Changing an airfoil profile
11-15-2009, 08:04 AM
#26
RE: Changing an airfoil profile
I don't know how accurate it is, but Wylam's drawings of the S.XIII are also in the MAN Scale Aircraft Drawings (Vol.I) book. Razor thin with a razor thin LE would be the only possible description! [:'(] It's amazing that they bothered to put lightening holes in it at all! But then, with close to 100 ribs on the two wings, I guess each one didn't need to be that strong.
11-15-2009, 06:31 PM
#27
Join Date: Jun 2005
Location: Princeton Junction,
NJ
Posts: 573
Likes: 0
Received 0 Likes
on
0 Posts
RE: Changing an airfoil profile
Hmmm. 'bout time some RCU'er built a working wind tunnel - WWI vintage design, 1/4 scale, of course. My third grader has a science fair coming up this Spring. Gives me an idea....
11-15-2009, 08:57 PM
#29
RE: Changing an airfoil profile
ORIGINAL: Mode One
Does the SPAD have lightening holes? SPAD used a pile of ribs in their wings! My guess is Balsa USA may have cut down on the amount of ribs used in the wing, also.
Does the SPAD have lightening holes? SPAD used a pile of ribs in their wings! My guess is Balsa USA may have cut down on the amount of ribs used in the wing, also.
The BUSA kit has a correct rib count. That's one of their advertising statements. I also believe that cap strips are not used.
Shoot, I'm just going to have to drag the dang thing out and look at it.
11-16-2009, 06:19 AM
#31
Join Date: Jun 2005
Location: Princeton Junction,
NJ
Posts: 573
Likes: 0
Received 0 Likes
on
0 Posts
RE: Changing an airfoil profile
Interesting - of course it's easier/cheaper to test wing sections rather than a full airframe and requires a much smaller tunnel - like the Wrights used. Here a couple "educational" windtunnels from NASA.
http://www.fi.edu/flights/first/makebigger/index.html
http://sln.fi.edu/flights/first/makesimple/index.html
http://www.fi.edu/flights/first/makebigger/index.html
http://sln.fi.edu/flights/first/makesimple/index.html
11-16-2009, 08:46 AM
#32
Senior Member
Join Date: May 2005
Location: Park Rapids, MN
Posts: 2,989
Likes: 0
Received 0 Likes
on
0 Posts
RE: Changing an airfoil profile
ORIGINAL: khodges
The fullscale wing has a top edge ''bow'' and a bottom edge ''bow'' with connections between them (not a trusswork). The wing has little cantilevered strength. With all the wires in place and properly tuned, each wing depended on the other for rigidity.
The BUSA kit has a correct rib count. That's one of their advertising statements. I also believe that cap strips are not used.
Shoot, I'm just going to have to drag the dang thing out and look at it.
ORIGINAL: Mode One
Does the SPAD have lightening holes? SPAD used a pile of ribs in their wings! My guess is Balsa USA may have cut down on the amount of ribs used in the wing, also.
Does the SPAD have lightening holes? SPAD used a pile of ribs in their wings! My guess is Balsa USA may have cut down on the amount of ribs used in the wing, also.
The BUSA kit has a correct rib count. That's one of their advertising statements. I also believe that cap strips are not used.
Shoot, I'm just going to have to drag the dang thing out and look at it.
I'm not following what you mean by: The fullscale wing has a top edge ''bow'' and a bottom edge ''bow'' with connections between them (not a trusswork). However, I certainly agree with: "The wing has little cantilevered strength. With all the wires in place and properly tuned, each wing depended on the other for rigidity".
I've only seen a covered example of the BUSA SPAD, so cap strips may not be used.
Good luck with your endeavor and above all have fun!
11-27-2009, 06:55 AM
#33
Join Date: Jun 2005
Location: Princeton Junction,
NJ
Posts: 573
Likes: 0
Received 0 Likes
on
0 Posts
RE: Changing an airfoil profile
I've attached some pdf's I sent Ken - one shows the Gott. 303, which I used for the tip section of my Pfalz DXV and the 303 fattened to 15% for the root section. 2nd and 3rd pdf's are the front/back 303 scaled to 14" and 15" chord for Ken's airplane (I figured it's eaier to print two 8x11.5 and tape them together). Rummaging around, I also found the Gott. 381, which is a tad thinner and would be another option.
