Step 4: How it works...

Picture of How it works...
Ram Pump CYCLE 2.jpg
Ram Pump CYCLE 3.jpg
Ram Pump CYCLE 4.jpg

Here's how to operate it:

To run it, you need about 5' of feed water pipe for every 1' of fall below your pond or creek water surface. I have 10' of fall and 50' of feed pipe supplying 3 gallons/min. (A little longer would be better say 5.5:1)

Now manually push (cycle) the valve stem up and down about 30 or 40 times to fill the pressure tank. These pumps need back pressure in the tank to operate automatically. When the pump starts to cycle on it's own, you will want to screw the adjuster cap up or down to make the cycle frequency about 60 - 150 cycles per minute.

Experiment with the cycle frequency to find what delivers the most water for you. Lots of troubleshooting guides on the net to help you fine tune it. You may need to add or remove some weight off the bottom of the valve stem if it cycles too fast or slow and you don't have enough adjustment available by turning the upper valve cap. A little denial and error and you will find the sweet spot to get it running smoothly.

I have found that if it cycles too fast, it won't build up any pressure and the delivery flow is low or stops. If it cycles too slow, delivery flow is weaker and you use more feed water than necessary and you can drain the feed pipe if your supply water is limited. Mine seems to deliver the most water at a cycle rate of 150/minute.

Enjoy your gravity powered water pump, it's the closest thing you may ever see to perpetual motion... Hopefully you can see the movie of it working.

This is the best hobby project I have ever built from scrap parts and recycled junk. We use it every day all summer long and it facinates everyone who comes to visit us while saving real money!

Diddi Ingi2 years ago
One question... with the pressure that the hammer builds up, how far upstream can you pump the water, using a regular garden hose? How far above the level of the original pond f.x.?
eltigre (author)  Diddi Ingi2 years ago
this pump has about 700 feet of 3/4 inch flexible plastic pvc water pipe attached to it and the delivery point is about 110 feet above the pump.

Garden hose is about the same diameter but more flexible so it may not deliver as much as the flexible walls will absorb some pressure. the shorter the delivery hose, the more water you will have at the end of the hose. The larger the diameter of the delivery hose, the less it will pump because it will have to push a large weight of water through the hose. There is a happy medium so you may have to experiment. You may want to use more rigid hose, like water line pvc, even up to 1 inch diameter and put a garden hose connector on the end of it where you want to use the water. that worked for me when I added another 50 feet of hose on the end of my delivery pipe to drip water the garden. A soaker hose at the end worked well to drip water onto the garden for hours.
Nelki3 years ago
Sorry but can you describe this sentence more colorfall I just can't understand them :,,To run it, you need about 5' of feed water pipe for every 1' of fall below your pond or creek. I have 10' of fall and 50' of feed pipe supplying 3 gallons/min. (A little longer would be better say 5.5:1) " Thanks in advance.
eltigre (author)  Nelki3 years ago
You must install a pipe to feed water from your pond down to your pump to make the pump operate. The length of this pipe should be about 5'6" for every 1 foot of vertical height your pump sits below the pond surface. (1.68 meters length of feed water pipe for every 0.3 meters vertical height difference from pond surface to pump location.) e.g. if your pump is 10' below the pond surface you should have a feed pipe 55' long. If your pump is 5 feet below pond surface then the drive pipe is 27.5' long.

_________5.5"________ pond surface elevation
I }
I } 1'
pump location

Your feed water pipe does not have to be straight. it can follow the contours of the ground from the pond down to the pump. The feed water pipe should be rigid like metal if possible. I used heavy wall ABS plastic because it was much cheaper than metal pipe and it seems to work ok but metal is reported by some to increase pump efficiency.
Nelki eltigre3 years ago
Thank you :)
Nelki3 years ago
Sorry but can you describe this sentence more colorfall I just can't understand them :,,To run it, you need about 5' of feed water pipe for every 1' of fall below your pond or creek. I have 10' of fall and 50' of feed pipe supplying 3 gallons/min. (A little longer would be better say 5.5:1) "
Thanks in advance.
laketango5 years ago
what a fantastic concept, very very smart, well done!
We are trying to farm on the banks of Lake Tanganyika and our solar pump is not coping, so this would be ideal.  Love this idea, need to know 3 things please:
1. you mentioned details on the gate valve but I can't see any
2. i don't understand how the check valve is connected to the pressure tank, does the cap move within the 1.5' pipe, then reduced to fit into the tank??
3. does the pump have to be below the water line to operate, i.e. water is forced into the inlet pipe by gravity?.
eltigre (author)  laketango5 years ago
Please look at step 2 above for gate valve details
Please have a look at step 1 above to see how it is all connected together.  I think you are asking 'How is the GATE valve connected to the pressure tank" and it is not connected.  The check valve is connected just below the pressure tank, please review step 1 above for details.
The pump does need to be below the water line to operate.  You will need at least 5 feet of fall to make gravity operate the pump. 
yendis5 years ago
hi there! i love this idea! yet, i would REALLY appreciate more detailed instructions and photos. I live on a farm in South Africa. please email me at info@hobhouse.co.za Kind regards
Great Pump! I Had to Comment about the discussions on this... First of all if you are trying to harness the energy from the water that has already been expelled from the device then you you will not subtract from what you already have exerted in the water getting there. Gravity ( a constant) is doing much of the work. The exhaust water us fair game for turbine use.. You people are getting confused - assuming the pump is doing some work ( pumping) in the traditional pump sense. This is a Gravity Pump , where gravity is a constant and gravity cant be impeded like other engines , the exhaust water is the kinetic energy release trying to keep up with the constant gravity! Ok OK Finally my main Point if you want to generate power then funnel the exhaust water into another hose and run it downhill into another one of these to pressurize the water and then into a micro-hydro generator! I will try this some day!
nabo00o6 years ago
Might I add a suggestion to improve this machine's efficiency? First, since you know this system pretty well by now, is there any way that you could make a directed beam of water go up, instead of going outward in all directions? The reason for doing this would be to maximize the highest ground this waste water could stay at. If you could get it high enough up, you would only have needed a small percentage of the power from your water output in order to pump the waste its last inches up to the source again. Btw, you might recognize me ;D
kleinjahr6 years ago
Nice build, especially like your valve design. If you don't mind, might I suggest? To allow reinflation of the inner tube, drill a hole in the fire extinguisher and epoxy the air valve in it. You might also pipe the waste water /overflow downstream, same size or larger as the intake( reduces back pressure). This would allow the use of a small water wheel for power generation. The greater the drop and volume, the better. Another possibility is to run your discharge pipe to a water tower, keeping the run below an angle of 15 degrees from horizontal. This will give you a gravity fed system downstream of the tower, which can also be used for a water wheel. You might like to check out the "PM Shopnotes 1905 -1930" or "Boy Mechanic" reprint series from Lee valley. Some good stuff there.
JonoH6 years ago
Only question I have is how much water do you lose? The picture shows a fair amount spraying around. We use an electric pump to get water out of the rain water tank, and the pressure in the tank would (normally) provide a fair amount of impetus to get the pump moving. However, water is in limited supply here (South Australia), so no leaks is a deal-breaker.
gfry6 years ago
Dynamite! I don't know where I've been the last 45 years, but I don't think I have ever come across a ram pump. If this thing pushes that much water you could tinker with it further and get it pushing a geared pelton wheel (or a flywheel of some kind)...get the thing making electricity for you at the same time.