Deci-scale
 

I have been looking at doing a large line of 1/10 scale (deci-scale) models for some time. Your ideas, suggestions and help are requested.

The smallest would be around ASP size and the largest the Honest John (maybe). Goal is simpler to prepare instructions. Like one sheet with exploded view and simple finishing for fun scale and more detailed backup for better scale.

1. Deacon (ST-6)
2. Cajun (ST-6)
3. Asp (ST-6)
4. Apache (ST-6 and ST-9)
5. IQSY Tomahawk (ST-8) (like Centuri)
6. Sandia Tomahawk (ST-8)
7. Sandhawk (BT-55)
8. Iris (ST-11)
9, WAC Corporal (ST-11)
10. Astrobee F (BT-58)
11. Aerobee Standard (BT-58)
12. Aerobee Hi (BT-58)
13. Nike Smoke (ST-16)
14. Nike Deacon (ST-16 and ST-6)
15. Nike Cajun (ST-16 and ST-6)
16. Nike Asp (ST-16 and ST-6)
17. Nike Apache (ST-16 and ST-6)
18. Nike Tomahawk (ST-16 and ST-8)
19. Nike Iroquois (ST-16 and ST-7)
20. Honest John (BT-70H)

and others

All would be in 1/10 scale. The BT-58 adds tube for Aerobee, etc. The only new tube is the ST-6 ( .610" ID and .650" OD ) which I have been meaning to order for some time for future 15mm engine.

Suggestion, comments, ideas, etc. are welcome! Centi-scale for Saturn V, 1B, Ares, etc. are also in process.

ST-6 and BT-58...

More tubes = more designs. And scale = challenge. You know I'm in favor of it!

Have you given any thoughts about that ST-4 size we batted around for 10mm motors?

So, will the CR-56's just be cut out of standard 0.05" fiber, or will they warrant making new paper centering rings? With ~1/32" gap all the way around between the ST-5 O.D. and the ST-6 I.D., just the fiber ones ought to work fine.

Also, will the Nike-boosted sounding rockets and the 2-stage Aero/Astrobees be built stock for 2 stage capability, or include provisions/plans for modifying the stock, basic designs, or just design them for single stage? As long as you could get a booster motor and deployment motor clustered in the booster (which would be a slight problem for the BT-58 Aerobees and Astrobees, they're about 0.02" too small I.D. to fit a cluster of 2 ST-7's, though, 2 BT-20's would just barely fit (0.026" of wiggle room)), it shouldn't be hard to design them for one or the other, and get a positive booster recovery system worked out with the ejection-capable tubes.

And finally, when coming up for design ideas for these, can/should we take into account future motors? For instance, 15mm motors seem to open up new clustering opportunities for the larger models, but if the kits are scheduled well in advance of any new motor developments, we should just concentrate on what's currently available.

These look like fun.

Carl, I know it's not "deci," but you're not leaving out the FSI Black Brant - II, are you (1/8
scale)?!

Early Test Design -- Deacon
 

Carl,

Here's what I could glean from the internet sources on the basic Deacon sounding rocket. The main diameter is roughly 6.6" diameter, and the booster (including tube and nozzle) is 109.2" long. From the photos of that nozzle, it appears to be about 9" long, so if we subtract that from the total, we get 100", which means it would be the ST-6100 designation on the tube.

Looking at the fins, they're shaped much like the IRIS, just smaller. I'm guessing the dimensions as 2BT in width, 3.5BT root length, and 2.5BT tip chord, parallel to the root.

The total length of the rocket was listed as 129.12", or a nose cone of about 20" in length, giving us a 2" length for the model. I don't know if the original used a conical or an ogive profile.

Designations might be BC-620C for a conical, and BC-620 for the ogive. I'm suggesting a 0.5" shoulder length.

For the model, we would get:

Length: 12.00"
Diameter: 0.650" (ST-6)
Fin Span: 3.25"
Weight: 0.37 oz


1/2 A3-4T......359'......Dv 2 FPS......36" x 1/8" rod
A3-4T.........701'......Dv 27 FPS......36" x 1/8" rod


A 15" x 1.5" streamer is suggested for recovery.

