Greg Smith's quest to spend even more money on rocket science...
I attained my L3 cert on 8/9/08 and was promoted to L3 TAP on 6/22/11. Let me know how I can help you achieve your level 3 on the very first try! Glad to serve. :)
I still owe two launch reports from January but did not fly in February (I've been traveling). In the interim I wanted to preview what I'm hoping to fly at BALLS 21 this September:
That Frenzy Massive kit is 10.5' tall (3.23m for those down unda) once constructed and you see the Pro98 6GXL casing will barely fit the length of the main tube! (for reference I'm 6'2", 1.88m). I'm considering one of three CTI reloads:
I'm way behind in my blog posts but wanted to note that all my previous whining about wind was offset by two brilliantly wind-free Saturdays at Plaster City and Lucerne, respectively. Video, photos, and data are on the way soon. Mother Nature and I are BFFs again. Keep up the great work, MoNa!
Despite the cold morning it was sunny and clear most of the day with essentially zero wind. Every once in awhile Madre Nature gives back. For awhile now I've been wanting to fly the AT 486I59 Warp9 8-second end-burner with a cored White Lightning kicker on the nozzle end:
Per the instructions I used some Gorilla Glue to bond the end-burning grain place and then liberally coated the liner with grease to [hopefully] minimize casing damage. This was also the first time I'd tried the new Featherweight Altimeters magnetic switch armed externally using only a rare earth magnet:
Yeah the wires are long but I wanted to be able to swap the switch around to other electronics bays as necessary. I didn't capture any video or pictures of the liftoff but it kinda sucked. The initial kick wasn't as great as I'd calculated and my .38 Spatial immediately headed north after leaving the end of the rail. It arc'd out toward the mountain range and the only way I knew the main ejection had kicked was that my Comm-Spec transmitter signal shot up about when I'd expected based on the visual trajectory. From the following flight graph you can see that I still managed to attain ~2,200' of altitude and, based on the post-main slope of the altitude curve, the descent on the 12" 'chute was probably too fast at about 55fps/32MPH:
I say probably because this rocket is a tank and I found it completely intact well over 1.5 miles north. You can just see a thin, horizontal line of cars to the right of the hanging smoke trail if you click the image below:
This was, by far, the longest I've walked north at Lucerne and, for reference, I shot another photo of the power lines near the base of the huge mountain from that position:
My cellphone has a pretty wide angle lens but you still get the idea. I was about 80% of the way up the illuvial fan and I'm glad I didn't get caught in the power lines! Unfortunately the greased liner didn't protect my awesome 38/480 Dr. Rocket Millennium edition casing and the anodizing's partially burned now:
I'm sad but I've flown probably 10 reloads in there and it appears structurally sound (no bubbling).
I'll reiterate that I'm a very slow on rocket prep and recovery so I only had time for one more flight as the awesome ROC volunteers were talking of tearing the range down. Rob Greenlaw was parked next to me and he agreed to a drag race with our fiberglass 4" Nike Smokes on CTI 1408K2045 Vmax motors. I'll forego my typical drag race suspense and simply tell you that Rob won:
Good for Rob and I've already requested a rematch!
Near the end of this year's Plaster Blaster event Sparky, president of DART rocketry in SD, asked me to check out a rocket he'd found years ago and was trying to identify. My jaw dropped when I realized he'd found my long-lost minimum diameter 38mm design!
I'd flown/lost it at Plaster City on a CTI 512I285 classic motor. This flight predated my obsession with radio tracking as an invaluable insurance policy but I was out there with "Eagle Eyes" LL so what could go wrong? Well both of us lost site of it after burnout and, despite scouring the area for over an hour, were unable to find it and gave up. I'm not sure exactly who found it but Mike returned it completely intact including my long-lost Pro38 4G casing. So thanks again and props to Mr. Jerauld!
Lesson learned: I should travel back in time and include a radio tracker before the flight.
Google just redesigned the profile page for Blogger.com and it now clarifies that the 'page' views I've been tracking are actually profile views. So that counter in the lower right of this page is correct. Thanks for reading, peeps!
