Would you mind explaining your choice on fin design?
Very interesting thread! I'll be following of course. I love the retractable rail buttons.
Alex
The fin design was a result of a compromise between several characteristics. I wanted a rocket that was stable on it's own but could still take flight input from canards without to much trouble. The rocket is also very long, almost 13', has its recovery section in the center and payload up front which pushes the Cg forward and increases the longitudinal moment of inertia. So to maintain good static stability the Cp had to move forward. I couldn't move all of the fin surface forward to accommodate and most other options would greatly increase the fin area, so I split them. I then worked through several scenarios of mass distribution and staging until I arrived at the current fin surface distribution and placement. So, what I have now is a rocket design that can fly safely in several configurations:
Standard: Any 75mm composite motor up to 60" long.
Hybrid: Any Hybrid motor up to 60" long(designed for the contrail, 59" long)
Heavy lift: Add 4' section forward of AV bay with up to a 22lb payload.
Staging: Add up to two more stages with up to 115mm x ~48" long
The above are directly correlated to my goals.
Standard, get my L3
Hybrid, because they are cool and I must have one.
Heavy lift, lifting school projects for local schools.
Staging, a reason to go to Blackrock.
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