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NeXT
March 28th, 2011, 06:38 PM
I'm throwing my PDP-11 into a rack for ease of maintenance but when it was originaly taken out of service, the slide-out rails were not kept together so I'm missing half my rails.

http://techpubs.sgi.com/library/dynaweb_docs/hdwr/SGI_EndUser/books/1450_MI/sgi_html/figures/slide.ass.extended.gif

I only have part A. Parts B-E are missing and are probably still attached to the old and long gone rack.
I'm wondering if I'm able to easily replace the old ones with newer ones or will I run into compatibility issues and have to drill new mounting holes?

Lou - N2MIY
March 29th, 2011, 02:32 AM
The type of rail shown in your sketch is from General Devices. You can still buy any part you need. The catalog is here: http://generaldevices.thomasnet.com/asset/GeneralDevicesProductCatalogReduced.pdf

You will see that they do come in different lengths and you will need to measure your rack.

Lou

RSX11M+
March 29th, 2011, 04:32 AM
The type of rail shown in your sketch is from General Devices. You can still buy any part you need. The catalog is here: http://generaldevices.thomasnet.com/asset/GeneralDevicesProductCatalogReduced.pdf

You will see that they do come in different lengths and you will need to measure your rack.

Lou
Thanks for the link Lou. Just looked... Top notch stuff... they have the pivoting ones too. Really nice!

You might answer a question if you can... are these parts compatible with the original ones?

Fact is, I kept all mine so I should be good.

BTW - That admonition about [I]checking the slide length / rack depth reminds me of a story.

One of the more motivated guys in my group got so tired of having to deal with field service techs who ordered the wrong slides for our racks, he had one of the mechanical guys come up with "extender adapters". [I'll post a pic of one] Made engineering drawings, assigned part numbers... everything.

He was constantly shipping em everywhere in the country. He had the shop make em out of Stainless Steel. [nice job] I'd see em whenever I went to the field on a job or a visit. Always makes me smile to see the ingenuity of people.

Hadn't thought of that in years. Wonder what Paul's doing these days? Oh well, just another tale in a long lost DEC history.

Lou - N2MIY
March 29th, 2011, 04:17 PM
Yes, it is amazing that good old General Devices Chassis-Traks are still good. It's a design that has stood the test of time. As far as I know, they are still the same. I have some from the early 70s, and some from the 90s, and they still play nicely. There are not many items that stay in production for this long without being messed up (for some reason the Technics SL-1200 turntable comes to mind).

As for chassis traks of the wrong rack length, well, I come across that often. My local surplus place still has a good number of them, but they are usually too short. Like your buddy Paul, I make extenders too. I am lazy, so I make them out of the brackets that Ikea gives you to secure your Billy bookcases to the wall (obviously not many of my bookcases are secured.....)

Lou

NeXT
March 29th, 2011, 09:22 PM
I should point out that the above picture was one I pulled off the web in hopes it best matched what is currently on my equipment. I don't know if that's waht I really have.

Qbus
April 1st, 2011, 04:58 AM
If you have not found any love for your rack rails let me know, I have bunches of rails from all sorts of stuff. You will have to know the depth of the rack from front rail to back rail and the width of the item you're mounting. My experience is that the RX type drives use standard GD rails, the Q bus frames use no rails and I had to re drill all the drive mounting holes on the rail to put together GD slide rails for the RL drives. Do not know because there were no rails or rack with the stuff when I got it but the RL driver rail system appears to be something unique to them. Also may recall that I had to mount the rails on the inside of the rack, behind the front rails to get good clearance for the drive to slide in and out smoothly and using the standard GD rail system had to cut about 1/8 inch off that stupid inspection cover on the side to clear the outer rail shell. Had I know in advance would have lowered the rail mounting holes 1/4 but only discovered that the cover hit after it was all together. The Q bus frame and expansion chassis are designed for regular rack mount in the front and side attachment in the back so if you donít have a Dec rack you have to build adapters to support back out to the rear rails. Have no idea how a Unibus frame hangs but think it takes a standard GD rail. I have a couple old six foot Dec racks at work that have other equipment in them that have been around the university for ever and have been making plans on replacing them with new racks just so I can get real Dec racks at home. Contact me directly with lengths and requirements and we can work something out.
Ray F.