You can add flap/aileron coupling to the Barnes Aegea wing by making a small modification and adding the required “top gap” to the flaps. Phil and Mark were kind enough at DBSF to suggest some ways of doing this without ruining the wing.
Materials
1. Long metal ruler 2. Snap-off blade knife 3. Stanley Razor Edge Blades 4. Double sided tape
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Place wing on a flat surface and make sure it does not move, you can do this by adding a few peaces of double sided tape to the bottom of the wing. You will probably want to create a 0.06” hinge top gap, measure and mark on all ends of flaps.
Add some double sided tape to the bottom of the metal ruler and place on flaps. Make sure the ruler aligns correctly with the marks you made earlier.
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With the Snap-off, firmly and slowly make a pass along the ruler; make sure you don’t apply to much pressure. Repeat this process four to five times or until you are sure all of the Kevlar has been cut. Wile making the first pass, make sure the snap-off is slightly turned towards the metal ruler to prevent any blade wandering.
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To cut the excess foam insert the razor edge blade into the gap you created at a very shallow angle, giving the blade the most amount of cutting surface thus creating a smooth cut along the foam.
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You will have to sand the correct angle into the ply end caps of the wing; you can do this with a sanding block.
Perfect job Jose. Thanks for posting the pictures and writeup.
I would only add that the hazard of doing this is that if you are not careful then you can push the Kevlar skin down into the foam with the knife rather than cutting it cleanly. This is why you should follow all of Jose's procedures carefuly and also do a few light passes with the knife rather than pushing too hard on the knife. Also be careful to make one clean cut that does not wander off the straight edge.
This can be done very easily as Jose has shown. Just be careful since the job will get very messy if you don't cut the Kevlar cleanly the first time or if you mash the Kevlar skin down into the foam. If those things happen you will have a hard time cleaning it up since Kevlar will not sand easily.
One other caution; The thinner the strip of skin you try to cut loose, the more it will want to mash down into the foam rather than cut. This is why you should use a new knife point of the type Jose shows. Also don't try to cut a strip any narrower than about 1/16" as Jose says.
I should also mention I used an old wing section to practice and test for those very things Phil points out, pushing Kevlar, edge proximity, wondering blades and foam trimming.
This image shows you what can happen if you don’t do it right.
Aegea flap hinge top-gap modification
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Posted - 07/27/2004 : 12:49:51 AM
