Brian,

If you are interested in seeing some of these designs become realities, I suspect you will need to also republish some of these pictures without perspective - that is, a simple flat plane like you did for me and the Intimidator design. Gordy will need these in order to derive true length, nose, and fin shapes.

I thought this would come up, and I will do that.

Hey, Brain...

I don't know what your final design specs are supposed to be for this one, but here's a QnD RockSim of the Bulldog. I used ST-20 for the main body size, but I don't make any promises the NC or TC are exactly spot-on. The fins are eyeball-calibrated, but I'm near-sighted... :D

Length: 20.25"
Diameter: 2.04" (ST-20)
Fin Span: 7.74"
Weight: 4.57 oz


D12-3......366'......Dv 7 FPS....48" x 3/16" rod required
E28-4......632'......Dv 18 FPS
F39-3......727'......Dv 17 FPS


All-in-all, not bad performance for a RT design. YMMV, of course...

Hope this helps!

Indeed it does... but let me throw a twist at you: in the original design each of the main fins coming off the fuselage is double (two of them side-by-side - with enough space in between for each of the three conduits that run up the side of the fuselage) until they meet the ring, then there's one fin on the outside. Let's see what RockSim does with that!

I need to get RockSim someday... over the rainbow... :p

Nonetheless, what you have shown and told me is gratifying and way cool. I saw this one as being a big 'D-and-up' bird myself, so I must have got my point across with just that pic! Sweet!

Here are few of those orthographic renderings I do have... thank you all very much! :)

And...

...and...!!

So that's what that was! I noticed something odd about the fins in the image you posted, but interpreted it differently.

I'll run this through RS and post something shortly!

Bulldog 24-D Mk II
 

OK, Brain, here is a revised version with your doubled fins...

Length: 20.50"
Diameter: 2.04" (ST-20)
Fin Span: 7.00"
Weight: 4.54 oz


D12-3......382'......Dv 5 FPS......Requires a 48" x 3/16" rod
E28-4......655'......Dv 14 FPS
F39-3......751'......Dv 21 FPS


I slimmed the main fins down to 1/16" balsa, since they're doubled. The outer tip fins are 3/32" balsa.

The conduit is a 1/8" sq strip of balsa for the RS plan. You could probably substitute 1/8" spruce dowel stock without hurting the performance.

Then this puts it on the fast track. This is really neat to see, thank you! I'm glad someone is taking the time to hook some of these up in RockSim... it's a great tool (when I played with the demo version I spent more time figuring out the design tools and not-so-much on the launching tools). Another set of othographic views is below.

Another orthographic fix...

SKY AYE Skyletto
 

Brain, this was interesting!

Length: 35.10"
Fin Span: 5.34"
Diameter: 1.34" (ST-13)
Weight: 3.26 oz


D12-0 / D12-7......1919'......Dv 14-17 FPS......Avg of 10 runs


All flights require a 48" x 3/16" rod.

Nice design. Should make a great kit!

Excellent! This makes for seven designs that have demonstrated worth, either in the field or on the screen:
*Dead Ringer
*Stanger
*D-Marie
*Bulldog 24-D
*Skyletto
*Nomad
*Big Brew (a re-bash of an Estes Menace [that I had originally bashed into the gloriously failed El Dorado], which I have not posted here before, but what a beautiful flyer!)

Question: Does RockSim generate a list of body tube sizes, NC sizes and such for designs?

The Nomad is left, the Big Brew to the right (that's the Gryphon SDV in the center... which flew OK its only time - might need weight in the nose or something, I dunno).

It uses a database of components that can be added to as needed. Somewhere here on YORF is a set of component files for SEMROC parts. It's been a while since they were updated, though.

Each design file [RKT file] contains a parts list for that design. It works OK for simple designs, but when we start putting together these complex birds, that parts list often gets really crazy to interpret. An example is where you might have a paper transition with a tube on the inside, but that tube also becomes an outside tube on the small-diameter end. It's often easier to break that long tube up in RS and treat each section separately; yet the tube in real-life is still a single tube. The parts list will show it as separate pieces.

When I'm working on a design where I have to break up a piece to work with it, I'll often make a notation in the "part name" field to show what I've done.

