Retrofitting new rails to old DEC gear.

[NeXT]

I gave up looking for compatible or cheap slide-out rails for my PDP gear and its cipher tape drives and instead went to the local recycler and bought several matched sets of heavy duty (You'll need some for an /84 and an RA82 because anything else will just buckle) slide-out rails for other rackmount gear. They don't have any speifically proprietary brackets hanging off of them, either they have regular holes that used to bolt them to their old hardware or keyed holes similar to this.
The problem obviously though is that they line up with nothing on the DEC gear. I need to figure out where everything should be first and then drill new holes and bolt everything in so that it looks like it's using the right rails. Is there much information in retrofitting new rails on?

 

[Qbus]

I used regular equipment slide rails that I have removed from old broadcast and telecom stuff that I had junked. The PDP-11\23 cases have a integrated pan that forms the case and were easy to hang, the RX drive used a standard slide rail system and lined up with regular rail holes but the RL drives had some stupid rail system that lines up with nothing and ended up drilling the rails I had for the original mounting holes on the RL, also discovered that the RL drives are just a little fatter then a regular item so had to mount the slide rails receivers on the inside of the rack rails to give just a little more space so the drive would slide out of the rack. If you need any additional rails I don’t have the original Dec rails but have tons of slide rails from old broadcast equipment and other telecom junk. They all have regular eyelets for attachment to the front of an equipment rack and have assorted clips, brackets and stuff for attaching to the back rails. Just be warned that you have to use a rack with back rails. If you pay the cost of shipping I will send you as many as you want but be warned they are heavy!
Qbus

 

[NeXT]

I don't think I need more rails at the moment as I bought five sets for the five pieces of gear I have. The toughest part was determining what rails would and would not buckle under the weight and how big my steel slug will have to be so that pulling a tape drive out does not tip the rack over.
How did you properly align your new rails ont he RL drive or did you not really care about losing a rack unit or so to misalignment?

 

[Qbus]

I used the original holes that were on the RL01 and think maybe one lined up with the rail that I used. Did end up drilling maybe one new hole in the slide rail center to align with existing hole on RL, maybe a second but cretin there are no more than three screws on the rail on each side to hold onto the drive. Also the screws were a cretin length and fit into a sealed threaded receiver to keep the seal of the drive. Looking at other system always appears that the drives are up top to spare the back of the operator in pulling out and loading the drives but I put mine on the bottom because of the whole if you pull it out the rack may tip over thing. Also by installing on the bottom you can use books to stack underneath and get the rack placement right. A signal with blank rack panel will fit between the RL and the bottom memory unit but did not put one in because clearances would have been tight in pulling out the drive but being that I only have two RL disk packs and one is bad almost never pull out the drive anyway. I have a couple of the five foot full size black Dec racks here at work with other stuff in them and if I ever get a unibus system will pull one of them for that being the original Dec racks have a sideways back rail to attach to the cases and the attaching points for the front outriggers. I did not put any outriggers on the little rack for the 11/23 but being that the drive is in the bottom it has no issues when I pull it out of the rack, do not know what would happen if it were on the top. Also another thing I did before wasting several days building up slide stuff for this was I had a six foot roll around rack with the system, two drives and a RX drive all in one rack and I just used the slide brackets that APC makes for their rack mount UPS system. They are way thin and can support huge heavy UPS systems and the RL drives or just about anything else can sit on them in a rack and slide in and out. The hairy thing was with a RL drive the CG shifts to outside the rack when you slide it out enough to open the drive so if you're not using slide rails attached to the drive things get real ugly fast if you try to change the pack.
Another thing to keep in mind is that if you're racking up a RX drive the rails have to be way long so you can pull the entire assembly out of the rack but still be attached so you can remove the bottom plates and replace the drive belts, maybe that’s why they come with long cables?
Got pictures of what you're racking?

 

[NeXT]

BuMP, because I didn't see your post.

Yeah, here's my rig:

I placed my RA and /84 near the bottom simply because my system would be a total tilt hazard if it was nearer the top. The only thing that can instantly be mounted is a backplane expansion.

Have not yet started installing the rails because I still need to get my hands on a drill...

 

[NeXT]

Old BuMP.

Finally got off my ass, bought a drill and using some cardboard spacers, a screwdriver, $20 worth of nuts bolts and self-tapping screws, and three drill bits (two of which broke) I managed to get the RA82 and /84 properly mounted this afternoon.

Tomorrow I'm shooting for installing the two tape drives and that should be it. Biggest problem so far is that the rails on the /84 obstruct the circuit breaker.

 

[tradde]

I am curious as to what rails you used for the /84. I have one, but have never had rails that would fit.
And I had lots of rails a few years ago.

 

[NeXT]

I found the most adaptable yet most heavy duty rails I could find in the Barrel-o-Rails. I found two sets that are being used now for both the /84 and RA82. They shouldn't buckle under the load compared to the dinky rils I sued for the tape drives.
By the way, I got those done too.

Now I can actually work on everything while it's pushed in the corner.

 

[tradde]

My /84 came with the tilt up adapters on the sides, and I never could find a rail that would fit those.
Sure is a nice feature to work on the bottom. Also mine has the power supply in the back and has
a full width Unibus. Your's looks different with the power supply on the side. Were there different
models like this. I had never seen one like yours till I saw the picture.

 

[NeXT]

I just ended up drilling completely new holes and using self tapping screws. If there's no mount point. Make them.
Mine has hex-width Unibus as well. You sound like you have something like a /44.

 

[Qbus]

True happiness can only be achieved when you have a computer that requires a nineteen inch EIA rack and slide rails! Next start looking for the raised floor, here at work we have one of our old server rooms that’s scheduled to come off line in the next couple years and can't wait to get the opportunity to collect up all the floor stuff. Best part of working for a university is you get access to lots of that type of stuff. Just picked up two full size roll around Dec racks that were on the way to recycling, biggest problem now is running out of floor space.
What issues did you have with the back attachment points for the slide rails? Also I found that when I did the slide rails for my RL drive the drive was just a little bit fatter then everything else and had to mount the receiving rails on the inside of the rack rails instead of over the rails like everything else, did you run into any of that kind of stuff?

 

[NeXT]

The rails for the most part didn't have anything that would interfere with the hardware. It was all flush sheet metal with a few millimeters of play on either side. I started at the bottom and placed the RA82 in top of two pieces of cardboard to make a gap, then after I was sure it was level from side to side I slid it out about six inches and drilled and bolted the front to the rails. Then I pulled it almost the rest of the way out, made sure it was level and drilled and bolted there. Rinse and repeat as you go up. The rails for the tape drives DID have attachment points at the very back but they didn't come close to the back of the shallower drives.

Next start looking for the raised floor, here at work we have one of our old server rooms that’s scheduled to come off line in the next couple years and can't wait to get the opportunity to collect up all the floor stuff.

Raised floors are for people who don't enjoy the style of ceiling hung cable trays/general rats nests.