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Manual / Sketch

Helix / Spiral curve

Create a constant or variable pitch helix to use as a Sweep path for springs and threads.

Edition: Standard+

What it does

Creates a helical curve (like SolidWorks) with constant or variable pitch, clockwise or counter-clockwise. Use it as the path for Sweep and Sweep Cut with any closed profile, for example springs and threads.

Where to find it

Model › Curves › Helix / Spiral

HELIX / SPIRAL box
HELIX / SPIRAL box

Option Default Description
Base plane XY Base plane (XY / YZ / ZX / reference plane)
Or use the circle of a sketch – Uses a circle in a sketch for the centre and size
Centre X / Centre Y 0 Centre point
Diameter 25 mm Diameter
Defined by Pitch and Revolution Pitch and Revolution / Height and Revolution / Height and Pitch
Pitch Constant pitch Constant pitch / Variable pitch
Height 20 mm Height
Pitch (start) 4 mm Pitch
End pitch (variable) 8 mm End pitch (when variable)
Revolutions 5 Number of turns
Start angle 0° Start angle (±360°)
Clockwise Off Turns clockwise
Reverse direction Off Reverses the direction

Steps

  1. Click Helix / Spiral and enter the values in the table.
  2. Click OK to create a Helix<n> curve.
  3. Draw a closed profile at the start of the helix, then use Sweep and choose this curve as the Path.

Try it: Split key ring

A split key ring is nothing more than 2.5 turns of thin wire wound on a helix. Build one in two minutes and you also know how every spring and thread is made.

  1. Click Model › Curves › Helix / Spiral and enter: Base plane XY, Centre X 0, Centre Y 0, Diameter 25 mm, Defined by Pitch and Revolution, Pitch Constant pitch, Pitch (start) 1.2 mm, Revolutions 2.5, Start angle 0. Click OK. You get Helix<1>.
  2. Click Sketch, pick the ZX-Plane, press C (Circle), click the origin, type 1.1 and press Enter. Click Finish Sketch. The wire (1.1 mm) is thinner than the pitch (1.2 mm), so the turns do not fuse together.
  3. Click Model › Boss / Add › Sweep. Choose the circle sketch as Profile (section) and Helix<1> as Path (spine), then click OK. The circle is not at the start of the helix, so Sweep moves it there for you.

Split key ring made from a Helix and a Sweep
Split key ring made from a Helix and a Sweep

Challenge: Change Pitch to Variable pitch (1.2 to 3 mm) and Revolutions to 6. Now you have a tapered spring.

See also