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Indestructible Certification Rockets

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lowga

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I'm a rebar, returning to the hobby after an absence of over 15 years. Hoping to certify Level 1 and 2 quickly. Initially, I searched for a kit that would allow me to certify L1 and L2 using the same rocket. That lead me to building a Madcow Cowabunga 4" diameter rocket. I'm pleased with the kit, though it's clear that my building skills are "rusty" to say the least.

Along the way, I learned a lot--and in hindsight, I'd have probably chosen another rocket.

There would seem to be demand for rockets that met the following criteria:

1.) Easy to build.
2.) Highly stable.
3.) Indestructible or close to it.
4.) Dual Deploy capability.

The closest kit that I've found so far is the Hawk Mountain Industries Transonic rocket. It's made from fiberglass, uses the Acme Fiberglass fin can, and has a stability of about 9 calibers. However, it has some serious negatives too. The biggest issue being that it's a nearly minimum diameter rocket, so it's going to go fast and high. Staying under the waiver might be a concern, as well as recovery.

Is anyone aware of a large diameter, fiberglass rocket that uses a fin can? Low, slow, and indestructible would seem like a rocket kit that would be much in demand for people looking to certify at various levels.
 

Woody's Workshop

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I don't do high power.
But what I can tell you is what I know.
The motors for a minimum diameter rocket to keep it under waiver are less expensive.
Life changing events a couple years ago moved me into the mini motor.
Most of them get up there, just for less $$.
 

DavidMcCann

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Not many using fin cans.... and fin cans are typically a no-go for certs. The easiest way to set fins with good results would be using fin guides, either self made, or a few places have them pre-made for kits.






there's also the estes fin guide, that works on thin HPR rocket fins-




Rockets at the top of my head that meet your criteria (minus the fincan)

Madcow 2.6" thin wall FG kits (Screech, DX3, Tomach) https://www.madcowrocketry.com/2-6-thin-wall-fiberglass-dual-deploy-screech/
MAC Performance 54mm body kits- https://shop.macperformancerocketry.com/collections/54mm-diameter-kits-1
Wildman Junior kits 54mm body- https://www.wildmanrocketry.com/ShowProducts.aspx?Class=463&Sub=1183

Any would make easy, nearly indestructible L1/L2 birds.
 

Exactimator

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You’re going to get a ton of answers here based on preferences. Great thing is there’s many ways to rocket zen.

Fiberglass is really durable, but you sacrifice some weight. You didn’t say what your waiver was, but you could do a 3” fiberglass rocket, dual-deploy ready that could fly on higher L1 and low L2 motors to get both certs. Something like a 3” Madcow Frenzy or Twitch or Reaper 3. Madcow kits come pretty complete with most things you’d need. Wildman also offers several good 3” FG kits. In both cases, make sure you check to see what other components you need to complete the builds.

To give you an idea, I have a Madcow Reaper 3. It weighs a little over 8 lbs without the motor. On a 38mm I, it’ll reach around 2,000 feet. On 38mm J’s, it’ll reach anywhere from 2500 to 5,000+ feet. Or you could put a K in it and hit the speed of sound and around 10K feet.
 

DavidMcCann

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3" kits are like crack. Manageable size, wide range of motors.
 

blackbrandt

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I'd recommend a 3" thin wall fiberglass kit. I got my L1 and L2 on it (I180 Skid for L1 and K700 for L2). Nice lobbing flight for L1, nice kick for L2.

Theoretically I COULD eventually get my L3 on it but that's a different story. :)
 

noffie79

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3" kits are like crack. Manageable size, wide range of motors.
Never a truer statement made!

I'd recommend a 3" thin wall fiberglass kit. I got my L1 and L2 on it (I180 Skid for L1 and K700 for L2). Nice lobbing flight for L1, nice kick for L2.

Theoretically I COULD eventually get my L3 on it but that's a different story. :)
I, personally, think you should.
 

noffie79

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In reply to the OP, my vote is for a 3" fiberglass kit as well. With either a 38mm or 54mm motor mount. If you have a high waiver, I'd get the 54. If your waiver is lower, go with the 38.
 

