Fliskits Cougar 660 - streamer duration

[Nytrunner]

Wow a CMR style pop lug - have not seen one of those in a long time. Howard Kuhn would have approved.

At first I thought you were talking about Centuri. I haven't heard of Competition Model Rocketry before. I would assume they specialized in light models for...competition?

 

[mbeels]

So does the pop lug pop off at motor ejection? Or after leaving the launch rod?

 

[mikec]

It stays on the rod, pulled off by a tape flag at the top of the rod.

 

[Nytrunner]

Maybe I can make a manual demonstration video

 

[kuririn]

At first I thought you were talking about Centuri. I haven't heard of Competition Model Rocketry before. I would assume they specialized in light models for...competition?

These plans are dated, but you might find the designs interesting:
https://plans.rocketshoppe.com/cmr.htmI find it fascinating how form follows function. Note the similarity between the Fliskits Cougar 660 and the ASP Thermal Seeker, available in 13 and 18mm versions:
https://www.asp-rocketry.com/ecomme...ation-Kit.cfm?item_id=1327&parent=9&navPanel=And hcmbanjo (Chris Michielssen) used pop lugs in last year's NARAM competition:
https://modelrocketbuilding.blogspot.com/search?q=pop+lugBut I think the real hardcore competitors use towers and pistons now days due to superior performance.
Makes me want to give competition rocketry a try, especially with the new rules.
Thank you for posting this informative thread.

 

[mbeels]

This is cool, it is interesting seeing what goes into a competition model. That is an aspect of rocketry that sounds fun, but I've never tried. Actually, now I remember that someone had the idea of a TRF competition. There would be some logistics work out, but we could designate a particular day for a competition launch (like streamer duration) and the participants would each launch that day, but at different locations. It would require finding accessible launch locations that are not closed due to the current situation, and in a responsibly isolated kind of way. But it could be done.

Actually, was it @jqavins that had any idea for a TRF science project competition?

 

[mikec]

But I think the real hardcore competitors use towers and pistons now days due to superior performance.

For some events certainly, although another constraint here is the available motor delays. For duration, going higher doesn't do you much good if the ejection happens before you get to apogee or way after. I'm not sure where the Cougar 660 fits into those parametrics.

And of course a huge element in getting long durations is the presence of thermals and the skill or luck to launch into one. It would be interesting to run a duration competition where dead air was required, that would put the emphasis on the rocket and not the conditions.

 

[caveduck]

At first I thought you were talking about Centuri. I haven't heard of Competition Model Rocketry before. I would assume they specialized in light models for...competition?

CMR was the competition source in the 1970s and early 80s. Somewhere here I posted scans of their catalog a while back, so you can see what was in the lineup. Howard popularized a lot of things that are/were standard in competition, like aluminized mylar parachutes, pop lugs, vacuum formed nose cones and egg capsules, slide-pod RG, and piston launchers. Howard was also the US rep to the FAI and was very involved in the early days of Internats competition. After Howard retired, Ken Brown's QCR took over the competition supplies niche, and subsequently ASP.

 

[Nytrunner]

But I think the real hardcore competitors use towers and pistons now days due to superior performance.
Makes me want to give competition rocketry a try, especially with the new rules.
Thank you for posting this informative thread.

Thanks for the link Kuririn! I haven't been much of a plan builder since I don't have a large stock of components gathered over the years, but you never know when the bug will hit
Be careful with duration events, you may have to bring a boat for recovery

It sure looks like the kitted lightweight duration models have been brought to a science. Elliptical wafer thin fins, small diameter bodies, round subsonic nose geometry, external shock cord for recovery balance, etc..
I find it a great optimization problem with the tradeoffs taken like Smaller body (and drag) vs larger recovery device.
Example, the ASP 13mm Thermal seeker has a small 13mm body and a 4x40 streamer compared to the Cougar 660's 18mm body and a 6x60 streamer
That means the Cougar has 92% more cross sectional are and is a little heavier, so it won't go as high, but it can fit 140% more streamer area!

Now the international competitors depart from the kitted standard and are fond of rolling crazy lightweight Vellum airframes that are ~1.5" in diameter, but can fit huge parachutes or helicopters in there.
And as Mikec mentioned, if you're running out of delay before true apogee, you're not getting the full performance of the design anyway (sim for Cougar is real close with 1/2A, but blows early for A's). The skill and ability to track thermals is critical too, (and something I know nothing about)

It would be interesting to run a duration competition where dead air was required, that would put the emphasis on the rocket and not the conditions.

Nice constraint! Similarly, altitude comp without pistons! Reduce all the drag you want, use a tower, use a pop lug, but no thrust driven mechanical assist! *Ducks back behind table

 

[caveduck]

The FAI style events now require 40mm tubes...that was done to stop the duration events from becoming altitude contests, and also to reduce performance somewhat as it was becoming too easy to piston an A PD model to nearly 1000 ft and reliably get a max. I will say the internal rotor 40mm helicopter duration models are pretty interesting.

 

[BEC]

Nice constraint! Similarly, altitude comp without pistons! Reduce all the drag you want, use a tower, use a pop lug, but no thrust driven mechanical assist! *Ducks back behind table

There was a proposal to eliminate pistons in the 2019 NAR rules change proposal cycle but it was voted down. There was a competing change approved that at least limits the length of pistons some. Apparently pistons have been essentially eliminated from FAI competition recently.

As someone who used pistons poorly at NARAM-61 (an error on my part that I didn’t really figure out until after the meet) I wouldn’t be heartbroken to see them go away. They certainly add their own challenges.

 

[Nytrunner]

I will say the internal rotor 40mm helicopter duration models are pretty interesting

The guy that showed them at our club used pink foam nose and a tiny axle bearing rig, and the blades all fit in the FAI body and were leaf thing. Very impressive.

