A Rocket That Launches Attached To A Horizontal Track That Transitions To Vertical

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heada

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I think NAR says the launch rod/rail has to be within 15 or 20 degrees of vertical. If the end of the track is within that range, can't see how it would be against the rules.
 

lakeroadster

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30 degrees, but who's counting.
If you are a lone wolf launching on private property and willing to accept responsibility for any consequences then that's nobody's business but yours.
Just my opinion.
I know that Lone Wolf guy.. :computer:
 

Blast it Tom!

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Interesting, but the translation from horizontal to vertical is still acceleration, and acceleration burns off energy. However... if, for some reason, your engine was building thrust slowly but you needed to get that energy converted to momentum no matter the slow velocity, then turn vertical as the thrust really builds, maybe keep the vertical height of your rail down... I dunno, though, if it were worthwhile I think we might have seen some examples.. Any reason in particular that you had in mind?

The Me-163 video was interesting, looks like it has some radio control capability - and also, it looks like it was launched with a match-lit fuse (I may be wrong there, and not to say I haven't done it...)
 

ThreeJsDad

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But the trick is supporting the curved launch track... without shearing off eyelets ;)
Rod guides could work except for that pesky bit about them wrapping all the way around. I wonder if a machine shop or custom muffler shop could bend a piece of Micro Rail? A skilled tubing bender may be able to bend the rail into the shape you want. I am not guaranteeing the buttons wont sheer off but that seems like the best approach. It could be supported on the inside of the curve.
 

neil_w

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The rocket would be very likely to bind on the curve, and that is the last thing you would want. Can't imagine how to make it work reliably without excessive machinery, like some sort of sled permanently mounted to the rail that the rocket somehow hooks into. But the weight of the sled would likely kill the launch.

Doesn't seem worth it to me.
 

heada

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The "rod" could be a hollow tube with a slit on 1 side facing down. The guides on the rocket could be similar to rail buttons but more of a sphere on the end of a shaft. Keep the shaft longer to allow for the curve of the tube and the ends being spherical should ignore the curve.

Interesting thought experiment but not something I'd try. LPR wouldn't benefit and HPR would be too heavy.

edit: fixed a word that my phone happily replaced for me. A "shower" on the end of a shaft doesn't make sense but a sphere on the end of a shaft does.
 
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RocketGeekInFL

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+1 on the sled idea, I think that is the only way this would work without some overhaul of launch rail engineering.

My question is why?
 

ThreeJsDad

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I don't think you would see any binding with only two points of contact if there was enough spacing in the guides. The bent tubing idea has merit, I would trust that more than rail buttons and machinery is already in place to bend the tubing. I do agree the radius would need to be pretty large.
 

lakeroadster

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For the folks saying "It doesn't seem worth it" and "why" ... the worth it part is to do something different. But then again I've always been like that.

Think of the visual.. and rocket sitting visual on a long track... the engine(s) fire and it hauls butt down the track, slides up the radius, off the track and up into the sky. You could even build it as a 2 stage so it stages while on the track... where the booster stage is heavy so it lumbers along until the second stage fires, at which point the acceleration seems incredible due to the light weight of the second stage. It could even be on a cart, where the cart falls away at the end of the ramp.

44 years ago I actually built a rocket with a track when I was in High School, but never launched it. The base was made from a 2x4 with a routed slot in the center. (Just a flat 2x4 about 6 ft long). It had two cover plates that were nailed to the top of the base. The rocket had (2) inverted T-Shaped metal hooks that hung underneath, one in the nose cone and one near the motor mount.

The rocket had a hinged door in the body tube so the chute would pop out the top.

High School Sled Rail.jpg

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The same track could be easily made, then notches added to create the curve.

Curved board.jpg
 
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ThreeJsDad

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For everybody that saying "It doesn't seem worth it" and "why" ... the worth it part is to do something different. But then again I've always been like that.

Think of the visual.. and rocket sitting visual on a long track... the engine(s) fire and it hauls rolls down the track, slides up the radius, off the track and up into the sky. You could even build it as a 2 stage so it stages while on the track... where the booster stage is heavy so it lumbers along until the second stage fires, at which point the acceleration seems incredible due to the light weight of the second stage.

44 years ago I actually built a rocket with a track when I was in High School, but never launched it. The base was made from a 2x4 with a routed slot in the center. (Just a flat 2x4 about 6 ft long). It had two cover plates that were nailed to the top of the base. The rocket had (2) inverted T-Shaped metal hooks that hung underneath, one in the nose cone and one near the motor mount.

The rocket had a hinged door in the body tube so the chute would pop out the top.

View attachment 407441
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The same track could be easily made, then notches added to create the curve.

