Need to know the CG for a Square Yard built from Flying MOdel Plans
09-28-2014, 05:14 PM
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Need to know the CG for a Square Yard built from Flying MOdel Plans
A gentleman from our club died and the club acquired some of his planes. One is a Square Yard built from Flying Model Plans. We flew it today but it was really a handful. We think the CG is wrong. Does anyone have a set of plans or a collection of Flying Model magazines and could check the CG for us. It's on the cover but I'm not sure of the issue. Any help would be greatly appreciated.
Thank you
Thank you
09-28-2014, 06:00 PM
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Dan,
It's 36" square. We assumed the CG would be at 1/3 of the chord. A picture of it is at the beginning of this You Tube video
http://www.youtube.com/watch?v=v4ZZGIMTVDI
ooney
It's 36" square. We assumed the CG would be at 1/3 of the chord. A picture of it is at the beginning of this You Tube video
http://www.youtube.com/watch?v=v4ZZGIMTVDI
ooney
09-28-2014, 07:21 PM
#4
Mooney, the mean aerodynamic chord (MAC) of a constant chord wing is the chord. The conventional and accurate wisdom now-a-days suggests that the CG of a radio controlled conventional configured model be place at 25 to 30 percent of the MAC. That’s 30 percent for a wing with a constant chord or 25 percent for the tapered type of wing on a P-51. Your model is far from conventional; in fact, it is tail less. You are lucky or skilled enough as a pilot to have survived. Keep moving the CG forward, to something less than 25 percent, until the model stabilizes and put in enough exponential in the ailerons and reduce the end points to control the roll rate. That was a great video. Dan.
