Pendulum rocket fallacy - quarterly challenge - second quarter

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mbecks

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hello TRF
Pendulum rocket fallacy or well, she's a bit top heavy.

Welcome to the second quarterly challenge. I now call it a challenge rather then a contest because there isn't enough finished submissions to pit against each other, yet!

Here is the second challenges criteria:
-Build a rocket where the rocket motor is mounted in the upper half of the rockets air frame.
-post your build thread and a video of the launch.
-have it launch and recover successfully. (Using a parachute or some means to slow its decent, not a free fall)
-all rocket sizes are welcome
-be creative and use your imagination.
-The challenge will run until the end of June.
-the rocket must be a new build.


For more info on the title of the challenge and the spirit of the challenge read this short Wikipedia entry.
https://en.wikipedia.org/wiki/Pendulum_rocket_fallacy
 

mbecks

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Thanks for the post. Looks pretty dang cool. I just updated the criteria so there isn't the confusion in the future. We are looking for new builds.
 

neil_w

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Omigod, it's a tractor motor competition... paging daddyisabar and rstaff3...
 

Daddyisabar

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Omigod, it's a tractor motor competition... paging daddyisabar and rstaff3...
Wow! Some love for tractor motors! Just started one last week called Heavenly Rider. Guess I take some build photos and use it for the contest. I might even be able to fly it at the local club. Three E12-4's mid cant with scythe fins. I will just have to get over the "questionable cluster and funny lookin'" requirements to get a pad assignment. Using the last of the Flis 3X24mm canted motor mounts in the box. BT 70. Love them tractor motors to pull things up attached to the hind end of the rocket. It was to be my Halloween rocket but who can resist a tractor motor competition:) Finally, the motors put where they should be, at the front of the rocket, just like the first ones in China. Nice smoke trails, good for CG, can haul stuff on the rear end, no fins needed or the fins can be up front.

Heavenly Rider.jpg
 

Daddyisabar

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Here are some past examples I have done testing the fallacy:

B6N NSL2.JPGD V pad 1.jpgBlackburn 1.jpgDSC_8452.jpgHS 123 5th number 2.JPGHustler 7.jpgJIB 109.jpgP3100165.jpgSquid Set up.jpgStuka One.jpg

You can fly almost anything with the motors up front, even an Ekranoplan. The sky is the limit, but that limit is usually quite restricted by the RSO. So be safe.
 

rstaff3

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I will be watching this contest closely! I doubt if I'll enter but maybe the entries will get be excited about building again. I wish these designs had surfaced 15 years earlier when I really was build crazy.
 

neil_w

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The mega tapeworm really is the stuff of nightmares... :eek:
 

mbecks

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Where can I see a video of the worm rocket? That thing is unique!
 

Daddyisabar

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The mega tapeworm really is the stuff of nightmares... :eek:
And it almost worked, but I thought back then you could do a three motor cluster with Starters. With oddrocs and mindsiming the only school is the School of Hard Knocks. Live and learn. One thing for sure, your canted tractor motored launches will make for some good stories to tell around the campfire. Some day I will build another tapeworm. So many possible designs and so little time and money to build and launch!
 

Daddyisabar

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Daddyisabar

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I will be watching this contest closely! I doubt if I'll enter but maybe the entries will get be excited about building again. I wish these designs had surfaced 15 years earlier when I really was build crazy.
A mid mount Gas Dynamic Stabilization rocket would work, not too hard. An Ekranoplan Mark Two with functional missile tubes would be awesome (just dreaming.) A D-Day Normandy grappling hook? A finless Easter Egg that could actually fly? A "Trying to avoid Mr. Krushnik" themed rocket? A spinning canted saucer rocket with something interesting hanging down from the middle? Pyramid or cone rockets. Flying Eiffle Towers or Space Needles. Jet pack Barbie. Telescoping rockets. All you need is the perfect cheer!
 

rstaff3

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A mid mount Gas Dynamic Stabilization rocket would work, not too hard. An Ekranoplan Mark Two with functional missile tubes would be awesome (just dreaming.) A D-Day Normandy grappling hook? A finless Easter Egg that could actually fly? A "Trying to avoid Mr. Krushnik" themed rocket? A spinning canted saucer rocket with something interesting hanging down from the middle? All you need is the perfect cheer!
Meh...no parts...no motivation.
 

