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#1 sdbruder Nov 24, 2011 02:04 PM

wing CG calculator (with multiple panels & forward sweep)
Ive used the excelent work of z80 in http://www.rcgroups.com/forums/showthread.php?t=973140 in the past,

but the limitations of one single panel and no forward sweep made me look for multi-panel CG calcs, and Ive found only very old windows programs.

Accustomed to the online and direct use of z80's tool, Ive decided to make my own online CG calculator, with forward sweep and multiple panels.

Its a 1.0 version, only metric for now. If you can ignore the area number showed to you, use it with the unit that you are used to, only be consistent (if using inches, use only inches in all measures, etcetera).


Translation in brazilian portuguese (my native language);
imperial / metric switch;
deep-link of wings designs;

#2 DT56 Nov 25, 2011 03:05 AM

Thanks for the calculator Sdbruder! :)

#3 sdbruder Nov 25, 2011 07:10 AM

Ive just learned that my calculator is completely broken with Internet Explorer 9 (I've used Chrome and Safari within development).

Until I have time to fix, don't use it with any IE browser.

#4 sdbruder Nov 25, 2011 01:18 PM


- brazilian portuguese and english versions;
- metric (millimeters) and imperial (inches);
- a little less broken in Internet Explorer (without CANVAS support you cant visualize the wing with Internet Explorer, you only get the numeric result);


#5 birdofplay Nov 25, 2011 09:18 PM


TRY Swapping the Tip and root dimensions !!!

Just put to tip size where the root goes and vicesersa.

Thai still does not fix the multi panel issue but GiveIt try !


#6 sdbruder Nov 26, 2011 06:51 PM


Originally Posted by birdofplay (Post 19971853)
TRY Swapping the Tip and root dimensions !!!
Just put to tip size where the root goes and vicesersa.
Thai still does not fix the multi panel issue but GiveIt try !

No need for that, you can use negative sweep values.

#7 sdbruder Dec 02, 2011 11:00 AM

Nem version, v1.2, uploaded in /beta/ ( http://wingcgcalc.bruder.com.br/beta/ )

* Added About and History in end of the page;
* Proper internationalization with gettext support. If you want wingcgcalc in your language and can contribute ith the translation, please contact me;
* Options moved to the start of the measures forms, a few users didnt found the CG % with it the end;
* Popups implemented with little helper texts for each entry.

Any sugestions to better write the little helper texts in the popups per-field, Im all ears.

#8 sdbruder Dec 07, 2011 09:42 PM

v1.2 now in production, moved from http://wingcgcalc.bruder.com.br/beta/ to http://wingcgcalc.bruder.com.br/ . The old version is still in /old/.

#9 Outback Joe Dec 07, 2011 10:59 PM

WOW, very nice work! Thanks for sharing this with us. Working on a new wing tonight and used it for the CG on it.

Can this get a sticky also?

#10 sdbruder May 24, 2012 12:16 AM

new version of http://wingcgcalc.bruder.com.br, now with deep linking with automatic url shortening. Lets share these Wing designs!

#11 sdbruder May 28, 2012 04:52 PM

After deep linking of wing designs, Im now working to better show you wing, part of what is coming:


#12 cleansurf2 May 29, 2012 06:07 AM

Awesome work sdbruder.

Your last post was going to be a suggestion, so excellent.
Any chance of making the sweep switch-able between angle (degrees) and mm ?

P.S. I tried several multi panel CG calcs a couple of months ago. Your's gave me the most accurate CG (which was confirmed with flight test CG tuning).

#13 sdbruder May 29, 2012 01:46 PM

  • BUGFIX: the MAC calculation for multi-panel was wrong, corrected thanks to LaercioLMB from e-voo.com.
  • New display code and html arrange in the page now shows the whole wing.

The error in multi-panel MAC calculation was simple but severe: I was using the 'local' coordinates of MAC for each panel (i.e., each panel has his own (0,0) point) when what I needed was the global coordinate of each MAC. More information about the topic, sources of formulas and so on (in brazilian portuguese) in http://www.e-voo.com/forum/viewtopic.php?t=133753

To compare, the wing pictured above is http://j.mp/KP81Au

QUICK TIP: And to the people that didn't 'get' the way that Ive made 2 panels with different chords in that wing, Ive used a intermediate panel with 0 span in the middle of the 2 panels.

Now with the correct multi panel MAC calculation:

#14 gazza2003au May 29, 2012 11:24 PM

1 Attachment(s)
this is my last wing i built its made from 4 piece cores u just use the standard CofG calculator to work out the CofG

#15 Zoltan Scotland May 30, 2012 10:36 AM

Great job sdbruder!

Simple, and easy to use
Thank you!

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