A Homemade Water Pump

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Introduction: A Homemade Water Pump

This is a small scale water pump. It runs on three volts DC and has lots of uses. I made this for use in a water cooler in order to cool a TEC. It runs nice, and there have been no problems for the three months that I have had it.
How does it work?
In order to understand this pump you must understand Bernoulli's principle which states; as fluid speed increases pressure decreases. But what does this have to do with water pumps? Well for those who did not know, air is a fluid along with water, and inside the pump there is an impeller. That impeller starts to move the air fast causing a pressure drop. The low pressure inside causes water to be drawn up the bottom tube and shot out the side. Simple.
How did you make it?
I got the idea when looking at a bottle cap, and it was so simple it just had to work.
First I took a bottle and cut the neck off.
Then I found the small dot in the very center of the cap and drilled it out to be snug with the lip sticking out of the motor near the spindle.
Then I glued the motor on the cap so it lined up with the hole.
Then I took a 1/4" tall piece of thin aluminum sheet metal about 5" long.
I cut it into 4 1/2" segments and bent them in half to form 90 degree angles.
I hot glued the four pieces of metal to form a plus shape.
Then I hot glued that on to the motor spindle making sure it is centered.
Next run the motor and make sure it is balanced well, if not rearrange it until it is balanced.
Then cut two 1" lengths of copper tube
Next drills a hole in the side of the bottle cap the size of the tube and hot glue it in. MAKE SURE THE IMPELLER STILL SPINS FREELY AND DOSNT HIT THE TUBE THIS IS VERY IMPORTANT
Then cut a small piece of Plexiglas and drill another hole in it the size of the tube. Hot glue this to the bottom and you're done!
NOTICE: BECAUSE OF THE NATURE OF THIS IN-LINE PUMP THERE MUST ALWAYS BE WATER IN THE LINE FOR IT TO WORK. HAVING THE PUMP ATTACHED TO A RESIVWAR WOULD HELP FIX THIS PROBLEM.

10/2/2009 EDIT: XDleader555 made an instructable! (which I was to lazy to do) go visit here!

4/6/2010 EDIT: A few days ago I went digging around in my junk box for this pump.  I found it...broken :\  The motor spindle had rusted and frozen in place....damn.  I am currently looking for another motor, so if anybody is actualy planning on doing this, try looking for a motor with analuminum spindle.  Or maybe just buy a pump, but hey this is Instructables not gououtandbuyables!  :)

5 People Made This Project!

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i've yet to test it fully i was hoping that the impeller wouldn't have to be quite so submerged. is there any way to get it to draw water up into the impeller so it could be mounted on a bottle?

I've made 2 of these 1 as a test and the 2nd to empty a blocked drain.

For the 1st, it was simillar to yours except the motor and the blade housing was seperated by 2cm of polystyene. this stoped the motor from being submergered. Unfortunaley I lost the 1st.

The 2nd I still have. I used 1 screw top tub as blade casing, 1 1" of bottom of another tub to keep a gap between blades and inlet, impeller/blades from a seized up diswasher pump, several metal and nylon washers and a shaft over 1ft long I salvaged from a pile of scrap metal. took a few hours to align the outlet with the blades and create the seals. By using the screw top tub I can clean it out and put it straight back together in just a few minutes.

It pumps water for fun!! The long shaft allows me to attach a cordless or mains powered drill while keeping them way from the water. I'll try and post pics of the crude looking thing once I get it back from my friend.

how to seal the motor?

Just use WD-40. It repels water and rust, plus it keeps the shaft lubricated nicely.

I need a really good water pump for a water fall diorama do you think you could help me I will be using the pump for the water fall "Becky Branch Falls". Please help me.

I'm thinking if you want to make a larger centrifugal pump,why not use a metal reel of the kind used used on reel-to reel video or audio tape recorders or a metal 8mm or 16mm movie film reel?

do you have any other ideas of how to make a impeller out of something else?

honestly anything will work, just find something shaped remotely like an impeller and give it a shot. You're only limited by your imagination.if i were to do this again I would try and use something like a reflector out of an incandescent mini maglite. theyre almost perfectly shaped for the job.

Thx, i decided to use cut up parts of a soda can and it worked and it doesnt rust. You should put in your description to use pieces of a soda can since you water pump rusted

I could, but the motor was what rusted not the impeller, thanks anyways though :)