DIY Linear Actuator or...

[Finster]

Hmmm...

Making it freewheel at both ends is a much more difficult problem. Something I'd really need to think about. You could grind down the threads at each end so the screw would just spin but you'd need some sort of spring arrangement (or something) to re-engage the thread when you wanted to move in the other direction. Looking for a solution I did come across this which I know is different altogether but you might be able to adapt the concept.

https://www.youtube.com/watch?v=5xZKDlhF_os

It's an interesting problem. I'll keep thinking about it...

[Rvjimd]

Ya, that thing looks cool!

Jim

[Finster]

Jim,

Found two more variations of a diy actuator with a clutch.

Output positions subject to input motion direction 3 by thang010146
https://www.youtube.com/watch?v=Zhz2hkQtg6U

And this one is pretty much how I was thinking of doing it.
Kraftheber mit Spindelantrieb und Rutschkupplung
https://www.youtube.com/watch?v=kQmJMxQA5C8

[Bo Wallen]

How about spring loaded door and rope and pulley system ........? Little motor and a drum......cheapest solution i can think of today.