what kits for streamer & parachute duration

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Justin

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Hello-
I'm doing NARTREK program levels and one of them is competition. For the award I have to pick two events and attain 50% of the national record in both (I don't know what this will entail yet, I don't have any records or a pink book). I think I'm gonna try chute and streamer as I have never competed before and it seemed like a good two to start with.

You folks got any reccomendations for good kits in these catagories? Any help would be great.

Thanks-Justin :)
 
The FlisKits Cougar 660 and Cougar 440 are two great candidates for streamer duration. They are both 13mm models (1/4A, 1/2A, A) and turn in some incredible times.

If the goal/requirement is to make 50% of the record I could also recommend the CAUTION! Rocket for both streamer and parachute as you can get incredible altitude with that model, but you would have to supply your own recovery device.

jim
 
Those Fliskits models look like they should perform well.
Here are some other ideas
https://nar.org/competition/plans/duration.html

I always felt there were several keys to doing well in these events.

Spend the time to get a very good fit of NC to BT, so good that you can't feel the joint with your finger or see a gap. To do this you need to use CA on the front edge of the BT to harden/toughen it, and sand carefully to get it perfectly square. Work the NC similarly to get the exposed surface to fit exactly to the BT. Get them both smooth enough to see yourself. Wax and polish, then DON'T TOUCH.

Put a good airfoil on the fins, including a rounded leading edge and a trailing edge that tapers to paper thin. This will occasionally lead to fin damage from rough landings, so build your comp rockets three or four at a time to have spares ready. Seal the fins and finish them smooth, so you can see yourself there too.

Place your shock cord/tether anchor point on the outside of the rocket so the combined main BT/fins/empty motor will hang horizontally----this adds a little more drag during descent and boosts your times a bit. For tether material, I used to use heavy sewing thread, wiped with some glue to toughen it, but now you have materials available like kevlar in 10- and 20-pound-test strength (that will be plenty).

Pack as much 'chute or streamer as will fit. Use a separate piece of paper (or two) as a liner or 'bushing' between your recovery device and the inside of the BT---this will help your gear slide out more easily. Powder everything (lightly). Do ***NOT*** use any internal anchor (Estes tri-fold, Centuri-style, etc) that presents any obstacle whatsoever for the recovery system to hang up on during ejection. Check/lightly sand the inside lip of the fwd BT to make sure it is not dented or folded inward.

Competition parasheet and streamer design and construction has as many approaches as there are rocketeers. Many will work well for you, there is no single 'right' answer. I used to (40 years ago) use dry-cleaner bags and sewing thread to get monster-sized chutes into tiny BTs, and had lots of success. Other people hate dry-cleaner bags (go figure).

Good mylar streamer material can be had easily by finding a 'space blanket' at your local sporting goods store. Those things are huge and one blanket ($2-3?) will last a loooong time.
 
Powderburner-
What do you use to wax and polish the rocket? And by finishing the fins you me to just use some sanding sealer and sand very fine?
 
What motor class? I use my Star Dart or Sizzler for both, and have hit 101 seconds (just 1 sec. short of the NAR record for my age division - that one upset me) on a chute in my sizzler, and have gotten 87 seconds on streamer with a Star Dart. Both were on C motors.
 
Originally posted by Justin
Powderburner-
What do you use to wax and polish the rocket? And by finishing the fins you me to just use some sanding sealer and sand very fine?

