You probably already know this but the Wag Aero airfoil is different than the Piper airfoil. You are correct, the Wag airfoil is the US35b, while the Piper is "Modified"....I think the 2+2 will work...
..... I need to make a rib repair jig and it would be nice to start with the correct shape.
:lol:
...I need to make a rib repair jig and it would be nice to start with the correct shape...
I did the exact thing Bugs. I attached the 12183 drawing from your website to an email and sent it to our local OfficeMax. I called them, asked them to print it on their 36" printer and it was done when I got there. Thanks for having the resource available!The drawing is 36x24 or so. Take the PDF on a flash drive to
I'm not an expert by any means, but I don't think there is a standout advantage to either airfoil. Here's a link to the thread where I compared them one on top of the other:Is there and advantage to having the "Modified" airfoil over the US35b?
This is very interesting. It shows that the stall angle is just below 20 degrees. I would not have suspected that it would have been that high. My guess was that it would have been nearer to 16 degrees. I think that I shall make a angle of attack indicator on a pole mounted on the wing. Perhaps I'll also fit a floating pitot tube to the same pole? The results should get us into some interesting conversation.Here's the wind tunnel data, anyway.. http://www.supercub.org/photopost/showphoto.php?photo=28113&title=usa-35b&cat=500
The AOA of the USA35b and USA35bMod were referenced to the bottom of the wing, not the chord line as is done now. That's the reason for the seemingly high stall angle.
The coordinates of the USA35b are screwed up at the leading edge radius. There are also discrepancies between different Piper rib drawings (false rib and full rib noses are shown different -- they aren't). There are quite a few mistakes in the Piper wing drawings.
The AOA of the USA35b and USA35bMod were referenced to the bottom of the wing, not the chord line as is done now. That's the reason for the seemingly high stall angle.
The coordinates of the USA35b are screwed up at the leading edge radius. There are also discrepancies between different Piper rib drawings (false rib and full rib noses are shown different -- they aren't). There are quite a few mistakes in the Piper wing drawings.
Any chance of naming those errors or at least the ones you remember?
I'm installing tile in the washroom today. Will get back in more detail later. In the meantime, as just one example, on different Piper drawings, the leading edge radius varies between 1.00 and 1.39 inches, and the radius point moves around. Just aft of the radius point on the top surface there are mistakes in the listed coordinates that make the upper front surface too flat. This has adverse effects on the stall characteristics of airfoils built to the coordinates shown (Piper didn't always build to the drawings).
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Note the zero reference line in Post #20. In modern wind tunnel work, the aoa is referenced to the chord line (a straight line drawn through the trailing edge and the radius point of the leading edge radius). In older airfoils like the 35b and 35b Mod, it was referenced to a straight line drawn from the trailing edge tangent to the lower surface of the wing. That makes the stall aoa of these older airfoils seem to be several degrees higher than it would be in modern usage. just subtract the angular difference between the two reference lines to adjust the old wind tunnel data to modern usage.