Thanks for the info Jack. 4 1/4" Is where my SE balances as built without having to move anything. Why would Sig reccomend 31/2 inches. Tried to balance it at what Sig reccomends and would have to add 8oz. to the nose to get the balance there. I knew that wasn't right. That's why I started this thread. I've been flying R/C for 20 yrs. and just came back after a 5 yrs. off. I didn't think airodynamics changed that much in 5 yrs. Starting to lose my faith in Sig