Archimedes screw that doesn't work

After the initial successful trial of my hand-crafted Archimedes screw , I've tried to improve on the trial version . Supplying enough power to get the thing to turn could be a bit of  a challenge and weight of it is probably a factor, so instead of 6" ducting i thought I'd try some downpipe - 68mm diameter or  about 2 3/4" . So after dismantling the original and taping the plastic tubing I had another go.

And this time it didn't work .

• Didnt pick water
• Didnt move it along the pipe
• Didnt come out at the end 

Either the outer tubing is too large or stiff for the diameter of the downpipe and its not patent (enough) or the pitch and incline  of the tubing and tube is important and Ive got it wrong.
So I think Im going to have to do a bit of research on the limits and design principles of this and then come back  once I've sorted out what is wrong.  I think the starting point will be here . An incline of 22 degrees is most efficient. So Some exploration of the burn is  needed as well.

I think I might need an Engineer!