1/12 Scale Little Joe I (was: Anyone care to ID this component?)

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James Duffy

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Funny how once you've seen that fin black on one side, you can't unsee it!
Tell me about it. I'm off to the hobby shop this afternoon for more black lacquer.

Here's what Peter is referring to: after building Little Joe models for the past decade and a half, Peter gently pointed out that one side of the orange fin is actually black. After staring at still and motion photography of this thing for sixteen years I had never noticed this major detail, simply assuming that this side of the fin was in deep shadow. Fortunately the modular construction of the model will allow the fin to be removed and repainted easily.

Never underestimate the power of a second set of eyes deployed in any situation.

James

Little Joe 1A Black Fin.jpg
 

hcmbanjo

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James, I'm following this build closely! Impressive work.

What? one side of the orange fin is black? All this time I thought it was one orange fin, orange on both sides.
I'm building the Enerjet News Little Joe right now.
https://oldrocketplans.com/pubs/Enerjet/1-73/enerjet173.htm

I know their scale data isn't really correct, I'm just building it like plan using the Estes re-issue capsule and tower.
With the black capsule it's closer to the LJ5, LJ5A and LJ5B versions without the orange on the body.
The orange fin is glued on, mine will stay orange on both sides.
It'll end up a sorta look alike semi scale flier.
 

James Duffy

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The erroneous orange fin face has been repainted, and mercifully there were no masking failures, overspray errors, or any of the other unscheduled drama that inevitably seems to accompany any last-minute repaint. The range safety antennas, nozzles, and tower probe were absent from this photo, but you should be able to get the idea. I confess that I actually prefer this scheme, as the black breaks up the monotony of the silver and orange.

IMG_1909.jpgIMG_1910.jpg
 

PeterAlway

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James, I'm following this build closely! Impressive work.

What? one side of the orange fin is black? All this time I thought it was one orange fin, orange on both sides.
...
The orange fin is glued on, mine will stay orange on both sides.
It'll end up a sorta look alike semi scale flier.
I confess fallibility here.

The awful truth is that I believed the fin was orange on both sides, based on limited photos, when I did "Rockets of the World." So I'm probably responsible for the misconception. It wasn't until James got me looking over his "Rocket Aero" videos closely, trying to figure out which way the total pressure probe on the front of the escape rocket was oriented with respect to the "orange" fin, that I noticed that the fin was black in some views.

By the way, there may be rounds where none of the fins have a contrasting color at all. I've got to pore over videos of all the rounds to sort that out.

Peter Alway
 

James Duffy

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Years ago a modeler from the UK named Peter McQuillan gathered a very impressive collection of reference material on the Little Joe series, often working in close collaboration with the dearly missed Bill Spadafora. It was (UK) Peter's work that spurred my early interest in the Little Joe over 16 years ago, resulting in a series of models ranging from 1/35 scale to 1/12 scale, with a couple of stops at 1/24 and 1/17.5 along the way. One of the things that he put together was a handy-dandy markings and differences guide for the whole series, which I have attached here. This chart may be helpful as a starting point as you sort out the various markings on the LJ series. Beware, though, as we know that there is at least one error on the chart (the black fin!). Also, I've never been able to find photo evidence of the presence of the red heat shield on the -1A round.

After starting a beautiful 1/15 scale model of Little Joe 5, he fell victim to a woman's charms, matrimony ensued, and he fell out of the hobby.

chart.jpg
 
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ThomasL

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Amazing detail (and patience)! Can't wait to find out about the maiden flight...
 

