Stacking Disk Shelves without shelves/brackets

[Bert]

I have a very sturdy rack that comes with strong base. I took advantage of the bars with the help of plywood and formed a strong foundation to stack my disk shelves. I am planning to stack one Ds4243 at the bottom and two xyratex/dell 1235 on top of it. They stand well today without any disks but I am worried about the impact of the disks when I added them.

I plan to secure all the shelves to the rack cabinet with bolts so they will be putting some of the front weight to the rack cabinet. My worry is that if the weight of two 1235 would crush the DS4243 chassis. Did anyone have previous experience on this?

 

[gregsachs]

I'd be hesitant-a loaded 4243 is ~110 lbs, and a 1235 is ~50.
APC 0M-756H rails are readily available for ~$25 on ebay and very robust, being designed for UPS units.

 

[John Piontkowski]

the weight probably isnt a problem, but stacking drive shelves is not advised because the vibrations transfer between units and can cause drive errors or even failures if different RPM drives are mixed

 

[Spartacus]

the weight probably isnt a problem, but stacking drive shelves is not advised because the vibrations transfer between units and can cause drive errors or even failures if different RPM drives are mixed

Unlikely, I've seen stacks of 10+ 2u Dell poweredge servers in rooms were there were no racks (cant work on any of them but wasnt my problem).
Other than the vibrations, which is pretty minor of a concern it should be fine as long as theres nothing to bump them too hard (which sounds like isnt an issue since they're secured to the case).