ORIGINAL: SeamusG
Em - and how about a mid-wing? Now, is that a setup or what?
BTW Gene - thanks for the idea of doing a CG test before covering!
Oh yea - I have a problem with determining ''what's friggen nose up or nose down'' when I'm balancing the plane on my finger tips. One technique that I have found simple, cheap and effective is the use a string level to make sure that the plane is level. I place the level on the horizontal stab and shim the plane on my bench using whatever you have available. This sets the plane at level ''flight'' because most of the planes have the stab set a 0 (zero) degrees incidence (aka - level). Then when I put my fingers under the wing and lift I watch to see which end drops - front drops - nose heavy. This works whether your plane is upright or inverted.
Yea, I've tried a bunch of ''devices'' including dowels with erasers and the Vanessa rig. This is pretty simple.
A true mid wing should be able to go either way but how often do you find a model that has the wing perfectly set at the datum. That's one of those common sense things that creates that thinking stuff. Knowing how I feel about having to think I have often CGed mid wing planes first upside down then right side up just to see what happens. They are usually off one way or another. Now comes that thinking stuff. I scrathc my head while looking at the plane then decide how I would like to do it. Usually upside down and slightly nose heavy.
I didn't read LNs thread but I'm sure it's a lot more detailed then what I do.
To date I have only had one plane that the CG was off but I knew about it in advance, I'm talking a bunch!! It was a giant scale Bipe I scratch built from plans and I measured the CG shown on the plans against my old stand by of 25% of the wing cord. The plane was way tail heavy if I went to the plans. My advanced instructor had me go to the forward mark of the plans stating the designer knew where it should be. He may have but the guy that inked the plans didn't. I always check the CG location of plans built planes before I fly after that. The CG calculator on the net works great so I use that too.