Last Christmas I got My GF's son a Estes Supernova that he had picked out in the catalog. I had also bought a Bullpup 12-D so that we could build alongside earlier this spring. Since then our usual summer schedules (i.e. Sailing-centric) took over, and it wasn't until yesterday that a nice morning opened up with light wind forecasts and no soccer practices scheduled for the field.
I also packed up an old, un-flown, Wizard and a semi-retired Red Max, both holdovers from high-school and early college. Figure, the more the merrier.
And so we began: Winds out of the West at 5, gusting to 10. A little unnerving as the forecast was for less than 3, and the field size is limited to 900 ft square from treeline to treeline, and there the sizeable salt pond of doom occupying one corner. The boy really wants to see his rocket hit it's max at 1600ft, but I'm hoping for something he can recover to fly again.
After a parachute, wadding and engine loading lesson, and safety brief, the wizard, bullpup and, supernova are ready to go.
In Brief: First up, the wizard on a 1/2 A6-2 as a sounding rocket to see what the upper level breeze is doing. Let the young man fire. Arrow-straight flight to about 200ft, and still showing westerly on the drift down. Relocated launch area accordingly. Wizard recovered about 20 ft away with some paint blistering, and a cracked fin root. Honestly not surprising as it was built and left unpainted for 26 years. The BT and fins were pretty dried out and brittle from sitting in my storeroom window, before I sprayed it orange a couple months ago.
Second: The young man launches his Supernova on an A8-3 (sustainer-only to test things out). Vertical flight to about 175ft, and perfect deployment. Touches down about 30 ft downrange. Smile is starting.
Third to the plate: Bullpup on an A8-3 for a short hop. (Finally I get to push the button) Maybe 120 ft with deployment at apogee, and safe landing about 50 downrange. Ever so slight ding on a fin edge, likely from the nosecone snapping back at deployment.
After a reload session on the Nova and Bullpup, I've managed to talk him down on going for max height for the Nova. After witnessing 200 ft flights, and realizing just how high 1600 would be, he decides he'd like to still actually see the Nova in flight. I had brought an 808 camera for the staged flight, but forgot it in the car.
Fourth Launch: The Supernova on an A8-2/B6-0 combo. Fwoosh-tick-fwoosh. Big smiles and a "wow"! Off the rod about a degree to the north, and some weather-cocking West after separation at about 200 ft. Apogee estimate at 550 ft, and 100 ft upwind. The booster flutters to 20ft downrange and the sustainer lands about 150 ft to the North and 50 ft downrange. Who knows? Maybe she could land in the park from 1600 with that small chute.
Fifth Launch: Second go with the Bullpup and a C6-5. Vertical boost with a slow axial spin, begins to weathercock during coast above 200 ft. Apogee about 850 ft up and 50 ft to windward. We almost lose it in the noon sun. At this point I'm grateful for the weathercocking, as I watch the larger chute carry her across the field, over the tall grass, and into a bush 10 ft shy of the saltpond, 740 ft down range.
The geese are spooked..
The two of us retrieve our rockets, and it's at this point we realize that the Supernova flight was not as perfect as it seemed.. she has had a fatal event... to be explained after..
A solitary crochety old geezer has showed up insisting to practice his golf swing. We politely ask to do one more flight before he trudges out to the middle of the range. He icily abides.
Final flight: the DRM on a C6-5 because DRM's don't die even at 33 years of age. The young man gets to push the button because "those skulls are cool".. Of course they're cool.. that's why It never got thrown out after High School. Vertical boost, but again some now heavy weathercocking after 200 ft up. Upper level winds must be picking up. Apogee at around 570 ft and 200 ft upwind. Touchdown about 200 ft downrange.
We leave Grumpy Guy to his golf swing, and the angry geese. Heading back to the car, I discover the 808 camera in my vest pocket.. DOH!
Damage report: So yeah, despite the beautiful ascent and perfect deployment, everything was not alright with the Supernova. First hint was upon finding the booster, and realizing that the motorcasing was completely MIA. Luckily, no damage or burns to the booster itself. Pristine even, just no case. Then the words from across the field.."My Rocket melted". Hmm.. paper doesn't melt. He brings it to me, and indeed, it looked as if it had melted. (see attached pics). So the back half of the tube is warped with heavy blistering on the paint. Closer inspection shows that the motor has been pushed about 3/4" forward into the tube.
I'm still not sure if its because the mount tube dislodged from the CR's, or if the motor stop ring dislodged, and the aft end of the motor mount tube burned away. This won't be known 'till I do a necropsy. But either way, the separation charge, while igniting the sustainer motor was violent enough to blow the motor up into the sustainer BT.
Perhaps those who are familiar with staging have seen this before, and could give ideas on the cause. Could the heat from the first launch have softened the titebond wood glue? Or is it possible that the "single layer" of cellophane tape had too much overlap where the tape ends meet? Ideas?
