The upper stage of the my solar flare is gone but I have that neat booster stage with the ring. What should I build to re use it. The ring is bigger than a BT 80, so my first ideas are out the window? It's bigger than the PS Nike smoke too.
Well, if I remember correctly, the ring fin is a BT-101. I believe that tubing can still be gotten through BMS.
Or with a little creative design, you could adapt a fin design to line up with the existing fins in a flush mount design and use whatever tube size you want. There's several possibilities. You could also just order the spare parts from BMS and clone the sustainer to rebuild the original rocket. There's a wicked design you could do with a transition and a second ring the same size.