Bat-mite

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There is no such thing as an indestructible rocket. Even an all metal airframe, if it were allowed, will crumple into an accordion if it lawn darts. Fiberglass is about as good as it gets. Fiberglass-wrapped phenolic is very strong, with the MAC Performance canvas phenolic being almost as strong but weighing less.

Walk around at a launch and ask questions. People love to show your their rockets.
 

lowga

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I have easy access to two fields here. One has a 5,000' waiver, the other is in excess of 20,000--but it's winter-time use only. We may even be done for this season. Birmingham, Alabama area.

I'm not familiar with Tripoli rules, but I don't see anything in the NAR rules that would prevent you from certifying using a fin can. Granted, they're easier to build. It's been years since I studied engineering, but one of the keys to engineering is to define objectives, and then design to meet them. If the objective is to certify successfully, then the best design would include stability, strength of construction, simple-reliable recovery, etc.

This is why "Low and slow" makes a lot of sense for certification flights. From an engineering standpoint, fin cans seem like a no-brainer to me. The objective isn't to build a complicated rocket to prove your modeling skills--it's to built a safe, reliable and receoverable aircraft to meet the certification requirements. Anything that adds complexity seems counter to meeting the mission parameters.
 

Trident

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I'd be more impressed with a person's true ability to actually deserve to be rated Level 1 if it didn't take a nearly indestructible rocket to achieve certification.
 

Bat-mite

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Only Level 3 disallows pre-fabbed fin cans.

All Giant Leap Rocketry kits come with the Acme fin can. They have dropped their Quantum tubing and are now using fiberglass. GLR kits make good certifiers. They supply you with almost all of the parts right in the kit (chutes, rail guides, etc.). I don't think a retainer is included, but they sell those, too.
 

rharshberger

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iirc pre-fabbed fin cans can only be used if the flier builds the fin can themselves, for cert rockets.
 

boatgeek

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You have a pretty great waiver in winter, so I would go to something a little smaller. My L2 project was a 2.6" Madcow Arcas with a 38mm motor mount. It'll stay under your summer waiver on small to medium 38mm motors, and a baby J will take it to about 6,000' this winter. That's a little high to depend on visual tracking, so you'll probably want a GPS if you go this route. You can do dual deploy or chute release pretty easily if you plan for it from the get-go. My first L2 attempt ended in failure after it hit the ground at about 100FPS under streamer (main failed to deploy). I had two cracked fin fillets to repair from that, no other damage. I think it's hard to beat that level of indestructibility.

For an L1/L2 project, I'd stick to 38mm motors for cheaper flying than 54mm. 3" or 4" body diameter might be a better choice to keep it a little lower if you aren't planning on a GPS tracker.
 

tomsteve

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it doesn't meet the criteria of fiberglass , but its my opnion that the LOC mini magg is a great rocket for both L1 and 2 cert. its a relatively simple one to construct and easy to make the fin can pretty darn solid. upgraded to a 54mmt with fins to the mmt( im not sure if LOc is makin the fins go to the mmt now, but back when I built mine they were jusy ttw about an inch), epoxy fillets at the mmt, on internal BT, then external fillets, plus foam it all in during construction, it can handle a lot of motor.and easy to use a 54 to 38 adapter.
then, add a section of body tube and ready for L2.
its also possible,after construction or during, to fiberglass it.

theres only one way ALL of us have gotten better building skills- only one way to remove the rust: practice.
and some studying on techniques.


basically, every rocket has a fin can.
 

Bat-mite

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iirc pre-fabbed fin cans can only be used if the flier builds the fin can themselves, for cert rockets.
Quote the rule please. I read the L1, L2, and L3 rules, and the only reference to fin cans is in the L3 rules. I got my NAR L2 with an Acme fin can from GLR.
 

Exactimator

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20,000 feet, you say? If you do the 3” rocket with a 54mm motor mount, you can adapt down to 38” and fly all those motors. After you L2 cert, you could put a 54mm L935 in it and go to 13,000 feet and 970 MPH / Mach 1.2.

If that’s not your thing then it’s not. But it’s possible.

Bat-mite and mikec are correct. There's no indestructable rocket. But fiberglass is a reasonably durable choice for the money and weight.
 

