Racks, rails and panels

On Tue, Nov 18, 2003 at 10:18:30PM -0500, Ian Primus wrote: That is completely ordinary. I have well over a dozen DEC racks... they have bare holes onto which you Clip tinnerman nuts, except for the really old racks (pre 1968) that are solid and have to be drilled for rivnuts (you install them like pop rivets, but there's no central shaft when you install them, just internal threads). In effect, yes. There is no guarantee that all rails will fit all racks. DEC rails will fit a DEC rack, though. I might have missed something, but it's possible that your Eagle came from a generic rack, not a DEC rack. In practice, in the past, I've seen systems that had mixed rack styles... DEC hardware in a DEC rack, and third-party hardware in another rack. My PDP-8/L + BM08 came in a third-party rack with third-party rails that just plain don't fit the CPU. Someone before me drilled extra holes in the CPU case, but that wasn't enough - the width of the CPU itself is about 2mm narrower than the space enclosed by the rails - I had to find a way to shim the CPU rails with washers to get a proper fit. When I got it, it would bind and occasionally hop the tracks. Worst installation of DEC hardware into a rack I've ever seen. If I had a set of rails for the -8/L, I'd have moved it all to an H960 long ago, but all of my -8/Ls came as table-top or rail-less. Your fit issues are nothing modern. Personally, I was surprised the first time I ran into "modern" racks for PeeCee servers. One of the things I like about DEC racks is that you don't have to worry about stripping out threads in the rack uprights. I've only ever had to throw away a few Tinnerman nuts, but that's a lot better than ruining a thread on a rack. Just this week, we ran into a rack incompatibility at work: we received rails for some modernish Compaq server that wants to mount into a rack with square holes that normally accept another style of clip-on nut. The rack, unfortunately, is of the pre-threaded variety. We ended up bending back the locking tabs meant to rest in the square holes, and boring out one of the threaded holes to accept a #12 bolt. For next year, though, I think we'll bring down a real HP/Compaq rack and replacement rails. -- Ethan Dicks, A-130-S Current South Pole Weather at 19-Nov-2003 13:20 Z South Pole Station PSC 468 Box 400 Temp -39.2 F (-39.6 C) Windchill -60.1 F (-51.2 C) APO AP 96598 Wind 6.6 kts Grid 031 Barometer 677.5 mb (10719. ft) Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html