[R-390] reply to Chris's loose screws

[Roger Ruszkowski]

Chris,

You are so right.
Just one more case of almost getting the science correct.

They added the part but in the wrong place.

Roger


-----Original Message-----
From: Chris <kc9ieq at yahoo.com>
To: r-390 <r-390 at mailman.qth.net>
Sent: Sun, Mar 2, 2014 7:55 pm
Subject: Re: [R-390] reply to Chris's loose screws


By conventional wisdom, that split washer should be be under the head of the 
screw, not the nut as it is held captive and not allowed to turn more than a few 
degrees by the clamp.  

By more modern knowledge, that split washer does basically nothing to prevent 
the joint from loosening-  Point in case, how many split lock washers are used 
on that new car that mysteriously doesn't vibrate apart?  VERY few washers of 
any kind are used, with exception of electrical grounds.  

For those integrated in the real facts about lock washers, and hardware in 
general, below is one of many very interesting an enlightening articles out 
there:

http://www.boltscience.com/pages/vibloose.htm

Regards, 
Chris 

Sent from my outdated iPhone wireless thingy

On Mar 2, 2014, at 5:55 PM, Roger Ruszkowski <flowertime01 at wmconnect.com> wrote:

> 
> Chris, You asked.
> 
> Can anybody tell me WHY they used split lock washers under the nuts on later  
units?? 
> 
> A lot of R390's were mounted in mobile vans and got shaken down the road.
> 
> The idea was the tension of the lock washer in the stack would keep the
> bolts from vibrating loose.
> 
> Time after time I would ship racks of stuff from San Diego to Fullerton 
California (100 miles)
> or cross country to Lynchburg Virginia and back.
> The stuff would work in San Diego, 
> Arrive in many loose pieces.
> Get put back together again.
> Operate through shock and vibration tests just fine.
> Get shipped home to San Diego and arrive in parts again.
> Get put back together and work again.
> 
> When you put things in trucks even air ride and setting on shock mounts
> they fall apart.
> 
> How our autos stay together for ever amazes me every day.
> 
> Roger AI4NI
> 
> ______________________________________________________________
> R-390 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/r-390
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:R-390 at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
______________________________________________________________
R-390 mailing list
Home: http://mailman.qth.net/mailman/listinfo/r-390
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:R-390 at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html