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i need to make a silent water pump using basic parts. help? Answered

i havent got much at my disposal, ive got tubing, glue, and brushless fans.
i have tested with distilled water and the fans do not short out from being in contact with it, nor do they appear to be rusting or locking up.
i have tried using a standard fan to make a simple pump, but with no decent results. the way i have it set up is the bottom is covered, and a tube is exiting out the side of the fan shroud. it is angled so that the fan blades should be pushing the water into the tube, but the water is just staying in the fan shroud. i currently have a CD as the intake, using the hole in the middle as the intake and the rest of the cd covering the other side of the fan. i was wondering if theres a way to make it work with a normal fan, and if i can do that, how do i need to have the hose set up?
if its impossible to do with a regular fan, i know a blower fan will work, since water pumps have basically the same setup on the inside.
i have a feeling the blades themselves are playing a big role in where the water is going.

any help is appreciated!

13 Replies

user
tgferreira184 (author)2012-06-14

what amount of water are you trying to move?

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user
zack247 (author)tgferreira1842012-06-14

i cant say for sure, i dont need to move a lot but i need enough pressure for it to go somewhere.

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user
steveastrouk (author)2012-06-13

The density of water is 1000x that of air. So a big airfan is going to really, really struggle to move water. Find a smaller prop, or trim what you have RIGHT down and try again.

Also, there is a phenomenon called cavitation which limits the maximum speed you CAN move water with bladed fans.

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user
zack247 (author)steveastrouk2012-06-13

speed isnt a big necessity here, i just need to move the water from point A to point B.

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user
steveastrouk (author)zack2472012-06-13

Wrong kind of device, there is no way you'll pump into a restriction.

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user
bwrussell (author)2012-06-13

Those fans are designed to move fluid axially not radially meaning the water is being pushed straight through, opposite the intake perpendicular to the blades, not away from the tips, parallel to the blades.

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user
zack247 (author)bwrussell2012-06-13

so set it up like the fan originally worked so that it moves the water like it originally moved air?

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user
bwrussell (author)zack2472012-06-13

Yep, that's how it was designed to work and how it will work best.

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user
Vyger (author)2012-06-13

You can get inexpensive water pumps from liquid cooling systems designed for cooling computers. They are 12 volt and have all the tube fittings in place. Using an air fan for moving water might only work for a short time. The bearings in them are not watertight and they will corrode pretty fast. The little water pumps from water cooling systems are designed to last for years. So far I have dismantled mine to upgrade motherboards long before any of them wore out. You should be able to find used ones somewhere.

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zack247 (author)Vyger2012-06-13

the only problem is money. i cant afford to buy the water pump. if i can make one out of stuff i already have, then i can do it.

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user
Vyger (author)zack2472012-06-13

25 bucks and free shipping. Not a bad deal for new. You can probably find used ones if you do some searching.

EBay

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user
rickharris (author)2012-06-13

How much water do you want to move

Is it volume or pressure your after.

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user
zack247 (author)rickharris2012-06-13

i intend on running the water through a couple feet of tubing, not a lot of water, so pressure is more preferable that volume in this case.

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