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

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.

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.

(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.

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.

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.

Keep in mind that while the TRA world records cannot be set with motors that have fallen out of cert, the NCR club records most certainly can. I have 2 AT F32's and 5 G55's... and there ain't nothing on the market that can even come close. There is no way an F10 can touch what an F32 can do and no 29mm G motor can touch the G55. Just can't be done.

Warren

Keep in mind that while the TRA world records cannot be set with motors that have fallen out of cert, the NCR club records most certainly can. I have 2 AT F32's and 5 G55's... and there ain't nothing on the market that can even come close.

Warren, until very recently, the very last rule at http://www.ncrocketry.org/modules.php?name=Content&pa=showpage&pid=7 was, and I quote, "Certified Loads Only"... Now they ARE allowed? Has the exec committee moved on this?

Another club member has some I132s (full "I", SU, 38mm, no longer certified load) which they offered for sale, but I passed since there was a rule specifically prohibiting non-certified loads. There is also a commercial entity that contacted some of us that has "about one hundred" H125s (!!!) which is an SU, 29mm, no-longer-certified FULL "H". We declined, in part because TRA has suggested we have no insurance with loads that have expired certification. They are not "EX" and they are no longer "Commercial".

This is a dicey issue. I don't think they should be allowed for altitude records. When I gave you those F32s, there was 18 months of time left on their certification. For my part, I feel the page has been turned and none of us should be using them. Just my 2NS worth...

another topic (same lines as above) - "modified closures". I have used them as they were not precluded by the NCR rules. I'm talking about drilling and tapping a fwd closure for retention, tailcones, etc. I would understand if they were prohibited along the same line of reasoning. If that were the case, then my J record is nullified.

I wonder what constitutes "modified closures"? if I fill the knurling of an aft closure with epoxy putty (to make it smooth), is that "modified"?

Murky waters indeed.

I'd have to check around but it seems as if a motor once "certified" that expires for sport flying use can still be flown on Research Days providing the RSO approves. As to records, I'd count it but not sure the AIA or TRA BOD or Guiness or anyone else would recognize the achievement. Up and back, in tact, counts in my book.

Was discussed during one of the exec meetings at my house since last O'fest. Since we are adding staged, clusters, complex and EX altitude records, was thought that allowing motors past their cert life to be used as well.

By the way, there was less than a year of life left on the cert on those F32's when you gave them to me. I believe you gave them to me last May or June and their cert ran out Dec 31st.

My point - the one I keep trying to make - is that no 29mm motor exists that can compete with a 24mm motor of equivalent impulse.

Warren

My point - the one I keep trying to make - is that no 29mm motor exists that can compete with a 24mm motor of equivalent impulse.

O.k., then send an F32 above 8422 feet and we'll talk about how an F10 can't beat it. 😉

I won't begrudge our contest director the latitude to say we can use motors that are out of cert for the NCR records, but I'll be happier setting records with motors that are certified and easily available so that somebody else has just as much of a chance to set a record as I do. It's a lot more fun when there's real competition, and I'm hoping that there are a lot of us --and not just myself-- setting a bunch of records this summer. I still have 4 Ellis G37s that will soon become collectors items (by the way, it turns out they're still in stock at : https://blastzone.com/performancehobbies/store.asp?groupid=410235834726) but I'm probably going to make this a 29mm summer and go for the G record with the new Aerotech G80. Both the new G80 and the G37 can go to about the same altitude. I have some carbon fiber fins cooking as we speak that I'm hoping to use for both F and G.

And as long as I keep getting the rocket back, I'll pop in a Roadrunner G80 for SSS and the G25 that Chris gave me to see what they can do. I'm looking forward to seeing the data out of all of this.

Adrian, I've got all the respect in the world for you and what you do. However, there is no way a 29mm bird on an F10 is going to go to 8400+ feet. I'll be happy to give you an F10 to try it with - I've got a full dozen of them since I, at one time, thought that was the motor to do it with until I tried it. In fact, your reported F10 altitude was the key reason I wasn't going to accept a Parrot altitude until Tom Rouse actually tested it and approved it for use in Tripoli world record attempts. When a Bill Inman or a John Wilke struggles to get to 6700+' on an F motor with years of MD experience behind them and a 100% F motor in 24mm, I'm just not going to buy anything much higher than that since I know how tight those guys optimize their projects. I do believe Bill Inman's F record can be beaten, but not with a larger diameter bird on the same impulse.

Again, all due respect to you and your skills. I just don't believe Rocksim simulations very much having had my share of over-optimistic simulations. (Hell, I've got a design for an F bird that Rocksim swears will do 9500' - just cuz Rocksim says so don't mean I believe it). Secondly, your Parrot is still an unknown quantity in comparison to the commercial altimeters used to set the current world record. Perhaps your Parrot is right and all the rest of the commercial altimeters read low - I certainly saw that at MHM when my 4" L bird which simmed easily over 11K' returned two very widely different and much lower altitudes using different altimeters. My understanding is Tom Rouse did not actually test the Parrot and just got details from you and added it to the list. That's why I've been dying to fly it with a known altimeter like a Perfectflight MAWD or a Missileworks where a true comparison is done. God knows we need a truly calibrated and repeatably accurate altimeter in this hobby.

Warren

TRA has had some discussions in both their forums and their email lists regarding loads that had their certifications expired. The general consensus from TRA was that loads - once no longer certified - could not be flown at a research launch. I disagreed with this on the grounds that a freshly expired but commercially certified load was probably more categorized than many EX loads. EX / Research seemed like the perfect venue for using those loads up - and it is much better to use them than to have them laying around forever.

I want to underscore the fact that if the NCR Exec Committee made the decision, I support it wholeheartedly - though the fact that TRA has a differing opinion is probably worthy of note as well.

By the way, there was less than a year of life left on the cert on those F32's when you gave them to me. I believe you gave them to me last May or June and their cert ran out Dec 31st.

My point - the one I keep trying to make - is that no 29mm motor exists that can compete with a 24mm motor of equivalent impulse.

Warren

Actually I gave them to you at Oktoberfest in 2006 after you helped me retrieve my K record shot. Their cert expired 12/31/07, so there was ~15 months of certification left on them.

I miss that load - along with the G55, H125, I132, the *original* K250, and the L330. All are out of production, though the L330 is still certified. The Tripoli records for the F, G, I, K, and L are held by motors that are no longer available. Drat. They don't make 'em like they used to...

I stand corrected John. I had remembered that K shot as taking place at MHM, but checking my flight log I realized I never flew anything in 07 and that MHM 07 was more or less rained out.

John, you reiterate the point I've repeatedly tried to make - that many records were set by motors that are no longer available and that have no substitute - High impulse in their class Single Use Motors. All those motors are near 100% of their letter class, the G55 being the least of them I think at about 75% or 80% of a full G. A Roadrunner (or AT) G80 is only about a 67% G AND it's 5mm larger in diameter. There are certainly higher total impulse G motors made than the G55, but the highest ones are CTI Pro-38 loads - even larger in diameter.

It's a drag thing - impulse being equal, there is no way a larger diameter rocket can exceed the altitude of a smaller diameter rocket. Even adding uncommon design tweaks like a Von Karman nose profile probably isn't going to be able to squeak past the altitudes achieved with an already optimized bird in a smaller diameter. The larger diameter motor is, for weight distribution reasons, going to need to be the same or longer in length.

Again, all due respect Adrian and I in no way want to offend with my comments. I am VERY interested in flying (and owning) a Parrot.

Warren