Submitted for your approval...

I'll take one of each!

Dave,

If you wanted to consider designing for the current situation, then couldn't you fit a cluster of 13mm A's into a BT-58?

Mark \\.

Found some additional data on Deacon / Cajun
 

For those who know sounding rockets, this info may be well-known, but bear with me, I'm still learning where to look! :D

The Deacon and the Cajun were basically the same case and fins, but different propellants. Cajun had about 30-40% better performance with the same payload.

Same holds for the Nike-Deacon (DAN) and the Nike-Cajun (CAN). The only dimensional differences will be a result of different payload compartments. Parts for one were virtually interchangeable with the other.

Looks like the most-common nose cone was a conical, about 34.2" long. Translation, a 3.4" conical balsa nose cone will be very close.

Below is a corrected Deacon / Cajun single-stage rocket, using a 26.6" (2.7") payload section, 107" motor section (10.7"), and a 34.2" conical nose cone (3.4"). The fins are also corrected from the previous file, which were grossly oversized...

Length: 16.80"
Diameter: 0.65" (ST-6)
Fin Span: 2.05"
Weight: 0.47 oz


1/2 A3-4T......314'......Dv 6 FPS.......36" x 1/8" rod
A3-4T..........688'......Dv 32 FPS......36" x 1/8" rod
A3-5T..........695'......Dv 4 FPS.......36" x 1/8" rod


Note to Carl: Take a look at the last line in the simulations above. Could a 5-second delay be worked into a 1.75" 13mm casing, using the DECAP style motor?

I'll try whipping out the Nike booster next...

Enjoy!

Craig,

That looks better! Do you have Rockets of the World? I am working on the falling sphere nose cone for it.

I would not plan on the small DECAP size! The manufacturability dictates a completely dedicated machine.

That is why we are looking at the 2.25" long casing. There are more options than with the 1.75" long version.

Which one?!!

I have been surprised that the booster fins and transitions differ so much from one upper stage configuration to another.

Ajax M5... 148.8" long...

ROTW: I wish! :D

I'm just using line drawings found on the internet, specifically some NASA page scans by Jim Ball via Rocketry Online.

I can easily change the Deacon / Cajun to use those 2.25" motors.

You'll have to share the picture of that "falling sphere" NC. I'm not sure I've run across it yet...

New Plan -- Nike-Deacon / Nike-Cajun
 

So, here's my interpretation for the full-up vehicle. I'm only single-staging this one, for simplicity, and the results still look good enough for me to build and fly happily... :D

(Corrected model specs)

Length: 31.68"
Diameter: 1.80" (Transition, to ST-16)
Fin Span: 6.00"
Weight: 1.82 oz


B4-4......333'......Dv 15 FPS......36" x 1/8" rod
B6-4......339'......Dv 12 FPS......36" x 1/8" rod
C6-5......755'......Dv 13 FPS......36" x 1/8" rod


As mentioned, this represents a Nike-Ajax M5 booster, with the same Deacon or Cajun upper stage as in the single-stage design earlier. I just removed the motor mount parts and the recovery parts (and the launch lug).

If I'm wrong on some of the dimensions, I can make corrections. I think these are very close even now...

Enjoy!

New Plan -- ASP
 

Here's the 1/10th scale ASP, updated with the 2.25" motor mount for Carl's 13mm longshots...

Length: 16.70"
Diameter: 0.65" (ST-6)
Fin Span: 2.00"
Weight: 0.45 oz


1/2 A3-4T......312'......Dv 7 FPS.......36" x 1/8" rod
A3-4T..........666'......Dv 27 FPS......36" x 1/8" rod
A3-5T..........670'......Dv 7 FPS.......36" x 1/8" rod


The body tube was reduced by 0.10" to keep it correct with the scale. The ASP was 1" shorter than the Deacon and Cajun.

Enjoy!

That's true, but I can't plan on having any 2-stage capability until we actually know if Estes is re-releasing the A10-0T.

Ack, I really want to get to designing some of these in RockSim, but my program is currently bugged-out (crashes on startup following a system restore last week; I reinstalled it--somehow it still was keeping track of the days since I installed it, before the restore--but now it keeps crashing when I try to run it. I've emailed Tim, and he said he's going to have to ask his programmer about it.)

