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TRF Summer Build Off: Space Needle

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d11rok

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Greetings all!
I'm on vacation in Seattle, and today went to the space needle. What a fantastic view, from bottom and top. What an awesome story and history behind it!

Anyways, likely similar to many of you, as I gazed upon the epic structure I thought , "this would be really neat to launch!". What's more, how awesome would it be if the top part (the URL looking bit) became a second stage and flew like a saucer?

But I have so many builds on the pile to start as soon as i move in, I say. Well, the build off always looked neat, but my creativity juices simply were not flowing until today. What a great reason to both join the build off and build a hopefully unique and functional scratch build !

Whilst I don't have a sim file, one can view pictures online of Seattle's space needle to see what my build will look like somewhat.

Besides the top piece becoming a 2nd stage, any other thoughts or ideas would be greatly appreciated! I don't know what motor size I'll be using, but I do have bt5 and methinks bt55. Will start sizing up the plans on the flight back home
 

Worsaer

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I think it would be a terrific rocket/oddroc combo. I messed around with one a while back, but never did more than a rocksim file.

 

d11rok

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Bill,
That looks awesome! Hope to glean more ideas from you as the build comes along!

Dan
 

KenECoyote

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Greetings!

I've been working here and there on something along those lines, but as a single stage (almost like an extended Squirrel Works "Pie In The Sky"); however the CP/CG issue may be a tricky one to overcome. I was brainstorming making one with a heavy/weighted ring forward which would help to shift the CG forward enough. Staged saucer should be awesome!
This one will be an interesting one! :pop:
 

neil_w

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For a moment I got my hopes up that you were going to build this. :)

Anyway, if you can get the saucer up top to fly as a second stage then it would be fantastic. The best part of the utterly amazing upscale Outlander launch (other than its hugeness) is seeing the pod up top go up after leaving behind the whole mass of stuff behind it. Given the general profile of the needle, I'd say you've got your work cut out for you making that thing stable (CP will be very far forward unless you add some fins back there.

Should be great if you can pull it off!
 

d11rok

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Ken, thanks for the tip. Indeed, a forward heavy ring, or making the pod itself heavy, will be in order. Thanks for following along and if you have any tips from your work in process, I'd be happy to hear them!

Screamin, thanks for following along as well!

Neil, you know, as soon as I put the initial message up I was thinking you'd find it haha ��. Although I was tempted to try, it would have been likely harder to pull off methinks. Thanks for the link, I'm in an airplane now so speeds aren't the best but will check it out shortly!
 

rstaff3

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I like it! No silly clear fins required (?) I converted a daiquiri glass shaped like the Stratosphere Hotel/Casino. But it needed fins. Hope you build this!
 

KenECoyote

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Ken, thanks for the tip. Indeed, a forward heavy ring, or making the pod itself heavy, will be in order. Thanks for following along and if you have any tips from your work in process, I'd be happy to hear them!
Well, this area is a very tricky one and I haven't quite figured out the right way to get something like this stable yet. From what I figure/guess: Pie In the Sky type (PITS) rockets can work due to the very large frontal surface area and I believe base drag (front flat face combined with vacuum in the back helps to stabilize). Spool rockets work since they also add the rear disc which further helps to stabilize in the same way...when the bottom gets off-vertical, more of the rear disc is in the airstream causing drag and pushing that side back in-line. The problem is when you do something like the PITS and then extend the rear...the CG ends up too far back and you have issues with stability.

Just brainstorming, but perhaps the "easiest" way would be making the saucer a weighted ring and possibly adding large clear fins on the bottom. I haven't done such, so I really can't say whether it would work.

If you don't care about altitude, you can add a large disc base...almost like landscaped base and that combined with a ring or disc up forward should get the first part up safely and behave like a spool; however a flat base would be very, very draggy, so you won't go high (then again, neither do saucers). Come to think of it, this version can be similar in some ways to the staged spool rocket Squirrel is working on, but with a cool new twist. I don't know if anyone's tried a stretched spool, so maybe some small scale tests would be in order. A larger base disc may be all that is needed.
 

rstaff3

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My 2c is that rockets that rely on base drag alone don't do well when stretched. Which is why base drag corrections are only applied to 3/4FNC rockets when they have a L/D < 10. The CP of an Art Applewhite delta saucer was measured to effectively be behind the base of the rocket. Stretch that up a couple of feet and you have a cone whose CP will be closer to 1/3 of the way up from the base.

