Anti-shock and vibration for computers in aircraft

[dillon68]

We're developing a custom chassis for a computer system and I'd like to find a COTS solution for a mounting tray that incorporates anti-shock and vibration dampening mounts. We would design and build the computer chassis to fit the mounting tray.

The computer should be quickly removable from the tray to simplify maintenance and storage of the computer (and because many installations won't require it because existing mounting racks will be available).

Additionally, I want to offer different trays that have anti-shock characteristics for different environments (fixed wing aircraft, rotary wing, automobiles, off-road, etc).

There are plenty of basic anti-vibration and shock mounts available, but I'd prefer to not design and build this particular part of the project.

Any leads for a provider of such a product?

Thanks in advance...

Mike

 

[tlee123]

Try Enidine's Wire Rope Isolators. Never used them, but I've heard good things for applications like this.

http://www.enidine.com/CWRMain.html

http://www.enidine.com/WireRopeIsolators.html

 

[tomaspin]

To narrow it down a bit, can you give an estimate of the suspended mass, the disturbing frequncies, and the required level of isolation? Operating and environmental conditions would also be useful
I work in industrial vibration control, and with the above information, I can probably point you in the right direction.

Regards,

Tom

 

[MRLOWVIBE]

I agree with Tom with more information of your application, it will be easier to point in the right direction.because there are quite a few isolators you can use for that application, silicone gel, wire isolators and many others. Take a look at

http://www.vibrationmounts.com

 

[dillon68]

Thanks guys. We're fairly familiar with the type of isolators available and we should be able to size them appropriately for our application.

What I was looking for is a vendor that offers trays outfitted for electronic enclosures that we could purchase off the shelf. We'd outfit the trays with the appropriate isolators (or ask the vendor to do it). Most of our customers don't like to leave their equipment in the vehicle/aircraft - so I wanted a system that would allow quick removal of the unit, and maintain suitable shock/vibration isolation.

I'm getting the feeling that it will be easier to design them and have them built locally...

However, if it helps, the equipment is small and pretty evenly balanced (~10 lbs, 10in x 10in square, 5in tall).

We'll use four isolators (most likely the wire rope style). There will be continuous sinusodal vibrations from engine noise (rotary wing helicopters) and the occasional turbulence).

 

[Timelord]

Dillon68,

What you want to search for is trays that conform to the ARINC standard. The ARINC (Aeronautical Radio Inc.) standards, I believe, cover trays and boxes to assure that there is a common interface and specifies details such as the connectors etc. for aircraft.
See:

https://www.arinc.com/cf/store/index.cfm

for a list of their current standards.

Timelord

 

[tomaspin]

Mike,

Barry controls have a range of aerospace instrument mounts, which use a steel spring in conjunction with a rubber air damping system, to control the resonant amplitude.
These are designed specifically as aerospace mounts for instrumentation/electronics, so you should at least take a look at these. There are probably other similar mounts of this type available, but Barry seem to have the widest range. (BTW, I work for a European AV mounting manufacturer, not Barry)

Your suspended mass is quite low, so you need to choose your mountings very carefully, otherwise you won't get the shock and vibration isolation you need. I have a feeling that the wire rope type isolators will be on the stiff side, so be careful if you go down this route.

As for buying a complete sub assembly with isolators, most mounting manufacturers will either quote for it themselves, or be able to point you in the right direction.

I hope this helps

Regards

Tom

 

[tomirvine]

You need to be cautious when designing isolation for computers. The potential problem is interference with the hard drive operation. The read/write head has a servo control mechanism. The engineer who designed the servo control may have assumed that the computer would be "hardmouted."

As a related concern, you need to consider the rpm speed of the hard drive.

So you need to discuss your isolation plans with the computer and hard drive vendors.

Tom Irvine

http://www.vibrationdata.com

 

[aviat]

I think what you are referring to is a LRU or line replaceable unit. They are standard size boxes that slide into trays that are mounted in A/C, with no tools required for installation/removal. The site below gives specs for different sizes. Also if you go to a local avionics shop they will have different size units and trays mounted that they could show you.

http://www.atrbox.com/reference/atrbox.html

There is a lot of information on COTS on the web, some negative.

http://www.behlman.com/custom.htm

http://www.cotsjournalonline.com/pdfs/2003/09/cots09_softside5.pdf

http://www.airweb.faa.gov/Regulator...16BC457FCBD94B9986256EC300444673?OpenDocument