Generator Coil help needed

I need some help sweeping a rectangular spiral. 

I'm winding metal conductor wires around a rectangular iron core.  Not as a spring coil style but as a flat pancake. 

I'm only aware of one way to model the sweep pattern and there seems to be a limit on number of turns allowed when using convert entities is used.

It'd be great if a rectangular spiral was an option. But it's not.  Here are my steps.

1) SKETCH on top plane 770x1600 mm rectangle w corners filleted 50mm
2) blind EXTRUDE 700mm w/ 45 taper outward
3) SKETCH a circle on top plane inside base close to boundaries
4) INSERT/curve/spiral select circle. Defined by height and revolution. Height 700 mm revs 15 start angle 180 clockwise
5) SKETCH a line along the Z axis off to the side, touch an endpoint, select the spiral and constrain w pierce. Line must extend beyond limits of rectangle.
6) INSERT/surface/sweep select the sketch line as the profile and the spiral as the path.
7) Now we need to Show where the sweep intersects with the extrusion.  Start 3D SKETCH, while holding the control button, select all extruded surfaces of the rectangle including the filleted corners (not the top or bottom) then select the sweep. Command TOOLS/SKETCH TOOLS/INTERSECTION CURVE.

8) Let’s now convert the 3d intersection curve into 2D.  Right click on top plane, left click on 3D sketch in tree, SKETCH CONVERT ENTITIES,

9) select then HIDE everything except the new 2D sketch.

10) Now we need to create a profile for a sweep.  It looks like the origin of the profile needs to be constrained to the inside of the spiral.  I have been unsuccessful constraining to the outside of the spiral.  Right click on right plane SKETCH to create a profile to sweep along the 2D path. RECTANGLE Constrain the lower left corner to the inside of the spiral. Make the rectangle Equal sides 7mm.  Note the real model will have between 4 and 8 patterned rectangles.

11) FEATURES/SWEPT select in the tree the rectangle for the sweep and then select in the 2D path.

12) Tadahhh pretty cool.

13) Why is this process limited to less than 20 turns?  I need 60 or more turns.

14) Is there another process that has simpler configurable steps?

Mac Baker

Richmond