Helicopter Rotor

How can I make something rotate indefinitely
for example a helicopter rotor

it’s not so hard.

  1. Make one turn of your rotor (360 degrees).
  2. Go to GraphEditor: make interpolation linear (or make vector anchors on rotation fcurve).
  3. Press N - you will see right pane with properties of active fcurve, go down and add fcurve modifier Cycles. That’s all :slight_smile:

thank you so much :slight_smile:


here is one with a driver and a custom property for per frame rotor speed. There is a custom property “spin” added to the rotor object (cube) and its z rotation is driven by the scripted expession

spin * current_frame

This way you can fiddle the speed, or key in speed changes to get differing strobing effects.

Added another file that gives you the rpm of the blade too… according to google the jet ranger goes at about 400rpm, which if my maths is correct is about 100 degrees a frame at 24 fps.

Couple of things, for the driver to work it needs at least one keyframe on the object, in the rpm driver i hardcoded 24 as the fps in the driver expression.

A benifit from using a property / driver approach is you could also use it to drive a shape-key for the angle of dangle on the blades when the chopper is stationary for instance.


rotor.blend (64.6 KB)rotor_rpm.blend (67.7 KB)

ok i’m interested in this blade rotating

how do you add this driver

any short video showing this ?

can it be easily done with a small a script for instance to make a short animation ?


analyse the blend files, especially in the graph editor, drivers tab, and bring up the properties panel (N): all the answers are there :wink: