Extruded rack rails - Available in the US?

S

Simon Coffin

Sophomore
Mar 2, 2011
133
1
18
State College, PA
www.medianengineering.com
Hey Folks,

After 16 years in Germany, work has planted me back in the US, for the near future at least, in State College, PA. Since my whole system was setup for 240v power I've had to convert and repackage the amps and wireless. Since three phase power seems to be nonexistent in any of the venues I'm likely to work in, I've had to take a wholesale step backwards and build a poorman's distro and get a bunch of Edison extension cables. And no, they're not yellow. So far so good, although I miss those really slick three phase CEE connectors already.

While tinkering with the problem of how to rerack everything I started looking at case manufacturers in the US and realized that none of them seem to use extruded aluminum rack rails, only the predrilled/tapped steel angle. Is this normal? In most of Europe, only the cheapest cases have the steel pretapped stuff. Everything from Bargain Basement on up uses extruded aluminum which give you a lot more flexibility with equipment location, is stronger and uses a larger 5mm screw with a nice broad head. Is it normal even at the pro level in the US to use racks with predrilled and tapped steel rack rails?

Here is a picture of the extruded rack rail I'm talking about.


Extruded rack rail.jpg

Ciao
Simon
 
Re: Extruded rack rails - Available in the US?

When you put some components into a rack, leaving space for something that hasn't arrived yet, how do you make sure you leave enough room? seems like there would be a lot of readjusting.
The extruded rails look handy for certain situations, but for every day use I'd rather have it mapped out.

Jason
 
Re: Extruded rack rails - Available in the US?

Those slidey rack rail things are so hard to work with! I hate it if I have to work with those!

I thought they were only sold by Thomann to people who don't know what they're doing?

What do you like about them?
 
Re: Extruded rack rails - Available in the US?

Hey Gents,

I much prefer the aluminum extruded rail because it uses a larger 5mm screw that can hold even heavy metal amps without problem, you can place equipment exactly where you want it and you never have the far too common problem of stripped or poorly drilled/tapped holes. If you do manage to damage a nut with the extruded rail, you just slide the bad one out and replace it. Also, I have never seen a steel rack rail with holes exactly where they should be, they always seem to be offset which reaks of poor manufacturing quality to me. To me, if you are going to do something, do it right. "Close enough" is not acceptable.

And as far as the 19" standard goes, in my day job I can point to lots of seriously expensive rack mount equipment that has oddly placed holes or non-standard height/width.

For large or fixed racks probably mostly in installations, I can see having the holes mapped out to be useful, but in the mobile sound arena, no. Just lay the case down on its back, loosen the screws, adjust as necessary and tighten everything up. Easy...

It's interesting, if you go into any quality case manufacturer in Europe, they all use the extruded rails. If you request a steel predrilled rail they'll laugh at you. America is the other way around. Weird.

On a side note, I considered becoming the European dealer for EWI cases a couple of years ago but didn't simply because the cases had steel rails and would be seen as inferior. The manufacturer was not interested in changing the rails, so I dropped the idea. With good quality consumer grade equipment coming out of Poland and the Czech Republic, and real pro level stuff from several German and English firms, EWI had no chance.

I guess my next couple of cases will come from Germany or I'll make them myself.

Ciao
Simon
 
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Re: Extruded rack rails - Available in the US?

Simon Coffin said:
Hey Gents,

I much prefer the aluminum extruded rail because it uses a larger 5mm screw that can hold even heavy metal amps without problem, you can place equipment exactly where you want it and you never have the far too common problem of stripped or poorly drilled/tapped holes. If you do manage to damage a nut with the extruded rail, you just slide the bad one out and replace it. Also, I have never seen a steel rack rail with holes exactly where they should be, they always seem to be offset which reaks of poor manufacturing quality to me. To me, if you are going to do something, do it right. "Close enough" is not acceptable.

And as far as the 19" standard goes, in my day job I can point to lots of seriously expensive rack mount equipment that has oddly placed holes or non-standard height/width.

For large or fixed racks probably mostly in installations, I can see having the holes mapped out to be useful, but in the mobile sound arena, no. Just lay the case down on its back, loosen the screws, adjust as necessary and tighten everything up. Easy...

It's interesting, if you go into any quality case manufacturer in Europe, they all use the extruded rails. If you request a steel predrilled rail they'll laugh at you. America is the other way around. Weird.

On a side note, I considered becoming the European dealer for EWI cases a couple of years ago but didn't simply because the cases had steel rails and would be seen as inferior. The manufacturer was not interested in changing the rails, so I dropped the idea. With good quality consumer grade equipment coming out of Poland and the Czech Republic, and real pro level stuff from several German and English firms, EWI had no chance.

I guess my next couple of cases will come from Germany or I'll make them myself.

Ciao
Simon
Click to expand...

Heavy amps should be supported in both the front and back; even with a heavier screw, there's too much torque on the flange.

I've never had any issue with pre-drilled rails, short of someone using a power drill to cross-thread the screw. Even then, it's usually the screw that loses, not the hole.

One of the best parts of pre-drilled is that stuff actually fits. It would seem likely that without a lot of care, you're going to end up with the wrong amount of slop between equipment - either too tight, or too loose.

