I definitely would not BOTHER printing a cone when a balsa one already exists for ordering.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !

After giving this some more thought, I had not realized the actual difference in diameter from Mercury and Apollo and Orion. So, here is a summary, double check me if I misread these from Wikipedia.

full scale capsule diameter:
80" Little Joe
154" Little Joe II
192" Little Joe III (Orion AA-2)

Estes kit scale/dia
1/34 2.34" Little Joe
1/45 3.42" Little Joe II

So, some scale/dia options for a LJIII model
1/96 2"
1/64 3" (Estes Big Daddy diameter)
1/45 4.27"
1/34 5.64"

I like the manageable sizes of a 2" or 3" rocket for 18 or 24 mm power, but if you are going to stand this up next to the Estes LJII, then you should match the 1/45 scale to show the relative size difference. Hopefully could still build it light enough for 24mm power, not sure how heavy the 3D printed cone/tower would be. You can always go bigger, I did not realize how large the model dia would be at 1/34 scale, I did not do that mental math very accurately at all earlier.

1/49 will get you a BT-101 and a 1/51 scale will work with a BT-100. These scale will let your model stair step to a larger diameter (though not same scale), but not too big if you want to be able to fly LP and MP.

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I love sanding.

That makes even more sense, to look at standard body tube sizes and pick an appropriate scale based on an available body tube dia... I think the BT-100 (3.744") or BT-101 (3.938") are very good options.

http://www.erockets.biz/body-tubes-2/

Back to the Screaming Eagle, I really like how the fin can turned out, and I just got some tubes and the balsa (BC-846 equiv to PNC-89) nose from eRockets.

I think your fin can is about 1/4" too short. The 3" engine mount tube protrudes 3/8" when inserted all the way to the step, but I think only about 1/8" should protrude. If you look at this image from the plans, it seems like there is a little more body tube on top of the fin root, another 1/4" would allow for the 1/8" protrusion. I think it will be fine and look close enough, and probably not impact stability to have the engine aft 1/4" beyond the built-in safety margin of the design. Here is a picture of the obligatory dry fit of the parts, next to an Alpha VI for size comparison, another similarly constructed kit with a plastic fin can.

Making my own metallic stickers will be a challenge, I may try to apply my own print at home ink-jet decals on a metallic sticker like Trim Monocote or something similar.

http://www.spacemodeling.org/jimz/kf-3.htm

http://www.spacemodeling.org/jimz/centuri/kf-3f.tif

http://modelrocketbuilding.blogspot...ild-part-8.html

I should be able to trim 1/4" off the length of the 3" engine mount, and insert the engine hook 1/4" closer to the top end to match the external appearance and get the engine position correct in the fin can.

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The inside diameter of the fin can is too small to fit the ST-7 engine mount tube. The original was not a constant thickness but had some ridges to hold the body tube which made it easier to slide the engine mount tube into the fin can. I am sanding out the inside of the fin can to make it large enough so I can get the engine mount tube to fit, this is a slow process.... UPDATE: I have been hand sanding using a dowel and medium grit, but still can only get the engine tube about half way in before locking up. I am going to make a little sanding drum from a dowel and medium grit paper to put in my drill, I don't have a mini-tool, so hopefully that will get me enough clearance so I can get the tube with an engine hook inside the fin can.

see this picture of the original fin can for the internal ridges or raised ribs that hold the engine mount tube, the fin can body is not a constant thickness all the way around the circumference.
http://modelrocketbuilding.blogspot...ild-part-2.html

PDF from NASA has a good side view picture on page 4, could use to extract dimensions of the Little Joe III...

https://www.nasa.gov/exploration/sy...media-resources
https://www.nasa.gov/sites/default/..._fact_sheet.pdf

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There is a printable version of the whole model on thingiverse I downloaded it myself, however I want as much detail as I can get into it because it is such a smooth model. Here is my WIP for my 3D model , I am designing it based on ST20 tubing, which is approximately 1/100. I will also re scale it and post it in multiple sizes based on several tubes. I should be done with mine tomorrow sometime.


thingiverse file Orion Ascent Abort Model
https://www.thingiverse.com/thing:1104468

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Funny, I was just about to order some ST20 body tube and a balsa cone to try to mock up one of these. I am going to go through the parts list for the Vanguard Eagle also and get some tubes to build that based on your nose cone model that I had printed, when I get done with the Screaming Eagle.

I have posted the orion LAS BPC in several size variations.

https://www.thingiverse.com/thing:3188333