Cg

[Trroscoe]

I recently recieved a NES Pulsar from someone in my club and need to know where to start when trying to balance it. Right now it is balanced at 3 1/2 inch back from the leading edge. I need to know if this is a good starting point. 33% of the cord is 3 1/4 inches. If any one has one of these or any good ideas I would like to hear them.

Rick

[NickW]

Hello, assuming the wing is fairly straight and does not have a lot of sweep in it, or any other unconventional layout: I usually start at about 32% of the root chord and go from there. There are definitely better methods out there to determine starting CG, and a quick web search should produce exactly how to calculate it.

Good Luck

Nick Wisdom

[Ollie]

When comparing CG locations the chord you should use is the mean aerodynamic chord (MAC) rather than the root chord. There is an on-line computer program for calcualting MAC at:
http://perso.wanadoo.fr/scherrer/matthieu/english/mce.html

The location of the acceptable CG range depends on the tail moment arm and area compared to the wing MAC and area.

The final CG location shoud not only depend on the configuration of the plane but also on the pilot's flying style, skill and preferences. The final CG location should be determined by flight testing and adjustment. See:
http://www.polecataero.com/
Go to articles and select the article on CG by Dr. Mark Drela. This is the best information available on the subject.

[amd123]

I also just purchased a used pulsar. When I balanced mine I used the ballast location within the wing to determine the c/g. A club member just gave me a copy of the pulsar papers, when I get home I will look to see if the papers state a c/g location. Good luck.

[amd123]

Rick, I found the papers concerning the Pulsar. It says that the c/g is 3 1/2" to 3 3/4" from the root leading edge. This paper also has the control throws if you need them.

Hope this helps.
Alan Dolley

[Trroscoe]

Allen if you could copy the paperwork and send it to me I would be grateful. I flew it today at 3 1/2 inches back from the leading edge and it flew OK. I hand tossed it several times first to check it out and it flew ok so I launched it on the highstart. It flew good but I had to adjust everything on it to get it to trim out. I finally got it to fly straight. It likes to fly fast and turns good. It really slows down when you use crow when landing. I am just learning how to fly gliders and am doing pretty good so far. This by far is one of the best gliders that I have flown so far. My other one is a Spirit Elite and it is set up the same way as the Pulsar. There was no lift today so I just got a bunch of quick flights in and got to practice my landings. I will try again on friday. Thanks for all of the reply's to this thread.

Rick