Starting off reading the thread, I was thinking that scratch is significantly harder because you have to figure out the shape of the fins and do more planning on stability. By the end, I've realized that the important thing is that you can do the engineering and fabrication. It's probably just as much work to check and modify a "standard" OR/Rocksim file as it is to build it. As long as the flyer can demonstrate doing the sims and checking the flight will work properly, the goal is satisfied. Other than cutting the fins and centering rings, the rest of the fabrication is the same. I had my friend with a laser cut those parts, so it didn't even require much effort from me.
Redundant dual deploy isn't super difficult. With a couple of altimeters and their manual(s), you can make that happen pretty easily, especially if you have a copy of Canepa or read TRF. Making an av-bay that's elegant is another matter entirely! Our group of high school rocketeers did the first part of this last year, with no prior controlled ejection experience. They definitely failed the second test, although this year should be better.
I went scratch for L1 and kit for attempted L2. No plans for L3, but I also wasn't going to do L2, so...
) What's the difference between buying a kit or scratch building something using essentially the same components as a kit? Not much... either way you're gonna have to do an OR/RocSim analysis to make sure it's gonna be stable and keep you within your waiver (which is getting to be an increasingly more difficult L3 requirement). Most kits capable of L3 performance are basically just the FG components, the hardware and recovery bits aren't included, so a L3 actually IS a test of your design skills.
