26 Feb
2022
26 Feb
'22
7:21 p.m.
On Feb 26, 2022, at 3:14 AM, Rob Jarratt via cctalk
<cctalk at classiccmp.org> wrote:
I am wondering if I have racked my 11/24 correctly.
As you can see here:
https://robs-old-computers.com/2022/02/10/pdp-11-24-progress/ I have put the
CPU at the top and the two RL02 drives underneath.
That seems fine. Others mentioned having them at the top of a low cabinet, but the RL02s
I used were in H960 (6 foot) racks, mid-level with stuff above them.
The problem is that the CPU enclosure catches on the
RL02 underneath. There
is a bit of play in the mounting bracket:
https://rjarratt.files.wordpress.com/2022/02/cpu-mounting-bracket.jpg. With
a bit of manipulation I can get the CPU to slide in. However, I am wondering
if I have racked it correctly? I don't think there is room to move the RL02s
down and it would presumably leave a bit of a gap below the CPU. There seems
to be very little clearance between the CPU and the RL02 at the front but
more at the back, but I am sure that the rails are mounted horizontally. Is
it just a matter of tightening the big screws that hold the mounting
brackets to stop the play? If so I am not sure I have a big enough
screwdriver!
Hardware stores can fix that. Or Brownells, where you can get really good screwdrivers
that are less likely to damage screw heads than standard hardware store ones do.
Something I observed on my H960 that wasn't all that obvious at first: the holes are
NOT evenly spaced. If I remember right, they come in groups of four where the spacing
between groups is something like 1/8th of an inch more than the spacing within groups.
The consequence is that if you attach your brackets using the wrong set of holes things
may be 1/4 inch (or whatever the delta is) closer than they were meant to be.
paul
