Q2 canard angle of incidence

Start
Prev
1
Next
End

Sveshnikov
Topic Author
Visitor

13 years 9 months ago - 13 years 9 months ago #929 by Sveshnikov

Q2 canard angle of incidence was created by Sveshnikov

We're building Q2 with GU25-5(11)8 canard. Our doubt was in the angle of incidence (angle of installation) of the canard.
So ?? we have fitted together the templates of canard and elevator with the original GU25-5(11)8 airfoil.
As we see, this angle is aprox. -0.5?.

Conc. airfoil:
www.worldofkrauss.com/foils/1391
From this document we know that such angle induces Max L/D.

The question is ?? do we REALLY have to install the canard with such angle (-0.5?) according to "level lines" given on templates?

Also the reason of doubt is the experience of Sam Hoskins, that finally had to re-install his canard with LE lifting to 1.25 degrees by such reason:
home.mchsi.com/~shoskins/early_years.htm

Yes, we know he had another airfoil on his canard, but we still are not sure...

Did anybody report that such angle is right and the elevator position in horizontal flight will be "zero"?..

Last edit: 13 years 9 months ago by Sveshnikov.

Please Log in or Create an account to join the conversation.

admin
Offline
Administrator

13 years 9 months ago #930 by admin

Replied by admin on topic Re:Q2 canard angle of incidence

Hey there,
My first inclination was to assume that you were holding the template on to the end of the canard and seeing a negative AOA. However, your graphic above makes it clear that's not what you're doing. (I was going to say that the tips of the wings have some downward twist to account for aerodynamic forces in flight.)

After seeing your drawings, I am inclined to question what the incidence on the jigging templates are? Note that you use the level lines on the center templates while the canard is upside down in the jig.

www.quickheads.com/q2-plans-chapter-10-page-10-05.html

Also while re-reading the plans it's clear that you set the level board on the canard in reference to templates that have been re-attached to the tips of the canard using their level lines. Since the tips twist down (as stated above) I'm guessing that leveling the tips will actually cause the center of the canard to have a positive "Angle of Installation."

All that being said, I haven't ever built a GU canard, but I will try to get others with more experience to chime in here. I hope this is helpful, please let me know.

Thanks,
Dan Yager
QBA Editor
www.quickheads.com

Flying an aeroplane with only a single propeller to keep you in the air. Can you imagine that?

— Captain Picard, from 'Star Trek: The Next Generation' episode 'Booby Trap.'

Please Log in or Create an account to join the conversation.

SammyQ2
Offline
New Member
1,780+ hrs on my Q-200.

13 years 9 months ago #932 by SammyQ2

Replied by SammyQ2 on topic Re:Q2 canard angle of incidence

Don't take my experience as anything definitive about the design, rather as a workmanship issue. The only thing I ever built before my plane, was a garage.

Others have built their planes and have no problems with incidence.

So what is right and true? Don't really know.

Sam Hoskins

Please Log in or Create an account to join the conversation.

Sveshnikov
Topic Author
Visitor

13 years 9 months ago - 13 years 9 months ago #933 by Sveshnikov

Replied by Sveshnikov on topic Re:Q2 canard angle of incidence

Hello )

Thanks for quick answers ))

Yes, the red line shows the "level line" given on canard template. So in that way the canard must be installed on the airplane (as I understand it). I just tried to measure the angle between this level line and the "level line" of the original GU25-5(11)8 theoretical contour (angle of installation of the canard relatively to Theory (thick dark-green (almost black) line)). Irrelatively of LE or TE.

If someone flying Q2 with such GU canard could say smth. interesting, it would be great! ))

Also ?? today I have made the similar work with main wing templates ?? so, the angle of installation of the main wing (according to level lines drawn on templates) is aprox. +0.5 degrees relatively to Theory of Eppler E1212MOD airfoil. I mean ?? NOT "zero" as I reported before, sorry