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Homemade stirrup pump ( high pressure)

Posted: Mon Mar 12, 2007 3:45 pm
by Brian the brain
Stirrup pumps are handpumps, that can put out pressures up to 300 bar.
This is possible because they have a very small diameter, so not much force is applied on the crosssection

Since I showed my "overkill"cannon I got a few private messages about how I plan to reach 30 bar.
I'll share my plans with you.
I plan to take 1 meter of 12 mm copper pipe (because of the smooth inside) and sleeve it with a 15 mm steel pipe for safety reasons.

On the bottom I'll put a metal 1" Tee, the middle port to the side.The 12mm pipe will be extended inwards like in a Tee-valve gun to create a sealing surface
The bottom of the Tee will be plugged, and I'll insert a rubber from the bottom and a spring to create a one way valve.The rubber seals the 12 mm pipe. This also creates a flat bottom for the pump-section, so I'm not left with any dead space.

The side port will have a bleed valve and a quick disconnect to attach it to the gun.

The pump rod will have a tapered rubber ( like the ones shown in my 100% seal-no O-rings thread) and a few washers to center /guide the rod and prevent the rubber from bending back too far and leaking.
The rubber will nead lubing, prefferably by something that doesn't burn ( diesel effect!!!)

I will not start this build for some time because I'm in the middle of moving.

Posted: Mon Mar 12, 2007 4:26 pm
by )DEMON(
Nice design :) I thought of something similar, just using brass check valves. Then you wouldn't need a lubed up piston.

What do you propose using for the lubricant? Something silicon based?

I guess it will be easyer for you to pump this up to 30bar because of your huge bouncer muscles.

Posted: Mon Mar 12, 2007 4:31 pm
by Hotwired
Sounds fine.

You will need that bleed valve. I have problems detaching my pump head at 200psi without ripping the rubber seal on the valve threads so I need to crack it to one side carefully to try and drain the pressure before I can remove it.

At 400psi I'd definitely be concerned about removing a pressurised pump connection and a very loud WHISSSSH! every time you detach it without being able to bleed it isn't good for the nerves :wink:


Ps. Muscles don't really come into pumping a track pump, you just drop your weight onto it if its getting hard to push down :)

Posted: Mon Mar 12, 2007 5:36 pm
by Brian the brain
Yep..the stirrup pump design makes excessive musle unnessessary..

Posted: Tue Mar 13, 2007 3:36 pm
by chaos
Thank you very much Brian you have made my life easier with this design, i still have one question tho... with you bought pump you got 23bar?if that is wrong please correct me, so i ask is did you modify your pump in any way? eg: sleeved a smaller tube into the remaining one for a smaller surface area.

peace
chaos

Posted: Tue Mar 13, 2007 3:47 pm
by Brian the brain
The pump I bought is supposed o get 16 bar, but I really insist....I get it up to 23 bar.

The stirrup pump ( if it's well built) will go much higher..

Posted: Tue Mar 13, 2007 9:40 pm
by Hawkeye
I made a stirrup pump which threads onto the back of a small sawed off style copper gun. I use the gun as the handle and place the conventional handle section of the pump on the ground and stand on that to pump it up.
The interior mechanism of the pump is simply an enlarged shock pump design. The one way valve is in the design of the piston head. I would estimate that it could be taken to 300 psi with little difficulty. It was remarkably easy to assemble and worked flawlessly on the first try. I did spend a lot of time locating all the parts so that nothing had to be modified to a significant degree. In fact the only thing I had to do was file the inner lip out of a copper reducer so the pump rod(half inch copper pipe) could slide freely, drill a hole in a copper end cap so the piston could be bolted together and lathed a nut down to a circular shape so that the piston could reach right to the bottom of the pump stroke..
I think this design is much simpler than what you have posted and you can just leave it attached. It makes a great rest :)

Posted: Wed Mar 14, 2007 4:35 am
by chaos
Hawkeye wrote:I made a stirrup pump which threads onto the back of a small sawed off style copper gun. I use the gun as the handle and place the conventional handle section of the pump on the ground and stand on that to pump it up.
The interior mechanism of the pump is simply an enlarged shock pump design. The one way valve is in the design of the piston head. I would estimate that it could be taken to 300 psi with little difficulty. It was remarkably easy to assemble and worked flawlessly on the first try. I did spend a lot of time locating all the parts so that nothing had to be modified to a significant degree. In fact the only thing I had to do was file the inner lip out of a copper reducer so the pump rod(half inch copper pipe) could slide freely, drill a hole in a copper end cap so the piston could be bolted together and lathed a nut down to a circular shape so that the piston could reach right to the bottom of the pump stroke..
I think this design is much simpler than what you have posted and you can just leave it attached. It makes a great rest :)
awesome mate, can you please post some pics. i have a good hand pump (260psi rated) but if im feeling a bit "extreme" one day i might want to go that little "bit" higher.

peace
chaos

Posted: Wed Mar 14, 2007 6:15 am
by spudthug
dude brian if u get internet wherer u r going u better post damage picks with this freaking pump....wow think of the destruction....

Posted: Wed Mar 14, 2007 6:41 am
by VH_man
You could fill your own paintball tanks with these..... but with air.... so theres no friggin CO2 liquid to mess your gun up. LPNitro!!!!! I might have to make myself one of these........ i wont have to pay for CO2 anymore!

Posted: Wed Mar 14, 2007 10:52 am
by Hotwired
Are you nuts?

You'd need to spend the best part of an hour pumping up a paintball tank to co2 pressure (1200psi)

These pumps do high pressure but they only do very small volumes.

Posted: Wed Mar 14, 2007 12:01 pm
by Hawkeye
It was done in the past and you can still buy a hand pump for reaching 3000 psi. I would imagine there are those who would devote that much effort if they had a pump and chamber capable of taking the pressure. Not to mention a valve system to meter out that hard earned air It would be interesting knowing how much time is actually spent pumping during the average shooting session for a 150-200psi gun.
Some of the time spent pumping to high pressure is devoted to pauses in order for the pump to cool. I know my pump gets very hot after about 25 strokes so I tend to limit it at that point.
I have posted a parts list for my pump on another thread and I will try to get a diagram and pictures up for those interested. Might have to do a build along as well. The pump really just looks like a copper tube with a copper t for a handle telescoping into a larger copper tube.

Posted: Wed Mar 14, 2007 12:09 pm
by Hotwired
Those that buy an air rifle pump for 4000psi+ are only charging a small chamber and they get multiple shots from it.

Posted: Wed Mar 14, 2007 3:03 pm
by VH_man
I dont care about the huge time it would take, id hook it up to a motor or something. i just wanted to save money....... where do you get an air rifle pump?

Posted: Wed Mar 14, 2007 3:58 pm
by Brian the brain
Pyramid-air..do a search
It could be spelled piramyd...I don't remember..

Oh..I have finished my competition gun.
It is not what you will expect...