Originally Posted by L8 ECU

Single phase for those who dont know is just normal mains supply

Most of what you suggest runs at a fixed speed or 2 or 3 fixed speeds as they have diffferent windings.

squirrel cage stuff is fixed (possibly 2 or 4 speeds as you say)

Drill controller will NOT be isolated from the mains so thats a safety issue if you link it to anything else.

who mentioned drill controllersl? i just used the drill motor as an example of a typical variable speed single phase ac motor! since you mention a drill controller however, these (and motor of this type) can be used with opto isolators to give mains isololation if required

As for stepper motors providing airflow needed for this application - No chance .... LOL