If I was wanting to put a smooth finish on balsa today, I would start by applying a light coating of CA. Drip it out onto the balsa and spread it with a Qtip. When the CA cures it will leave the balsa with a rather rough surface because the loose wood fibers rise up. Sand with fine sandpaper (100-180 grit).
Then I spray with something like KilZ primer. Other guys here on TRF have lots of other good ideas for similar primers (do a search). Sand again with fine sandpaper (200-300 grit). If necessary to get a smooth finish, repeat the spray sealer and sanding. Remember that your purpose is to get a smooth surface, not to pile on gobs of primers and sealers. Sand until you think you almost see the balsa coming back through. Spray *lightly* one last time and sand lightly.
When you are happy with the finish you can proceed to the paint stage, but if you are building a competition model you don't want to put a lot of paint weight on the rocket. Spray lightly if you must paint at all. Sand again with even more fine sandpaper (400-600 grit?)
DO NOT overlook getting a tight/smooth fit between the NC and the BT. The diameters should match. Exactly. NO forward- or aft-facing steps (differences in the diams of the NC or BT). Almost all NC parts, as they come from the factory, will require some fitting and sanding to attain this fit. Wrap the shoulder if needed to get a snug, smooth fit inside the front of the BT. Use CA inside the front of the BT and sand smooth. To hold the sandpaper, DO NOT use your finger---the paper will flex uncontrollably and you will sand all sorts of unwanted contours into the inside of your BT. Roll a small piece of sandpaper around a dowel that is small enough to fit inside the BT but big enough to come close to matching the same curvature and contours. Put pressure on the sanding 'stroke' only when drawing your sanding tool out of the rocket. Roll the BT as you make this stroke to try for an even finish around the entire inside surface circumference. After you are done, the BT insides should be hard, smooth, and even, and the front edge of the BT should still be square and full-thickness. If not, throw it and start over (cut off the end of the BT and move down the length of your stock----you did start with a full length of BT, didn't you?). You cannot get a good NC fit if the BT is junk.
For a balsa NC use CA to reinforce the shoulder, and sand gently until you have a snug, smooth fit. Then go to work on the external surfaces of the NC, sanding or filling to make a smooth joint. You may need to insert the NC into an alternate piece of BT to get the NC shape just right if you are heavy-handed with the sanding, because you may damage the outside of the BT near the lip when you are trying to work the NC. OTOH, if you can manage a light touch and not kill the BT, you might be able to work the NC while using your 'good' piece of BT. After your initial joint is smooth, CA the NC near the joint (remove the NC before applying the CA) and then sand lightly to remove the roughness. Proceed with the NC finish like you did on your fins.
If you use a plastic NC you may still have to do a lot of sanding to make the NC diam match the BT diam. Beware of thin spots that may result. Drill a hole in the base of the NC and swab in a little epoxy if you need to fix up a thin spot.
You can use a wax like Future over all external surfaces. Years ago, some of the gang I competed against would argue over which was the best **car** wax to use. Hey, anything that gets you a smooth surface is OK! Polish/buff until you can see reflections!
Don't forget to use an external anchor for your chute/streamer (before you paint or wax). Load the rocket with a used motor casing, pull out the NC and recovery system, and find the balance point in 'descent' mode (you *want* the rocket body to hang sideways during descent to add a little more drag). Anchor your tether there, on the outside of the rocket, and use a piece of heavy linen thread or light kevlar line. To prep for launch, you will pull the excess line snug & straight up the outside of the BT, gather the excess tether and place it inside the front of the rocket on top of your wadding, followed by the chute/streamer.
If you are serious about competition you will not use launch lugs. You will need to make a tower, and you will probably soon want to make yourself a piston launch booster.

OK, all the rest of you guys, it's 'open kimono' time----let's hear all your secrets too!
 
powderburner-
Thanks once again. I'm eventually going to publish all your posts to a book..Don't worry law students, I'm kidding.:)

Very cool thoughts forum. Keep
'em coming. I hope to someday contribute as much as I have gained here.

I Think I may go with fliskits ( a few of them), and I'll see what happens. The big Cougar has a boat tail. They make sense when I go shooting, and they make sense here. Plus the the lugless deal it offers, I need to investigate that. I don't have the resources for a tower or piston system now with bills, life,and other projects.

estes stardarts and sizzlers. I think I have a couple left from NARTREK bronze....

-Justin
 
Originally posted by Justin
powderburner-
Tha Plus the the lugless deal it offers, I need to investigate that. I don't have the resources for a tower or piston system now with bills, life,and other projects.

Yep, Pop-Lugs, the poor mans solution! :) Actually, pop-lugs are truely unsung hero's of competition. Pistons are great, towers are kewl and they all do their job very well, but in the world of competition, there is something to be said for simple and reliable (beleive me, I know from experience).

The pop lug seemed to have virtually vanished from the rocketry world ever since CMR closed their doors. It is very exciting to see them coming back (maybe not *mainstream* yet, but coming back :) )
 
Yes, the 'store-bought' launch towers are nice. They can be adjustable to use with different sized rockets. They can be 'high tech' looking (intimidate your competitors?). But they are indeed expensive, and you don't have to spend a lot to make your own. Take a quick peek at the attached file for a couple cheapo tower concepts.
The one on the left shows a rocket surrounded by tubes----these could be some more 34 inch lengths of BT, or could be PVC pipe (the sizes over 1.5 inch are more stiff), or even metal electrical conduit (again, the sizes over 1.5 inch yada yada).
The one on the right shows a rocket surrounded by aluminum angles. You can get this stuff fairly cheaply at your local hardware stores.
Basically, you can use anything that is straight and smooth. You want to check over the surfaces facing the rocket for smoothness. File/sand/whatever any burrs or snags that you find. Keep the tower clean of motor exhaust residue buildup.
You will want to offset these guides a small distance from the surface of your rocket or else the rocket will be 'fighting' to get clear (kind of counterproductive?) You can set the bottoms of BT in a small can and fill the remaining space in the can with plaster of paris. Or you can use a larger container to set the bottoms of PVC or conduit, and fill in with cement.
Position your tower guides by first wrapping your rocket BT with a few layers of paper (this will increase the diam and achieve the offset I mentioned above). Outside the added layers of paper, position the guides and hold them in place temporarily with a few wraps of tape. If you have rails of any significant length, you probably will want to use a spacing guide at the top, middle, and bottom to ensure a uniform guide spacing. After the potting material sets, you can remove the tape (and take the paper off the rocket BT) and you will be ready to rock(et).
 
