Why Won't My Archimedes Screw Elevate Water?

[cdssdr18]

Hi guys. I'm *attempting to make* an archimedes screw for my engineering project.

The only stipulations for this project are as follows:
Create a machine that will move water from point A to point B
The machine must be powered by my professor's desk fan.

So, I bought a small wooden dowel, some clear plastic tubing. I wrapped the tubing around the dowel countless number of ways. I attached a pinwheel at the top of the dowel, so as to utilize the desk fan in powering my machine.

I see seven year old kids making archimedes screws on youtube...I absolutely cannot get mine to work. I have tried wrapping the tube around the dowel very loosely, very tight. I am making sure the structure of the tube is in tact...The tube will pick up water but it will not move UP the tube. I have even tried changing the angle of the whole structure to help the water move up the tube. I am beyond frustrated. PLEASE HELP!

 

[Borek]

What is happening? Can you post a picture?

 

[AlephZero]

You can't make an archimedes screw that lifs water vertically. Start by trying to move the water horizontally, then see how far you can raise the top of the screw before it stops working.

If you trace the path around one turn of the helix (when it is not turning), it needs to go up and down again, so a "bubble" of water gets trapped in the lowest part and then gets carried along (and upwards) as the screw turns.

 

[NascentOxygen]

There are plenty of video clips on youtube. Here's one. You can clearly see what AlephZero is referring to. The tubing is not wound as directly about the cylinder as one might be tempted to construct it. I think the constructor has actually wound two Archimedian screws onto this axle here, one screw fits inside the other.

 

[Danger]

If you're allowed to buy stuff, which you indicated by your purchase of the dowel, I would start with a large auger-type drill bit and a plastic tube that it just barely fits inside of. Also one large and one very small pulley.
Smear Vaseline, goose grease, or similar substance around the perimeter of the auger to seal it, and slide it into the tube. Using whatever support structures you want, mount the large pulley on the drive-end of the auger. Remove the blade unit from the fan and replace it with the small pulley. Link the two pulleys with some sort of belt.
I leave the rest to your imagination.