Rectangular Helix

Rectangular tubing bends joined by a metal coupling

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.

Design plan of the two tiered rectangular helix

And the links are joined by a rectangular coupling.

Rectangular tubing bends joined by a metal coupling
A freshly made rectangular bend fitted with a metal coupling

Or, go with the 180Deg bend.


Rectangular bend next to cooling blocks on the table

Below is our test on a bend on the minor axis, 24″R 8″ tangents with a 2.5″ rise. Very happy with the result.

Model Stage to the right.

Rectangular tubing on a work table

A model comparing the minor bend (blue) with the major bend (clear).

A small model of the rectangular tubing helix

Here is the first tier completed in early March

Here is the first tier of the helix. Notice the set screws in the couplings and the rise.

Model of the rectangular helix joined by metal couplings and set up on wooden blocks

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.

Rectangular tubing set on wooden blocks. Caption says, "measure the pitch at first 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.

Rectangular tubing next two stacked wooden blocks

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