Hi Bernie
This is my first attempt at crane motors. As you can see there are two motors and a servo. I have used one motor to drive a worm gear for the rotation system. The second motor is geared to a pulley drum to lift the hook. The servo is on a long arm to push the crane arm upwards.
I've found the forces needed are greater than plastic will withstand, so have started on a second version, using steel plate for the frame and a better gearing system.
I came unstuck when it came to lifting the arm, as it was pushing the whole crane out of the boat. The original design was to insert the whole crane down into the drive hole, but I had not thought out out a latching system to keep it in place.
I'm afraid I've stuck at this point and left it to go on to another boat, so it's just sitting there looking pretty at the moment.
Hope this helps.
Cheers...Ken