I'm pretty sure it's a flexdrive... He's mentioned that in almost all of his posts.
Running a flexdrive without a load is sure to toast the driver, though unless you have very fast reflexes and building skills I'd doubt you'd be able to fry the diode before the flexdrive gave up the ghost. With the only two flexdrives I've ever bought I ended up hooking them each up to a diode that had apparently gone open circuit without me knowing, and I nuked the two flexdrives instantly upon trying them on that diode. Best $58.30 I've ever spent :