And knowing the length of said transition & front section can just be added together with the small tube length you have, and voila!
Computers are stupid... ;)
But if anyone wanted to take a crack at this Gryphon bird in RS, here's the ortho (I'd like to know what the problem was - it went fairly high, but arced over way more than the other ones we flew that day, same engines - all Estes; and the nose on the actual bird is not rounded as in this pic, but a simple cone; I can provide measurements, if necessary - I can tell you the upper body tube is BT-20, the transition is 20 to 55 [I think] & the lower tube is off-spec [close to 55] - "Best guess, Mr. Sulu."):

I'm fudging on this first draft, Brain. I like the feel of Centuri (SEMROC) tubes, so the body tubes in question spec out as ST-7 and ST-13. You didn't say if the pods were hollow or top-plugged (I'm presuming hollow, like tube fins). I'm also taking a rough stab at the shapes of the two fins I'm looking edge-on at. If your flight vehicle is close to this, then the dynamics should be close.

You also didn't mention which engines you were using. I'm selecting a D12-5, and so far, the numbers are good.

Length: 32.215"
Diameter: 1.34" (ST-13) and (ST-7)
Fin Span: 7.59"
Weight: 2.4 oz


D12-5......870'......Dv 10 FPS......use a 48" x 3/16" rod......Avg of 10 runs


Let me know how close I got on those fins...

As far as I'm concerned, everything is perfect!
I always sway to the notion that things like engines are going to be determined somewhere later in the design process, based on - like you said - preferentials and/or whatever materials you have available to you to use. The design itself screams for a 'D' or better, so we're right there. 32''... yes!!

The fin shapes are always mutable at this point, but you got them right on. I launched the real Gryphon (which may differ slightly from the version I've created [and you've created] for all this) on a C6-3, but I never considered using a 'D' in it, even though the off-spec main tube would have allowed it (I just don't want to spend more money on engines than I need, so I stick with the 'C's... for now! I keep looking at that Estes Ventris... yummy!) The side tubes are made from Nerf darts (closed end up), so whatever gets close will work. Probably don't even need to stick with those squared-off tips...

Once again, my gratitude. This is all very enlightening and what I would have had to do myself anyway, were I to get serious about this... :D

If that "off-spec" body tube is just slightly larger than the Estes BT-55, it's probably the Centuri ST-13. Estes calls it their BT-56, and they use it a lot in their ARF/RTF designs. I'm partial to the Centuri (SEMROC) version, as their's has a slightly thicker tube wall.

Something I've learned with RS is that fin shape can be more important than fin area or size. Some shapes generate more corrective action than others. There is a lot of "play by ear" with this, and what works on one design doesn't always work on another.

I actually thought you might have used a "C" in this model, from the way you described the flight. A quick run of the simulation with a 24mm C11 didn't give me satisfactory results. The ideal time delay would be 4 seconds, but there ain't no such animal...

What RS lacks in graphic ability, it more than makes up for with the simulations.

New Design for Sky Aye -- Auriga
 

Brain, this one was a challenge, but I think the results will be satisfying.

Length: 36.70"
Diameter: 2.64" (Transition Diameter; ST-13 main BT)
Fin Span: 8.14"
Weight: 4.69 oz


D12-5......706'......Dv 4-7 FPS......48" x 3/16" rod required


There may be a need for some additional internal stiffening underneath those cardstock transitions. You could probably use some 0.02" matteboard rings to do that, with plenty of material removed from the rings to reduce mass.

The Dv numbers are what got my attention once the design was tested. I never thought the numbers would be so low (good thing!).

I can tell you that the off-spec tube is just that - my wife handed it to me from a depleted roll of something (plastic wrap?) - and it's got to be only by coincidence that the sizes are close.

in your estimation, the top problem with the Gryphon is using the right engine (size)? I had it in my head that nose weight might have been a possible problem. I recall that one of the fine folks on this forum sent me that main transition as a favor (but I don't remember why...), and that I did have to do a little work on the inside of the tube to make it fit.