Till then, I can just work out dimensions and design ideas.

New Design -- Nike-ASP
 

Here's the Nike-ASP, with a correct booster length, and a reasonable facsimile of the transition section.

Length: 31.78"
Diameter: 1.64" (ST-16)
Fin Span: 6.00"
Weight: 1.71 oz


B4-4......346'......Dv 14 FPS......36" x 1/8" rod
B6-4......352'......Dv 11 FPS......36" x 1/8" rod
C6-5......762'......Dv 15 FPS......36" x 1/8" rod


Enjoy!

Nike-Apache Info
 

From what I'm reading over on Astronautix, the Nike-ASP was not as successful as a replacement for the Nike-Cajun. The Nike-Apache was the fourth design in that series, and shared basically the same dimensions and appearance. The differences were both internal (propellant and nozzle lining), and payload container size and shape. The length of the Apache motor might have even been shorter (102" versus 106" for the ASP, and 107" for the Deacon/Cajun).

Otherwise, Carl, you could get eight models out of one set of components, just changing decals (for all eight) and fins (for the 2 ASP versions).

I visited the Virginia Annex of the Smithsonian Air & Space Museum in June of 2007.

There was a Nike Cajun on display.

Of course, I took some pictures. ;)

Bob

Bob,

What rocket is the one that is second from the left in your first picture? It looks very much like something that could have inspired the design for the FSI Intrepid.

EDIT: Actually, the third one looks rather interesting, too.

Mark \\.

Can't wait!


Anything scale sounds great. Love the idea of a BT70 Hojo. Any of the two stage Nike rockets like the Nike Cajun(I love the cone on that one) would be cool to see gap staged....if it's even possible.




I took some similar pics at the Udvar Hazy, Bob. I knew they might come in handy some day!



Mark, that rocket next to the Nike Cajun is called the Far Side. Now THAT's one I'd like to see in kit form. I've been toying with scratching that one since the day I saw it in the museum. The color scheme and build challenge would make for a great model rocket.

That third one is cool too. It's called the F-23 and it's got some pretty neat looking ram jets attached to it.

Here are a few of the pages we are using for reference:

ROTW drawings

All of the "Nike" offerings sound great but it would be even better if you added the Nike-Ajax.

Thanks, Carl !

The Aerobee 150A is being worked up right now, so the data from those pages will come in handy.

New Plan -- Aerobee 150A with Booster
 

This was an interesting challenge. The booster adapter section took some lateral thinking, for sure. In keeping with the ROTW theme, the interface design was "borrowed" from Pete's American Spacemodeling construction article from almost 20 years ago. I built one of his upper stages from BT-60 components and it flew great. I never did build the booster, but his did use the BT-55 tube...

Length: 36.70"
Diameter: 1.54" (BT-58)
Fin Span: 6.17"
Weight: 3.41 oz

Average of 5 sim flights:

D12-0 / D12-5......1313'......Dv <10 FPS......48" x 3/16" rod

This version represents a round carrying the 87.8" ogive nose cone and a 9.4" payload section. A scale-appearance booster nozzle would be restrictive of the 24mm motor, so it had to be represented by the motor tube. The model has long mounts (to handle 3.75" motor casings) in both the booster and the sustainer. In the sustainer, the motor tube extends past the coupler to act as a reinforcement of the joint.

Craig,

I get a GP Fault reading "External Pod". Are you running 8 or 9?

V9. You must be running V8... :(

And would you launch it from underneath a balloon...? :eek: :p


Very cool, although now that I have gotten a better look at it, I can see that it doesn't look all that much like the Intrepid. It would be a pretty ambitious project to fly a scale model of that F-23 rocket using motors just in the ramjet tubes. (An interesting challenge, though...) I don't want to stray any further off this thread's topic, but I think that Semroc might even have all the parts needed for a least a stand-off scale version of it. (Hmmm... ;) ) (EDIT: Upon further review, now it looks to me like the central pod does house a motor.)

Mark \\.