After posting two foreshadowing images below I'm finally getting around to documenting our nifty drag race three weeks ago. I had trouble editing the Flip Slide video in Final Cut Pro 7.03 for some reason so I threw this together in Final Cut Pro X:
[I'm not really a huge fan of that software yet as it seems to be half way between iMovie and v7.03 in capability.] Three of us flew the CTI 7521M840 and Mark Clauson chose the AT M650. A HUGE thanks to Joyce Chan who skillfully photographed our drag race and was kind enough to share her source files with me. Please head over to her site for larger versions or to buy prints of these or any of her other awesome shots: http://fotos.nahcpj.com/
L-to-R: Art/Tom Just, Frank Hermes, yours truly, Mark Clauson
Mark smoked us all with his minimum diameter L3 vessel on the M650!
I was second off the pad, then Art, then Frank. I honestly thought we M840 flyers would have had an ignition advantage because there's a 29mm propellant grain with an embedded pyrodex pellet at the top of the core. That plus the insane 459 pounds of initial thrust has me scratching my head. Perhaps Mark was using a special igniter but, whatever the reason, he won the liftoff cleanly.
I again used my Beeline GPS module to track the rocket as it was well out of site. I threw in the beacon as backup and thought I'd need if as my Yaesu radio didn't receive any distance data until about 20 seconds before the rocket landed. Not sure what's up with that but, in the end, the Beeline did the job and the Google Earth data was robust as shown in the post below.
As a fun aside we all kicked in $20 and employed a scoring equation including liftoff rank, peak altitude, and distance from the pad (highest score takes all):
Mark won with the highest overall score so congrats again! While Frank didn't win this year he was the only participant to incur zero damage after a clean recovery. Mark hit a power line on the way down and burned a 1/2" hole through the airframe and aft motor closure. Art's 1/4" Kevlar shock cord snapped but he got all the parts back. Mine suffered a hard impact that ruined my motor retainer ring and it took hours to free my motor casing. I was able to salvage it however and will replace the ring with 10-32 screws through the retainer side wall. Here my altimeter data if you're interested:
I'm a week late on my Plaster Blaster 2011 entry but I'm still waiting for a few elements to come together. I'll foreshadow a problem with an otherwise great M840 drag race flight last weekend: my Slimline motor retainer ring would not unscrew due to an impact with some harder soil. Frank Hermes suggested that the retainer tube was probably out of round due to angled impact and I think he was right. I started my Sunday trying to resolve that and get my motor casing out.
After 45 mins. of trying other methods I finally busted out my Dremel tool to grind a notch in the slot of the Slimline retainer ring. I then used a chisel to wedge down into the threads and snapped the ring at that spot. I was finally able to pop out the ring and extract my Pro75 6G casing. Although the retainer's threads are trashed I think I can drill into the sides of the retainer tube, tap them, and use tiny screws to retain future motors. This is cool because I really didn't want to trash the booster despite a heavier-duty version being on deck:
Those who have flown moonburner reloads know that they rank among the more difficult cleanup jobs; especially when stuck in a booster and untouched for a week! I was able to get the casing apart and the liner out without issue. As expected some threaded parts and the casing interior were filthy despite liberal use of grease during assembly of the reload. I emptied my tall-ish office trashcan, placed my casing into that, and poured hot, soapy water down into the casing. I repeated the fill and then added a bit of white vinegar to the solution. After soaking for a half-hour I flipped it over and started cleaning with a toothbrush taped to a dowel. A few iterations later I then dried the casing and busted out the screwdriver to scrape and the brake cleaner to dissolve the crud. This process took almost two hours in total today but my casing and parts are quite clean now.
During the soak I started repairing other rockets. My Madcow Squat suffered a minor zipper during the I445 drag race over a year ago. The short body tube is cardboard so I simply wrapped a swath of Gorilla Tape around the top of the tube. It looks pretty cool and should survive another I445 flight.
