LDRS-41 took place at Richard Bong State Recreation area in southern Wisconsin. July 6-9, 2023
My flights went as follows:
Day 1 - Winds were out of the north 5-10 - which is unfavorable because rockets get pushed into the tree line. Strategy was to launch low altitude and see how it goes as this was our first time at Bong.
Flight 1: Rocket R&D Brutus on an I-161 WL motor. This motor was built using cut and cored grains procured from RCS. Estimated Altitude was 2000 feet, no altimeter was on board. Flight was good and landing was lucky as it just missed landing in a small pond just east of the flight line (near the away cell).
Day 2 - Better winds, nice weather, 75 F and sunny most of the day. High clouds rolled in around noon.
Flight 2: Loc Big Nuke on a K550. The motor was built using cut and cored 54mm white lightning grains.
Dual deploy with Altus Metrum Easy Mini as primary altimeter, and Eggtimer Classic as backup altimeter.
Launch was good but the rocket veered to the south just after leaving the 15-15 rail (which was too short at 6 feet). Recorded apogee of 3821 feet, with a maximum speed of 515 fps (mach 0.5). Drogue descent rate was 51 fps, and main chute descent rate was 19 fps. The eggtimer classic functioned correctly in providing the backup charges,
The Altus Metrum TeleGPS was utilized for tracking and it worked flawlessly, leading me directly to the rocket which was located in tall grass and shrubs near the tree line to the south of the flight line.
Day 3 - Started with rain lasting until about 10:00 am and then a low cloud deck until about 11:30. Then became partly cloudy and warm
Flight 3: Punisher 3 on an I284 (cut and cored RCS grains). Launch was good but the rocket veered north shortly after leaving the pad. The reason for this is unclear as the rocket was at least 6 feet above the rail before turning, and the wind was low. This rocket had flown perfectly straight on a blue thunder motor at the previous launch.
Possible causes:
1. Nozzle was not drilled straight causing a slight thrust vector. (I hand drilled the nozzle for this motor).
2. Debris from the burning propellant clogged a section of the nozzle. Maybe the grain core was "shaggy" and not smooth allowing for more debris. I have to wonder if white lightning propellent is more prone to produce slag that could clog the nozzle.
The eggtimer quantum recorded an altitude of 2955 feet. Once again the TeleGPS provided the guidance to easily locate the rocket north of the park access road on the north side of the launch field. Recorded max velocity was 453 fps, drogue descent @ 55 fps and main descent rate was 16 fps.
Chip's Flight log
Day 1 - Unfamiliarity with the site was cause for apprehension. Experienced members gave insight as to what to expect. With the winds blowing in the atypical North to South, caution was the approach. I was not alone as others seemed to hold back until we could get a hint as to what the results would be. Seemed like a safe bet to send up the 3" Cherokee on an H128 with the JLCR.. The H-128 was the last commercial motor for that case I believe. The launch was typical for the Cherokee, straight and true. Without an altimeter, Open Rocket calculated a flight of 970’ AGL. Did not have a sim at the time so I guessed at the 6 second delay, which was very close to perfect. The RunCam shut off on the pad therefore no launch video.
Day 2. - Trying to get the recovery monkey off my back with the Cherokee 3XE. Added a Stratologger altimeter to the existing RRC2 for redundancy. This would be the fourth launch on this and it had yet to come down under full parachute! Careful preparation and packing of the recovery system resulted in the first main parachute recovery. The liftoff on an I-211 reload (Which I believe was an EMK with 38mm cut grains lifted it to 1352' AGL and FINALLY produced a main chute recovery. Drogue and main chute both functioned properly. The main parachute was a homemade 50” black and yellow ripstop nylon chute. The descent rate was good, although I need to buy the cable to download the data from the Stratologger. All charges fired! The recovery was not flawless as the location of the drogue caused the two harnesses to become entangled. The seems to be an ongoing issues with the owner. On the plus side, Mom had previously sewn a deployment bag for this one, out of yellow Nomex fabric, that can be seen in the recovery pic. Randy snapped a recovery pic also known as “evidence.” Once again, the Runcam failed to get video which means that it has flown its last flight.
Day 3. Time today was cut short by the miserable early weather.
Finally getting to the 5.5” Slugbuster!
More careful preparation ensued as the two altimeters were set up with charges. The Eggtimer Proton taking the lead and the Eggtimer Classic (under new programming) would handle the cleanup. No more relying on single altimeters for me. Also joining the electronic party, the altimeters would be accompanied by an Altus Metrum GPS tracker, for the first time. The rocket was loaded with a 54mm J-415 EMK 54-1280 with cut grains. That rocket shot off the pad to an altitude of 2842' and both altimeters functioned perfectly.
A very nice flight, straight and true. The dual recovery worked well EXCEPT it almost became entangled - I really need to change the location of the drogue! The descent rate was nearly 30 feet/second so this bird is going to receive new laundry in the form of twin 60” diameter chutes..It went off into the field to the south and the tracker proved its worth. It led us to the recovery location without a hitch.
