As strange as this word may sound, the word was named after the Fourth Duke of Orrery, for whom one of these devices had been made.  The plural form of the word is orreries.  

For those of you into DND (Dungeons and Dragons), the fifth edition has an adventure titled "Orrery of the Wanderer".  It's a marvelous artifact with multiple geared components and sweeping hands that is the "Timepiece of Travel". 

I don't suppose any orrery could be constructed to actual scale.