SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Jun 30, 2012, 08:53 PM
Arrarrar!
josh18's Avatar
Australia, NSW, Wagga Wagga
Joined Jan 2010
3,392 Posts
Sorry guys, what is Longditudinal dihedral? Is this decalage or something different?
josh18 is offline Find More Posts by josh18
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 30, 2012, 09:41 PM
Just fly it!
wyowindworks's Avatar
Cody, WY
Joined Nov 2007
6,915 Posts
Quote:
Originally Posted by josh18 View Post
Sorry guys, what is Longditudinal dihedral? Is this decalage or something different?
Decalage traditionally refers to angle difference between the two wings on a bi-plane. Longitudinal dihedral is the angle difference between the wing and the tail plane.

So if the wing was +0.5 degrees to the datum line of the fuse and the stab is at -0.25 degrees the longitudinal dihedral would +0.75 degrees.

The word "decalage" has become widely used in place of longitudinal dihedral....so use whatever you want.
wyowindworks is offline Find More Posts by wyowindworks
Last edited by wyowindworks; Jun 30, 2012 at 10:00 PM.
Reply With Quote
Old Jun 30, 2012, 09:47 PM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,834 Posts
i'll change the wings Dihedral to 1 degree and leave it at that....

Posted from the Dreamfactory
Keenan
Keenan smith is offline Find More Posts by Keenan smith
Reply With Quote
Old Jun 30, 2012, 10:12 PM
Just fly it!
wyowindworks's Avatar
Cody, WY
Joined Nov 2007
6,915 Posts
Quote:
Originally Posted by k.smith459 View Post
i'll change the wings Dihedral to 1 degree and leave it at that....

Posted from the Dreamfactory
Keenan
For a DS plane you are better off putting the wing and zero and the tail plane at -1*.

Many people put them at 0 - 0......0 degrees longitudinal dihedral and then use elevator trim to trim the plane.

To optimize the rigging you want to first calculate the planned DS speed objective, then calculate the circle circumference for your site. Using this you can calculate the g-load on the wing for your approximated glider mass. Using this you can calculate the required CL (lift coefficient) of the wing. Then using your air foil and planform you calculate what AoA the wing must be at to generate the required CL. The wing would be put at this angle compared to the zero lift line of the fuse. The pitching moment of the wing at this CL would be calculated and the stab would be positioned at the correct AoA to counter the pitching moment of the wing (this is variable depending on the CG).

In the end the whole calculation is an approximation because changing the CG or ballast would change the optimum rigging.
wyowindworks is offline Find More Posts by wyowindworks
Last edited by wyowindworks; Jul 01, 2012 at 12:12 AM.
Reply With Quote
Old Jul 01, 2012, 12:10 AM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,682 Posts
You will most likely have to shim your stab after a few test flights to get it perfect, unless of course your calculations are perfect!
Aerogance is online now Find More Posts by Aerogance
Reply With Quote
Old Jul 01, 2012, 01:48 AM
Arrarrar!
josh18's Avatar
Australia, NSW, Wagga Wagga
Joined Jan 2010
3,392 Posts
Was going to say the same thing!
Thanks Adam
josh18 is offline Find More Posts by josh18
Reply With Quote
Old Jul 01, 2012, 08:28 AM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,834 Posts
Okey doke ...
Keenan smith is offline Find More Posts by Keenan smith
Reply With Quote
Old Sep 20, 2012, 09:53 AM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,834 Posts
Well ive been away from this project a While.. and now im finally getting back to work on the Raptor
i have attached some images of the fuse plug... (not completed yet.. )
I will Continue work on the Raptor On Saturday When i will Be hotwiring the Wings
K
Keenan smith is offline Find More Posts by Keenan smith
Reply With Quote
Old Oct 08, 2012, 04:30 PM
100% crasher
Sverige, Skåne Län, Hässleholm
Joined Sep 2011
19 Posts
progress??
alfa166 is offline Find More Posts by alfa166
Reply With Quote
Old Oct 10, 2012, 05:22 AM
ich bauen groß modell flugzeug
Keenan smith's Avatar
United Kingdom, London
Joined Dec 2010
6,834 Posts
Not currently as I have been busy ....
Keenan smith is offline Find More Posts by Keenan smith
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Build log PIK-12 Gabriel, 1:3,2 (5m) tuootal Scale Sailplanes 18 Jun 11, 2012 03:47 PM
Mini-Review Soaring USA bag for Explorer 4.0 Hoot Multi Task F3X 7 Jun 21, 2011 01:48 PM
Build Log Raptor GS Version 2 Build log metroidrc Scratchbuilt Indoor and Micro Models 8 Apr 14, 2010 11:10 AM