hudmun

From where should i measure to balance my plane. I hope my illustration shows. (vq p-51 mustang 40 size)

Korps

If I understand the illustration correctly 5.2in will be at the spar...so balancing in the spar will be where the cg should be?

GOGGLES PIZANO

the mustangs i had were all measured from the leading edge if the wing,not the xtention portion.so 5.2 in from the actual wing leading edge should be correct.

Lnewqban

You can calculate it graphically.

Check this thread out:

http://www.rcuniverse.com/forum/m_94..._2/key_/tm.htm

You could also reproduce a half-wing in carboard (it can be scaled down), and find the centroid of the shape by holding a plumb from different points.

Regards!

jaka

Hi!
What does the instructions say???

Lnewqban

hudmun,

I have traced a picture of your model, and have calculated the location using the graphical method.

If we locate the CG at 25% of the MAC of the total wing, which is a conservative first location, the right location will be at 3.34", measured from the leading edge, where it meets the fuselage.

However, your schematic shows 5.2", which should be correct, although it places the CG way aft the point I have calculated.
Assuming that the manufacturer has performed some tests to determine that point, I recommend you to measure those 5.2" back from the LE at the center of the wing.
In other words, if not sure, start at the safest point, which could make the model nose heavy, but not dangerously tail heavy.

hudmun

Thanks a bunch, very helpfull.[sm=thumbs_up.gif]