I know you've been having a 13mm challenge, but here is a big one. Over 4' tall and 24mm powered.
I'm working on the EMRR challenge. #5 is to design a rocket using a simulation program and then build and fly it. Here is my design.
Some things I've had to work around in Rocksim.
The mid and bottom fins (extending into landing points) are connected with 1/4" dowel.
The launch lugs will be on the ring fin and on the upper tube fins (I will need a spacer for the upper one).
This is my first real attempt at a Rocksim design. It has been doing weird things. It always
shows I have margin - sometimes even over-stable. But when I do the flight profile, sometimes it is stable and other times it is not (once I just exited without saving and re-started with no changes and got different results). When it has shown to be unstable for the flight sim, I've removed a part of the design. It then flies stable. I then add the original part back, and it is still stable. I've also noted that when I make a design change, the 2D view would not immediately update. If I switched to the 3D (or rear) and then back to 2D the view would then be updated. Could this be part of my stable/unstable issue - when Rocksim updates?
Anyway, please look over and let me know what you think.