Wouldn't it just be easier to use a flash drive?

"Frank Whiteley" wrote in message
oups.com...
I plan to build a sealed case. This leads to temperature and sealing
concerns. As the field elevation at my club is 5500msl, we clearly
spend most of a good soaring day well above 10,000msl, above the rated
spec of most small HDDs. There are some drives rated to 10000m, but
I'm not sure they'd work in this device, so I'm not going there at this
point.

I plan on visiting a local aluminum vendor. They have a huge selection
as they are an outlet for Lockheed/Martin Marietta scrap. At least one
side of the case will be an aluminum heat sink for the case as I think
heat buildup is an issue with spinning a small HDD for several hours.
Could be a sandwich style with aluminun on either side of an acrylic
frame would give the most rigidity and cooling. The PSI load will get
relatively large, so latching the case shut will be the key to an
effective seal. The V500 is looking more attractive due to it's more
compact size and simple power requirements and stowage.

I'd add a small pressure gauge of appropriate scale and a strip
aquarium thermometer. Probably install a small screw valve and blow a
little pressure into the case. I envision that at our altitude, I'd
pressurize it to 1-2psi above ambient field air pressure to get a
positive indication on the pressure gauge, for confidence in the seal.
It could simply be closed at ambient pressure also. Since any small
pressure gauge is going to register a relative increase in pressure,
near sea level sites to maybe 5000msl with the expectation of going
above 10000msl, sealing might be enough as the gauge would indicate
positive pressure during climb. I think I'd consider the effects of
density altitude also, since on a hot, relatively humid day, airfield
density altitude is getting close to the operational limits of the HDD.

The HDDs have a low pressure limit, but they also have a high pressure
limit of about -1000ft/-300m msl which is 15.23psi, so real care with
positive pressurization is warranted.

Frank