Yes, Aerotech kits have thicker metal motor hooks than the wimpy Estes ones. Real mid power kits!Bigger metal clips?
Yes, Aerotech kits have thicker metal motor hooks than the wimpy Estes ones. Real mid power kits!
Launch Report
My wife and I launched the Hammerhead Shark.
The rocket flew stable.
View attachment 525358
I gained a lot of respect for you folks that post up flight videos and photos. We were so focused on not losing the rocket since it was its maiden flight, that I wasn't able to get any apogee or recovery photo's.
So... my apologies in advance for the poor-quality photos and video.
View attachment 525011View attachment 525012View attachment 525023View attachment 525024View attachment 525015View attachment 525016View attachment 525017View attachment 525019View attachment 525020
A normal scratch-built would spiral, but this one is so symmetrical, it rocks instead.
For standard 3FNC or 4FNC rockets (I.e., NOT OddRocs) I might find obvious deviation from “straight and true” flight path disappointing. For OddRocs, if the net trajectory is mostly vertical, it gets up over 50 feet, and recovers without hurting anyone or anything, and damage if any to rocket is easily fixable, i chalk it up as a win. I think @Daddyisabar would agree, fishtaiking, coNing, corkscrewing, who cares, as long as as it’s safe and you have fun. Personally, perhaps because I am a low power guy, when I went to NSL a few years ago after a while the only really interesting high power launches from a spectator standpoint were the ones that DIDN’T go picture perfect.
for OddRocs, a little waggle just adds character.
in fact, it actually INSPIRED one of my favorite builds
https://www.rocketryforum.com/threads/squirrel.69006/
I bet the folks at Apogee, Estes, Quest, etc. have this same level of "wonderment" when they're designing and testing new "Odd Rockets".
concur in part, safety is always number one concern. Interestingly “stability” May have more than one definition, technical and practical.I agree. But to be clear, my goal is "Straight, True Vertical Flight Paths, and Safety". That's why I follow the NAR rules, run simulations in Open Rocket, perform swing tests, etc.
concur in part, safety is always number one concern. Interestingly “stability” May have more than one definition, technical and practical.
I suspect many have experienced rockets, often kits, that were by design, build, and even swing test stable but when launched were….not. OTOH, I am not sure that some OddRocs either are unstable on sims or more commonly probably CANNOT be simmed because their contours are outside sim parameters (my understanding is that sim programs don’t like rockets without round body tubes. There are work around s but sims themselves are estimates, and when you workaround you are compounding estimates with estimates. While I admire your adherence to ”straight and true”, and i am not sure if sim programs like RockSim and OpenRocket would find rockets like Odd’l Rockets’ “CorkScrew” stable, many of them fly just fine despite some corkscrewing or waggling. I would call those rockets “practically stable”. I do confess that while I get a kick out of some asymmetric fin designs that screw their way into the sky, leaving entertaining smoke trails along a (net) straight trajectory, it is kind of fun to have a wacky looking rocket fly straight. It will be interesting to see how @neil_w ’s Shear Insanity actually flies.
I was going to use the story that scientists proved the bumblebee couldn’t fly, but I googled it and the story is a myth. Same with breaking the sound barrier. Light speed, on the other hand, is going to be a lot more challenging!
Indeed. Regrettably, I have no launches anywhere on the horizon right now. Gotta figure something out.It will be interesting to see how @neil_w ’s Shear Insanity actually flies.
"Wonderment" is not a term I have heard when discussing commercial oddroc kits with the top designers from those companies. More like " Idiot Factor."I agree. But to be clear, my goal is "Straight, True Vertical Flight Paths, and Safety". That's why I follow the NAR rules, run simulations in Open Rocket, perform swing tests, etc.
But since these aren't kits that have been vetted and tested (and they aren't 3/4 FNC designs, as you stated).... stuff happens.
I bet the folks at Apogee, Estes, Quest, etc. have this same level of "wonderment" when they're designing and testing new "Odd Rockets".
