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guewald
06-27-2021, 05:29 PM
Hello guys this is Gustavo i'm from Brazil.


Here in Brazil whe have an airplane simmilar to kitfox called Águia. I believe the construction is based on the Raven model.


One year ago i have ground looped my plane after an engine failure on the takeoff. Now I'm starting doing some research to begin the restoration.
I have a broken wingspar so i removed all the covering to inspect the wing. After the inspection I decided to build new wings because they are very old and the ribs are in bad condition.


Now I'm working on the drawings to CNC cut the ribs but I'm not certain that my drawings are good as I draw them using a rib picture on Corel Draw.
I'm wondering if someone has this drawings and can share with me. If no drawings some rib pictures will be very usefull too.

I'm also thinking in changing the profile. From my researchs this seems to be an very old profile.


Here some pictures from damaged wings and my drawings.

28316283172831828319

FoxbuilderWill
06-27-2021, 09:32 PM
Hello guys this is Gustavo i'm from Brazil.


Here in Brazil whe have an airplane simmilar to kitfox called Águia. I believe the construction is based on the Raven model.


One year ago i have ground looped my plane after an engine failure on the takeoff. Now I'm starting doing some research to begin the restoration.
I have a broken wingspar so i removed all the covering to inspect the wing. After the inspection I decided to build new wings because they are very old and the ribs are in bad condition.


Now I'm working on the drawings to CNC cut the ribs but I'm not certain that my drawings are good as I draw them using a rib picture on Corel Draw.
I'm wondering if someone has this drawings and can share with me. If no drawings some rib pictures will be very usefull too.

I'm also thinking in changing the profile. From my researchs this seems to be an very old profile.


Here some pictures from damaged wings and my drawings.

28316283172831828319

I have a Kitfox model 1 so pretty much the same thing as the Raven and I got the coordinates for the Riblett airfoil (model 4 and later kitfox) and overlayed it on the original airfoil, lining it up leading edge to trailing edge (note that i have the PVC leading edge drawn in on the original airfoil). As you can see the aft spar isn't completely inside the wing. In order to get it to work you'd have to change the angle of incidence on the wing, or change your fuselage. No matter what you'll have to change the flaperon mounts and most everything associated with them. Not trying to talk you out of it, just saying it's pretty involved.

Yellow lines are the Riblett airfoil red is the original kitfox airfoil28320

Sorry for the lousy pic my only internet is on my phone so I had to take an actual photo of my screen.

FoxbuilderWill
06-27-2021, 10:21 PM
Just did some playing around and figured out a relatively easy way to use the Riblett airfoil. Just as a disclaimer I'm not an aero engineer so this is all guesswork use at your own risk.

Looking at my first screen grab in my previous post you can see that the trailing edge will have to be raised in order for the aft spar to be in the middle of the wing. According to my cad program that lowers the angle of incidence by about 1.5 degrees relative to the original airfoil. But if you drill out the bushings on the front carry through spar and weld in new ones that mostly stick out the top of the carry through instead of the bottom28321

28322

Then the angle of incidence is 1 degree more than the original which is probably a good thing since the riblett airfoil doesn't create quite as much lift. And the trailing edge of the Riblett airfoil(black lines in this screen grab) is only about half an inch (1 cm) above the trailing edge of the original airfoil (red lines)so mods to the flaperon system would potentially be minimal as well.

In all reality you'll probably have to change the angle of incidence on your horizontal stab and the list goes on but it's fun to think about.

guewald
06-28-2021, 05:50 PM
Thanks for the cuoperation.

I'm almost decided that the modifications will be only changing the upper false ribs type and add bottom false ribs. I'm also changing the flaperon system putting the brackets on the upper side of the wing.

Link to download my last airfoil drawings (DXF and CDR). Please guys feel free to opine.
https://drive.google.com/file/d/1v2fXRUXhZpFGDmfPkhr9peFXtS-rHCJl/view?usp=sharing