Justin

The trick to duration is to use the largest, lightest parachute or streamer you can stuff into the lightest airframe you can build and and dependably deploy from.

I modified a couple of FlisKits Cougar 660 kits to take 18 mm B6-6s for our B streamer duration multi-round competition (This was my first contest.). The modification imvolved substituting a 12" BT-20 for the stock airframe, and used the competition 6"x60" paper streamer that came with the kit. It was a windy day, so I didn't launch straight up, but even so my first flight was 77 seconds, and the second was 86 seconds. Unfortunately the 3rd was a lost track, which turned out to be a failed deployment because I packed the wadding in too tight, but the first two were good enough to get second place. I agree with Jim that pop lugs are the way to go.

There was a tie for first place and one of the winners also had only two good flights and used an ASP competition rocket with a tower. His flights were about 10 seconds longer than mine. I think the difference was due to him doing a better job finishing his rocket than I had, rather than a difference in the rocket designs, and that he launched straight up.

During this contest, we also had a C Egg Lofter duration competition. I scratch-built a rather standard design similar to the ASP egg lofter, but made my own huge 40" square parachute from 0.3 mil polyethylene from Home Depot. I won this competition with a time of 151 seconds (till it hit the power liines) and another 10 seconds unofficially to land on the gropund after a gust blew it off the lines a minjute later).

Bob Krech
 
Bob-
What was the "better finishing" that made the differense for your competetor. I have read stuff about waxing and sealing in different manners. I wonder if it is a good idea to just smooth and spry clear (krylon or the like). I also read on emrr about running comp kits just outta' the box with CA'd smoothe fins and nose. And then sanding sealer...............etc...etc..

I'm not sure what it best to do to slick these guys up. :(
 
I just re-read all these posts again (thanks guys) and I saw Powderburner mention future floor wax. I have some of that stuff. It seems to work really well with decals and gloss finishes. It self levels, and even I have a hard time messing it up:D .

If I use that stuff to slick a bird up, how would I buff it? Just a really smooth towel of some sort?
 
Justin

What I could have done better.

I didn't do a great job sanding and finishing the NC, and was pretty sloppy with masking tape to retain the motors. That probably cost a few tens of ft. on altitude.

I also did not launch straight up. That probably also cost a few tens of ft. in altitude.

I used trapazodial fins instead of a clipped delta design. This probably cost another 10 ft. or so in boost.

I used a thrust ring on one of the 2 models and probably used a bit more tape than necessary on the streamer. This added weight and probably lost a few tens of ft. on boost.

The resulting penalties were approximately 2-3 seconds on boost and about 5-7 seconds on descent.

What I did right.

I did make sure the fins were exactly perpendicular to the central axis of the rocket by making a fin alignment jig. Not to have done this, and having the fins skewed would probably cost 100 ft. or more in extra drag, and thus reduced the flight time by 10 seconds or so.

I also carefully measured the balance point to insure that teh body of the rocket would be horizontal on descent. This probably increased the descent time by 10-20% by adding extra drag on the descent, probably adding 10 seconds to the flight.

I used a pop-lug to eliminate the 15-20% launch lug drag. Using a pop lug or a tower probably adds about 100 ft. or adds 10 seconds to the flight.

I used the comeptition streamer that came with the kit vs a smaller sport streamer. This probably is the biggest contributer to the flight duration. This probably added 25 seconds to the flight.

So with basically the same model, depending to the attention you pay to the details, you could have a 35-40 second flight or a 90-95 second flight. There's a bit of luck involved too.

