I had the chance to go to the URRF, in Potter NY June 21-23,2013, sponsored by URRG (Upstate Research Rocketry Group). I was able to successfully launch my PML D-Region Tomahawk, and figure out how to use a new Boostervision HD.
Long term plans for the Tomahawk are to cut out a section of the tube for an electronics bay and learn to implement a dual deploy system, then, if it survives, learn to use hybrid rocket motors. My goals for URRF were to demonstrate a safe first flight of the Tomahawk and obtain flight video of a launch.
PML D-Region Tomahawk
The Tomahawk has a couple modifications. The ejection piston is removed (err, misplaced 🙂 )but probably won’t be used for the dual deploy system.. The launch lugs were replaced a button (lower) and a PML Linear Rail Lug (upper). The nosecone is held by three screws instead of simply a pressure fit. I also added the PML HAMR motor retainer.
Presently the rocket only has an initial undercoat of paint, with some reflective duct tape at the payload joint.
The Boostervision harness was attached to the payload section. Three strips of electrical tape were wrapped around the payload tube at the ends and the middle if the harness. The camera was placed in the harness, then taped around the ends and the payload tube.
I had trouble verifying the camera LEDs were lit properly on the field in the sunlight. I used a flannel shirt to cover my head & the camera, but it was still difficult. I failed to get video of the first “G” motor flight. But after reviewing the Boostervision startup procedures again and memorizing the button sequence, I was successful for the second flight with the “H” motor. I think that if I had started the camera while the launch rail was lowered I could have read it with shading.
I did two launches on Saturday. First with a single grain 38mm CTI HP-141G115-13A White Thunder set to a 6s delay. The second motor twas a three grain 29mm163H133BS-14A Blue Streak set to 9s. Preliminary WAG altitudes were 600 and 1800 ft respectively, based on semi-similar motors in PML’s altitude charts. The first launch delay was close to perfect. The 2nd was a little long, it may have dropped a second or two after the peak. I still need to develop an OpenRocket model to make better predictions.
I intend to add a couple swivels to the shock cord an parachute to reduce cord twisting.
The conclusions are, I had a successful first flight, and obtained in-flight video. And please ignore the ” timestamp” on the video
© David B Snyder 2013