Thursday, August 23, 2012

Launch Report 2012-12

Location: Mattie Stepanek Park
Weather: 82 degrees, wind 0++ mph, partly cloudy
Total flights: Today - (3); YTD - 80
Total motors: Today - 0; YTD - 95
Motors by class YTD: (Air -6); MicroHybrid -1; MMX -6; A -6; B -5; C -32; D -7; E -23; F -6; G -9

Yesterday, I threw together two quick air powered rockets. I haven't bothered naming them. For this log, I'll call them stubby' and 'stretch'.

Stretch (30psi) -  This rocket is an experiment to see if an ultra-loose nose cone can slip off and deploy a parachute.  I started at a low 30psi. The rocket was tight on the barrel and, to my amazement, it pulled the 4' metal pipe out of the fitting rather than launch. I hadn't tighten the fitting, thinking there was no way this could happen.

Stretch (40psi) - I tightened the fitting and tried again. Evidently, the first launch not only unseated the barrel but it breached the end of the pressure tube. This time, only the nose section popped off. DOH! I will trim the top and re-build the plugged end.

Stubby (40psi) - This short rocket boosted nicely but the altitude appeared to be about the same as the large HoJo. I assume this is due to the relative length of the pressure tubes(?). The weren't many people at the park so we moved to the main recreation area and flew into the grass field. The rocket's nose was slightly deformed. I removed it, pushed it out from the inside, and re-installed it.

Stubby (60psi) - This launch was the highest pressure that I've tried in the launcher. It really took a long time to build up! The rocket clearly flew higher, but not as much as I expected. I know the hard core spudders say to modify/replace the diaphragm on the sprinkler valves. Maybe mine is not releasing the pressure quickly or maybe it's not venting all the stored charge. I don't know.  However, I do know this is working well enough and I'm not inclined to fiddle with it.

Here are just a couple of photos of the event. I couldn't catch the little one in flight.