Bob Krech
 
I've got two kits named:

Steamer Duration

and

Parachute Duration

They work great and are designed to be sturdy and fly many times. They use a birch nose cone primarily to make school programs go easy (they don't crush and are easy to paint or color). Birch is heavier than balsa, so for extreme duration (and models that can "thermal away") I suggest substituting a Pratt lightweight nose cone or a BMS light balsa cone.

https://www.geocities.com/fredeshecter/index.html

Originally posted by Justin
Hello-
I'm doing NARTREK program levels and one of them is competition. For the award I have to pick two events and attain 50% of the national record in both (I don't know what this will entail yet, I don't have any records or a pink book). I think I'm gonna try chute and streamer as I have never competed before and it seemed like a good two to start with.

You folks got any reccomendations for good kits in these catagories? Any help would be great.

Thanks-Justin :)
 
Here's a graphic of the one that we sell. We also include it with our two Cougar competition models.

Basically, you have a launch lug (2 - 4 inches long) with a tri-pod of soft wire attached to it (two wires on the rear and one on the front of the lug)

The two rear ones are bent to curve over the trailing edge of two fins. The front one is bent downward and pokes into a small hole in the body tube.

It is held in place by the friction of the connection points. Placed on the launch rod, a wrap of masking tape is placed on the rod tip. When the rocket is launched, the pop lug catches this tape and "pops" off of the rocket, staying behind.

jim
 
cls,
Jim has shown you a good pop-lug system. That little device (together with a tape tab at the top of the launch rod) worked fine for me about nine out of ten times.
Maybe it was just my perception/apprehension, but it seemed to me that on many launches the pop-lug caused the rocket to 'snag' a bit at the top of the rod. Maybe I had this suspicion because the rocket experienced a fairly hard hit (and tip-off) at the tape wad.
At any rate, I tweaked the concept by using a straight pin in place of the wire shown on the front end of Jim's concept. The head of the pin was glued to the LL, the shaft of the pin was gently bent into a (very) small offset, and the tip of the pin was slid into the side of the rocket's BT. I did *not* make a hole through the side wall of the BT, but slid the tip of the pin in between the paper wall plies, pointed toward the front of the rocket, so it would pull out in a direction going straight aft when the pop lug separated. No more snags at the top of the launch rod.
 
There is an amazing amount of information on this forum. From 13 year old kids to people that have been making rockets for like 30 or 40 years!

I appreciate all the posts.

Jim-
Very cool pic of the pop lug. I understand how it works now. Pretty nifty idea. Who invented that gizmo? Is it one of yours?
 
I'm not sure who invented it, but it is an interesting question. Someone else here may know. I may also post that question on other forums too.

The one that we sell is one of my own design, but the basic geometry is the same for all of them. Probably the best known would the the ones from CMR (Competition Model Rockets). His were about 4" long. I never liked them and used his kits to develop my shorter version.

They really are great and are far FAR cheaper than towers or pistons, very reliable and easily fit in your range box :)

I also have towers and pistons at home but very rarely use them. The pop lug is just too easy to carry and use. And don't let anyone tell you that a pop lug based rocket can't beat a tower or piston launched rocket. They'd be wrong :) It can be done and happens all the time.
 
I have clones of the NARAM-46 contest event tips on my website:

https://members.aol.com/GCGassaway/gcghome.htm

Click on the NARAM 46 Event Tips link to get to a master link page.

From there, you can go to the Streamer event tips page.

The tips pages have the NARAM-46 headers on them, but they are all on my site. I put them there initially as a test site, then decided to keep them there long-term as I’ll be updating those event tips for each NARAM. But if you click on the black colored links (like “home” and “registration”) you will end up at the NARAM.org page (which at some point will change for NARAM-47).

At the bottom of the page are some suggested kits and plans. Of course those suggestions were for B Streamer, not any other power class.

Anyway, you can also check out the B Egg Duration page for some tips on chutes (there was no PD event at NARAM-46). Any model you make for Streamer can be used for Parachute too, just a matter of selecting a chute and engine combo that will put it over the time needed, without risking flying away too much. An 18” chute in a 18mm model flown on a C would stay up plenty long, but would be at a big risk of flying away. Of course since you are shooting for 50% of a record time, you might have to try for a time that would run a risk of losing the model, especially for Parachute. A lot of the duration records usually (but not always) reflect at least two if not three of the following:

low wind
good thermal that does not take the model away
decent sized field (without high plant growth)
luck

And I didn’t include anything there about the raw performance of the model, or a flier’s prepping skills. Just that a model that doesn’t work won’t set a record. And that thermals can help to make up for shortcomings in raw performance but of course hit a thermal too well and it may take the model away. But since you can pick and choose which two events to go for, and the time you need is 50% of the record, the right choice of which ones to go after might not require the use of thermals or high raw performance. In some other events you could have the best model ever made to fly that event and never get close to 50% (and get the model back) since the record setting flights got caught into huge thermals then the model came out of the thermal so the flier (or somebody) was able to find it and get it back.

