I shrank the sail in my ship and made the rotators easier to see.

Activate 1 + LandingGear off to fold them

The red and green rotators are powered while the whites are floppy.

Red rotates forward while green rotates backwards.

You can check their properties in overload to see how they work. Pay attention to the rotator's Range, Min and Max Values

To prevent the sails from going backwards if the wind is blowing from the front, the mast and red section of the sails has thier collisions enabled.

sometimes the game bugs out and disables the collisions of fuselage blocks close together them quickly enables them. This is why the mast is just 1 piece of fuselage block to prevent the parts from getting stuck inside it if its made of multiple blocks.

Also, dragScale and massScale determines how much the wind affects your sails. Disable them in the rotators