@natsu that should have worked as long as you only had one fusion coil on the map. if you still cant get it, try loading an empty map and testing it. If you made the first fusion coil and set its min and max count to 1 and 1, then went on to add more coils, this would not work. The min and max count are inclusive for all the fusions coils. so for example, if you made 6 fusion coils, the min and max counts should both be set to 6 and so on.
if you want to make it rain coils(or anything really), build a plaform somewhere in the air. place a lot of coils on top and set them to instant spawn. then, remove the plaform. coils should spawn in the air and automatically fall.