Page 2 of 2

Re: Pump design.

Posted: Mon Jan 07, 2008 1:42 pm
by Necrosis
ALIHISGREAT wrote:well this is my pump design which i need some advice on, firstly is the basic design satisfactory? i will be using 22mm copper as the body and 15mm as the shaft? will casting an epoxy piston be easy if i put the o-rings in the mold?

thanks Alasdair

and now for the hassle of insterting an image :roll:
If you hook up a compressor to the inlet valve you can pump up to 7 times as fast. (depending on the output pressure of the compressor)

:wink:

Re: Pump design.

Posted: Mon Jan 07, 2008 2:03 pm
by ALIHISGREAT
Necrosis wrote:
ALIHISGREAT wrote:well this is my pump design which i need some advice on, firstly is the basic design satisfactory? i will be using 22mm copper as the body and 15mm as the shaft? will casting an epoxy piston be easy if i put the o-rings in the mold?

thanks Alasdair

and now for the hassle of insterting an image :roll:
If you hook up a compressor to the inlet valve you can pump up to 7 times as fast. (depending on the output pressure of the compressor)

:wink:
that would be nice but i don't have a compressor as i don't have high volume cannons, high-ish pressure is more my style 8) so i haven't got one yet.

Posted: Mon Jan 07, 2008 2:18 pm
by Necrosis
also make the shaft a tight fit inside of the other pipe, this reduces wiggling, and thus makes it more rigid, allowing you to pump better.

:P

Posted: Fri Jan 11, 2008 3:33 pm
by ALIHISGREAT
ok time for an update i think :)

i will use a 1/2" tee at the bottom with 1/4" check valves (maybe 3/8" or 1/2") i will still make the piston with epoxy and o-rings (how tight does the fit need to be? and will two be alright?) and use a plastic shaft. the body will be 22mm and i will protect it with some 28mm copper or maybe some 3/4" pvc if i have enough left. i will use a 0-41 bar guage and the tube will be this http://www.airlines-pneumatics.co.uk/we ... de=S080043 which says 20bar but the tube has a 3:1 safety factor and i will use quick connects rated to 35bar and i think thats about it.

p.s. all this stuff is gonna cost a bomb (including piston cannon stuff) i estimate ~ £140 :(

Posted: Fri Jan 11, 2008 6:29 pm
by Necrosis
That much for a simple pump?

Or do you mean for the pump and a piston cannon?

Posted: Fri Jan 11, 2008 7:34 pm
by MaxuS
It's for the pump and piston cannon, it isn't simple.
I would just buy a stirrup pump, 250bar.

Posted: Sat Jan 12, 2008 2:34 am
by ALIHISGREAT
Necrosis wrote:That much for a simple pump?

Or do you mean for the pump and a piston cannon?

p.s. all this stuff is gonna cost a bomb (including piston cannon stuff) i estimate ~ £140

Posted: Sat Jan 12, 2008 5:39 am
by seudo411
Could it be possible to use an old gas lift as the pump body, I mean what else could one ask for, a solid body straight and centered shaft, check this out, :
http://www.alibaba.com/catalog/10439520 ... rings.html
by simply attaching a 2check valve system to it... you can make a pretty decent pump.

Posted: Sat Jan 12, 2008 8:05 am
by ALIHISGREAT
seudo411 wrote:Could it be possible to use an old gas lift as the pump body, I mean what else could one ask for, a solid body straight and centered shaft, check this out, :
http://www.alibaba.com/catalog/10439520 ... rings.html
by simply attaching a 2check valve system to it... you can make a pretty decent pump.
i'm not sure, i have never seen those before :?

Posted: Sat Jan 12, 2008 8:11 am
by Hawkeye
I mentioned a gas lift as a possible source for a pump body. You would need to replace the piston and I don't think the rod of the gas lift is long enough to reach the bottom of the cylinder. The threads may be an issue as far as connecting fittings to them.
While the materials are perfect in structure, modifying them may be more bother than it is worth.