I did try to recreate one of my designs (Stanger) in OpenRocket, and I think I was successful in coming up with a working bird (a flight sim gave me all green) that uses a C6-7. Only as an exercise, though... I have already launched that one on a C6-3 and it was great! So, OpenRocket seems to be a good rough draft prog, if nothing else. I don't know what issues are involved with the delay-time differences.

Somehow, I inadvertantly missed this post before... thank you for looking into this Auriga design. Interesting, eh?

Uproar
 

A new design, the Uproar: I ran across this image of a rocket launcher toy that was a little outrageous & reminded me a bit of the Thunderbird kit that Fliskits offers.

This one - the Astrogator - already has a Semroc parts list ready for payday numero uno this Friday, so this virtual project list will get more real here soon!

For you OpenRocket users: I have put together several of my kit designs in ORK & have run them through simulations, and except for one flight sim (which I eventually did get a good sim from by merely changing where I had positioned the parachute) I keep getting good flights.
Now, I'm not going to poo-poo results like that but I have that nasty feeling of Something-Must-Be-Wrong-On-My-End. Granted, I have had a good percentage of good flights with my custom builds... but life is never that easy. Could ORK be too simple to get results like RockSim from? Can I trust the results from ORK for any sort of legitimate evaluation?

I'm loving the first one in the first post, the Classic. Does anyone have a technique for getting those curved ilnes that doesn't involve fiberglas?

Sol,

I'd do it using what, in 2-d space, is called piece-wise linear fashion. From the tail to the white ring, I'd use a cone, sort of like I did with this rocket. For the bulged payload section (above the white ring), I'd use a couple of rings on the outside of a tube (whose diameter is the same as the white ring). These rings would be placed 1/3 and 2/3 along the length. They would be such that they add only a slight increase in outside diameter. It might be best to simply make them using a few wraps of kraft paper glued around the tube.

Then I would form two cones - fore and aft - and a cylinder - middle - from kraft paper, glue these on to the payload section, and let them dry. Then I'd lightly sand it, then start apply FnF with a wetted finger to try to build the piece-wise linear section into a smoothed, continuous curve.

That's what I'd try.

Of course, sometimes, after I get a couple days into a project like that, I realize it's not gonna work and have to go back to the drawing board :o

HTH.

Doug

.

Thanks again for the interest!
Sometimes you just have to mimic the look-and-feel of what you're trying to achieve, and for this design I veered towards some sort of 'authenticity' and left it for the craftsmen (and women???) amongst us to give it a go.

But I expected to have to eyeball the right cutout sizes and positions on the balsa (or whatever, you sadists!) and use small NCs for the spaces. Then some Squadron Green Putty (or what-have-you) and some elbow grease and voila! you 1950's auto genius, you! I suspected perhaps some fluency in painting would be of help for the finish, but if this was a kit it'd have decals - although I'm certain thin balsa strips could be implemented to create that chrome trim along the body tube (and they'd look more authentic)... you'd have to paint that light-colored area between the trim strips, and it might be a little tricky to paint it and keep it off the trim. Or not. I wouldn't think it'd be beyond most of us here, though.

Semroc has a couple of ramjet NCs that would be suitable candidates for this build (if fact, seeing those cones prompted this design). I would think you could find something for a tailcone, too. I'd love to see updates!

Are you talking about the coke looking rocket?
Certainly those '50s style fairing on the fins can be made from nose cones.

Perhaps not the easiest thing in the world to do but hard foam is often able to be carved and sanded. As the author says, "sometimes just go for the spirt" of the model.

I've picked out my favorites that I'd like to try and build Brain. Do you have some shots of the designs with a ruler or some type of reference that I could see to get some idea of what size to build them? Or are you just leaving that up to each person to make it "their own" so to speak?

I know when I look at that Astrogator I think ping pong balls split in half and then "lengthened" to make the round bits...

I don't have any specific dimensions in mind. I do want to leave it up to the builder to decide how they want to realize it. Generally-speaking, though... some of these designs (being mostly LPR) will be slave to available parts sizes and hence it ought to be not too hard to do a little math with the orthographic views I provided earlier in this thread to figure out how long, say, the BT-50 tube ought to be on the Empress, for example.

As for the ping-pong balls: I anticipated painting the white stripes on the blue, but there may be other methods.

