Last fall, I picked up a large pattern plane from a retired club member. The ony thing he knows about it is that it was built by another person. I haven't been suscessful in determining the model so I am unable to get recomended CG and throw info. I've just about got it air ready, but I'm at a loss as to where to place the CG.

I've been playing around with a couple of the CG caculators and I'm a bit confused as one shows a range between 6 and 7.75 inches from the root LE. This looks like a huge range from planes I've built. The wing span is 74", Root cord is 15.75, and tip cord is 11.5 with a 3.5" sweep on the LE. The horziontal Stab is 32" span, 10" root cord, and 6" tip cord with a 1.5" sweep on the LE. The Root LE of the wing to Root LE of the stab is 37"

Based on this and using a 10% static margin, I get the 7" CG from the Root LE. using this caculator. http://adamone.rchomepage.com/cg_calc.htm

I'm looking for someting that is going to let me get it up and flying without fighting a nose heavy, or tail heavy condition. Based you your experience, does the 7" sound OK???

Don