After the successful trial of my homemade Incubator now am trying my luck with 38 Eggs.But looks like I did a mistake by wrapping the incubator with aluminum foil from inside, as a result of that temperature is getting high even if I lower the voltage and it also loses heat very quickly
Put the eggs in [EDT: Topless, cardboard, to allow for airflow] cartons and tilt the cartons to turn them. It's much easier. You can also rotate the cartons so that different ends are closer to the heat source, so your chicks bake evenly.
Put rocks or water-bottles inside the incubator. They're heat sinks and will make it so that the incubator doesn't change temp so quickly.