Argo D-4 Javelin
 

This one wasn't on The List, but I thought it might be an interesting design to think about:

The Argo D-4 Javelin, 1/10th scale (of course!)

Similar to the SLS Brighton, I designed this to have interchangeable motor mounts based on an ST-20 parent tube. The 3 arrangements I've tried out so far are 4x 18mm, 2x 24mm, and 1x 29mm. In the case of the 2x 24mm, the gap between the tubes and the wall is so small (~0.004") that it would not be possible to have this particular mount be "Hollow Tube Coupler"-based as the others can be; it'll probably just need a bit of added reinforcement/cross beams/heavier centering rings to make sure it's durable enough. Interchangeability would most likely be accomplished with an engine hook retention system like in the Brighton (the way it is currently set up presents a bit of a problem for 29mm motor retention (anything that can't use a hook), because it currently needs the aft centering ring flush with the end of the body tube; this could be solved by just putting up with a 29mm mount that extends out the back a bit). The rocket itself is based on BT-70H for the Honest John booster, ST-16 for the 2 Nike stages, and then a bit of an interesting piece of work on the upper stage container/payload. The payload, to be true 1/10th scale, would need to be 1.9" in diameter, which is fairly far off from any current tube size (ST-18 is closest at -0.06", ST-20 would be next at +0.14"). To solve this, I had the payload based on ST-18, then the modeler could apply a few sheets of ~6"x6" paper to build up the diameter to the proper (20 lb. copy paper is ~0.0038" per sheet, which would probably end up being around 6 or 7 wraps, depending on the gluing method used). Another method might be to use self-adhesive label sheets, but that would probably be tricky to apply/expensive. Anyway... once the diameter has been built up to 1.9" to match the corresponding nose and transition pieces, the rocket can be otherwise based on off-the-shelf parts. Stability doesn't seem to be a problem, despite all the fins (the ~1/2 oz "paper weight" at the top probably helps a little bit). Fins could be accomplished in a similar manner to the Saturn 1B, with a set of 3/32" or 1/8" cheater fins that could probably take more abuse from the more powerful 24mm and 29mm motors, or a set of scale fins that could be built up. The built up fins, due to their size (4.5"x4" for the booster) might need something a bit more rigid than paper for sheeting, perhaps even a skin of 1/32" balsa or 1/64" plywood, depending on how the structure can be laid out. The thicknesses of the fins are reasonable, ranging from 3/16" at the center of the root of the booster fins, to a bit more than 1/32" (0.039") at the tips of the 2nd stage fins (3rd stage fins are actually thicker at the tip at 0.046"). The booster fins are also TTW, since the bottom 3.25" is actually a subtle paper shroud, making slotting quite simple. The shroud is supported at its forward end by a double centering ring that is glued together on its own; due to the thickness of the BT-70H, having a 'halfway' centering ring to support the shroud would leave much too large of a gap, so instead, I designed the rocket to use a standard 2.175" diameter ring flush with the end of the tube, glued to a 2.238" (just large enough to account for the slope and thickness of the shroud) diameter ring that butts against the aft end of the tube. The only other issue I can recall is the difficult looking Honest John to Nike transition, which has a few sharp steps that might present an issue to the nose cone machine. If this is the case, the cone could be modified so that a paper shroud would fit over the top (like in the Apollo capsule kit) to provide the sharp separation within the transition.

Well, that went on a bit longer than I though.

Flights:
Many of the most popular motor configurations turned out to have some nice Dv's. B6's appear to be a nice motor for demo flights (and are still able to fly from a 36" rod), though even 2 E9's doesn't go too high (it even gets up to speed within 36" as well). With the new ValueRockets site making a lot of the smaller composites affordable again, I also included D10's, D13's, and E15's in the list, all of which give great deployment velocities, though I fear some of the maximum velocities (over 350 MPH, in the case of the D10) might be a bit quick for such a skinny, balsa-finned rocket.

