There have been some arguments that the following two questions (and perhaps others like them) are off topic at this site, and perhaps should be migrated to electronics.SE. What does the community think?
After the migration of Why do we need brushed motors? from an electronics.SE moderator:
This question did alright, but Electronics.SE is about designing electronics and actually does not include mechanical issues such as motors except at a superficial level. We will see if that changes, but unless it is a good motor question, please do not migrate. – Kortuk
Now we have at least one rule about things to not migrate.
It might be worth getting some feedback from Electronics.SE. They certainly have more of an engineering/design feel to them, but both of these particular questions could have been asked before the discovery of the electron, and thus predate "electronics" as such.
I'll pop over to their chat and ask people to have a look.