Turning mechanisms are easy. All you need are a couple of microswitches, a clock motor and a gear motor. When I started making them I actually machined the swing arm from solid stock because I was converting old incubators to auto turning and the tray width varied so the arm length varied, and I coud machine in the cam on a rotary table with a single set up. Now I would just get a swing arm from Dickey, or GQF and keep the tray dimensions the same as those incubators. pictured below is an incubator I made in 1964. I made quite a number of these in the early sixties. Take note that all the controls are front mounted and readable at a glance. These were three quarter inch Marine Ply sealed with a boat sealer. The primary thermostat is mounted on the back wall because the tempature could be controlled more precisely when mounted thusly with the wafer thermostats availabe at the time.
