Construction starts with a 1" steel shaft, 4 drilled and countersunk flanges are welded to this shaft. to these flanges are screwed 4 laminated plywood 16" diameter circular frames. To these frames are glued and screwed 7 longitudinal 1 X 4's and 1 - 2 X 4. Extra long screws are used on the 2 X 4 and it is drilled to take the top of the door cables.
Here are the laminated 16" plywood frames and the steel flanges.
I am using # 14 X 2 1/2" screws, so I laminated screw backers on as well.
Here the flanges are welded on.
And here the frames are screwed on to the flanges.
Starting to install the longitudinal frame members.
All done, trying it out for size.
It will be mounted on 1" standard duty flange bearings and driven through a 1:60 worm gear.
I will operate the worm gear with pulleys and a crank over the winter. If everything holds up well I will motorize it next year. Next the welded mounting brackets.