What equipment do you plan to use that doesn't have standard rack holes? The only thing I can remotely think of is that a few pieces of gear want to have a hole in the middle of a rack space, instead of the usual top and bottom, but every pre-drilled rail I've gotten in the last 15 years has 3 holes drilled per "U".
 
Re: Extruded rack rails - Available in the US?

Simon Coffin said:
Hey Gents,
It's interesting, if you go into any quality case manufacturer in Europe, they all use the extruded rails. If you request a steel predrilled rail they'll laugh at you. America is the other way around. Weird.
Click to expand...
Simon,

Lots of weird shit in North America, we never adopted metric even though we tried once..
I wish that would have gone through, I still have to convert to inches and feet to centimeters and meters when it comes to anything that is technical.

Although I have never encountered the extruded rail here in the USA, I clearly think it is a superior design, as you wrote:
"If you do manage to damage a nut with the extruded rail, you just slide the bad one out and replace it".
There are replaceable Tinnerman nuts behind larger (sloppy) holes on some aluminum rack rails, but they are still stuck in a specific spacing.

Since the extruded rail allows for any placement of rack gear, you are not stuck trying to shoehorn in some slightly over sized piece (usually because of screws on the bottom and top are slightly over a "rack space") or shimming up an undersized piece.

I have always used 1/4" (near 5mm) screws in "T nuts" through plywood (or lumber) rack rails on amp racks.
The steel pre-drilled/tapped steel angle rack rails have been adequate for most lightweight processing equipment, other than the deviations from standard "rack spacing" that is ever present when "rack spacing" is an inch based system while most of the world uses metric.
 
Re: Extruded rack rails - Available in the US?

Hey Art,

At work, I have upwards of two dozen, full height installed racks. A few are non-standard vendor specific things, amongst the other so-called standard racks, there are three different threads used. Even I have bunged up a hole using the wrong screw. Because the threads are so poorly cut, its hard to tell if you are messing up the threads, have an already messed up hole or just have a tight screw. That is never an issue with the aluminum extruded rail. They all use a 5mm screw with the same thread pitch. Always. The only variable is the length of screw, usually 15 or 20mm depending on the thickness of the rack ear.

The 19" standard, while being a good idea, is hardly precise. Manufacturers will stretch/shrink the dimensions to meet their own needs which makes the fixed spacing of the predrilled rails all the more impractical. Add some poor manufacturing quality to the mix and the situation can become unworkable.

An interesting note from a case manufacturer I worked with on a project in Germany. While you are right that the 19" standard is non-metric, the metric system defines it more precisely. A rack space is 44.45mm if I remember correctly. That is the size of the space, the equipment that goes into it needs to be approx 0.5mm smaller than that. The distance between the rails, the center to center distances of the screw, the maximum allowed width etc. are all precisely defined and adhered to. Try seeing that level of precision here in the US. Every rack I look at is +/- 1/8".

Ciao
Simon
 
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Simon Coffin said:
Hey Art,

At work, I have upwards of two dozen, full height installed racks. A few are non-standard vendor specific things, amongst the other so-called standard racks, there are three different threads used. Even I have bunged up a hole using the wrong screw. Because the threads are so poorly cut, its hard to tell if you are messing up the threads, have an already messed up hole or just have a tight screw. That is never an issue with the aluminum extruded rail. They all use a 5mm screw with the same thread pitch. Always. The only variable is the length of screw, usually 15 or 20mm depending on the thickness of the rack ear.

The 19" standard, while being a good idea, is hardly precise. Manufacturers will stretch/shrink the dimensions to meet their own needs which makes the fixed spacing of the predrilled rails all the more impractical. Add some poor manufacturing quality to the mix and the situation can become unworkable.

An interesting note from a case manufacturer I worked with on a project in Germany. While you are right that the 19" standard is non-metric, the metric system defines it more precisely. A rack space is 44.45mm if I remember correctly. That is the size of the space, the equipment that goes into it needs to be approx 0.5mm smaller than that. The distance between the rails, the center to center distances of the screw, the maximum allowed width etc. are all precisely defined and adhered to. Try seeing that level of precision here in the US. Every rack I look at is +/- 1/8".

Ciao
Simon
Click to expand...

I just got some GLD stage boxes and while the front panels were 1U & 3U, they had riveted on feet that would not go through the opening. Sigh...


Sent from my iPad HD
 
Re: Extruded rack rails - Available in the US?

Rob Spence said:
I just got some GLD stage boxes and while the front panels were 1U & 3U, they had riveted on feet that would not go through the opening. Sigh...


Sent from my iPad HD
Click to expand...

Rob, the feet *look* riveted on but they aren't--there's a little expanding plastic fastener that lets you pry them off, if you haven't already done so. The stage boxes will fit in 1U and 3U after you remove the feet.
 
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Re: Extruded rack rails - Available in the US?

