Mailing List lml@lancaironline.net Message #51273
From: <Sky2high@aol.com>
Sender: <marv@lancaironline.net>
Subject: Re: [LML] Cowling Fasteners
Date: Tue, 28 Apr 2009 10:00:48 -0400
To: <lml@lancaironline.net>
Rob, et al,
 
I use SS camloc devices from Skybolt.  There have been 2 issues:
 
1. Camloc style fasteners are spring loaded and do not provide a rigid attachment even though I used a little tighter spacing than the plans called out.  The combined positive pressure in the cooling plenum and the low pressure over the top of the cowling puts a great upward strain on the  cowling.  I have frequently found bug residue in a half inch sliver on the top face of the cowl because it did not stay in line with the spinner.  I have somewhat resolved this problem by epoxying small phenolic blocks to the top inside of the cowling that are stops against the fuselage upper forward deck joggle leading edge.  This has reduced the ability of the cowl to lift up and slide back on the upper fasteners.  Myself and others have had to reinforce the bottom center most holes in the cowling after in flight strain has worn those holes. 
 
2. Most of my original Camloc SS fasteners were installed with pinch washers whose fingers firmly held the camlocs in place in the cowling.  When I replaced these with the Skybolt SS equivalents, the fastener body was made of much harder SS and the pinch washer fingers could not hold them in place (could not grip the body).  I was forced to use the split washers that allow the Camlocs to pull back out to the latch pins in the tip and thus contributing to paint wear and chipping around the holes.
 
Were I to build another cowling, I would prefer a more rigid set up - either by making some use of hinge-type fastenings or better and tighter fasteners (whatever those might be).
 
Scott Krueger
 
In a message dated 4/27/2009 6:51:57 P.M. Central Daylight Time, rwolf99@aol.com writes:
Tw years ago I asked a group of three aircraft designer / builder / manufacturers which were the best fasteners to use for my Lancair cowling.  These guys were:

Carsten Sundin (of Lancair fame)
Chuck Harrison (Composites Universal in Scappoose Oregon)
Mark Bettosini (AirBoss Aerospace)

They all said the same thing, in unison.  "Skybolt Fasteners"

I have read Brent Regan's discussion of LiveLock fasteners and I'm certain that they are very good.  My recollection was that they were far more expensive than Skybolt with marginal extra "niceness" (yeah, that's a technical term...)  This is the Tridair offering, is it not?

As for Camlocs, these are the originals and will certainly do the job, but I think the Skybolts look nicer.  I did not want to save an insignificant amount of money for something that would be so readily visible to a non-aviator that was already nervous about riding in my "toy glued-together airplane".  Those types judge the workmanship solely by the appearance of the paint and interior (we all know better, right?) so I figured they would benefit from the shiny fastener...

Your mileage may vary.  All of them will work.  Read Brent's missive on the Livelocks in the archives and choose for yourself.

- Rob Wolf
(Cowling presently held on by clecoes...)


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