Improved easy assembly spiral for motorized Gravitrax lift

Remixed easy assembly spiral for better printing.

For use with the Gravitrax Motorized Marble Lift.
https://www.thingiverse.com/thing:4178353

Reason for this remake:
There is something in the design of the spirals that causes a slicing error* near the top of the spiral.

Details:
The spiral is hollow, it starts with a 15mm diameter hole at the bottom and there is a 5mm hole at the top. This diameter changes abrubtly within one layer near the top of the model. This results in the printer printing the inner part of the circle of that layer in mid air. Look at that layer after it is sliced, you will see what i mean. I used Cura 4.8. The result is a big mess and the part fails miserably.

• Maybe other slicers handle the file differently, but since i only use Cura 4.8, i altered the design to make it slice and print properly.

Changes:
I added a gradially inclining transition from 15mm to 5mm diameter. This way there is no need for supports and the part prints perfectly on my Ender 5.

Files:
Gravitrax 120mm CCW v2.stl
Counter Clockwise spiral for use with lifts up to 100mm.

Gravitrax 140mm CCW v2.stl
Counter Clockwise spiral for use with lifts up to 120mm.

MotorHub_Asymmetric.stl
The part that connects the motor to the spiral, unchanged but included so it is complete.

Thanks to ffleurey for designing the original Gravitrax Lift:
https://www.thingiverse.com/thing:4178353

Thanks to Rainerlan_2 for making the easy assembly spiral.
https://www.thingiverse.com/thing:4691255