From: BOBPAS26@aol.com
Message-ID: <71.6a3982d.26f43b54@aol.com>
Date: Fri, 15 Sep 2000 22:56:20 EDT
Subject: IV-P Main Wing Skin Trimming
To: lancair.list@olsusa.com
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

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A fellow builder that we share tips with asked yesterday how we trimmed the 
inside edge of the main wing skins. It occured to me that others might 
appreciate the technique I used. It;s very simple, accurate and quick.

You'll need two pieces of flat aluminum flashing about 6" wide and long 
enough to extend beyond the leading and trailing edge of the wing to 
establish the trim line for the inside edge of the wing skins. This aluminum 
is available at Home Depot, or similar places--cheap.

Square off the two pieces of the flashing long enough to extend about 3-4 
inches beyond the leading and trailing edge of the wing. Place one piece on 
the top near the inner edge of the skin and hold one up against the bottom 
skin parallel to the top strip. Carefully align the edges closest to the 
fuselage, drill and cleco the two pieces of flashing together just beyond the 
trailing edge. I did the inside edge first, then aligned the front edges, 
then added a couple more clecos along the back edge of the aluminum just 
beyond the flap trailing edge (you do need the flaps installed and locked in 
the retracted postion for all work on the fairings) You'll have a sandwich of 
two aluminum strips with the wing between and a top and bottom inside edges 
that are parallel and perpendicular to the top of the wing. Then go to the 
front and pull the alumimum forward so the clecos are close to the trailing 
edge but not distorting the aluminum. Check the inside edge alignment at the 
front, slide the sandwich in or out along the wing to where you want to 
mark/cut, ensuring that both the top and bottom skins extend at least a bit 
all along the cut line. Then tape or cleco the aluminum temporarily to the 
wing and scribe your cut/trim line. There will be a slight gap along the 
outboard edge of the aluminum flashing that covers the bottom skin because of 
the wing taper--it won't affect the straight inside edge appreciably, but you 
could shim it equally along the span if you're a perfectionist. After doing 
one wing, carefully take the sandwich off and use it to do the other wing--it 
will align to the other side of the flashing. I marked the aluminum and wing, 
and drilled a couple of alignment holes for clecos through the aluminum and 
wing skin just inside the innermost rib (had about 1/4" to play with there) 
so I could re-establish the trim line after installing the fairings to butt 
up against the wing skin and adding micro to make a smooth mate. After 
sanding to the required contour, I slipped the flashings back on to the 
original position, re-marked the join line and cut through the micro to 
separate the wings and fuselage/fairings. Worked well.

Bob P
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LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
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Please send your photos and drawings to marvkaye@olsusa.com.
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