Finally i am able to bring a video i was challenged to do a while back. a spiral piston door with the double piston extender coming from the ceiling.

This has 2 little advantages, 1st you can pass through the door whithout haveing to wait untill the opening sequence is finished and second you can have a lamp in the ceiling / middle of the piston door which is pure style in combination with the smooth opening and closeing sequence. Let me know your thoughts in the comments.