Part Chainsaw, Part Grinder, Pure Tool Envy
Jason from Fireball Tool is quite the manufacturing badass. He's made unbelievable vises, jigs, squares, and even an enormous go-cart belt sander. They guy makes tools like the world used to make tools. Rock solid design and never under-powered. Since he's back in the shop after the holidays, it's only natural he'd come up with an idea like a chainsaw belt grinder.
Call it a sander all you want, but when it's thin and used for metal, it's a grinder. Granted, this is his first design of this, and odds are it'll end up refined into a lighter weight mechanism and available as a chainsaw accessory for purchase. Sign me up for two.