Mounting HP7970e 9-Trk 1/2" Tape Drive

Fred Cisin cisin at
Mon Feb 11 11:16:35 CST 2019

On Mon, 11 Feb 2019, Jack Harper via cctalk wrote:
> Hello Chuck -
> I like the idea of those sliding rails - and they appear by the link to be 
> good to 200-pounds.
> However, with the HP7970 Drives, I would worry about the moment pressure 
> exerted on the rack with the unit slid all the way out.
> . . . 
> The 19" rack that I have is actually fairly flimsy and I worried about the 
> thing flexing with the stop/start (15ms stop) of the two Tape Drives.
> Last thing I want is for the tape rack to start wandering about the room with 
> tape action like some of the early disk drives (I remember reading that the 
> original "large" UNIVAC Fastrand drum units laying horizontal would turn 
> circles by gyroscopic action as the Earth rotated :)

A few hundred pounds slid all the way out will topple it.
If the center of gravity is NOT within the perimeter of the base, . . .
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.

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