-----Original Message-----
From: owner-rv8-list-server@matronics.com
[mailto:owner-rv8-list-server@matronics.com] On Behalf Of Garey Wittich
Sent: Saturday, September 06, 2008 5:24 PM
To: rv-list@matronics.com; rv8-list@matronics.com
Subject: Dimpling of Elevator Trim Tab Piano Hinge ????
Greetings:
Ref: Elevator Trim Tab PIANO HINGE
Anybody have any idea why Vans recommends Dimpling the Elevator Skin,
machine countersinking the Trim Tab Spar and then attaching the Elevator
Trim Tab Piano Hinge ??
Why not dimple the Elevator Skin (per Vans directions), DIMPLE the Trim Tab
Spar and DIMPLE the Piano Hinge ?? This does away with the machine
countersinking the Elev Trim Tab SPAR ????
Just wondering. Thanks, Garey
Garey: You can dimple the hinge. The material is fairly soft but the
tendency when dimpling is to distort the hinge leaf. It can be difficult to
straighten and the hole spacing can be compromised. Even leaving the hinge
pin in place and the opposing leaf attached is not sufficient if the
dimpling is too rambunctious. There is plenty of material for machine
countersinking.
With regard to your earlier post about panel oilcanning, I have noticed the
problem and have no good explanation for it. I suspect the sequence of
riveting in a long string plays a role and have had best results by starting
to rivet in the center of a long string and working toward each end. At
least you don't chase all the tolerances to one end that way. Perhaps the
way the sheet metal has been handled enters into it. It doesn't take much to
create a tiny stretch in the sheet which could cause such behavior.
Gordon Comfort
N363GC
