Has anybody used this software (AeroCFD)and can you share impressions, results, experiences? I have a bird that Rocksim says will be overstable, but when launched with very little breeze, it was virtually unstable and became a skywriter, only achieving about 575 feet in altitude, about 1/10 of what it should have done. Now I am trying to find out why and Rocksim will not take me there. I am looking for help. Joe thought it might be unstable becasue the fins looked too small to him. Dave Bishop agreed. RASAero simulations showed that it would be stable also. This is a 38mm bird, 39.5 inches long, 3 fins, 5.5" span, using a G54.The fin root is only about .500" and .375" at the tip, with a barely airfoil to the fins that are .030" thick. The fins are about 6" up from the bottom of the rocket in an attempt to get the stability close to 1, but the nose is too heavy and it is showing a 6 calibre separation between the CG and the CP. Any thoughts or ideas? 😕