Woody's Workshop

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The 1st rule is a little unclear.
I read it as the engine needs to be inside the top end of the air frame.
Hence, the rules don't mention the use of pods or other air frames for mounting engines.
Canted or other engine pods should be added to the rules to be clear.
Someone like me might drill out a balsa nose cone and stuff an engine in it for a blast n burn take off.
 

mbecks

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The 1st rule is a little unclear.
I read it as the engine needs to be inside the top end of the air frame.
Hence, the rules don't mention the use of pods or other air frames for mounting engines.
Canted or other engine pods should be added to the rules to be clear.
Someone like me might drill out a balsa nose cone and stuff an engine in it for a blast n burn take off.
I want this to be open to interpretation so we get a veriety of ideas and rockets. If you do the nose cone idea I'll watch.
 

Woody's Workshop

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I want this to be open to interpretation so we get a veriety of ideas and rockets. If you do the nose cone idea I'll watch.
I've been thinking about it, since I've got a V2 type BT-80 nose cone that I don't have a clue what I purchased it for.
My thoughts have taken me into to how the recovery would happen...
I probably won't do it, but it's got my thought's attention for some reason.
 

Daddyisabar

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Take a big plastic nosecone, cut the bottom and tip off, insert a motor tube at the top. Put some more tractor motors up top on an umbrella, good fer CG, the cut nose cone acts as a long skirt, good fer CP. Dress it up and call it Mary Poppins Flies Again! Little Bo Peep has lost her sheep!

I think the B-58 might not make it under these rules but the rest would. Radical cone rockets with rear eject would work marvelous, as would flexible tractor motor rockets like the Crazy Train, modified into snakes, fish, tube worms, etc.
 

Daddyisabar

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I've been thinking about it, since I've got a V2 type BT-80 nose cone that I don't have a clue what I purchased it for.
My thoughts have taken me into to how the recovery would happen...
I probably won't do it, but it's got my thought's attention for some reason.
Beware of your thought's attention. It can lead to mindsiming and the Dark Arts of Model Rocketry.
 

Daddyisabar

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Darn it! Instead of dragging a skeleton up to Heaven I couldda done a scuba diver behind behind one of those torpedo like pullers! The big flippers wouldda been great fer the CP. Maybe some other crazy fool can do it!
 

rstaff3

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I don't know if the canted mounts on the Chesapeake Sea Monster are far enough forward to qualify. Unless you say the canted mounts merely hold time delayed parachute ejection devices. But, anyone who wants to do their own could just move the central mounts further forward.
 

Daddyisabar

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Tractor motor, mid motor or mid cant rocket ideas - top half: Christmas trees, Tiki huts, Pad abort test rockets (scale), Congreve rockets (scale), Old Time Life Line rockets (scale), Flying Guitars, wagons, Hi bypass airflow designs. Steam Punk rockets, Staged Saucers, Rack Rockets? Certain types of Girandolas?
 

Daddyisabar

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I don't know if the canted mounts on the Chesapeake Sea Monster are far enough forward to qualify. Unless you say the canted mounts merely hold time delayed parachute ejection devices. But, anyone who wants to do their own could just move the central mounts further forward.
But those eight other motors up front would sure qualify it! And mid cants/mounts count too. Manta Bomber like. . . Star Wars Y Wing like....
 

rstaff3

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But those eight other motors up front would sure qualify it! And mid cants/mounts count too. Manta Bomber like. . . Star Wars Y Wing.
Maybe all entrants should compute the CMT for their designs (Center of Mean Thrust)
 

Daddyisabar

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Maybe all entrants should compute the CMT for their designs (Center of Mean Thrust)
But that would take Rocket Science Knowledge and knock out all the mindsiming Liberal Arts Majors who have none. Like Wiseguy Joe Pesci " I'll show you the Center of Mean Thrust!":)

goodfellas-joe-pesci.jpg
 
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