My L1 rocket was a Giant Leap T-bolt (38mm MD, Magna-frame). Successful L1 first flight (H148R, as the signature says). Second launch at the same event was total destruction, didn't use enough BP in the DMS motor's ejection well (followed the instructions to only use half, was already questioning that at the pad and shouldn't have flown it), so it never separated, came in ballistic and was destroyed, gave up on that rocket immediately because there really wasn't anything to rebuild. But my next kit was a Giant Leap Firestorm 54 (54mm MD, Magna-frame), and I guess I got much more attached to this one, as much as it maybe didn't really want to fly.
Perhaps as a bad omen, when I started building the rocket the first thing I did (after ensuring that I had it right with a few dry-fits) was to epoxy on the Slimline retainer backwards.
And the fin-can was already epoxied to the airframe as well. So after lots of work I had the fincan separated from the airframe without damaging it (airframe was destroyed, obviously), a new airframe section (longer than the original, rather than cut the tube to the 'proper' length I kept it long to allow for longer motors) and a new retainer (at least got to move from a snap-ring Slimline to a threaded-ring slimline, which I liked better anyway, the T-bolt came with a threaded-ring unit). I hated filling the spirals on the T-bolt (they were still faintly visible after paint), and had decided that the Firestorm I'd use the lines to paint a spiral pattern instead (still filled them, but I knew the lines didn't have to be hidden this way), so it was named Bumbl-B and had alternating black & yellow stripes running the entire airframe. I really liked the way that turned out.
Anyway, first flight (XPRS 2014) on an I215R was an early separation. My analysis was that I didn't consider the longer airframe (and small motor) had more air trapped, and while I drilled the one vent hole GLR suggested, I really should have had two. Result was a ~1.5" zipper. So I cut off the zippered part (since I'd lengthened the airframe I figured I had some to lose), added a second vent hole, and it was now Bumbl-B mk II.
Next flight later the same day, on an I65W. The first shake-down flight was just motor eject, this time it's a plugged motor, and my first DD flight. I used squibs provided to me by another flyer. Well, the apogee charge never fired (resistance good before and open afterwards, but squib was unfired). The main charge fired at 700', rocket ballistic at that point, so the wood bulkhead split separating the rocket (though it pulled the drogue out at that point, so both separated halves had a chute to land on). But the end result of that flight was a 15" zipper on the lower airframe, all the way to GLR's 'supermount' (thick coupler with a perpendicular piece of all-thread that the shock cord attached to) and a 1.5" zipper on the upper airframe. Still had one more day at this launch and it was my only rocket, so the second set of field repairs were more drastic, I cut off the airframe just below the supermount (good thing I'd provided for longer motors), epoxied in an Aero Pack M54E retainer (for the shock cord mount not retention, after drilling some bypass holes into it, so that I could still use motor eject motors), and epoxied in a coupler and riveted the upper airframe to the lower (so no more DD). This was Bumbl-B mk III.
First flight on mk III was the next morning, I280DM, completely successful flight. The running joke from my Dad (who got his L1 on his T-bolt at the same event) was that my rocket was just settling-in to it's proper length. Went from 83.5" to 82" to 66". Added a Mobius camera shroud and GPS tracker in the nose, and 10 more successful HPR flights until the 13th (total) flight, I245G-L, that while drilled for 12s took 16.7s to fire (so it was long even for its stock 14s), and it was already starting to come down at a pretty good clip (~120mph), so yet another zipper, 2.5" this time. Shortened the rocket another 2.5" and this was mk IV (and more "How much shorter is your rocket this time?" jokes from my Dad).
mk IV did exactly one flight, it was an I357T, the fated RMS-EZ version. Well, I was one of the many victims of an early delay firing, went off over 7s early. The original upper airframe which was now riveted to the coupler added at mk III zippered the entire length, and the cord must have then snapped in the other direction, the airframe tore at the rivets and the upper airframe came down as a separate piece. The rest (nose and lower airframe) held together and came down on the parachute, but the rocket managed to land on one of the larger rocks at the Snow Ranch site, crimping the threaded-ring retainer such that it wouldn't unthread. Had to hacksaw the retainer off the rocket to get the motor out (and had to hacksaw the retainer itself to get the aft closure out of the retainer), ordered a new airframe section and replaced it, while the coupler was partly zippered it still had enough strength to be reused. I also ordered a new av-bay coupler and bulkheads, and re-built the rocket as DD this time. Painting half of the rocket ~2 years later than the other half, the fluorescent yellow wasn't a perfect match, so it never looked as good after this repair. But this was mk V, back to 82".
mk V also did exactly one flight, I225FJ. This was sort of an in-air ground-test, it was my first flight using a shear pin on the nosecone, and I wasn't positive that it would shear but didn't have time for a proper ground test, so I put a 36" chute in each section rather than a traditional drogue, figuring if the main never came out I'd still land at a safe speed. Well, the drogue charge failed to pull the larger chute out of the airframe, so just like the second flight things were coming down pretty fast (~133mph) when the main charge fired and separated the rocket (at least the shear pin wasn't an issue). The lower airframe had another serious zipper, but I still had leftover tube from the previous repair, so it was replaced pretty quickly, except now it was 3 separate paint jobs and now 3 shades of yellow. :rant: Enter mk VI, still 82".
First flight of mk VI (I303BS) wasn't totally successful, I had decided to go with 2 shear pins in the nose instead of 1 (don't remember why), and the nose didn't separate when the main charge fired. So it landed under drogue only. No damage to the rocket, didn't need to be rebuilt for once.
The next flight, however was the last.
Final flight (still mk VI) was on an I327DM. This one was totally pilot error (not that the others weren't at least partly on me), while I had a checklist and was marking things off as I went, I failed to connect the quicklink attaching the lower airframe's shock cord to the bottom of the av-bay. So at apogee the rocket separated into two pieces, and the cord didn't pull the drogue out of the lower airframe. The lower airframe came down ballistic, the upper airframe fired its charge at 700' and landed undamaged. But the lower airframe was destroyed (doesn't help that instead of landing on the soft field it impacted the hard-packed access road next to it). All of the previous damage had just been airframe tubes (and motor mount), now the fin can was destroyed, so at this point I gave up and decided not to rebuild.
So after 17 total HPR flights and 5 rebuilds I was finally done with this kit. Still the most flights I've done on one fincan, though finally some other rockets are getting close. I did, however, order up a customized Madcow Go Devil 54, with different tube lengths than the stock kit and yellow tubing instead of red, and have called it Bumbl-B FG, so it looks pretty different but kept the name (plan to eventually paint some black bands on it to make it a bit more bee-ish), so I guess maybe that counts as a rebuild. Hopefully with it being FG instead of Magna-frame it won't zipper as much.
Here are the different incarnations in order (original -> mk VI, end of mk VI, new FG version).
