

May 25, 2004, 10:24 PM  

Here ya go
http://www.palosrc.com/instructors/putte.pdf 
May 26, 2004, 10:59 AM  

I took Ron Van Putte's equations and put them into an Excel spreadsheet a while back. It is here: http://www.chrisgood.com/rcplanes/fwiw/index.html at the bottom of the page. Just enter your values into the yellow areas on the spreadsheet and it will tell you the CG.
Chris Good 
Jun 13, 2004, 08:34 PM  
SE
Joined Mar 2003
365 Posts

Quote:
I've checked your Excel spreadsheet and notice an error at the canard P calculation. You have entered (R*T) at far right of the formula as shown below: The correct formula is: P(canard) =(L x S(tail)) / S(wing)) + (1/15) ( (R^2 + RT + T^2) / (R+T) ) The formula you've entered in Excel is: P(canard) =(L x S(tail)) / S(wing)) + (1/15) ( (R^2 + RT + T^2) / (R*T) ) You might wish to make an amendment. 

Dec 03, 2005, 04:34 PM  

ron van putte
hi
i came aross this post while looking for a canard c of g calculator can you help me i must be doing something wrong i have tried to work out a c of g for a canard with a nearly identical forplane to that of the wing the answer i get must be wrong as its just in front of the ac on the canard yes the canard thinking it was the way i entered it into my calculator i downloaded the excell version from the link in a previous post and i still get the same position try putting some figures into the spread sheet with similar wing and canard sizes i think the LS/S on the P calculation should be divided by 2 all the best kev 
Dec 04, 2005, 02:35 AM  
SE
Joined Mar 2003
365 Posts

Hi,
I don't think your math is wrong. The trouble is that your plane is more a tandem than a canard. The formula used for the canard CG may only be valid to Foreplanes areas ranging from 15% to about 50% of the aft Wing area. In your case, you may try using the following formula to find NP (Neutral Point) as % of the Wing's MAC forward of Wing's AC: NP = Distance between ACs * Foreplane Area / ( .8 * Wing Area + Foreplane Area) Then add about 10% Static Margin to the result in order to get a 'safe' CG location. I think that will put you on the ballpark. But if you're not so keen on formulas you may use the following calculator: Canard CG Calculator Good luck 
Dec 04, 2005, 06:55 AM  

Quote:
I woiuld say CG on a pair of almost equal planes would be somewhere around the TE of the foreplane. Quote:
Make up a chuck glider of depron and try...if you mistrust the calculations. 