View attachment 407442
Bending ply glued up in layers holds the final shape. I love creating new and crazy stuff so if I can help feed the insanity let me know. I was lying on the couch last night and telling my wife I need to finish my land sled so I can build a big sugar motor to mount under it. I got the look with a very authoritative NO... I live for crazy !!
 

lakeroadster

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I had the honor of working on the Phanthom Eye project. The entire project was awesome.. and the use of a cart for takeoff has always been something I've wanted to do on a model rocket.

 

kuririn

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Take it up a notch. Powered flyaway rocket sled, delayed rocket ignition while in mid air, maybe with a safety fuse ignited same time as the sled motor (with a clip whip). Varying the length of the fuse varies the delay. Rocket ignition will have to be while the subject is still moving at a stable speed. Probably breaking a bunch of rules. But...….:cool:
 

boatgeek

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Great minds think alike [Chorus: So do ours!]. I was thinking that you could stage this. I’m envisioning more of a parallel staging setup with a sled, a booster, and a sustainer. Spitballing here, the sled would have a cluster of 2 motors that are powerful enough that they are pushing the rocket. The booster motor fires at the same time as the sled motors. The booster separates from the sled at the end of the rail and stages shortly thereafter. Sled and booster are under tumble recovery. In theory, you have a very high rod/rail exit velocity and a nice stable flight. Also, in theory there’s no difference between theory and practice. :)

Motor selection to make this all work, a suitable curved rod/rail, and a complex set of burn strings to hold it all together if motors don’t light are left as an exercise for the student.

Has anyone done it? Probably not. Is it a good idea for performance? Doubtful. Will it be awesome if it all works? Definitely. Is this too many rhetorical questions? Assuredly. :D
 

lakeroadster

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Take it up a notch. Powered flyaway rocket sled, delayed rocket ignition while in mid air, maybe with a safety fuse ignited same time as the sled motor (with a clip whip). Varying the length of the fuse varies the delay. Rocket ignition will have to be while the subject is still moving at a stable speed. Probably breaking a bunch of rules. But...….:cool:
And that's why my very 1st post on this is does it break the rules.... I don't see where it does. It comes off the ramp perpendicular to the earth.

Again, where I launch, it doesn't matter. But I'd like to follow the rules in any event... it's part of the challenge.
 

ThreeJsDad

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That was a really cool video. The cart system is often used in RC Aero Towing. A sailplane is towed up by a large powered RC plane and the glider sits on a cart until it lifts off the ground.
 

boatgeek

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I agree that it doesn’t break the rules if it’s vertical and at a safe speed when it leaves the rod.
 

lakeroadster

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Great minds think alike [Chorus: So do ours!]. I was thinking that you could stage this. I’m envisioning more of a parallel staging setup with a sled, a booster, and a sustainer. Spitballing here, the sled would have a cluster of 2 motors that are powerful enough that they are pushing the rocket. The booster motor fires at the same time as the sled motors. The booster separates from the sled at the end of the rail and stages shortly thereafter. Sled and booster are under tumble recovery. In theory, you have a very high rod/rail exit velocity and a nice stable flight. Also, in theory there’s no difference between theory and practice. :)

Motor selection to make this all work, a suitable curved rod/rail, and a complex set of burn strings to hold it all together if motors don’t light are left as an exercise for the student.

Has anyone done it? Probably not. Is it a good idea for performance? Doubtful. Will it be awesome if it all works? Definitely. Is this too many rhetorical questions? Assuredly. :D
This ^^^

Quote of the year:

boatgeek 2020-02-25: ... "in theory there’s no difference between theory and practice."​
 

Steve Shannon

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And that's why my very 1st post on this is does it break the rules.... I don't see where it does. It comes off the ramp perpendicular to the earth.

Again, where I launch, it doesn't matter. But I'd like to follow the rules in any event... it's part of the challenge.
My first thought when I read your first post was “No,” because I thought that too much could go wrong and I thought NFPA 1127 probably was worded to prevent this.
I’m still concerned about the “what can go wrong?” part, but my review today found nothing in NFPA 1127 that prohibits it. Technically, the challenge will be to control the course while changing the course. In doing so all of the impulse spent accelerating the rocket purely horizontally is spent once the rocket finally is vertical.
I would support the rocket rather than suspend it. Either way centripetal force will be significant.
 

lakeroadster

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My first thought when I read your first post was “No,” because I thought that too much could go wrong and I thought NFPA 1127 probably was worded to prevent this.
I’m still concerned about the “what can go wrong?” part, but my review today found nothing in NFPA 1127 that prohibits it. Technically, the challenge will be to control the course while changing the course. In doing so all of the impulse spent accelerating the rocket purely horizontally is spent once the rocket finally is vertical.
I would support the rocket rather than suspend it. Either way centripetal force will be significant.
Thanks for your reply... much appreciated.
 
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