Mounting HP7970e 9-Trk 1/2" Tape Drive

Tapley, Mark mtapley at swri.edu
Mon Feb 11 12:48:59 CST 2019


> On Feb 11, 2019, at 12:24 PM, Jack Harper via cctalk <cctalk at classiccmp.org> wrote:
> 
> At 10:16 AM 2/11/2019, Fred Cisin via cctalk wrote:
>> ...Need to bolt the rear to the floor, or something SOLID, and extend the "footprint" of the front to include where the center of gravity is when fully extended.  And a bit more, so that setting a tool or elbow on it doesn't topple it.
> 
> I bolted the 19" rack with the two HP7970 drives down to a 3/4" thick plywood base about 36" square or so and then anchored that to the concrete floor - before I installed the drives.
> 
> See http://frobenius.com/190203%20Tape%20Drive5.jpg for yet another exciting photo :)
> 
> 
> Best to the List -
> 
> Jack in the Rocky Mountains.

Jack, this looks like a pretty good idea in the short term. But, every piece of concrete I have ever been associated with has been off-gassing water at a slow rate. I have stored wood face-down on concrete enough times that I should know better, and it has always been ruined - rotted - by constant exposure to that water off-gassing. The wood traps the water (which would normally have no problem evaporating, because it is a very slow rate) which then rots the wood. Now whenever I store wood flat, I put bricks or something between it and the concrete so there is an air-gap.

Unless there is a pretty impermeable water barrier between the plywood and the concrete, I would say that solution is not trustable for more than about 6 months of service at the outside. Even if there is, I would check pretty often around the bolt holes, because I think the bolts penetrated the barrier and the wood around the bolts will be rotten soon.

Comments and corrections most welcome from anyone who has more experience, of course; YMMV and I Am Not a Carpenter…
								- Mark




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