Incongruent

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The current push is to finish up the escape towers in the next couple of weeks. Assembly of the tower lattices and antenna sections was documented in a few previous posts, and now we will paint those bits and assemble them into a complete escape tower. Paint work on the tower lattice is the first step. Take a look at this photo of the Little Joe 1A round, noting the contrasting bands of color on the tower uprights and cross members (you may need to download and zoom in to see the markings):

View attachment 289621

We need to make an intelligent guess as to what these marks might be. Duct/duck/gaffer tape was already in wide use at this point (late '50s-early '60s), having been introduced a couple of decades earlier. It strikes me as highly likely that these marks are bits of duct tape attached to various points on the tower, so we're going to reproduce them with grey paint. The first step is to paint the entire lattice a medium-darkish grey. Next, the duct tape locations are masked with narrow bits of Tamiya masking tape.

View attachment 289622

With the masking tape in place the tower is airbrushed with black paint.

View attachment 289623

Next, the tape is removed to reveal the grey paint under the black, simulating the bits of duct tape.

View attachment 289624
View attachment 289625

Finally, the orange antenna section, the black "coolie hat" blast deflector, the tower base, and the lattice are glued together. A section of BT-5 tuning aligns with holes located in the former rings for the recovery section, coolie hat, and tower base. Two plywood centering rings will allow the completed tower to fit into the core of the boilerplate Mercury capsule.

View attachment 289626View attachment 289627

More later,
James
Based on this photo, there were a lot more marks and they seem to be only on the outside of the tower structure though it's not present on every picture of the tower structure, even those with the rocket on the pad, but the angles are different and so perhaps the markings are only on one side. It seems to be a regular pattern with two different colors (lower is darker), so it might not be duct tape.
https://upload.wikimedia.org/wikipedia/commons/c/c9/Little_Joe_Launch_Vehicle_-_GPN-2000-001270.jpg
While it may be because the grainyness present after zooming in, some of the marks seem crooked, so tape or something similar would be my best guess.
 

TheAviator

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I was just looking through James's old thread for inspiration and realized he never shared a video of the launch! For shame, James! Anyways, here you go! Prep work starts at 18:30.

https://youtu.be/QoM3hlvNTEI?t=18m30s

Quick question for James: would you mind posting final specifications? Weight, height, diameter, etc. Thanks!
 

James Duffy

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I was just looking through James's old thread for inspiration and realized he never shared a video of the launch! For shame, James! Anyways, here you go! Prep work starts at 18:30.

https://youtu.be/QoM3hlvNTEI?t=18m30s

Quick question for James: would you mind posting final specifications? Weight, height, diameter, etc. Thanks!
Thanks for the kind words, Brian! Here are some final specs for the model that flew in the Ukraine last summer:

Overall length: 1231mm/48.47"
Booster Diameter: 169.3mm/6.67"
Fin Span:541.9mm/21.33"
Ready to fly mass: 1470g/51.9 oz.

First stage propulsion: 2x Aerotech F42-4, 4x Estes A10-PT
First stage recovery: 2x Top Flite 30" thin-mil parachutes

Second stage propulsion: 1x Estes B6-2
Second stage ignition: Perfectflite MiniTimer 4
Second stage recovery: 1x 16" Top Flight parachute (capsule), 1x 10" Top Flight parachute (tower)

Estimated altitude:175-200m

Two fins were irreparably damaged when the booster landed on the back side of the video display tower, but can be easily replaced due to the model's modular construction. Additional repairable damage was inflicted on the booster.

It was really, really cool. Critical assistance was provided on launch day by Jim Filler, Steve Humphrey, Matt Steele, Bob Kreutz, Matt Berk, Kevin Johnson, Jay Marsh, and many more. Assistance with CAD work on many components was provided by Josh Tschirhart.

James
 

aerostadt

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James,
I am looking at Peter Alway's Rocket of the World for the Little Joe I and he mentions 8 motors, while you list only 6 motors for the 1st stage in the previous post. OK, I see on the first page of this thread, post #26, that there is a version with only 2 large motors. So, I understand now.

Also, you mention Aerotech and Estes motors. I thought the competition in Ukraine had to use the overseas motors. Am I wrong on this?

