RE: How do u Check the CG of a plane?
 

Balance it close to the point given in the instructions and you have a good starting point. If it'll sit there a little up or down is no big deal on a trainer. This is also just a starting point and not etched in stone. Remember for this and all your future planes that adjusting the CG in small increments will completely change how your plane flies. A friend bought a used plane and told me he hated it. After trying a differant engine that weighed a lot less the plane came to life and was all the sudden very aerobatic. Start out slightly nose heavy but don't be afraid to experiment with CG, engine incidence and control throws. All those things will change the feel of a plane and can be the differance between a good performing plane and a dog. Trainers have a smaller range of performance but it is a good lesson to learn early.

RE: How do u Check the CG of a plane?
 

Jason, the PT40 sounds just right. A little nose down for first flight is a good place to start. As for the table top method of finding the C.G. of a bi-plane, it comes out almost the same as all other mothods. so its time to fly this thing. JEff