The Archimedes Screw is one of the constructions in front of our shop that seems to draw the most attention of our visiting customers. There's something almost mesmerizing in watching the water being pumped uphill and dropping off into the receiving receptacle. This instructable will show you how to build this water pump. In addition to standard K'nex parts and a standard K'nex motor, you will also need about 5 to 6 feet of flexible 1/4" plastic tubing, a small metal bowl to hold the source of water and a small square baking pan to catch the water in the receiving end of the pump. Please watch the video above to check out the Archimedes Screw in operation.
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Step 1: Construct the Center Rod Support for the Archimedes Screw
The center rod is primarily constructed from 2 red rods at either end and two yellow rods in the middle, joined together by orange two-way connectors. 2 white 8-way connectors are used to secure the motor and an additional 5 white 8-way connectors are used to support rods that will be attached in the next step to form the frame that the plastic tubing can be wrapped around.
2 tan interlocking clips are used to secure two of the white 8-way connectors to the center rod so that the entire assembly will turn as one unit.
Step 2: Create a Mounting Tube Frame Around the Center Rod
Rods are added to create a frame upon which the plastic tubing can be wrapped Start at the bottom of the center rod to install 4 yellow rods joining two of the white 8-way connectors.
Attach 4 red rods from the free connector positions on the second white 8-way connector to the third white 8-way connector (as you count connectors from the bottom).
Likewise, attach 4 red rods from the free connector positions on the third white 8-way connector to the fourth white 8-way connector.
Finally, attach 4 red rods from the free connector positions on the fourth white 8-way connector to the fifth white 8-way connector.
As mentioned in the previous step, make sure the two tan interlocking connectors are locked into the white connectors.
Go ahead and turn on the motor to ensure that the tube assembly rotates correctly.
Step 3: Wrap Plastic Tubing Around the Tube Frame Assembly
Anchor one end of the plastic tubing between two adjacent yellow rods on the bottom of the tube and center rod assembly. Allow about one inch of tube to extend outward at the bottom. This will allow water to be scooped into the Archimedes Screw.
Evenly wind the tube around the tube frame assembly until you get to the top of the assembly and anchor the end of the tube between two adjacent red rods. This will be where the pumped water will exit.
Use purple or gray clips (doesn't matter which color) attached to the tube frame rods to evenly space and separate the plastic tubing.
You may also want to add a clip to secure the yellow connector at the bottom of the assembly as shown in the photo.
You are now done with the toughest part of the assembly. Go ahead and place this aside.
Step 4: Construct the Left and Right Supports for the Archimedes Screw
Looking at the completed assembly photo, you can see the screw is supported on the left side by a frame that will eventually sit on top of the bowl supplying water to the screw. The right side of the screw is a vertical frame supporting the upper end of the screw. We will start with the left side frame.
Step 5: Construct Left Side (Water Supply) Frame
The 4 yellow rods extending outward from the top of the frame will allow the frame to sit on top of the bowl containing the water source. The two inwardly pointing white rods on the lower part of the frame are where the yellow connector at the bottom of the Archimedes Screw tube assembly connects into the frame.
Step 6: Right (vertical) Frame Support - Bottom Assembly
Step 7: Right (vertical) Support - Top Assembly
Step 8: Right (vertical) Support - Attach Top to Bottom Assembly
Step 9: Right (vertical) Support - Add Bracing and Complete Assembly
Step 10: Install the Archimedes Screw Tube Assembly and You're Done
Attach the bottom of the screw assembly to the left support and the top of the screw assembly to the right support. Put the right assembly on top of the water supply bowl and place the left assembly in a square baking pan. Fill the water supply bowl so that the plastic tube extending out the bottom of the screw will alternately dip underneath the water and extend above the water as the screw rotates.
If everything is working properly, you should start to see the water start to climb inside the tube. Really cool!
Hope you enjoy building this. Let me know any of your ideas and ways you enhanced this project.