It's small and cheap for HPR (justification for the wife)

It won't take up much room.

It won't take too long to build.

Go on, buy it! You know you want to.

Just wait for the altitude junkies to chime in. I haven't even broken a mile yet!

Ken

I say hitch up 'yer skirt and buy that sucker (old NCR joke for those of you not familiar with the phrase! cross-dressing probably not really a good idea with this group - end of disclaimer).

Actually, DON'T buy the PML kit, but scratch build something better! By going scratch you can use a lighter, hollow nosecone and put a transmitter up there. You can also shorten the build and go higher than the PML kit would go on it's own. The fins are also a bit larger than you might want to fly.

I flew "Beyond Consolation" at MHM. It is essentially a Cirrus Dart with the above modifcations. I got 13K on an I600. Chris LaPanse did pretty much the same thing, so phenolic will sure work.

For me, the most influential rocket I ever built was a PML "Nimbus" - from that I learned about minimum diameter, dual deploy, and fiberglassing all at once. The Cirrus Dart will open similar doors for those wanting to go really high - though I still say lose the solid nosecone and use smaller fins. If I can help you I am glad to do it. 14 of the last 15 rockets I have worked on have been minimum diameter (fin tabs seemed like a good idea on our "O" project).

The next O project is going to be minimum diameter... hehe 😯

Dual deploy on a min diameter....
you had me at dual deploy.....

I am a member of the mile high club with a single deploy L2 flight (7012'), that was what got me thinking about high altitude....

Humm, I do need a hollow nose cone anyway for my Beeline/Pico-P1 combo.

I'm not too up on scratch designs for high power, I'm still at work so I'm fumbling through this a bit.

So, if I use a 1.525" tube, will the case slide in? What is the actual OD size on the 38mm case? I want to go with G10 fins or is that bad medicine? How about tubing? Filament wound fiberglass or phenolic with fiberglass? I've never seen a H.A. rocket up close and never been in a discussion on one.

I think I'll set down with rocksim and plug in some designs this weekend...

I've done min diameter birds from 18mm up through 54mm so far. My preference is to work with FWFG (filament wound fiber glass), but that's purely a labor convenience. On 29mm and 38mm you can definitely go with phenolic - even for a J350 or hotter so long as the airframe isn't too long. Personally, I do everything with composites now - I have a helluva carbon over Estes paper tube airframe material for 24mm. The nice thing about FWFG is that finishing is a snap - a little wet sanding, probably no filling except where you've tip to tipped... easy and low labor by comparison.

Warren

Don't waste your time if the kit is the gray plastic, Quantum tube, version.

Like JW said, a scratch built is just as good if not better. For my SSSS bird, I started with the Cirrus Dart, but strayed a bit by cutting down the overall length and fins a bit. It's also glassed phenolic. I've flown it once with the 5:1 conical cone from Performance Rocketry and once with their 6:1 version. Both have been fun flights the 6:1 shot went to 11,784 and 12,361 for the 5:1 (but I left a bit of the twist & tuck wires hanging out so I sure I could have gone higher.)

The reason I say this is that I'd strongly suggest you get the nosecone from Performance. You will DEFINITLY want to get that tracker in there for your for your shot.

G10 fins will be fine, and you probably want to lay in some glass in the fin root, or a tip to tip. On that small rocket you will likely sand through much of the glass at the tip & edges of your fins anyway.

No need to buy an expensive sheet of G10 when you only need a small amount. I've bought G10 in 4ft x 8ft sheets so I'd be glad to cut of a chunk for you for this project.

BTW, the altimeter was a PerfectFlite MAWD using the coin cell batteries.

Greg,

Do you notice how no one offered to take the gun away. Pretty much everyone one here would be handing you ammunition instead.

Tell your wife how much money you would save by scratch building. Yeah, that's right.... your saving money....

GEEEEE Thanks guys.
That dang guns a smoking right now. And to top it off I get a call from Jeremiah last night saying he's got it on the brain too. Now I have to deal with HIS wife.....
Mine won't really care, she thinks it interesting and the kids do too.

