Flew it on a 38mm Cessaroni single grain G46. I had trouble with the interchangable motor retainers, and my single grain case is lost in the sage for the time being. The flight was very nice. A show stopper if there was an audience. Nice and easy for the first second and a half. This is a great rocket however I'm just going to set it up for 38mm and forget the rest of the mounts. I would love to be able to start over with the kit. I have learned a few things since then.