1/4 turn Fasteners & Vibration

[MadMango]

Fastener Question

I'm not too familiar with 1/4 turn fasteners, but have an application where they might be very nice for the end user. I design equipment that is installed under buses, trains, shuttle vans, etc. Our equipment requires periodic maintenance, and access panels (30"x40") that are removed on a monthly basis.

These panels can have anywhere from 10-30 fasteners (normally 1/4-20, 5/16-18, M5, M8), and what we have noticed while visiting some maintenance/repair depots is that all the fasteners are never replaced. I guess that has to do with the culture of transportation maintenance- just stick enough fasteners in there so it doesn't rattle (apologies if I offended anyone).

So I want to redesign the access panels on our latest project, and was considering the use of captive 1/4-turn fasteners. The problem is these will have to be installed with the head of the fastener pointing towards the ground, and will experience a fair amount of vibration and shock (road surfaces, potholes, etc). I am looking for information from folks that have experience using these types of fasteners in this type (or similar) application.

Am I worrying too much? Should I go with a different type of "maintenance friendly" fastener?


Thanks in advance.

Ray Reynolds
"Computers in the future may weigh no more than 1.5 tons."
Popular Mechanics, forecasting the relentless march of science, 1949
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[MintJulep]

The Southco 1/4 turn fasteners are commonly used for access panels on subway, commuter and light-rail vehicles.

Dzus 1/4 turns are popular on aircraft and race cars.

If you follow the manufacturer's recommendations regarding the application they should be fine.

The the fasteners the only thing holding the panel to the vehicle? Is the panel hinged on one side?

It can be a real pain-in-the-a## to get a large number of any type of captive fasteners all aligned properly at the same time. Keep this in mind when designing your covers.

 

[MadMango]

Thanks for the input.

Most applications of these fasteners I have seen place the axis of the fasteners in the horizontal plane. I guess I am concerned with placing them in the vertical plane. Also, due to road debris, I am worried about objects striking the fasteners, making them twist out.

The panels are not hinged, but there is a supported flange running along one edge of the panels.

Ray Reynolds
"Computers in the future may weigh no more than 1.5 tons."
Popular Mechanics, forecasting the relentless march of science, 1949
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[CorBlimeyLimey]

Could you possibly recess the head of the 1/4 turn to make it less of a "target".
Also some of the 1/4 turns have springs which could be replaced with more "powerful" ones to help resist accidental removal.

from (the City of) Barrie, Ontario.

Support bacteria - they're the only culture some people have

 

[sreid]

Dzus is synomimous with quarter turn fasteners. Go to

http://www.dzus.co.uk