So, now to business.
I'm thinking the 1.525" Phenolic and a 5:1 from GLR is a good place to start.

Recovery:
What about dual deploy? I'm assuming that is a must. I have a choice between an RRC2-mini and a Perfectflite Hi-Alt45k to choose from.

Tracking:
I have to take a picture of it, but I "removable" mounded the P1 to the mount on the Beeline and it is a nice compact design. But, I don't need the P1 since both the computers log peak altitude. And I will save a tiny bit of weight and space.....

Time to get to work on the house, I have to head East today for work...
Greg

I'm thinking the 1.525" Phenolic and a 5:1 from GLR is a good place to start.

Recovery:
What about dual deploy? I'm assuming that is a must. I have a choice between an RRC2-mini and a Perfectflite Hi-Alt45k to choose from.

Conical cones will do you better if you are really pushing things (which you are in this case). I don't think G-Leap has conical cones? if not, www.performancerocketry.com

Given the outstanding recovery area, you can save an ematch and a couple inches in airframe (plus 0.2g of black powder!) by going with apogee deploy. I recovered from 13K at MHM on an apogee deploy. Note that I had a chute the size of an apple 😯 but that is why you build them tough.

Always -- ALWAYS -- check the CG/CP on these things. When you make shorter rockets with smaller fins, that can be an issue. Manageable, but an issue nonetheless. Be safe!

I didn't catch that Ogive part, thanks. I was looking at stuff sitting at work yesterday and didn't take the time to think about it much.

Do you build in a slight spin to the flight or just call it good and go with no spin? I was wondering how that would effect the altitude vs keeping the rocket from weather cocking if we have wind. I was thinking of something as simple as a bead of CA glue on the aft of the fin.

If you go with the Performance Rocketry part, get it through Wildman or Liberty Launch Systems, rather than Curtis himself. Much quicker and more reliable.

Just another thought, if you're even thinking of TRA altitude records, it needs to be a certified altimeter (which the Picos are not). Hook up with Adrian (parrot altimeter guy) if you get tight on space and weight.

Ken

For true altitude records birds - not going after the low hanging fruit - you definitely need to go apogee deploy only. No question but that the inches you save in airframe length will definitely grab you a bunch of extra altitude. The shorter the bird, the more altitude you're going to gain.

In the low-end range, Adrian just set a new A motor record of 589' - almost double the previous record. The B through D motor records are equally open with plenty of room for folks to make new attempts. The E record is held by me, but there is certainly some room for improvement there as the bird I flew was too heavy and the fins too large to really push the limit. Unfortunately, Tripoli doesn't track records below F impulse and NAR doesn't accept electronic altimeters for altitude records. The current E record is likely a world record, but no one cares. I could see someone with the right design and the right motor adding another 1000' to the that record if they did things right.

Truth to tell, there's not much low-hanging fruit left in the mid-range. The F and G records basically are untouchable as they were set with 24mm 100% F and G motors that are no longer made. It MIGHT be possible, but you'd be talking a rocket length and fin size that would be very difficult to make stable without adding too much weight for optimal altitude. The H record is pretty damn solid too; John's club record exceeds the world record by a tad, but not by the required 2% TRA needs to establish a new record. The current I record still has almost 1000' to go before it touches the world record. The J record would be tough as well although there is some room for improvement given that the club record of 17144' is 2000' below the world record. John has made many attempts on the J record and I've made one myself - all with the J570 - and most seem to fall in the 16K+ range (mine was 16191', John's had multiple flights between 16K and the current club record.) Mine wouldn't have qualified though since it came back in non-flyable condition missing a fin and a nose.

Above there, NCR club records have some room to increase and the current records aren't nearly what the world records are. John pushed the K record up to almost 21K which would have been a new world record if not for a new record set at BALLS that year. One difficulty with the K, as with the F and G, is that the best motors are no longer made. The Aerotech single use K250 was the premier K altitude motor and those are long since out of production. Current K motors just don't measure up although there are some possibilities on the horizon.