I'm betting some of the commercial oddroc kits, during the development phase, were full of wonderment, until they got them dialed in."Wonderment" is not a term I have heard when discussing commercial oddroc kits with the top designers from those companies. More like " Idiot Factor."
true, and this may be the death Nell for Back Sliders. If I understand the physics, the post ejection flight mode is dependent on orientation after the forward puff yanks the rocket out of stable flight, at which point the rocket stops (or nearly stops) in the air, and starts falling. The orientation post “puff” is pretty random, can be anywhere in an infinite number of positions in a sphere around the center of gravity. For a long rocket, as long as it is not pointed straight downs it should transition to a back slide recovery. The longer the rocket the closer it can come to being NEARLY vertical and still backslide. But if it unfortunately happens to randomly orient straight nose down, it’s gonna come in ballistic. I fear this is unsolvable for “pure” back sliders, although fixable with a small streamer for the less finicky.
Rule number one of Oddroc Club: The rocket looks cool.Another factor is nose cone weight. Oddrocs, more than meets the eye. Oddrocs, rockets in disguise.
The hammerhead nose cone is crazy heavy, 9.3 ounces (the rocket w/ motor weighs 18.3 ounces). Normally we think of an ejection charge as "popping off the nose cone". On the Hammerhead I wanted it to eject after apogee, thus the ejection charge is pushing the fuselage back and allowing that heavy nose cone to keep falling, thus pulling out the parachute.
It really depends on the rocket design.
Take as an example my F-79 , which is a rear eject design without a spool. During flight the rocket never "nearly stops", and the nose cone doesn't come off, so it never becomes unstable / non-aerodynamic. That's why it's so important to get the chutes out before apogee.Pre-apogee also gives the chutes a chance to deploy while the rocket is slowing down on its own, instead of picking up chute shredding speed.If I knew then (pre-flight), what I know now (post flight) the F-79 probably wouldn't have those cool looking speed stripes on its nose.
I didn't know it isn't true, but I'd rather call it a parable than a myth. And as a parable it's frequently misunderstood.I was going to use the story that scientists proved the bumblebee couldn’t fly, but I googled it and the story is a myth. Same with breaking the sound barrier. Light speed, on the other hand, is going to be a lot more challenging!
No, no. Someone, the story goes, using the prevailing theories of the day, showed that bumblebees wouldn't fly, and that was offered as proof that the prevailing theories were wrong, and he and his colleagues had a lot of work to do. Proof by reductio an absurdum.
Good point that rear eject models (ignoring the chute, which is the elephant in the room) remain STABLE throughout the flight.Another factor is nose cone weight. Oddrocs, more than meets the eye. Oddrocs, rockets in disguise.
The hammerhead nose cone is crazy heavy, 9.3 ounces (the rocket w/ motor weighs 18.3 ounces). Normally we think of an ejection charge as "popping off the nose cone". On the Hammerhead I wanted it to eject after apogee, thus the ejection charge is pushing the fuselage back and allowing that heavy nose cone to keep falling, thus pulling out the parachute.
It really depends on the rocket design.
Take as an example my F-79 , which is a rear eject design without a spool. During flight the rocket never "nearly stops", and the nose cone doesn't come off, so it never becomes unstable / non-aerodynamic. That's why it's so important to get the chutes out before apogee.Pre-apogee also gives the chutes a chance to deploy while the rocket is slowing down on its own, instead of picking up chute shredding speed.If I knew then (pre-flight), what I know now (post flight) the F-79 probably wouldn't have those cool looking speed stripes on its nose.
Does max V on ascent exceed max V on a ballistic recovery?
Your rear eject is also a bit different than many rockets, which rear eject but use a pod that ejects with the motor mount and chute, with a shock cord connecting chute to pod and a second connecting pod to rocket body. These may or may not be stable post deploy, but certainly will be draggier even if chute shreds. Shredding may be less likely, as chute deployment from a pod may be a tad slower than the immediate deployment from your more direct approach. Pod systems also take up a LOT of space which makes chute packing a PITB, and often limits available space so tend to go smaller.
Anyway, please post the D12-3 flight I hope is imminent!
Enter your email address to join: