I may be incorrect about this, but I think the problem with a non-horizontal mounting is less about shock protection and more about stress and wear on the drive spindle bearings.

The bearings are designed to run with the disk spindle in a vertical position -- they are only designed to accept thrust loads from that direction, the thrust being supplied (under normal conditions) by Uncle Gravity.

When you tilt the drive, the weight of the disk platters (admittedly small, but so are the bearings!) is applied at an angle the bearings are not designed to accept, at least not during continuous operation. The shock mounting is just to protect against brief, transient bearing loads caused by sudden accelerations in more or less random directions.

That said, I have no information (theoretical nor empirical) about how tough these drives really are. For all I know, running them at an angle will reduce their MTBF from 200,000 hours (or whatever) to 199,000 hours -- or maybe it'll give an anticipated life measured in minutes instead of years. Bonzi -- are you willing to experiment and let us know the results?

I have heard of disk drives (full size desktop drives, not laptap drives) that were spec'd to run either horizontal or vertical -- but NOT anything in between.

tanstaaafl.

"There Ain't No Such Thing As A Free Lunch"