Tuesday, August 21, 2012

Launch Report 2012-11

Location: Mattie Stepanek Park
Weather: 75 degrees, wind 0++ mph, partly cloudy
Total flights: Today - (3); YTD - 80
Total motors: Today - 0; YTD - 95
Motors by class YTD: (Air -3); MicroHybrid -1; MMX - 6; A - 6; B - 5; C - 32; D - 7; E - 23; F - 6; G - 9

Today, I launched the AlaskaPaperModelworks Honest John using a PVC air launcher.  I went to a few potential launch sites only to find them populated with people enjoying the mild weather.  Although the 39" rocket is fairly light, it has no recovery mechanism and I wasn't sure if there was any slightly-upper level breezes.  My launcher is complicated by the fact it it either has to plug into the car or I have to lug the launcher, pump and 12v portable battery around.  I finally found a sufficiently open area, which unfortunately had more pavement than grass. Photos of the launch are at the bottom of this report and below the jump break. 

My old tire pump has a hard time getting over 30psi. I don't know if this is expected or it is fighting a small leak in the pressure chamber.  I had a hard time getting my pressure chamber sealed but it passed a soapy water test at 30psi.  The last leak was at the pressure vent on the air valve (made from a 1" Orbit sprinkler valve). The first photo shows the set up.

Flight #1 (40psi): Being under the flight and having no landmarks, it was hard to estimate the altitude. However, it was a pretty satisfying boost.  The rocket fell sideways for a while but ended up lawn darting onto the pavement.  Ouch. Two 'after' photos are attached.

Flight #2 (50psi): I straightened the nose, popped the broken body section in, and pulled the nose section off the body. The flight was noticeably higher but the profile was the same. BOINK! I only have a before shot of this flight.

Flight #3 (60psi): Thus time, the nose tip was beyond straightening and I couldn't get the two sections back apart. So, I launched it as-is.  The altitude seemed closer to that of the first flight and, yup, BOINK! The final photo shows the compacted stomp rocket next to the one that I converted for 24mm motors.

Launcher set up.
After the first flight.
After the first flight.
Before the second flight.
Videos of second and third flights:

The final aftermath.