Simon Coffin said:
Hey Art,

At work, I have upwards of two dozen, full height installed racks. A few are non-standard vendor specific things, amongst the other so-called standard racks, there are three different threads used. Even I have bunged up a hole using the wrong screw. Because the threads are so poorly cut, its hard to tell if you are messing up the threads, have an already messed up hole or just have a tight screw.
Click to expand...
So you're working in a university that's built up its equipment over a number of years, and has a variety of standards. Welcome to the real world. 10-32 is the standard...it's what every rack will ship with today, unless you spec differently.
That is never an issue with the aluminum extruded rail. They all use a 5mm screw with the same thread pitch. Always. The only variable is the length of screw, usually 15 or 20mm depending on the thickness of the rack ear.
Click to expand...
Sure they do...but they didn't always. Someone's taken the initiative to implement a standard and use it, retrofitting stuff as necessary. Kind of what you're trying to do. BTW, you'll never bottom out a screw in NA rails.

The 19" standard, while being a good idea, is hardly precise. Manufacturers will stretch/shrink the dimensions to meet their own needs which makes the fixed spacing of the predrilled rails all the more impractical. Add some poor manufacturing quality to the mix and the situation can become unworkable.
Click to expand...
Fair enough. So what you're saying is that American manufacturers, who build to the EIA spec, shouldn't be so picky?

An interesting note from a case manufacturer I worked with on a project in Germany. While you are right that the 19" standard is non-metric, the metric system defines it more precisely. A rack space is 44.45mm if I remember correctly. That is the size of the space, the equipment that goes into it needs to be approx 0.5mm smaller than that. The distance between the rails, the center to center distances of the screw, the maximum allowed width etc. are all precisely defined and adhered to. Try seeing that level of precision here in the US. Every rack I look at is +/- 1/8".
Click to expand...
Saying 44.45mm is more accurate than 1.75" is absurd--they're exactly the same thing. Someone took the imperial 1.75" standard and converted it to metric--that's all. Good luck finding 44.45mm on a tape measure, though :P
I'm not understanding the +/- 1/8" bit. I wooden rack, OK, fine...but it's wood. It flexes. A steel rack, though? I know Middle Atlantic uses 19 1/8", but there's no +/- about it...it's exactly 19 1/8". Sure, it's not EIA spec, but they're giving you some space to slide things in and out. I'm totally fine with that.
As an installer who doesn't have the luxury of laying a rack on its back, I'll take the preset holes any day of the week. Last thing I need when trying to install a heavy amp is to have things slide around on me. Plus, getting things square is a no-brainer.
Incidentally, there is a common type of rail here that may be more to your liking - it's a called 'cage nut', and I'm sure any rack manufacturer would be able to provide you with a rack using that. The rail has (EIA-standard spaced) square holes in it, into which you slide a replaceable cage nut. Middle Atlantic Products - Rack Rail

Previously, you mentioned how great the heads were on the 5mm screws, relative to what you've been relegated to using here. I'm curious as to whether you're using hardware-store screws, or actual rack screws purchased from a rack manufacturer? Rack screws have a much larger head on them. Also have pilot bits that make them easy to align. Middle Atlantic Products - Hardware
Ciao
Simon
Click to expand...
Cya,
Jonathan
 
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Re: Extruded rack rails - Available in the US?

Jonathan Kok said:
So you're working in a university that's built up its equipment over a number of years, and has a variety of standards. Welcome to the real world. 10-32 is the standard...it's what every rack will ship with today, unless you spec differently.

Cya,
Jonathan
Click to expand...

Perhaps in this industry, but that other industries that use EIA racks commonly use M6 or 12-24 screws instead of 10-32. Something about heavier equipment and stronger screws...

And that's if they are even using threaded holes, and not the more common square holes and cage nuts if needed (and the cage nuts are a major pain, which is why many servers are designed for screwless monting in the square holes).
 
Re: Extruded rack rails - Available in the US?

Simon Coffin said:
An interesting note from a case manufacturer I worked with on a project in Germany. While you are right that the 19" standard is non-metric, the metric system defines it more precisely. A rack space is 44.45mm if I remember correctly. That is the size of the space, the equipment that goes into it needs to be approx 0.5mm smaller than that. The distance between the rails, the center to center distances of the screw, the maximum allowed width etc. are all precisely defined and adhered to. Try seeing that level of precision here in the US. Every rack I look at is +/- 1/8".

Simon
Click to expand...

Jonathan Kok said:
Saying 44.45mm is more accurate than 1.75" is absurd--they're exactly the same thing. Someone took the imperial 1.75" standard and converted it to metric--that's all. Good luck finding 44.45mm on a tape measure, though :P

Jonathan
Click to expand...

That's why he didn't say that.

Accuracy and precision - Wikipedia, the free encyclopedia


Chris
 
Re: Extruded rack rails - Available in the US?

Rob Timmerman said:
Perhaps in this industry, but that other industries that use EIA racks commonly use M6 or 12-24 screws instead of 10-32. Something about heavier equipment and stronger screws...

And that's if they are even using threaded holes, and not the more common square holes and cage nuts if needed (and the cage nuts are a major pain, which is why many servers are designed for screwless monting in the square holes).
Click to expand...
Fair enough. However, since we're talking about our industry, 10-32 is the standard.
As for the cage nuts...I did mention those.
 
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