So, what you actually end up with could be a little different than what's pictured, and I expect that I will have to make the same considerations... but if they fly, they fly!

Two more designs: The SaturnX and the Circular Logic.

Those are both extremely cool...

Love it! OL JR :)

For the SaturnX, I'm thinking ST-16, ST-13, and ST-10 for a small one, and maybe ST-20, ST-16, and ST-13 for a larger one. The large one needs a 4-engine cluster of 18mm "C" engines to be impressive. Maybe even 4 24mm engines to get off the pad!

New Design for Sky Aye -- SaturnX
 

OK, Brain, here's my interpretation of the small SaturnX, using ST-10/13/16 tubing. The engine required is a D12-5, which is the only engine I recommend. I tried the C11-5, and the Dv was too high for comfort.

Length: 32.95"
Diameter: 1.64" (ST-10, ST-13, ST-16)
Fin Span: 6.39"
Weight: 3.98 oz


D12-5.......884'......Dv 18 FPS......48" x 3/16" rod needed......Avg of 10 simulations


24" parachute brings it down slow (~10 FPS).

Enjoy!

I am enjoying... this is all very cool and I am indebted to anyone here who's jumping on this bandwagon at least a little... thank you very much! :cool:

BTW: The SaturnX is my vision of a Saturn V without all the ugly angled transitions in between the stages... curves, man, curves!

SKY AYE Business Proposal
 

The following is a business proposal draft that I felt was necessary when I started thinking about all this model rocket business stuff. I wanted you folks to read it and give me some feedback, please. None of this was lifted from any other sources (excluding, of course, researched info), straight from the Brain.

****

SKY AYE Rocketry
A Business Proposal

The invention of the modern rocket is still less than a century old. Robert Goddard’s original ‘Nell’ design paved the way for the successful utilization of modern rocket technology - whether for peace or strife. But even before the invention of the rocket, writers, artists and engineers conceptualized upon and dreamed about the excitement of space travel.

The advent of rocket technology spurred a huge cultural interest in space travel and science-fiction (as a vehicle for the imagination), culminating in an actual Space Race by the end of the 1950’s. The world was mesmerized in 1959 when the Soviet Union reported the successful launch and orbit of the Sputnik satellite. Visionary Arthur C. Clarke’s 1945 prediction had become reality.

But the United States responded, flexing its rocketry muscle and winning the race to the Moon with the Apollo 11 manned moon landing. Again, the world was mesmerized…

Even though rocketry is associated more with government entities and sci-fi storylines, for more than 60 years the ability for the average person to build and fly actual model rockets has been in existence. The history of the development of model rockets and model rocket motors is a winding one, and dates back to the late 40’s and early 50’s. Harry Stine (the father of modern amateur rocketry) legitimized the kinds of safe materials and construction techniques still used today, and Vern Estes designed and built the first automated model rocket motor fabrication machine.

And that history is one of impressive safety considerations. To date, there have been 250 million model rocket launches around the world, and there has never been a single death due to commercial model rocket motors or their use. Over the years, fathers and sons and friends have painstakingly breathed life into their boxes or bags of balsa and cardboard (and nowadays, plastic) and produced not only a scale model of a real military missile, but one that can function like the real thing! For decades, schoolchildren have been introduced to model rocketry, and - by default - scientific principles. There are resources available to help teach with rocketry, and many vendors offer bulk pricing for school groups. And let’s not forget the important lesson that can be learned by creating something worthwhile with your own hands!

People who flew model rockets in their youth have discovered a fervent and enthusiastic community online (known as BARs, short for ‘Born Again Rocketeers’), re-igniting their own past interest. There are a number of companies producing either low-power, mid-power, or high-power kits, motors and/or other accessories for rocketry. Electronics have been used to measure altitudes, flight characteristics and other kinds of information about aerodynamic performance; inexpensive digital cameras have been used during flights for some spectacular video footage; and some of what the big-money boys have achieved in this ‘hobby’ is nothing short of stunning. One ‘amateur’ broke a record and put one of his creations up to 96,000 ft., while another constructed, launched and successfully recovered a 1/20 scale Saturn V monster! And hopefully some youngster somewhere is putting a lizard in the payload tube of his new model rocket for its first taste of altitude adjustment…

