John, we don't keep club records by rocket or by design... we keep them by impulse class. The club J record is a snitch over 17K. That was on a J570, and it was recovered intact.

I had a Cirrus Dart that flew over 12K and Chris LaPanse flew his on an I motor to 13K or so.

Warren

I had a Cirrus Dart that flew over 12K and Chris LaPanse flew his on an I motor to 13K or so.

Warren

Seams kinda high for an I. Been playing with rock sim in anticipation for the SSSS. Cant even get 13 with my dart on a J350. 😯

Scotte

I did about 12.3K with my "slightly" modified Cirrus Dart on a J350. And that was with twist and tuck wires sticking out a little bit.

I'll be trying again this summer....

I may be mis-remembering things. Perhaps Chris only did 11K+ on his I600. On checking my flight records, my flight was on a 5 grain Cesaroni J285, not an I.

Warren

IIRC Chris did just under 12K - he flew it with one of Adrian's Parrots. He was flying the I600, I believe.

I flew an I132 to 12,136'. I sure wish I had used that motor in an optimized bird 😯 I put it into a rocket that was too long, wrong shape nosecone, too heavy, etc. The AeroTech plant burned down about that time, and I never saw another I132. I wasted mine. Drat. I'm sure I could have gotten over 13K with that load.

The I132 was a very full I, and it was a 38mm SU motor. What a dream altitude motor...

JW

His Cirrus Dart went about 11,950'. There was very little wind, he launched from a tower and it was plenty hot. Also note that he used an electronic timer for deployment; this rocket and motor combination would likely shred with motor ejection.

http://www.rocketryforum.com/showthread.php?t=37915

I also link to it from www.featherweightaltimeters.com as example data.

Yep - 11,950. It was an absolutely gorgeous flight, and the flame out of the I600 was probably as long as the rocket. I also got incredibly lucky with the wind - it would have been incredibly easy for that rocket to vanish and never be seen again given the altitude. As previously said, mine was launched from a tower, and it also had a glass-smooth finish (auto paint). Peak velocity was ~1200mph (M1.7ish). Exterior was stock, though the nosecone was a PR glass cone (saved a LOT of weight), and I flew it without the piston (so I could fit the non-stock recovery harness and chute). Flight weight was ~15oz with everything but motor, and the motor weighed almost 22oz - the heaviest motor with relation to the rocket that I have ever flown 😀

As Adrian said, I used a small timer (actually, the EFC) for the flight, as the optimal delay was around 22 seconds.

Chris, that was an extraordinary blast. I always thought my "I" record was the safest one I had, thanks for the wakeup call 😉

15 oz. is very light. When you say "stock finish" does that mean you did not glass the airframe? I'm astounded it survived if it was not glassed... Yipes!

Tremendous flight.

JW

My Cirrus Dart was the first HPR bird I built and I wrapped three full wraps of 6oz glass around that baby. It flew successfully a three times and the forth flight was a spur of the moment attempt at L2. It dissapeared. After the fact, I simmed it at over 13K on a CTI J285 and flew it on a very windy Sunday at MHM '04. Not surprised I lost it... given the construction though, I'm sure it probably core sampled and is fully intact and about 10' deep in the prairie somewhere.

Warren

Chris, that was an extraordinary blast. I always thought my "I" record was the safest one I had, thanks for the wakeup call 😉

15 oz. is very light. When you say "stock finish" does that mean you did not glass the airframe? I'm astounded it survived if it was not glassed... Yipes!

Tremendous flight.

JW

There were 3 items on that rocket that were glass/glassed. The fins were t2t with 6oz glass, the nose was PR glass, and the lower body tube joint had a single wrap of 0.5oz glass, more for aesthetics (a perfectly smooth joint) than for strength. Everything else was bare phenolic.

And yes, it was phenomenally light. The elimination of the brick of a urethane nose cone helped, and the elimination of the piston saved a little weight too. It also helped that I didn't (significantly) glass the tube.

Chris,

How did your Cirrus mass compare with the optimal mass for that motor?

I would've bet my lunch regular phenolic would have shred. I'm quite impressed / surprised that it did not. Seems like years ago I read in PML's FAQ that 38mm and 29mm would survive pretty much anything, but you should glass 54mm and up if you pushed it.

Having a lighter cone helped a lot. That flight probably pulled 70 gees. The PML website says that cone weighs 4.3 oz. That translates into a nosecone that exerts 19# under boost. The negative gees at burnout would have been another major factor... hard to do shear pins in those solid cones.

JW