For the L record, you're again in terrain where existing motors don't measure up to the motors that have been used to set the record. The Ellis Mountain L330 is the motor of choice for the L record and the current world record was set using it. Bob Ellis passed away this past winter and as far as is known, that motor is now gone the way of the dodo bird. Aerotech used to make a single use L1500T that also had the necessary impulse, but alas, that is also out of production. I have a bird built around the L330 motor that's been ready to fly for the last 2 years - unfortunately the 35K waiver either hasn't come through or the winds were too much. (You really need to pay attention to where the jet stream is when you're flying above 10K.) I've just discovered a way to trim 7" off the length of the bird so I'll be re-building it a bit shorter and it might, just might have a chance at the world L record (31K+). NCR's Pawnee North launch site, with the 35K windows, can easily host attempts on world altitude records up through L.

The M world record is no longer possible at the North site with only a 35K waiver but as far as a club record, everything is wide open - at least until John makes his 3" MD flight - also postponed due to upper level winds. Current club altitude record on an M is 23550' and was flown at Black Rock during BALLS 2007 by John. This is easily beatable at the North Site although you out of luck as far as setting the TRA record. N and above motor records are also wide open - even more so - but don't expect to set a world record, the current N record is well above our waiver at 41K+. No NCR O or P motor record currently exists.

Hope this gives folks some food for thought. Altitude records are perhaps THE most fascinating aspect of this hobby for me. To be successful at it, you have to be right on the bleeding edge as far as design and construction technique, your launch needs to be perfect and you need to have more than a bit of luck to succeed. Personally I find it the most challenging aspect of this hobby and if it weren't for the high proportion of lost rockets I've experienced, I'd probably only be flying MD projects. However, with the new tracking options that seem to be falling out of the woodwork these days like the Beeline GPS and the DC20 dog collars, I think that, at least for 38mm and larger, we're about to see a significant push by a lot of people to grab a record or two - at least club records.

One final note - pretty much every world altitude record up through L has been set with single use motors instead of reloadables. (H and J are the exceptions as no suitable single use motors have been available) due to the reduced weight of the motor. More of the mass of the motor is propellant giving a better mass-fraction.

Warren

Two words. HOLY COW

While the records seem pretty fun to shoot for, I'm thinking since I have no background on this, I am going to work on it for a while.....
A little competition makes it more fun though, so who knows how long it will take me to get up to speed. I hadn't thought about the smaller than G stuff, but that too is quite interesting and my kids may like it.
All my chores are done for now, so I'm going to do a bit of playing.

I still have to finish my Vert A. and try my first dual deploy, but, I see some parts coming in the next week or two - heh heh heh (evil laugh) 😀
I'm going to try and have at least one M.D. bird though.

Have a good Saturday guys.
Greg

ADD

I was a BAAAAAD boy.... 😛 I ordered some 1.1 stuff too 😈

For my part, I'm very confident the TRA "I" record will fall soon. There are several capable flyers in NCR that are looking at it. I always thought that record was untouchable, but now I'm thinking it will get incremented. I flew a far-from-optimal "I" rocket to 13K that I'm going to make a bit shorter, etc. I think I can eke out 14K on a good day. Chris LaPanse is also going to do an attempt, I believe?

The H record is going down 🙂 again, there are multiple players that can move the bar there. The TRA "J" is insane, and unless I have a brainstorm, I'm calling it good at 17,144'.

There are no good K motors. The L330 gave me fits (long story). If I go at the "L" again, I'll use a 75mm core-burning motor. The add'l diameter will make it very difficult, but you do get some more NS....

Finally, I predict the M record will be broken 3 times in the next 12-18 months. I and another NCR flyer (who may or may not wish to comment about his project 😉 )are going at it from two very different angles...

N project at BALLS '09...