SimplyMaya demonstrates a quick way to rig a spring in Maya using a constraint to make a Blend Shape.
This new and handy tutorial from SimplyMaya shows a fast way to rig a spring in Maya. The technique shows making a spring with some hooks on either end that remains rigid.
SimplyMaya runs through how you can use a standard Helix primitive in Maya and its history in the channel box for the animation. The point on Poly constraint moves the hooks along with the helix attributes.
Then, it’s simple to create two shapes with the newly minted rig and create blend shapes from those. This is an excellent example of using simple tools within more extensive techniques to create more complex things.