I have a design i'd like to laser cut and need to put a circle in the middle of the red lines. 
Do you know a way to link the circle in the middle of each line without having to do it manually and keeping the thickness editable ? 
For instance, if I change the thickness of the red line, the thickness of the circle would also change. 

Thank you !

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/3gJWl.png