On the Space Needle, I tend to doubt it will be stable without added fins (or maybe a plate as Ken mentioned). But that's just a 1st order mindsim. I also don't think the top will be stable. There is not much overhang on the top section, and what looks to be a tail cone would be destabilizing. Maybe 2 clear plates, one for each stage, would work???? I can tell you one sure way to find out.
 

Daddyisabar

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CANTED TRACTOR MOTORS UP FRONT!


Well Daddy, there you go again, being a terrible influence on decent minded rocketeers by urging them to delete fins in back and move the motors up front!
 
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Daddyisabar

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CHAD stage the saucer, easy peasy lemon squeezy. Use one motor in the rear cluster with a long delay to deploy booster frame recovery system - POOR BOY DUAL DEPLOY.

RSO at fist sight of CHAD staged, cluster tractor motored abomination Space Needle:

Hush Hush.jpg

But it was the most stable rocket at the launch:( . . . Son, I don't care, it just looks too funny!
 

Daddyisabar

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You even have a center line tube for a fourth booster motor located traditionally in back for the booster frame recovery deployment! Lovely base drag with the lower building structures. This space age building was meant to fly!

space-needle.jpg

But if all the motors don't light, then remember Mars Attacks!

Landmark_hotel_1986.jpg
 

Daddyisabar

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I bet if you hide the motors just right the top man RSO will never know. Boy, that is one purdy rocket, very stable, go ahead and put her on the pad!

Lisa Marie.jpg
 

Daddyisabar

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Rear eject from the base portion and center tube. Very doable. Could eject using the motor section as the nose cone but I would worry about drag separation. Wish I could build two for the contest:( A Good 24mm Tres mount, some BT70 and other tubing, some plastic plates for the saucer and you are off to scratchville:):)
 
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neil_w

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When I posted to this thread this morning, I was actually gonna mention putting tractor motors up there in the saucer... but then I thought for sure Daddyisabar would be along any minute to handle that end of the conversation. As the day moved along I started to get nervous... was Daddyisabar OK? Was he boycotting this thread? Had he given up tractor motors and switched to doing nothing but Alpha upscales?

Well it took 8 hours but I guess I needn't have worried. :grin:
 

rstaff3

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Hive-mind-sim, activated :) If you don't want a lot of thrust at it's nether region, one could stuff a properly delayed motor up into the tube, add a quasi-legal metal liner (actually a retainer) to protect the tube and let Mr. Krushnik control that unwanted thrust.

Now, I'm just not helping...
 

dhbarr

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Hive-mind-sim, activated :) If you don't want a lot of thrust at it's nether region, one could stuff a properly delayed motor up into the tube, add a quasi-legal metal liner (actually a retainer) to protect the tube and let Mr. Krushnik control that unwanted thrust.

Now, I'm just not helping...
BMS sells foil lined tubes, jussayin.
 

dhbarr

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The foil lined tubes help on the ejection end, but on the business end?
They should be pretty good at reflecting IR, and the exhaust cone shouldn't actually be touching the walls else Krushnic, hence the calibers-up-the-pipe rule of thumb.

I might be underthinking it though
 

dhbarr

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They should be pretty good at reflecting IR, and the exhaust cone shouldn't actually be touching the walls else Krushnic, hence the calibers-up-the-pipe rule of thumb.

I might be underthinking it though
I missed the part where we -wanted- the thrust reduction, my bad :)
 

rstaff3

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Don't worries, my mindsims can be pretty warped.
 

jflis

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When I get a chance I will post the drawings I've done for the Space Needle.

For stability I chose to fly mine upside down... :). Stability is less of an issue this way...

Also, I used our BT-2 tubing for the supports. Very kewl and flew well.

Point of information: the SHAPE of the Space Needle building is Trademarked, and the holder is very aggressive in protecting the trademark. I was going to put my design into production and was shut down quickly. Neither were they interested in licensing it...

Fwiw
Jim
 

dhbarr

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When I get a chance I will post the drawings I've done for the Space Needle.

For stability I chose to fly mine upside down... :). Stability is less of an issue this way...

Also, I used our BT-2 tubing for the supports. Very kewl and flew well.

Point of information: the SHAPE of the Space Needle building is Trademarked, and the holder is very aggressive in protecting the trademark. I was going to put my design into production and was shut down quickly. Neither were they interested in licensing it...

Fwiw
Jim
Seems like time for one called the Nayce Speedle, which goes upside down and does ridiculous things. Parody / satire is a wonder.
 

Cabernut

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I was thinking about doing the CN Tower here in Toronto. Very similar to the Space Needle. Might be more stable too.
 
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