There was a proposal to eliminate pistons in the 2019 NAR rules change proposal cycle but it was voted down.

I'm not a competitor and have no stake in it, but I'd vote for it. Like Mikec said, the emphasis gets away from the rocket.
Sort of like why there's a rule that your pad has to be under 2m from the ground ever since someone who shall not be named stuck is micromaxx launcher on the end of a 30ft fiberglass reaching pole

 

[BEC]

That 2m limit was the competing proposal I was referring to. The discussion was mainly around the really long pistons that some folks have been using in recent years....which perform better but are a real pain to replicate and travel with for most folks.

All NAR members can vote on the rules proposals each year. I find it kind of sad that less than 100 votes are cast in an organization of over 7000 members each year.

 

[Nytrunner]

All NAR members can vote on the rules proposals each year. I find it kind of sad that less than 100 votes are cast in an organization of over 7000 members each year.

Interesting. When does this take place? I've only seen the notices for NAR board elections

 

[BEC]

Interesting. When does this take place? I've only seen the notices for NAR board elections

All the gory details are here, including the schedule: https://www.nar.org/contest-flying/rules-revision-process/

There are 10 rules change proposals to be voted on this cycle.

 

[mbeels]

Sort of like why there's a rule that your pad has to be under 2m from the ground ever since someone who shall not be named stuck is micromaxx launcher on the end of a 30ft fiberglass reaching pole

That's nuts! That takes gaming the rules to an entirely new level! Someone who does that wants to win more than they care about making everyone else angry.

 

[Nytrunner]

All the gory details are here, including the schedule: https://www.nar.org/contest-flying/rules-revision-process/

There are 10 rules change proposals to be voted on this cycle.

Fascinating. I'm not sure I've worked my way that far down the contest pages on the website. I guess I should pay more attention to when the e-rocketeer or other emdia announce the submissions are in for member review

 

[Alan15578]

The FAI style events now require 40mm tubes...that was done to stop the duration events from becoming altitude contests, and also to reduce performance somewhat as it was becoming too easy to piston an A PD model to nearly 1000 ft and reliably get a max. I will say the internal rotor 40mm helicopter duration models are pretty interesting.

SD was originally intended to be an alternative to altitude for folks who could operate a stopwatch, but who could not manage optical tracking., but then competitors figured out how to build SD models that could thermal.

FAI competitors apparently could not figure out how to get their models optically tracked, so they went with some screwy 40mm rules that lowered performance and gave them a larger visual signature for opticlal tracking. Eventually they gave up on optical tracking entirely, by using barometric sensors to measure pressure altitude. Sadly, they kept the 40mm rules.

 

[jqavins]

Actually, was it @jqavins that had any idea for a TRF science project competition?

No. OK, not that I remember.

Oh, should I comment more?

I've never really been interested in competition flying except in passing thoughts. But some sort of science project competition - a build, flight, and documentation that in some way advances the state of the art - that sounds cool. Judging would inevitably be subjective.

I don't know how one would go about organizing such a thing, but maybe along the lines of the summer build-off that was done a few years ago. Sign up by such-and-such date, publish a statement of purpose (what will be built and what's to be learned) by this-or-that date (perhaps the same date), then build and fly your test bed and publish a report on what's been learned by some-other date. Then the winner is decided by voting, which may or may not be confined to the participants. And by "publish" I mean in a forum thread (but if it winds up also in Sport Rocketry or Peak of Flight that would be awesome).

To be clear, I am not volunteering to organize this. That is really, really not one of strengths.

 

[beeblebrox]

These plans are dated, but you might find the designs interesting:
https://plans.rocketshoppe.com/cmr.htmI find it fascinating how form follows function. Note the similarity between the Fliskits Cougar 660 and the ASP Thermal Seeker, available in 13 and 18mm versions:
https://www.asp-rocketry.com/ecomme...ation-Kit.cfm?item_id=1327&parent=9&navPanel=And hcmbanjo (Chris Michielssen) used pop lugs in last year's NARAM competition:
https://modelrocketbuilding.blogspot.com/search?q=pop+lugBut I think the real hardcore competitors use towers and pistons now days due to superior performance.
Makes me want to give competition rocketry a try, especially with the new rules.
Thank you for posting this informative thread.

I used Pistons with a tiny tower on the piston top, back in the 1970's when I was hardcore into competition...

 

[mbeels]

But some sort of science project competition - a build, flight, and documentation that in some way advances the state of the art - that sounds cool. Judging would inevitably be subjective.

OK, that's what I remember. I won't derail nytrunner's thread further, but it would be interesting to revisit a competition or science project in the future if there was interest here on TRF. Currently I don't have the bandwidth to organize or participate in such a thing, but it sounds like either could be fun.

 

[mikec]

I've never really been interested in competition flying except in passing thoughts. But some sort of science project competition - a build, flight, and documentation that in some way advances the state of the art - that sounds cool. Judging would inevitably be subjective.

That's basically what NAR R&D is: https://www.nar.org/contest-flying/competition-guide/miscellaneous-events/research-development/

FWIW, I've found that doing a project and writing it up for Sport Rocketry scratches whatever itch I have in this direction. Plus, they pay for articles.

 

[Nytrunner]

If the weather holds out, this streamer duration model will fly 1/2A at HARA's first launch on Oct 10th.
If weather is REally good, I may 1/2A fly the 13mm thermal seeker parachute duration model too.
If I have it finished, and there's enough time in the day, I may even try the Spek for a 1/2A altitude flight.

Since the events got cycled over to next year, I wonder if I can talk our secretary into making it an NRC launch so I can record times just for the fun of it!