I have the h9 edge also.I built two of them.My first one came out 12 lbs ,with 2 elev.servos and 1 rudder servo in the rear.os 160 in the front.No additional wieght required.I lost radio contact with it and watched it fall what seemed like a mile till it crashed.So I bought another one.Second one set up same as the first.I was not real critical with balancing because of just building one identical to it.Well it turned out that I was extremely tail heavy.I had to add 7oz to the nose.So check your cg for yourself.What someone else did does not always apply.I would say you are probably way off on laderal balance or cg.I fly mine inverted and then watch the plane.If my nose falls fast inverted then I remove nose weight till it stops.I havnt had any tip stalls with either of them.They really fly well.I dont have a alot of throw on my elevator though.I think some have problems because of too much throw. Tivey