Cirrus Dart????

[muleParticipant]

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.

[new2hprParticipant]

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

[Warren B. MusselmanModerator]

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

[muleParticipant]

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 😈

[Anonymous]

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…

[Warren B. MusselmanModerator]

I have a 4″ MD project being built around the CTI M795 motor – the current record motor – that’s pretty close to optimal. I’ll be tweaking it and planning on flying it either at NCR later this summer or next year – depending on how long it takes to tweak the project. I won’t get into the details, but I’m using every trick I know and have learned from folks like you John. I’m simming in the right ball park to be able to take the record, but of course we know it all comes down to hiking up your skirts and doing it plus a bit of luck and the right upper level winds.

The DC20 dog collar is what really makes this possible for me – I lost a lot of heart after losing 3 altitude birds in 06 including my SSS bird, a 38mm J bird and another project that basically ignited and dissapeared forever. Three Perfectflight MAWD’s are sitting out there on or beneath the plains and I felt totally crushed after the third one. GPS changes EVERYTHING. The bird may end up as confetti or a particularly expensive fence post, but at least I’ll find the damn thing.

Personally, I think right now the difficulty isn’t building the bird but getting the waiver window AND the right upper level winds to coincide. I’ve been waiting 2 years to fly my 54mm MD L bird and it hasn’t been the rocket that’s holding it up but the combination of waiver and winds. (I also need a better tower, but I’d be willing to take the shot on the 6′ PHITS tower sitting in my garage right now.)

Warren

[Anonymous]

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

CORRECT! Look at all the money you will save by not having a motor retainer OR centering rings! And fins are cheaper too, since you don’t have fin tabs. I can’t believe how much money I’ve saved going MD!!!

I just thought of the name for my next rocket – “Twisted Logic”.

There is another M project that I was thinking of that will contend or break the current record sooner vs. later… 75mm, in fact.

[djsrocKeymaster]

I only wish I could try for altitude records but my eye site is quite bad and anything over around 3000′ is out of my range. I also dont like the idea of loosing rockets with hardware and altimeters, just too heart breaking. Ive got an VB extreme 38 that ive had for over 6years and never flown. I may fly it on a 29mm sometime. I would be interested in the smaller A-D records sometime though.

[muleParticipant]

(I also need a better tower, but I’d be willing to take the shot on the 6′ PHITS tower sitting in my garage right now.)

Warren

You really need to look at the unit I built and see what it would take to make it work for you setup. I’m going to ring both of them in June, I want to try my shorter one out. The bigger one is 8′ 10-10 but I can make braces for it.

[AdrianParticipant]

I’ve certainly been hooked on the record attempts. I got about as much satisfaction out of finally getting a clean, high A shot for the record as I did when I got my level 1 and 2 certs.

Here are my predictions for the records in the near term, based on way too many hours playing with Rocksim:

I think all of the TRA and NCR records for J and below are well within reach. Above that, I haven’t looked into it much. The new A record was pretty sub-optimal, using a relatively long 18mm rocket with an A8-5 rather than a mini-A. I have gotten over 700′ in non-sanctioned launches using an A8-5, and an A10 should go higher. Likewise, all that’s required to set the B and C records is an hour or two with with Rocksim, an evening of rocket building with Estes parts, and a Parrot altimeter, and a very visible streamer.

A Beeline transmitter, after a date with a belt sander, almost squeezes into an 18mm tube. So for an Apogee 18mm D10, the streamer has to be big and bright enough to keep it visible from up to 4kft.

I think anything above D definitely requires a tracker, but on the plus side, they don’t require good eyesight.
The E record will next be set using an Apogee E6.
The F world record (6780) will be crushed with an Apogee F10. Only one out of 6 F10 attempts of mine mostly worked, but after it went over 8400 feet the shockcord broke, and I only found the nosecone. It matched the sim well within the uncertainties in the inputs. I’m still learning how to put sufficient conservatism into my record attempt rockets. Designs that are somewhat more conservative than what I flew last November still sim over 8k.

The G record could be set by an Ellis G-37 or the new 133 N-S Aerotech G-80. Either of the above should go over 9k. A well-executed SSS record attempt with the Roadrunner G-80 could in theory beat the TRA record also, but it’s pretty close. I think someone could set a world record in F, G, and take the SSS with a single 29mm rocket with different nosecones.

The H record will go higher, using the same full-impulse H-268 that set the world record the last time.

There is still room to increase the I record with the I600 redline
Same thing for the J record with a J570.[/b]

For F and below, the optimal mass is at or below what can be built, so a rockets flying with a Parrot will have a distinct advantage. For G and above, mass isn’t much of an issue so a PerfectFlite 15k would work.

[Author]

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