4x18mm

4x B6-4 ... 314' ... 97 MPH ... 8.49 ft/s Dv ... 3/16" x 36" rod
4x C6-5 ... 823' ... 171 MPH ... 12.07 ft/s Dv ... 3/16" x 36" rod
4x D10-5 ... 1732' ... 361 MPH ... 9.12 ft/s Dv ... 3/16" x 36" rod
4x D13W-7 ... 1746' ... 337 MPH ... 5.59 ft/s Dv ... 3/16" x 36" rod

2x24mm

2x E9-6 ... 1331' ... 220 MPH ... 7.62 ft/s Dv ... 3/16" x 36" rod
2x D12-5 ... 802' ... 172 MPH ... 11.86 ft/s Dv ... 3/16" x 36" rod
2x E15W-7 ... 1914' ... 317 MPH ... 4.87 ft/s Dv ... 3/16" x 36" rod

1x29mm

1x F25W-6 ... 1721' ... 296 MPH ... 10.68 ft/s Dv ... 3/16" x 36" rod
1x F40W-7 ... 1807' ... 329 MPH ... 4.24 ft/s Dv ... 3/16" x 36" rod
1x G33J-7 ... 2197' ... 341 MPH ... 4.04 ft/s Dv ... 3/16" x 36" rod

Enjoy.

Oh, and in all that, I forgot to mention:

It's really big. Close to 5 feet tall with a 10 inch fin span, though it weighs in the 9 oz range.

Recovery is by 2x 16" parachutes, the sections either tethered together or recovering on their own.

It's big? You mean, like this?

Mark \\.

They stole my idea!

Man, I picked a bad week to be on the road away from my stash of scale data and Rocksim files! I would love to see Semroc rolling out with some at least "semi scale", especially given the great variety of tube sizes available. Of the originally proposed list, I would think the Nike's would be biggest sellers, other than the clearly significant pent up demand for a Saturn V.

Re: the Javelin, I think that would be an excellent scale candidate, though probably not quite as popular/well known. In fact, when scale altitude was announced for NARAM-49, I originally opted for one of those, flown in a 3-stage configuration, and Semroc was the only place I could get all the tubing. I wound up scratching that idea, though, when I realized the prototype mock-up really couldn't achieve very good altitude carrying all that extra weight initially and the inevitable staging tip-off compared to a basic minimum diameter sounding rocket, so I never finished one.

One thing to keep in mind, though, as we salivate over all the possibilities. I know Carl's probably looking at this as a labor of love/benefit to his customer base, but there probably needs to be at least a breakeven profit plan on a new kit. Scale kits are lots of development work and tend to be less appealing to the model rocketry community, so very low volume. This is especially true as you move from semi scale that looks about right closer to true scale that holds up well when you break out the calipers.

The Black Brant series are probably among the biggest sellers, but already pretty well saturated by ARG. I'm thinking Nike's would be the next best bet--not terribly difficult to build and paint, so a good first model in the world of scale.

What would REALLY be sweet is if there were a few of these that could take advantage of Semroc motors, though I'm under the impression motors are still a few years away...

YES! Then I don't have to spend umpteen zillion buying an old FSI version of this kit on eBay. ;)

Some random thoughts...

I would love to see Semroc reissue the Javelin as a kit. I am planning on cloning the FSI Javelin (part of my ongoing FSI project) with Semroc parts, but if Carl creates a kit for it, I'll happily go with that, instead! I agree with Chan that scale modeling is a more specialized branch of the hobby, but after seeing what people did with those Saturn 1B's, I think there is definitely a market for them. Many BARs and adult rocketeers go from constructing sport model rockets to building sport high power rockets in order to keep challenging their modeling skills, only to run into the dual brick walls of expense and access to launch sites. But there's another way to really challenge yourself: building to accurate scale. Each builder can decide to what degree of accuracy he or she wants to build, but, as I am starting to find out, even getting reasonably faithful on the major features (such as in the fins, for example) can involve lots of problem-solving, even when one possesses all the scale info needed. You CAN build to scale without needing to spend a fortune to outfit your shop with all of those sophisticated and expensive tools in the Micro-Mark catalog, if you use a little ingenuity. Having good scale info is key, but so is having a supplier of accurately scaled parts, or, even better, a supplier of a scale kit.

