Best 3D printer for schools?

[djprinter]

I'd suggest a Printrbot Play. It's inexpensive so you can buy a few of them, and students don't really need a large build area since they'll want their prints to not take too long.

https://printrbot.com/shop/assembled-printrbot-play/

PLA is non toxic so don't worry about enclosing it. The power tools in the wood working shop are a hell of a lot more dangerous than getting burnt on a hot end.