if you get a chance to put the rocket up with an altimeter, I'd be very curious to be able to compare with your data.
Will do, but it won't be that one because it's not built and won't be since I have a similar one which I will also sim with the latest sim versions and eventually fly (again). I will say that years ago with that same custom tube-finned model and Rocksim 9, the projected and measured altitudes were
amazingly close. I was using Aerotech E20s if I recall correctly.
The following is not about tube fins, but in 2014 I did a half-a**ed test of a six fin design which was a
subscale version of a 4" OD design which gave me
radically different results from Rocksim vs OpenRocket.
https://www.rocketryforum.com/threa...pr-1-2-altitude-of-rocksim.53242/#post-709474
In that case, with the subscale version at least, OpenRocket was
much more accurate than Rocksim when using thick, flat leading and trailing edge fins and only slightly more accurate with the same fins rounded.
The whole point was to be able to safely fly an intentionally draggy 4" version with six 1/4" fins with flat leading and trailing edges. One needs an accurate simulation to know what delay to set. Sims of that was what led to my experiment with the subscale version due to the
huge difference in the results between Rocksim and OpenRocket. The 4" version was
already built before I discovered that huge difference, but slight coning of the subscale version flying on F32s in the tests made me afraid to ever fly the 4" version which I haven't. Otherwise, I would have flown it definitely using the OpenRocket results.