2016-04-02 - Will Ferry's Bumbl-B

Flight Log - 2016-04-02 - Will Ferry's Bumbl-B

During initial construction I managed to JB-Weld the motor retainer backwards (even after double-checking). Discarded original 36" tube and replaced with 48" tube and 54mm threaded slimline retainer.

Initial rocket length: 83.5"

First flight (2014-09-13, I215) resulted in ~1.5" zipper on lower BT due to ascent separation. BT cut 1.5" shorter. Renamed "Bumbl-B mk II".

mk II rocket length: 82"

Second flight (first as mk II, 2014-09-13, I65W-P) resulted in ~1" zipper on upper BT and ~15" zipper on lower BT due to failed drogue charge (bad e-match). Cut upper BT 1.25" shorter and lower BT another 15" shorter. Renamed "Bumbl-B mk III".

Lower BT had to be cut below the original hardpoint anchor as zipper ran down to the hardpoint. Replaced with Aero Pack M54E retainer (drilling 5 holes for motor ejection bypass). Upper and lower BTs epoxied together at coupler (no longer separates). No longer capable of carrying electronics other than inside nose cone.

mk III rocket length: 65.75"

Thirteenth flight (tenth as mk III, 2015-03-21, I245G-12) resulted in 2.6" zipper on lower BT due to late AT motor eject. BT cut 2.6" shorter. Renamed "Bumbl-B mk IV".

mk IV rocket length: 63.125"

Fourteenth flight (first as mk IV, 2015-04-04, I357T-12) resulted in significant airframe damage due to very early AT motor eject. Lower BT zippered down to coupler from mkIII repair. Additionally the Slimline motor retainer was crimped during landing, had to be hacksawed off rocket. Rocket finally rebuilt March 2016, with two new airframe sections and new avionics bay coupler to replace damaged piece and restore original dual-deploy design. AeroPack M54E used to replace original Supermount during mk III repair now used for motor retention. Renamed "Bumbl-B mk V", used name "Return of Bumbl-B" on first flight card but name was not announced.

mk V rocket length: 82"

Fifteenth flight (first as mk V, 2016-04-02, I225FJ-P) resulted in ~18" zipper of lower BT due to failed apogee chute deployment (36" chute stuck in airframe). New BT section zippered entire length, down to coupler from mk III and mk V repairs. Rocket is awaiting rebuild once again (mk VI).

Flight Date:	2016-04-02
Rocket Name:	Bumbl-B
Kit Name:	Giant Leap Rocketry - Firestorm-54 {Kit}
Flyer's Name:	Will Ferry
Motors:	I225-P
Expected Altitude:	1,924 Feet
Launch Site:	LUNAR - Snow Ranch
Actual Altitude:	1,816 Feet

Rocket was configured for in-air test of shear pins (first time used on any of my rockets). Ground testing not possible due to inability to run wires out of avionics bay or to fit Eggfinder TRS in bay for remote ignition. Will be able to use Eggtimer Quantum (built afterwards) for future ground testing. As such rocket flew with two 36" parachutes, one in lower airframe (for apogee ejection) and one in upper airframe (for main ejection). Intent was to land under at least one 36" chute, assuming apogee chute would deploy and main chute could fail due to lack of pressure to shear pins.

Apogee charge failed to pull oversized parachute out of lower airframe. No parachute deployment until main charge at 700'. Parachute deployment at high velocity resulted in severe damage to airframe.

Flew with AltimeterThree, used keychain ring attachment, altimeter not lost during rough separation.

Flew with StratoLogger CF and Eggfinder @ 910.25MHz. Data downloaded from both altimeters. Good visual on flight, GPS not needed to recover rocket. Landed about 435' from launch pad, on other side of observation hill.

Flew with Mobius camera. Camera shows upper airframe along side lower airframe during initial descent. Upper airframe in frame when main charge fired.

First and final flight in the "mk V" configuration. Lower airframe zippered down to damaged coupler just above shock cord mount. Will replace this airframe section again.

Stage	Motor(s)
1	I225FJ-M

Post a Comment