here are the pictures of the second prototype of my tilting garage
doors. They're big enough for the new fire engine and easy to get
(opposite of old town roller doors, which are too narrow and rare).
http://www.kostky.org/data/mocs/gd.mpd
The file just displays the final model, in order to build it correctly,
build doors, then half of frame with rubber belts, then put there doors
and finish the frame with rails.
I've used one unofficial part: x783 - technic pin long.
Number and length of rubber belts is up to you. Currently I have there 4
mid black ones, but it seems that the door movement is a bit lazy. It's
also possible to replace 1x7 liftarms with 1x9 and move the pin with
bush farther from the long pin.