DIN Rails ??

[Buddym]

Hi all,

Are the mounting rails in the pedestal referred to as DIN rails? If so, is there more than one style/type? I see lots of them on ebay but I don't know if they are the right part, they don't look tapped..maybe a twist lock of some kind ( DZUS )??... I see that OpenCockpits has the replica DZUS fasteners, but looks like they have a screw/nut on them. Will that work correctly with the DIN rails?

I see that some builders use a wooden rail and screw directly into that, is that the norm?

Thanks,
BuddyM

[Michael Carter]

I've never heard of them refered to in that way, but it is a standard rack width, so I could see them using DIN to refer to them.

There is only one type that the manufacturers use that I'm aware of but I don't have the specification for it on hand.

The rails are not tapped. There is a small stiff length of wire attached to the underside of the rail at each hole for the Dzus fastener to grab as it's pushed and turned in the hole.

I built my overhead but didn't use the rails because of the cost. Instead I used 1/2" aluminum angle with holes drilled for the fasteners. A cotter pin acts as the retaining wire for the fasteners.

In the control stand, nothing is attached in this fashion. The units are all just sitting in the rack in drilled holes in the rails. They aren't going anywhere in a horizontal position.

You can use wood, but I don't recommend it for the overhead. You'll need to fasten everything in with wood screws to keep it from falling out. They don't quite have the same effect as Dzus fasteners.

A machine screw and nut will not work with a real Dzus rail because the achoring wire is in the way.

[Rodney]

You could also use a slip on nutplate on the backside to secure a 8/32 or 10/32 screw. But if you use a pre-made rail, then use the dzus fastner. Just depends on the look and how much of a purist you are. They are available from some sim vendor sites and not that expensive. The design is for quick release to remove modules for repair. I prefer to use them where designed. Way too many screws of different lengths, size and metal type in a cockpit.

[Michael Carter]

Way too many. They use a half a dozen different fasteners just on the instrument panel. All brass too.

The 1/2" aluminum angle/cotter pin method works good too for Dzus fasteners. Saves a lot of money on rails and you can't tell anyway after installation.

The downside is that you have to have access to both sides during panel installation unless you tack weld or JB Weld the cotter pin to the underside of the rail. Still, cheaper than the real rails.

[vidarf]

I bought DZUS replicas from FlyEngravity and used a standard M4 bolt with nut to secure the overhead panels. Works very well. My overhead is made of aluminium L -shaped rails and hardwood (oak, maple or similar). Just drill holes, thread the bolt and secure the nut from behind. A little hassle to do, but you do not need to be able to remove just one section/panel anyway - Typically, the different panels are wired in such a way that you can't remove one single panel. For a sim, it does not make any sense to go through a lot of work just to be able to remove one specific panel.
The only exception is if you use real panels from real planes, I guess.

The neat thing by doing this like I did, is that you can line up all the "DZUS" fasteners so it LOOKS like the real deal. :) I've seen people using threaded rails underneath, and the DZUS fasteners points all over the place. Not like the real deal. Details, folks! :)

Here's an image of my overhead showing the lined-up DZUS replicas:
http://www.fagerjord.org/cockpit/img/fwd_ovhead/elec_pnl.jpg

[Mike.Powell]

There are a lot of industrial standards for mounting equipment. "DIN" is one of them, but is not the standard used in most aircraft equipment bays. This gets confusing because of some tradename issues.

In 1936 William Dzus founded the Dzus Fastener Company. He invented the quarter turn fastener that was used to mount a great deal of avionics. This fastener design became a mil standard (Mil-F-25173A), and is the type of fastener you frequently see in use today. The original fasteners had "DZUS" just below the screwdriver slot.

Somehow "DZUS" became a legally registered trademark of Hartwell-Dzus.

The Dzus Fastener Company changed its name to DFCI Solution, Inc. It still manufactures the Mil-F-25173A approved DFCI type 3506-SC quarter-turn fastener. However, it no longer sports "DZUS" below the screwdriver slot.

In 2004 Southco, Inc. acquired Hartwell-Dzus along with the tradename "DZUS". Southco manufactures a variety of quarter-turn fasteners. Some are used in aerospace, but they are not the ones you typically see holding panels in the cockpit.

The fasteners seen in the corners of avionics panels are often referred to as "dzus fasteners" and the rails they mount to as "dzus rails". However, they are more correctly called "Mil-F-25173A quarter-turn fasteners and rails".

So, if you want to know about "dzus fasteners and rails" take a look here: http://www.dfcis.com/pa-3500/index.html

[Michael Carter]

Mike, I'm going to copy this post and paste it in the glossary.

Thanks.