Sender: <marv@lancaironline.net>
To:  lml@lancaironline.net
Date: Wed, 29 Apr 2009 10:20:33 -0400
Message-ID: <redirect-3610344@logan.com>
Received-SPF: none
 receiver=logan.com; client-ip=209.55.3.84; envelope-from=2thman@cablespeed.com
From: "John Barrett" <2thman@cablespeed.com>
Subject: re:Cowling Fasteners
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Thread-Index: AcnIxU0B7u4jcj/NRfKD4Unu5NTNIw==
Content-Language: en-us

The question below and Scott's answer explains very plainly and =
graphically
why hinged attachments using Carbinge is the best answer for cowl =
fastening.
Shameless plug, but experience - Scott's in this case - is often the =
best
teacher. =20

www.carbinge.com

John Barrett
Leading Edge Composites

Rob, et al,
=20
I use SS camloc devices from Skybolt.  There have been 2 issues:
=20
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. =20
=20
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.=20
=20
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).
=20
Scott Krueger
=20
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...)=20


=A0=20