Currently we are preparing for a rectangular helical bend for a cup company. They are conveying squat cups and want a holding area for them. Thus, their engineer wants a 2 tier helix where the cups will travel in a vertical position. This would require the "hard bend on the minor axis."
Here are two links on a 24" Center-Line Radius Bends, 60° with 3" tangents.
And the links are joined by a rectangular coupling.
Or, go with the 180Deg bend.
Below is our test on a bend on minor axis, 24"R 8" tangents with a 2.5" rise. Very happy with the result.
Model comparing the minor
bend (blue) with the major bend (clear).
Here is the first tier completed in early March 2017
Here is the first tier of the helix. Notice the set screws in the couplings and the rise
The Helix is never parallel to the ground. In order to enter and exit the helix parallel to the ground we need a slight bend. The angle rise is about 3.8 degrees and the entire helix rises 12" in each tier.
The formula for the parallel-bend is Arctan(Pitch/Pi*D) If your cutter diameter = D and your Pitch Angle = A then the pitch will be; P = Pi * D * Tan(90-A)
Helix rise angle at 3.8 deg.