My '.38 Spatial' suffered a narrow Kevlar zipper in the payload section on its J350 flight. I used a length of 38mm coupler, two layers of release film, a slice of 38mm body tube, and carbon-fiber-loaded-epoxy to patch that up. I then wrapped the assembly in shrink tape and applied heat with a heat gun. This shrunk the film very tightly and I expect the gap to cure/fill quite nicely.
On its last flight my Loc Bullet suffered a 1x2" zipper/chunk due to an excessively long J500 delay. I used a technique similar to the above but this time I sandwiched a layer of carbon fiber fabric in the repaired area. It's worth a try as I was about to trash this rocket and start again.
I also scraped some unintended and ugly primer drips off of the 4' long payload section remnant of the otherwise lost Viciously Mean Machine. It looks pretty cool now and I think I'll fly it with the Fity-Fo booster:
...the view might look something like this:
Here's the onboard video from my M1230 Imax flight this last Saturday at Roctober/Lucerne Dry Lake (best in 720p, full screen)(note the ill-fated desert beetle scaling the igniter just before the flame deluge):
This was my first solid, high-altitude Beeline GPS data set as plotted in Google Earth with a peak altitude of 14,434' AGL and recovery 0.8 miles S-SE from the pad:
It's interesting to note the the ARTS2 reported a peak barometric altitude of 13,915' and the Raven gave 13,925' for an average of 13,920'. That's the closest I've ever seen two altimeters! (Only 0.07% disagreement). I also passed mach 1 at about 3 seconds into the boost on the way to a peak of mach 1.15 or ~887MPH. Here are links to the data images if you're interested:
Next up is that same rocket on an M840 White moonburner at Plaster Blaster 2011 from November 4-6. We're hoping to pull together a drag race but approval is pending. You should come check it out!
Update: I forgot to include the cool liftoff shot by LL. Unfortunately the full-size shot is significantly back-focused due to the lens sitting in the sun for awhile. LL has razor sharp vision and manually focused about a half hour before the flight but even this smaller size rendering with significant sharpening is quite soft. Not complaining... just explaining. I recommend that you keep all your big lenses in the shade at all times if possible:
My fourth and final flight at Plaster City's June '11 launch was my new 4" fiberglass Extreme DarkStar. I've sort of resisted the 75mm motor class for a decade but now I'm into it. I ran some calculations and the cost in $/N•s is identical between 75mm and 98mm reloads (~$0.06-0.10/N•s). This means the overall cost is lower with identical impulse per $. Big fan.
The wind was kicking up big time but I was confident that dual deploy combined with shear pins would bring the rocket down reasonably close. Unfortunately my keychain video camera died on the K740 flight below so I have no onboard or ground-based video. The pix are still good though. KO snapped this prep shot and I like it! (ignore my photo credit as that's an artifact of batch export):
Here's the pressure up:
And liftoff... note the excessive wind blowing the plume:
The ascent was arrow-straight but I lost site after apogee ejection because I was using CO2 deployment and a tiny drogue 'chute. This was also my first time using the Beeline GPS unit because the fiberglass structure doesn't attenuate the signal. Unfortunately I forgot to tape the unit down to the foam mount so I think it dropped to the bottom of the electronics bay on liftoff as my GPS altitude data was wonky. I did receive what appeared to be directional information, however, so I started walking NW. Then I heard a loud pop as the 4g main black powder charge blew at roughly 1200' as expected. I watched the rest of the descent and it landed only ~1/4 mile NW of the launch site (closer than most flights in low wind!). Luckily the dragging parachute caught on a bush so no damage was done by subsequent dragging. Stupid mass convection. Here's the Raven Altimeter data with a barometric peak altitude of 7,489':
And here's the ARTS2 altimeter data with a barometric peak altitude of 7,233' for an average of 7,361' (1.39 miles) at sub-Mach velocity:
I also ran the ARTS2 motor analysis and the report says it's an L680 (vs. the nominal L585).
Finally the ARTS2 coefficient of drag was roughly 0.5 at peak velocity.
I next plan to fly this rocket on the same propellant type but twice the motor size (M1230) so I expect roughly twice the altitude or ~14,000'. Fingers crossed for October 8th!
