Arcs, constrains, scale action with rotation

[Anonymous]

Hi guys

I am having some trouble with constraining a door opening arc to a scaling block of doors. I would like to constrain the arc points to a scaling door block.

The center point of the arc is fixed, but when stretching the width of the door the arc should slightly rotate.

I don't know how I should constrain this, there are no tools for scaling, stretching arcs in dynamic blocks.

Red, blue and gree lines shows how the arc rotates when I strech door. The angle of rotation is variable 😐

I have straight auxiliary lines coming out of the center of rotation and they extend correctly. How do I constrain the arc to them?

Regards

[Libbya · Accepted solution]

Don't use constraints.

Use a chained polar parameter and use a polar stretch to 'rotate only' the arc.  See screencast.

[Anonymous]

thanks, very helpful

[Anonymous]

I have used a chained polar parameter and use a polar stretch to 'rotate only' the arc.  

eventhough arc's one of the end is extend with proportional to adjusting length

I have attached the file below. also adding flip parameter's ,after two or more flips arc moving weiredly.