I’m on homemade incubator MKIV. First was still air, cardboard box, second a cake tin, third was a pick nick cooler and forth is an old cabinet, insulated with fans, heated with propagator heater, and a pivoting egg turner, which is manual but means I only need to open the door to add water.
It’s not that the original MKI,II and III didn’t work, I just like messing about to see if I can improve the design. Get about 80% success with the present one, although I must admit I do have a good thermostat that I salvaged from a scrap machine at work.
If anyone is interested I can try and take some photos and do a more detailed description. Although should only be built if you have time as if I calculate up all the time I spend messing with them I probably could have brought a rather expensive, state of the art production model.