How to cut out a series of Helix to form channels?


After better understanding what you were wanting here is how I would do it.
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Step 1:
Create a spiral (not a helix)
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Step 2:
open a sketch and convert the spiral curve to a sketch entity.
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Step 3:
project the sketch onto the conical face.
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Step 4:
make a plain at an end point of the new curve that is perpendicular to the curve.
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Step 5:
make a circle and sweep cut along the curve
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Step 6:
circular pattern