to)
a file and a drill.
Grind them down untill they are round and snugly fit into the pipe ( I used 15 mm OD copper pipe.ID would be about 12 mm.
The bottom nut needs a leak hole or channel, to vent on the up stroke.I simply sawed a cut into it.
The top nut just needs to be flat and a nice smooth snug fit.You teflon tape the rod in the place where the top nut goes.It needs to form an airtight surface.
You place an O-ring in between the nuts.THe O-ring needs to be big enough to seal against the inside of the pipe.It should also remain free of the threaded rod.I filed the section of rod smaller in diameter, wich worked better.That enables air to pass through the center of the O-ring.
Pictures should explain what my broken English can't

Posted: Thu Nov 15, 2007 5:59 pm
by ALIHISGREAT
what diameter pipe do you think i could use if i was pumping to 300psi max?

Posted: Thu Nov 15, 2007 7:36 pm
by Hawkeye
3/4 inch copper and about a 2 foot long pump body. Please read the threads on making these pumps.

Posted: Thu Jan 03, 2008 9:04 am
by Mitchza89
Sorry for kicking up an old thread but what gun did you use this pump for BTB? It's volume isn't too big at all so for your sawn-off I'm thinking.

Posted: Sun Mar 30, 2008 8:21 am
by Antonio
Brian the brain wrote:I've made one and nearly knocked my teeth out when it broke.
THe handle hit me in the face, two teeth were loosened, one got chipped.The inside of my upper lip was cut up pretty bad.
The gums were torn off my front teeth.They still look weird, kinda "dawn of the dead" like..
I might have broken part of my upper jaw, but if I did, It healed on it"s own.It felt wiggly for some time.
My nose still "pops"when I touch the tip of it, it didn't before.
I did how.ever reach over 900 psi.You want blueprints??
Sounds deadly, but I would like some blueprints:)

edit: Ah k I see ehm above:)