Re-create Heron's fountain from water bottles

Picture of Re-create Heron's fountain from water bottles

I originally made this project for the MAKE blog. It's a fun experiment that led to a lot of discussions about perpetual motion and free energy. My version does not exhibit either of these properties, but you may be able to fool people into thinking it does.

This is a really easy build and would be a perfect project for to build with your kids. Maybe you could even sneak in a lesson on fluid dynamics or perpetual motion?
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Step 1: What You need: Supplies

Picture of What You need: Supplies
Here is a lit of the items you need for the build. As you can see, it's not a lot. The total cost of build = $2 (you can scavenge the 3 water bottles)

(3) 16.9 FL OZ Water bottles
(1) 9" length of tubing
(1) 11" length of tubing
(1) 15" length of tubing
Small amount of clay

Note: The tubing is for aquariums and is 3/16" thin wall rigid tubing. Almost any tubing would work, even flexible, but the rigid makes it really easy. I was able to pick some up at a local pet supply store for about $0.50 per foot.

Step 2: What you need: Tools and equipment

Picture of What you need: Tools and equipment
Here is a list of the tools needed for this instructable. All you need are very basic hand tools, and that's about it!

Drill (hand or electric powered)
5/32" drill bit (slightly smaller than the tubing diameter)

Step 3: Make the fountains' reservoir

Picture of Make the fountains' reservoir
Cut (1) of the bottles in half as pictured. Keep the bottom of the bottle, you can use it to fill the fountain when we are all done.

Step 4: Drilling the holes

Picture of Drilling the holes
You are going to need (2) holes in each cap. Start by drilling the (2) holes in (1) cap, use a piece of scrap wood to support the cap.

When you are done with the first cap, use it as a guide to drill (2) holes into the top of the remaining (2) caps. You can place the caps top-to-top when drilling the holes. Now you should have (3) caps, each with (2) holes drilled in about the same location.
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jduffy542 years ago
Oh, and also, thanks for the instructable, I had been looking for one of these a few years ago, but couldn't find any cheap designs that didn't use lab-type equipment. Good job, I think I'll build one.
wurx (author)  jduffy542 years ago
Thanks! Send me pics if you build your own!
jduffy542 years ago
Unil the middle bottle is emptiedish. Basically, it's powered by water going from the middle to bottom bottle, and once the pressure it too low, it stops.
Boogy man2 years ago
I'm making this for my mom thanks ; D
HamenChips3 years ago
How long will it last?
wurx (author)  littlechef376 years ago
Thanks for voting! I appreciate it.
I wonder if would an EXTREMELY large version of this (with a generator) would produce enough energy to add and remove water to keep it running forever.. and possibly generate enough power to run a house or charge an iPod or something ?
if you used the water to run a generator, then yes you would get electrical energy. the problem is, you arnt going to make more energy than is used up adding the water back into the system. the system can be as complex as you need, but with our laws of physics, it is impossible to produce more energy than used. this includes using temperature change, gravity and all forces that arnt part of the actual system as well.
wurx (author)  littlechef376 years ago
Yes, a larger version would produce a larger amount of energy, maybe even enough to harness. However, the energy will eventually be used up. Unfortunately perpetual motion and/or free energy it is not going to happen with this fountain. Sad, but true.
A good name4 years ago
Perpetual motion doesn't exist. There are many devices that utilize energy with amazing efficiency (perpetual motion clocks can power themselves for two days with a change in temperature of only 1 degree)

But perpetual motion defies the laws of physics.

However, I thought this was pretty neat.
actually just because it defies our laws of physics doesnt mean its not possible, that sounds impossible to most but try to explain black holes while staying in the lymits of our laws of physics, i would explain some of this more scientificly but iv been stripping paint on 2 guitars all day as well as repainting several and to put it simply the fumes got to my head
No, perpetual motion is physically impossible.
really, huh? then what is powering all these spinning atoms that make the entirety of the thing we call physical reality? is it mass delusion? everything that exist is perpetually moving.. we are being hurled through space and even that space is being hurled through larger space and everything is constantly spinning..large and small. all of it. moving - perpetually.. someones gotta to say it.
That isn't what perpetual motion means.
Add a small turbine that can turn whatever water flow there is into electrical flow. This electrical flow can run a small compressor which will add pressure and keep it going forever :)
Can't believe I didn't realize this until after I posted.

We didn't consider the waters' evaporation from the unit. Eliminate that and it'll last muuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuch longer.

Maybe seal the top or something?
wurx (author)  MillenniumMan5 years ago
 Nope, won't help. It's all powered from the pressure in the 2nd bottle. Once that pressure (generated from the gravitational forces on the water) is gone, the shows over. :)
Gonazar5 years ago
After the water goes into the bottom container, and the air in the second, how does it reset, or is that the point where it stops?
jhonny6 years ago
I wonder if u could make one that runs forever? (>_<)
wurx (author)  jhonny6 years ago
That would be awesome.....but it isn't going to happen. Perpetual motion/free energy it is not. Eventually the pressure runs out and the water stops flowing. Although, it does last a surprisingly long time.
juanvi wurx5 years ago
water stops running because its viscosiy, if you managed to do that same fountain with liquid air, as it has 0 viscosity, you could make it running forever
SoapyHollow5 years ago
Wow, neat!
Hey that is so cool! What if there was a way to drain the lower container without disrupting the system, and use rain water to refill container b (the middle one). Then it could run forever, as long as it rains. I forget the name, but it's this cool little trick cup that when you start drinking out of it, it drains out the bottom onto the lap of the victim. It usually has a structure extending out of the middle of the bottom of the cup (on the inside). Once the top of the structure is exposed to air (after some drinking) little holes at its base let the fluid flow out. I wish I could remember the name of it so I could find out how it works. So basically, something like it would drain at a certain point when the water got to high.
Jaycub6 years ago
You should make a giant one that is powered by rain.
wurx (author)  Jaycub6 years ago
That's a great idea! I have been thinking of a rain collection system, why not make it fun too!
Arbitror6 years ago
I'm doing this right away! (rated 5 stars***** and favorited!)
wurx (author)  Arbitror6 years ago
That's great! Please take some pics or a video and post them up online. Oh, and send me a link. I would really appreciate it!!!!
good job! it is quite interesting, considering how simplistic it is. 5*
wurx (author)  angelofdeth686 years ago
Thanks. It was a lot of fun to make. Hopefully you you will try it too. It's strange to see it in person. It seems as though it shouldn't work, but I can assure you it does!
FaqMan6 years ago
It is interesting, green, and classy good job.
wurx (author)  FaqMan6 years ago
A good name6 years ago
Oh and I subscribed, hope to see more of this stuff from you!
wurx (author)  A good name6 years ago
I will be making more instructables in the future. Thanks for subscribing.
A good name6 years ago
:) Just a note Html doesn't work on here.
wurx (author)  A good name6 years ago
Oooops! Thanks! I fixed it.
A good name6 years ago
I agree, you got this thing made! Genius idea! Lol I feel like I finally understand physics.
wurx (author)  A good name6 years ago
Thanks! The real credit goes to Heron! Although he didn't use plastic bottles! ;)
nepheron6 years ago
Enjoy your new voltiac backpack! You have this contest by the NECK...
wurx (author)  nepheron6 years ago
Thanks for you vote of confidence. There are a lot of great entries, and I am sure a lot more to come.
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