And yes, the nova will fly again. I've already ordered a new motor mount, BT and a coupling to graft onto the intact front half.
I also packed up an old, un-flown, Wizard and a semi-retired Red Max, both holdovers from high-school and early college. Figure, the more the merrier.
And so we began: Winds out of the West at 5, gusting to 10. A little unnerving as the forecast was for less than 3, and the field size is limited to 900 ft square from treeline to treeline, and there the sizeable salt pond of doom occupying one corner. The boy really wants to see his rocket hit it's max at 1600ft, but I'm hoping for something he can recover to fly again.
After a parachute, wadding and engine loading lesson, and safety brief, the wizard, bullpup and, supernova are ready to go.
In Brief: First up, the wizard on a 1/2 A6-2 as a sounding rocket to see what the upper level breeze is doing. Let the young man fire. Arrow-straight flight to about 200ft, and still showing westerly on the drift down. Relocated launch area accordingly. Wizard recovered about 20 ft away with some paint blistering, and a cracked fin root. Honestly not surprising as it was built and left unpainted for 26 years. The BT and fins were pretty dried out and brittle from sitting in my storeroom window, before I sprayed it orange a couple months ago.
Second: The young man launches his Supernova on an A8-3 (sustainer-only to test things out). Vertical flight to about 175ft, and perfect deployment. Touches down about 30 ft downrange. Smile is starting.
Third to the plate: Bullpup on an A8-3 for a short hop. (Finally I get to push the button) Maybe 120 ft with deployment at apogee, and safe landing about 50 downrange. Ever so slight ding on a fin edge, likely from the nosecone snapping back at deployment.
After a reload session on the Nova and Bullpup, I've managed to talk him down on going for max height for the Nova. After witnessing 200 ft flights, and realizing just how high 1600 would be, he decides he'd like to still actually see the Nova in flight. I had brought an 808 camera for the staged flight, but forgot it in the car.
Fourth Launch: The Supernova on an A8-2/B6-0 combo. Fwoosh-tick-fwoosh. Big smiles and a "wow"! Off the rod about a degree to the north, and some weather-cocking West after separation at about 200 ft. Apogee estimate at 550 ft, and 100 ft upwind. The booster flutters to 20ft downrange and the sustainer lands about 150 ft to the North and 50 ft downrange. Who knows? Maybe she could land in the park from 1600 with that small chute.
Fifth Launch: Second go with the Bullpup and a C6-5. Vertical boost with a slow axial spin, begins to weathercock during coast above 200 ft. Apogee about 850 ft up and 50 ft to windward. We almost lose it in the noon sun. At this point I'm grateful for the weathercocking, as I watch the larger chute carry her across the field, over the tall grass, and into a bush 10 ft shy of the saltpond, 740 ft down range.
The geese are spooked..
The two of us retrieve our rockets, and it's at this point we realize that the Supernova flight was not as perfect as it seemed.. she has had a fatal event... to be explained after..
A solitary crochety old geezer has showed up insisting to practice his golf swing. We politely ask to do one more flight before he trudges out to the middle of the range. He icily abides.
Final flight: the DRM on a C6-5 because DRM's don't die even at 33 years of age. The young man gets to push the button because "those skulls are cool".. Of course they're cool.. that's why It never got thrown out after High School. Vertical boost, but again some now heavy weathercocking after 200 ft up. Upper level winds must be picking up. Apogee at around 570 ft and 200 ft upwind. Touchdown about 200 ft downrange.
We leave Grumpy Guy to his golf swing, and the angry geese. Heading back to the car, I discover the 808 camera in my vest pocket.. DOH!
Damage report: So yeah, despite the beautiful ascent and perfect deployment, everything was not alright with the Supernova. First hint was upon finding the booster, and realizing that the motorcasing was completely MIA. Luckily, no damage or burns to the booster itself. Pristine even, just no case. Then the words from across the field.."My Rocket melted". Hmm.. paper doesn't melt. He brings it to me, and indeed, it looked as if it had melted. (see attached pics). So the back half of the tube is warped with heavy blistering on the paint. Closer inspection shows that the motor has been pushed about 3/4" forward into the tube.
I'm still not sure if its because the mount tube dislodged from the CR's, or if the motor stop ring dislodged, and the aft end of the motor mount tube burned away. This won't be known 'till I do a necropsy. But either way, the separation charge, while igniting the sustainer motor was violent enough to blow the motor up into the sustainer BT.
Perhaps those who are familiar with staging have seen this before, and could give ideas on the cause. Could the heat from the first launch have softened the titebond wood glue? Or is it possible that the "single layer" of cellophane tape had too much overlap where the tape ends meet? Ideas?
And yes, the nova will fly again. I've already ordered a new motor mount, BT and a coupling to graft onto the intact front half.
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