Nytrunner

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I wouldn't call it "indestructible" but I'll throw out the Madcow 4" Patriot (fiberglass or standard. that cardboard is pretty tough)

Stick a 54mm mount in it, add an ebay, and you can easily do 1 and 2 in it. I built mine stupid so it's only an L1 flyer, but that just means I get to do something cooler for L2.
 

DavidMcCann

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I wouldn't call it "indestructible" but I'll throw out the Madcow 4" Patriot (fiberglass or standard. that cardboard is pretty tough)

Stick a 54mm mount in it, add an ebay, and you can easily do 1 and 2 in it. I built mine stupid so it's only an L1 flyer, but that just means I get to do something cooler for L2.
It can be an L2 flier. Once.
 

ksaves2

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Anything fiberglass with TTW fins in the 54mm diameter class on up to 3 inches for L2 stuff. G10/12 fins with good fillets. If the chute doesn't open or tangles, as long as the rocket lands in nice Midwestern farm soil, just repack and fly again.
Occasional tumble recovery won't hurt it. This is about the most "indestructible" one will be able to achieve. Sure land on "ceeeeement" sumptin's gonna break. Kurt
 

cerving

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Only Level 3 disallows pre-fabbed fin cans.

All Giant Leap Rocketry kits come with the Acme fin can. They have dropped their Quantum tubing and are now using fiberglass. GLR kits make good certifiers. They supply you with almost all of the parts right in the kit (chutes, rail guides, etc.). I don't think a retainer is included, but they sell those, too.
I did my L2 with an Escape Velocity, great kit. The one that I built had the Magna Frame tubing, basically it's like blue tube. Comes with everything except electronics (including the retainer)... I got plenty of electronics laying around. :)
 

woferry

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Quote the rule please. I read the L1, L2, and L3 rules, and the only reference to fin cans is in the L3 rules. I got my NAR L2 with an Acme fin can from GLR.
Yes, I've seen many people get both TRA and NAR L2's with Giant Leap's Firestorm 54, which uses a plastic fin-can. I did my L1 with a T-Bolt, a GLR 38mm kit with a plastic fin-can. I flew plenty of L1 motors on my Firestorm 54 (was the Magna-Frame, not the newer airframe material they're using now), so it should be fine for a L1 cert as well. Only thing I'd see in this specific case is being a 54mm MD it'd probably be tough to keep under 5000' with a L2 motor in it.
 

rharshberger

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You guys are correct as NAR only specifically declares prefab fin cans as not allowed in L3 cert rockets.
 
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EeebeeE

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A couple thoughts... I too am in the camp of fiberglass for "damage resistant" builds. My Madcow (formerly Rocketry Warehouse) fiberglass kits are awesome. Their 1.6" DD kits come with all the hardware except the sled for a DD project, but they all have 29mm motors.

Nothing is indestructible, though. whether it is a failed altimeter, a tangled or stuck chute, or a CATO, any rocket can and most likely will, get seriously messed up at least twice in its life. Sure a FG rocket may not zipper, but I know from experience that it isn't that hard to rip 1,500-lb. Kevlar cord. It is amazing how much damage to your AV Bay can be generated when a forward closure gives way, and an aluminum-tipped nose cone will break a fin off if it hits it just right.

A good 50-60% of indestructability depends on how you build it and how you fly it.
 

DavidMcCann

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You guys are correct as NAR only specifically declares prefab fin cans as not allowed in L3 cert rockets.

https://www.tripoli.org/Level3
Airframe – The rocket must be built by the flyer. The rocket shall have a display on the exterior identifying the calculated center of pressure. The rocket must be of “conventional rocket design”. “Odd Rockets” including flying pyramids, saucers and flying spools will not be allowed for any certification flight. The rocket may be either a kit or scratch built. Scratch built rockets may contain commercially built components. Commercially available pre-fabricated fin cans, either as part of a kit or obtained separately, may not be used for level 3 certification flights.


edit: i totally misread that..... carry on lol
 

Bkdoubleu

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Madcow 2.6 Fiberglas Honest John
* see my signature.
 
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