Re: Can you see what it is?
This reminds me of my garage door opener that came from Germany I think. Anyway it has a captive chain in the top rail and a sprocket follows the chain..the Chain does not move. So the motor is hooked to door. Sprocket spins and walks down the captive chain moving the door
Very Smooth and almost silent. So this is probly a smooth set up and way before its time.