Many have bemoaned the state of space exploration, with budget cuts and politics constantly short-shrifting planned space activities. But while NASA and similar entities have had to take it on the chin, the advent of privatized and commercial space activities is upon us, and soon we will be seeing an unprecedented level of activity from these entities as they offer services including - but not limited to - delivery of satellites, ferry services to orbital installations, and space tourism. A number of the vehicles built by these private concerns have already been made into model rocket kits. There will be more inspiration for kit design as these private aerospace companies go after the final frontier. Other nations are starting their own space programs, and inspiration for model rocket design will undoubtedly be drawn from these areas as well.

Ultimately, all this means is that there is a future in helping people keep up with the coming New Space Age by letting them get involved in some exciting way – and model rocketry is one way to do just that, and has been for years.

But scale models of existing technology are only part of the fun. Designers have created many futuristic and singular kits over the years. Many excellent fictional designs from days of yore (like the Estes Interceptor) have become bonafide classics in the world of model rocketry, and there are vendors who cater to those wanting to ‘clone’ one of these OOP (‘Out-Of-Production’) kits by supplying cloned parts, instructions and decals for the task. And then there are the amateur designers who have the ability to realize their own flights of imagination in glassine-coated body tubes, plastic or balsa nose cones, and balsawood or basswood fins.

This is where SKY AYE Rocketry comes in. We have a fervent interest in model rocketry, especially in providing rockets that offer unique designs and performance parameters. Vendors are available to provide even custom parts for any project, and the internet is flush with information, sources of materials and designs to utilize or adapt. Along with the design and implementation of rocket kits, we want to provide other sources of rocketry interest and fun (such as our Rocket Surgeons comic strip concept), as well as creating a corporate look and design sense that we want to instill in everything we do, whether it be kit materials, clothing, and other related items. We have access to internet design software, 3D design and imaging abilities, rocket design-and-performance software, and the capability of social networking to get the word out.

We will secure the SKYAYEROCKETRY.COM domain and immediately set up an interim Flash-designed web destination for visitors to learn more about SKY AYE Rocketry, with the idea to eventually present our SKY AYE catalog and merchandise. Our corporate blurb: FOLLOW YOUR IMPULSE!*

We are in the process of determining which of our current designs meet the qualifications for kit roll-out. One design we are pursuing involves a performance parameter never seen in model rocketry before. Vital information about each of our kits must be ascertained and finalized (length, weight, altitude, engine types, etc.), and we will need to acquire simple equipment to make these determinations. We will send out test versions of kits to selected online hobbyists and vendors for reviews and opinions. And there is always the possibility of other vendors carrying our products, if we don’t outright market and ship them ourselves.

We envision a schedule of kit releases (called ‘Squadrons’), consisting of four models each. We will have to create packaging materials, instruction sheets, decals and shipping processes for our kits. Press releases will be issued, advertising can be secured on various online rocketry sites, and a grass-roots e-mail campaign to every possible enthusiast that has an online presence will be mounted to raise awareness of our products, a campaign that worked well for a previous online project.

It would seem that the future for model rocketry could be rosy, and if so SKY AYE Rocketry hopes to position itself favorably in the hobby. Thank you for taking the time to read this proposal, and we hope you will follow your impulse!


*Impulse being a term referring to the propellant energy of a model rocket engine.

Just wanted to say this is a great thread.

Randy
www.vernarockets.com

And I wanted to say (again) thank you!
Check out this ugly brute...

New Design for Sky Aye -- Declinator
 

Early look:

Length: 41.10"
Diameter: 2.54" (largest diameter transition)
Fin Span: 7.52"
Weight: 6.71 oz

24" parachute...

Uses only AP engines:


D15-4.......563'......Dv 10 FPS......48" x 3/16" rod
D24-4.......529'......Dv 13 FPS......48" x 3/16" rod
F21-6......1525'......Dv 12 FPS......36" x 3/16" rod



Enjoy!

Too much, actually!
I was playing with the idea of a rocket that had more transition length than regular body tube length. I wasn't necessarily going to post it, as I was fighting with a color scheme - but there ya have it!