I think that I can see the second stage ignition in the video, but it is so far away I can't tell what is happening. I see from page 2, post 38, that you use a B6-2 for the escape tower. Is this an escape tower jettison or is the escape tower somehow pulling the mercury capsule away? It looks like in post #36 that you have the standard 3 nozzles for the escape tower. I assume that this is for display, but not for flying if you are going to actually fire the escape tower. I am curious. Can you have the display tower for static judging and then switch to the operating flight escape tower within the contest rules? Pardon me for all the escape tower questions. On my 1/12 scale Atlas Mercury I use an escape tower jettison. I've been using an A motor. Perhaps, I should go to a B6-2. I assume that your escape tower parachute is in your escape tower motor. Where is the parachute for Mercury capsule?
 
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TheAviator

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James,
I am looking at Peter Alway's Rocket of the World for the Little Joe I and he mentions 8 motors, while you list only 6 motors for the 1st stage in the previous post. OK, I see on the first page of this thread, post #26, that there is a version with only 2 large motors. So, I understand now.

Also, you mention Aerotech and Estes motors. I thought the competition in Ukraine had to use the overseas motors. Am I wrong on this?

I think that I can see the second stage ignition in the video, but it is so far away I can't tell what is happening. I see from page 2, post 38, that you use a B6-2 for the escape tower. Is this an escape tower jettison or is the escape tower somehow pulling the mercury capsule away? It looks like in post #36 that you have the standard 3 nozzles for the escape tower. I assume that this is for display, but not for flying if you are going to actually fire the escape tower. I am curious. Can you have the display tower for static judging and then switch to the operating flight escape tower within the contest rules? Pardon me for all the escape tower questions. On my 1/12 scale Atlas Mercury I use an escape tower jettison. I've been using an A motor. Perhaps, I should go to a B6-2. I assume that your escape tower parachute is in your escape tower motor. Where is the parachute for Mercury capsule?
I don't know the specifics of the parachute, but I do know that the B6-2 is in the base of the capsule. Mike Nowak did something similar with an Apollo/Little Joe II at the same event. It's not in the scale location, but you take what you can get.
 

James Duffy

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Also, you mention Aerotech and Estes motors. I thought the competition in Ukraine had to use the overseas motors. Am I wrong on this?
FAI competition allows the use of any single-use motor that can legally be shipped to Europe, which includes most smaller Estes and Aerotech motors. For scale, nothing beats the reliability of US motors. Heck, for many of the events (scale, scale altitude, RC rocket glider, and the new FAI version of TARC) the US makes the best motors in the world.

I think that I can see the second stage ignition in the video, but it is so far away I can't tell what is happening. I see from page 2, post 38, that you use a B6-2 for the escape tower. Is this an escape tower jettison or is the escape tower somehow pulling the mercury capsule away? It looks like in post #36 that you have the standard 3 nozzles for the escape tower. I assume that this is for display, but not for flying if you are going to actually fire the escape tower. I am curious. Can you have the display tower for static judging and then switch to the operating flight escape tower within the contest rules? Pardon me for all the escape tower questions. On my 1/12 scale Atlas Mercury I use an escape tower jettison. I've been using an A motor. Perhaps, I should go to a B6-2. I assume that your escape tower parachute is in your escape tower motor. Where is the parachute for Mercury capsule?
As Brian notes in the previous post, the capsule staging event takes place using a single motor in the base of the boilerplate Mercury capsule. This is not at all prototypical, but it looks cool. At 300-400' feet of altitude above the judges' heads it really doesn't matter where the motor is located.

The escape tower base fits into the top of the capsule much like a nose cone would fit. There is an extended "spool" attached to the base of the tower into which the parachutes for both the tower and capsule fit, protected in a cold compartment. The ejection charge of the B6-2 kicks out the spool, the parachutes spill out, and laundry fills the sky.

You are correct, the escape tower nozzles are strictly for show, not for go.

James
 

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