Circles do not move correctly when scaling dynamic block.

[YoshiCoolen]

I'm modeling a dynamic block.
It represents a simple chimney for a roof plan.
The dynamic block has two stretch actions.
These are displayed in the properties menu and have have grip points.
The total width and length.
One action scales three circels.
The circels are equally divide over the length.
Unfortunately they won't move equal when scaling.

[Libbya · Accepted solution]

If you want the circles to scale their respective radii without moving then the base of the scale of each circle must remain at the center of each circle.  To accomplish this with a single linear parameter, add a scale action for each circle and set each scale action's base to independent and place the added grip or base location at the center of its respective circle.  Move each scale action with any action that moves its respective circle.  See screencast.

[YoshiCoolen]

Thank you, @Libbya 
You were very helpful.