I just finished putting together a Goldberg Obsession and cannot get it to balance. Iam using a gp cg machine with modified arms for the extra lenght. Set at 9 3/8 from the leading edge. One time it balances nose heavy and the next tail heavy. Any tips on balancing a large plane like this one. I can even get it to balance the remove the weight and nothing changes. Thanks

Low wing planes must be balanced upside down

High wing planes right side up

It is upside down. I just cannot get the same results two times in a row. Do you think the balance point is not right. The book said 9 3/8 from fuselage side and 9/ 38 from the leading edge

Do you have fuel in it that is sloshing around?

No fuel it just came off the bench. However I think I might be close this time. I might have had the balance arms to far from the sides of the fuselage. what we need is a jumbo CG machine for big planes. I have never trusted my finger tips for balancing because I like my results to be consistent. I think Iam close now and will fly one or two flights and see how it feels. I could always build my own CG tool.

Ok I get it high wings right side up low wings upside down, right ? What do you do with a mid-wing? I've been fighting a Mid-West Super Hots ( 60 size) I built from plans. When balancing either way , I can get it"balanced" (slightly nose down) for a short while & it wants to start drifting away from the balance point. I've been told, if it stays there for a while,it is OK to fly. I don't think so.. I've flown a "tail heavy" plane before. -It AIN'T no fun. Especially after all the hours in this plane !!

Balance it heavy side down. Initial balance is just a starting point, usually a bit forward, and subsequently adjusted according to flight needs. Have fun!

As Jim Dines says

Start out definitely not tail heavy and make your final adjustments by flight test.

When pitch control on landing approach starts getting squirmy, you are getting tail heavy.