Also there’s a few events with no existing records. There’s a few 1/8A records unfiled for, and a handful of other records not filed for (Hmm, no F or G Flex-wing duration records. Problem there would be getting the flex-wings back if they worked). The G Streamer record in C Div is 182 seconds, it would be not be hard to get 50% of that (Man if you are planning to get at least 50% of the lower power streamer events, that would be quite a task. Without knowing any specifics, all but perhaps the 1/8A flight must have been in very strong thermals). G Copter at 17 seconds is ripe for a new record with pretty much anything decent that worked. Something like a VERY sturdily built Tri-F-O (flying saucer that spins) at original size (not scaled up) could probably get 9 seconds (over 50%), but I highly doubt it could beat 17 seconds for an outright record. The F and G R/G records are pretty low too, the Alway Brother’s “Backslider” type designs could probably stay up for 50% and depending on the mass and glide might have a shot at the record (see the R/G tips page).

Also the C Dual Eggloft Duration record seems an easy target to at least get 50% of, at 84 seconds. At least 42 seconds for two eggs on a C, not that hard. Check out the eggloft duration tips page and imagine a dual egg capsule in place of a single capsule. Biggest problems with dual eggloft are packing the eggs right so they do not break each other, and having the shock cord system and chute sturdy enough to not rip at deployment. For C power I think 1/8” elastic is still adequate (run 36” or more of elastic from the capsule to the chute), but for sure the chute needs to have the lines over the top so the lines can’t pull out.

Whatever you do, finishing wise, finish is nice for pure altitude models. But usually not so much for duration models. The extra weight usually brings the model down faster than the extra altitude a slick finish provides for the model to descend from.

- George Gassaway
 
Wow, thanks george.

That was a pile of stuff I hadn't considered. I'll check out your tips page.

And welcome to the forum!

-Justin
 
I'd agree with George about conventional finishing techniques and duration rockets--it is rarely worth the effort because the reduced drag doesn't offset the added weight. Another impediment to seeing the expected benefit is the lack of long delay motors--the situation would be a lot different if you could use A3-6T instead of A3-4T motors.

However, if you must get that last little bit of duration performance, I'd suggest using thinner balsa covered with water shrunk Japanese tissue (Peck Polymers is a good source.) The taut tissue will add stiffness and strength, increasing the speed at which you encounter fin flutter. This is particularly important if you use pistons--the high speeds can easily result in shredded fins. Done properly, you can get a reasonably smooth surface.
For instance, I built Bob Kaplow's Rotocrock with 1/32 tissued balsa, instead of the suggested 1/20 balsa (also available from PP.) I got a nice 74s flight on a 1/2A3 for one of my Advanced Competition requirements. Of course, with a helicopter you gain more because the blades represent a greater fraction of the total weight, but I think you get the idea.
 
Just starting building one of Jim's Cougar 660's yesterday. Saw the thread, and thought I'd take a couple of build photos. The tailcone is complete, and aside of a slight wrinkle on the tailcone, went together without a hitch. I will try to smooth out the wrinkle in the finishing process. This is my first exposure to "pop-lugs", but I'm looking forward to seeing how well they work, because I simply won't spend money on a tower!

It's a somewhat challenging build, as I had a hard time putting ANY shape on the fins b/c they're so small & thin, and my fingers are so big and clumsy. I'll be using the competition streamer for NARTREK Streamer duration requirement. I decided to have fun with this one, and I'll try the hard way first by using a ½A motor to get my 30-seconds. If that doesn't work, then an A10 should be more than enough.
 
Here's a shot of the semi-completed rocket...... the fins match well with my table! :D
 
very kewl. Keep us posted on results.

man, i sure wish they'd bring back long delay motors, like the A10-6T (perfect for the Cougar models)

jim
 
Finished the Cougar finally. It's a bit more challenging than the typical 3FNC build. I was a little sloppy with the pop lug, but I think it will serve it's function just fine. It was an odd thing for me to build, but each subsequent one will get better. Just one question, I've re-read the instructions and re-evaluated the diagrams, but is the shock supposed to be on the outside of the BT? Or did I just mess up somewhere? It seems unorthodox to me, that's all. Anyways, here's a nekkid photo of the Cougar 660.
 
And here's a rear photo of the pop lug. I had a little trouble with the cord unraveling on the lug while I was trying to get it to stick with CYA. As long as it's parallel with the BT, I think it will serve it's function well.
 
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