The first chickens I ever had were hatched in a cardboard box with a
lamp for heat, and a garden thermometer. We just hand turned the eggs,
either once or twice a day. I cant remember which, we did this in the
early 70s.
I can tell you it does not have to be slow and constant. Incubators turn
slow and constant because that's easier to design, and it still works.
If not turned, the embryo will stick to the shell. But if you miss one
day, nothing bad is likely to happen. Turning more frequently than
necessary shouldn't cause any problems either. If somebody here can't
give you a more precise turning schedule, google it on the internet, and
you will have no trouble finding an answer.
You might look at a website that sells incubators. Look for one that
doesn't self turn. See if you can download the instructions. That will
tell you how often to turn.