dumb question about rackmounts

jinithith2 · #1 03-16-2008, 07:56 AM

I have always been puzzled by them since I do not readily have an access to look at a fully set up rackmount system in person. I always wondered how the back of the rackmount units stay up meaning...

the front has 4 screws to mount it, but do the 4 screws really have that much strength to hold it up perfectly parallel to the floor? I always pictured the rear of the rackmounts sagging or something.

sorry for the stupid question. finally had to come out

BryanM · #2 03-16-2008, 08:04 AM

The screws at the front generally do hold it up, the chassis of rack mount gear is specifically designed so that the rack ears are weight-bearing, to prevent equipment from sagging in the rack.

bongomania · #3 03-16-2008, 11:37 AM

+1, however note that some power amps require additional support in the rear, and some racks have rear-mounting systems for that purpose. But it's only the biggest and heaviest gear that needs rear support.

jinithith2 · #4 03-16-2008, 08:05 PM

does this factor make the mounts really fragile?

bongomania · #5 03-16-2008, 08:06 PM

Which factor?

jinithith2 · #6 03-16-2008, 08:08 PM

the whole "only screwed in front" factor

niftydog · #7 03-16-2008, 08:12 PM

No, it doesn't, at least not as a general rule, I'm sure there's exceptions. Rack mount 'ears' are usually made of 5-6mm thick steel, and all rack mount enclosures are designed to carry their own weight canterlevered off the ears.

bongomania · #8 03-16-2008, 08:15 PM

Right, the whole point is that the gear is designed that way on purpose, and has been for decades. Granted some gear is manufactured to very low quality standards, but the majority of rack gear is perfectly safe being used in the manner for which it was designed.

Hoover · #9 03-17-2008, 10:09 AM

Quote:

Originally Posted by bongomania

Right, the whole point is that the gear is designed that way on purpose, and has been for decades. Granted some gear is manufactured to very low quality standards, but the majority of rack gear is perfectly safe being used in the manner for which it was designed.

I think it's important to add a caveat to the above:

Yes, rackmount gear was designed to be mounted in a rack so that the face is perpendicular to the floor on purpose, & yes it has been that way for decades. However...the original design was for stationary racks in permanent installations. As soon as you throw "transportable" into the equation, all bets are off. Very few pieces of rackmount gear, even at the highest level of construction, can be mounted in a rack that's going to get shipped around the country (or world) and survive unscathed without some additional rear support. If you're building a bass amp or effects rack that you'll be carrying to gigs & rehearsals & recording studios, loading it in & out of cars or trucks or trailers etc, it would behoove you to not rely exclusively on the (4) screws & faceplate to support your equipment, but rather to add some form of rear support. Becase otherwise I can almost guarantee that the first time some idiot accidentally drops your rack off the tailgate, your rackmount equipment will bend right at the front panel faceplate/rackears. Seen it happen hundreds of times.

TrevorOfDoom · #10 03-17-2008, 10:14 AM

yeah. it's designed that way.

that said, i stuck some of those clear plastic feet under my amp at the back to help support it, just in case.

jinithith2 · #11 03-17-2008, 10:33 AM

thanks for the great responses guys! Hoover, thanks for the little heads up.

bongomania · #12 03-17-2008, 10:35 AM

Quote:

Originally Posted by Hoover

I think it's important to add a caveat to the above... Very few pieces of rackmount gear, even at the highest level of construction, can be mounted in a rack that's going to get shipped around the country (or world) and survive unscathed without some additional rear support.

That's a fair statement for sure, it is important to look at how the rack will be handled. I guess I should alter my original point to say "outside of being dropped from a height", as that is -as you say- when rack gear will get damaged without extra support.

Hoover · #13 03-17-2008, 10:48 AM

Here's a tidbit of advice if you are transporting rackmount gear: Carry the rack face up in the car/truck/airplane. This way the rack rails are supporting the weight of the gear, and there's less leverage on the back of the equipment when bumps, bounces, vibrations etc are encountered. If you transport the rack in it's "operating" position (face forward) all of the weight is on the heads of those four rackscrews, and the unsupported back end of the gear can bounce enough to torque those screwheads off.