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Offline Dennis P  
#1 Posted : Wednesday, January 3, 2018 11:57:01 PM(UTC)
Dennis P

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I am getting ready to cut new wing cores for a Giles G202 I started to build many years back. The plane was all framed up and the cores for the wings and stab where cut. I finished up the stab and elevators but never finished the wing. The project stopped and I cannot remember why, but it is time to finish it. I plane on attending a few IMAC events with it and so I have been looking at different airfoils. I made up template patterns of a S8035 14% airfoil which has a bit more forward high point and a little thicker front to the wing. The plane is based on the old Midwest 27% G202 kit which has a 72" span and around 970 sq" of wing. It will have a 3W24 for power. Does any one know much about my possible airfoil choice or a better option with an explanation. Hoping for a final max weight of 11.5 pounds, hopefully less. I know it is an old girl but it needs to see the sky. IMG_1563 (002).jpg (113kb) downloaded 2 time(s). IMG_1557 (002).jpg (64kb) downloaded 2 time(s). Thanks for any advice.
Offline Jim7216  
#2 Posted : Thursday, January 4, 2018 6:40:14 PM(UTC)
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Dennis,
I scratch built a similar sized Extra and used that very airfoil. The plane flies fine. I also scratch built a 41% Extra and used that airfoil but reduced the thickness to 12% instead of 14%. The trend in aerobatic airfoils seems to be going with thinner airfoils. My 41%er also flies well. I am not an expert and I am sure there are people with more knowledge than me but I think that airfoil would work fine.
Jim
thanks 1 user thanked Jim7216 for this useful post.
Dennis P on 1/6/2018(UTC)
Offline Jerry Hailey  
#3 Posted : Sunday, January 14, 2018 9:23:06 PM(UTC)
Jerry Hailey

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The S8035 14% should work fine. If you do thin to 12% you might want to move the high point even further forward. As is it's not as far forward as some of the modern wings.
Dropping to a thinner wing, in general, reduces drag but you also lose a bit of lift. Don't worry about the lost lift. It will fly just fine plus it will help your spin entry.

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Offline Dennis P  
#4 Posted : Wednesday, February 7, 2018 11:43:16 PM(UTC)
Dennis P

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I ended up just using the stock airfoil cores I had cut years ago as they where very similar but with a bit more rear word high point. Thickness was identical. Here are a few photos of some progress. I put two thin wall carbon arrow shafts stringers in the lower fuselage to prevent damage lifting the plane and working on it. I have a zero datum and engine box with plus 0.6 on the wing and zero on the stab. Presently finishing up the tail assembly .

IMG_1612.jpg (96kb) downloaded 0 time(s). IMG_1613.jpg (117kb) downloaded 1 time(s). IMG_1580.jpg (70kb) downloaded 1 time(s). IMG_1567.jpg (64kb) downloaded 2 time(s). IMG_1601.jpg (97kb) downloaded 1 time(s). IMG_1569.jpg (68kb) downloaded 0 time(s). IMG_1603.jpg (73kb) downloaded 0 time(s). IMG_1566.jpg (90kb) downloaded 1 time(s).
Offline Dennis P  
#5 Posted : Monday, March 19, 2018 3:44:29 PM(UTC)
Dennis P

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IMG_1663.jpg (97kb) downloaded 0 time(s). IMG_1634.jpg (78kb) downloaded 0 time(s). IMG_1665.jpg (133kb) downloaded 0 time(s). IMG_1666.jpg (136kb) downloaded 0 time(s). IMG_1633.jpg (68kb) downloaded 0 time(s).

Getting some more done on the plane. Just primed the cowl and getting the wheel pants and pilot ready.
Offline Kevin Wilson  
#6 Posted : Tuesday, March 20, 2018 8:03:12 AM(UTC)
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Very nice!
Can anyone explain why the full scale Extra airfoil is so different than what we use? Seems to have a very big and rounded leading edge with long flat surface behind.
Offline Dennis P  
#7 Posted : Friday, April 13, 2018 12:11:09 PM(UTC)
Dennis P

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Thought I had better add a few finished shots to this thread. IMG_1690.JPG (1,747kb) downloaded 0 time(s). IMG_1695.JPG (2,816kb) downloaded 6 time(s). IMG_1691.JPG (2,804kb) downloaded 5 time(s). IMG_1694.JPG (2,912kb) downloaded 5 time(s). IMG_1693.JPG (2,864kb) downloaded 5 time(s).
Offline Doug Pilcher  
#8 Posted : Friday, April 13, 2018 12:41:22 PM(UTC)
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Very Nice INDEED!
Doug Pilcher
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Would rather be flyin than workin!
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