Sunday, July 13, 2008

Flew The Patient again

This time I flew it on an Aerotech E15-7W motor. This went to a maximum 1822' feet at 300MPH. The rocket performed well but the ejection charge caused some problems. The chute, e-bay and rocket all came down separately. We located the rocket and chute early on but spent 15-20 minutes trudging around the grass/marsh area to find the e-bay and altimeter (Thanks Justin).

More to come on this launch.
Justin took most of the pics using my gear, so thanks to him for that.

We started off with the Snarky - hence forth known as Eulogy. To re-cap it has now flown 3 times:
Flight 1- 6" zipper
Flight 2 - E motor Failure
Flight 3 - Roof landing, but the owner was nice enough to assist in recovery.

We fired off the Estes 36 "D" Squared 3 times, the results were: 1 motor launch, long delay before recovery, landed safe. 1 motor launch, wild flight, recovery fired on the ground (below) and finally a 2 motor flight that was perfect.

Lesson Learned - Time for a clip-whip.

Ground Recovery:

Launching on 1 motor:

We also flew the Commanche-3 as a 2 stage C-C, that was a solid flight.

Final flight was the Dragonfly. Slow launch, crazy flight, eventually lost sight of it.

I also met a nice guy and his 2 kids flying some Estes starter kid rockets. They had several nice flights and very close recoveries.


MrTidy OTR said...

Wow - bummer about the super-large ejection charge. When flying E and larger motors, be sure to use extra-long shock-cords - don't know if that was a factor in this event but the larger motors pack a pretty good sized charge since they have to pressurize a potentially larger airframe at a potentially higher altitude. I make my shock-cords about 5x the length of the rocket. It's a pain in the butt to pack the ultra-long cord but the intent is for the airframe and nosecone to slow down before the shock happens.

Murdock said...

Thanks, I plan on re-attaching everything, switching to Kevlar line and extending the length a great deal as you recommend.

I think I'm going to make a minimum diameter 24mm rocket as a final practice before the Aspire.

Thanks for the info.

MrTidy OTR said...

I prefer kevlar on mine as well. Kevlar is great because it doesn't wear and is flameproof. Two problems with kevlar that have to be considered when putting it in: it gets brittle when bound by glue and it appears to me to be more likely to cause zippers. By using the longer shock-cord, I avoid the zippers. To keep from breaking the cord, I tie the cord to the motor mount. Doing a repair (where there is nothing to tie to), I would glue in a nylon elastic cord (the kind that comes with LOC or Semroc kits) and then tie the kevlar to that. Looks like you might launch at County Commons, perhaps I'll run into you there sometime and we can look at some different styles.