simplicity does make it simple i tend to use what is availible at handHey I found a thread showing somones Home made incubator simulating a Dickey. third picture down shows a view through the back of the Bator.
Looks like the turners are attached to a single motor that pulls them down one way..... I suspect the trays are weighted the other way to lift them back up....
https://www.backyardchickens.com/a/dickeys-incubator
Ilike the design because there are doors both front and back to access individual components for maintenence. Like someone said.... simpler is better and I do agree.
deb