Question: what are dwemer gyros used for?
Answer: Dwemer gyros can usually be found in Dwemer Ruins, and cannot be smelted into Dwarven Metal Ingots. In the Dawnguard add-on, one of the quests for the Dawnguard (A New Order) requires that the Dragonborn retrieve a Dwemer gyro for Sorine Jurard to be recruited.