Wing Tips page 1

November 1, 2010

The Fiberglass wing tips came from Bob Barrows (R&B Aircraft).  Some fitting of the wingtips to the wing is required. When you get your wingtips, the edge will have a slight lip on the them where they came out of the mold.  This lip must be cut off to allow the wingtip to be more pliable.  Simply mark the edge to remove about 1/8" and cut with some tin snips.  The rough edge can then be smoothed with a file.  

Next make some reference marks on the wing 5/8" from the edge of the skin. The overlap you want a 5/8", so these marks will help you know how much your wing tip is overlapping your wing.  Slide the wing tip in place and push it back hard against the leading edge of the wing, then tape it in place to check the fit.

Now, check the fit and how well the tip lays down on the wing. If needed, you can adjust the fit, moving the wing tip up or down, increasing the gap on either the top or the bottom to get the wing tip to lay as flat as possible against the wing skin.  Here is the initial fit of mine:

As you can see, it was gapping up about 1/4".  

To help alleviate this, I trimmed the wing tip along the leading edge until it was only overlapping the wing about 1/4" along the leading edge only. You can see through the fiberglass wing tip, so just run some tape along the edge where the cut will be made, blending it back into the edge further back:

You can see the 1/4" overlap above.  

The wing tip was removed and cut along the tape line, then filed smooth.

The other trick I used was to VERY slightly bend the wing tip outer flange and skin.  This was done with a dead blow hammer and a piece of 2 x 4 wood:

Be careful to not overdo it. Just a slight bend is enough.

After doing the above two things I was able to get the wingtips to fit enough that I could drill and cleco them in place with the 5/8" overlap.  The holes were drilled every 3", going between the existing rivets on the wing. Hold the wing tip down firmly against the wing skin while drilling each hole:

The other side was also drilled and clecoed.

The trailing edge of the wingtip is left unfinished so you can get the best fit possible with your wing.  The goal is to make the trailing edge of the wingtip match the trailing edge of the aileron.  Start by installing the aileron on the wing and clecoing the wingtip in place:

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