Aside from the Argo/Javelin, I think that Chan is right that the Nike-boosted sounding rockets would probably be good choices. Also, a kit of the Aerobee-Hi with the booster stage would be really good, too, as so would be the others that Carl listed. Looking at the competition, Dr. Zooch already produces a variety of scale kits, originally concentrating on the Saturn series, and now branching out. His kits are almost all of space race-era manned launch vehicles and test vehicles from the US and the Soviet Union. I don't have any of them, but they all seem to be about the same size and scale (15" to 18" tall, flying on a single B or C motor). ASP also makes scale kits, but Andy hasn't created any new ones in several years. Aside from the WAC Corporals, most of his kits are of relatively less-well known rockets from outside of North America and Russia. There are several makers of Nike Smokes, but they are almost all high-power versions. The exception was the now-discontinued Quest Nike Smoke, but that version utilized a multitude of molded plastic parts (it was, in fact, a Quik-Kit). I haven't seen much evidence that kit makers have offered scale kits of any of the other Nike-boosted sounding rockets either now or in the past. Deci-scale kits, ranging, for the most part, from 20" to around 50" in length (similar in size to the SLS kits) and from 1" to around 2.34" in diameter would be big enough to be "detailable" (without being too much so) while being small enough to be flyable in most of the fields that most of us can access.

Just some gut reactions, not necessarily totally thought out! ;)

Mark \\.

Well, Enertek WAS planning to bring out a Nike-Cajun... :rolleyes:

http://www.ninfinger.org/rockets/ca...89enertek4.html


Bob

Gah.

Unless you are buying FSI kits for your collection, I would pass on all of them.

I bought the Nike-Smoke and Sandhawk FSI kits direct from FSI back around 1990.

The Sandhawk nose cone had a circumferential 'gouge' all the way around it.

The Nike-Smoke was worse. The nose cone was not to the correct shape while no two fins were the same size/shape.

I built the Nike-Smoke, replacing the kit motor mount tube for one that could hold 29mm diameter motors.

I flew it at NARAM-33 with an AeroTech E15-7W motor.

As for Black Brant kits, I understand the ARG kits are very nice. I have the Cosmodrome Black Brant II which is very nice and I hope to build it, someday. :rolleyes:

A line of Semroc scale kits?! Carl, my wallet can't take it! :eek:

Bob

The transition on my Eos wasn't worth having. The shoulders were too short, and the ends weren't co-axial; it made the rocket crooked. I turned a replacement out of cedar.

And the BT-55 tubing on my Echo 1 was really a sloppy fit...oh, that's because it was BT-56 :o :)

Did someone tell me the balsa pieces being sold at Firefox are leftovers from FSI?

Doug

.

That's why I'm happy to save my money, and instead clone the designs using parts from Semroc!

Mark \\.

Something Old and Something New...
 

Here is a comparison between two variants of the same basic design. What intrigues me the most is realizing how much better the older version was, when you use the same power in each stage. The three-fin version whips the younger four-fin version each time, so in the real world, the newer "Model A" had to be using a much-improved powerplant, or much lighter components, in order to have justified the penalties it suffered.

The models are matched to their respective lengths as shown on the various data sheets.

Specifications:

Aerobee 150 Standard:

Length: 35.66"
Diameter: 1.54" (BT-58)
Fin Span: 6.24"
Weight: 3.3 oz


Aerobee 150 A:

Length: 36.70"
Diameter: 1.54" (BT-58)
Fin Span: 6.17"
Weight: 3.42 oz


Flight Performance:


Std......D12-0 / C11-5......1226'......Dv 21 FPS
A........D12-0 / C11-5...... 988'......Dv 10 FPS
Std......D12-0 / C6-5.......1319'......Dv 4 FPS
A........D12-0 / C6-5.......1062'......Dv 28 FPS
Std......D12-0 / D12-5......1608'......Dv 24 FPS
A........D12-0 / D12-5......1307'......Dv 9 FPS
Std......D12-0 / E9-6.......2140'......Dv 3 FPS
A........D12-0 / E9-4.......1738'......Dv 32 FPS
A........D12-0 / E9-6.......1751'......Dv 32 FPS


The A150A has been revised just a little, to maintain a component match with the A150 as closely as possible.

I'll try to get the A300 "Sparrowbee" next...

Enjoy!