Very interesting. It might be an idea to do some post mortems on the failed drives. [1] Why not take apart some failed drives and see what you can find out as

Very interesting. It might be an idea to do some post mortems on the failed drives. [1] Why not take apart some failed drives and see what you can find out as to why they failed vs. ones that did not. Perhaps info that might be of interest to the manufacturer but in any case would make an good blog post. Or maybe you can cannibalize and use again. [1] I did an "air crash investigation" on a RC Chopper that had crashed. I found out that a servo failed because a part in it was plastic (a gear) (as opposed to, I think, brass). Consequently the jerky move that I made was enough to cause the plastic gear to loose a tooth and then I lost control.