A very popular method for lifting the balls in Rolling Ball Sculptures, is the spiral. This is based on an ancient lifting mechanism more commonly known as the Archimedes Screw.
On this page, I attempt to demonstrate the method I use for creating wire spirals, with varying diameters and pitches, for use in the Marble Lifting mechanisms of Rolling Ball Sculptures.
To explain graphically:
(Click images to enlarge)
Pipe diameters determine the pitch, while the hole positioning determines the spiral ID.
If your spiral diameters are critical, it is necessary to take the wire diameter into account when drilling the holes through the pipe.
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Fitting the central support. Dowels act as spacers to ensure "concentricity"... Whew!, big word eh!
Spot Welded Spacers. Done on my Home Made Spot Welder.