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1/72 Saturn V - making the best of a “Dragon” situation

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Moving the Saturn V portion of my Grand 1/72 Launch Vehicle Extravaganza here for the group build.  Planning on representing the Apollo 16 LV.




Here are some Dragon Kits … along with a New Ware detail set for the CSM/LM and some awesome decals from Space Model Systems … plus I’ll be adding a lot of my own goobery scratch-build parts.

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S-IC Forward Skirt Exteriors - stringer tedium continues

Earlier this week I removed stringers and mapped out part placements on the second S-IC forward skirt. Tonight I’ve started the process of attaching the laser cut parts and all those extra stringers. I’ll try not to bore you with the details, but this is what I’ll be working on for the next few days.



Raw laser-cut parts ready for clean-up and a pile of styrene strips for stringers.



Parts and stringers being added.


S-IC Forward Skirt Interiors  - planning and 3D modeling


So I've also started thinking about what I'd like to do with the forward skirt area. I've decided to try to add the most accurate, yet simple, details I can. So I started in on the research and fired up Rhino.


Comparing photos of S-IC-14 (JSC) and S-IC-15 (Infinity) the best I can tell is there were 4 equipment boxes populating the S-IC ’s forward skirt. One is midway between position “D” and position “I” for LOX level measurements, one at position “I” that contains the ODOP transponder, another midway between position “I” and “A” that contains various RF related equipment, and the last located at position “II” just right of the crew access hatch that contains a litany of things including the launch safety equipment. Looking at the photos it appears that all but the ODOP container are similar in size and shape. I’ve 3D modeled both sizes and will be printing them to eventually cast the quantities needed in resin.



Here’s an example of one of the equipment containers on S-IC-14 at Johnson Space Center. (LOX level equipment)



My 3D models. ODOP is on the left the other common sized box is on the right.


I’m still working on how to represent the internal structure of the forward skirt.  I’m going try to not get too “in the weeds” with this so it will likely be reasonably accurate, but slightly rudimentary in execution.

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S-IC Forward Skirt Exteriors - stringer tedium continues  


Plowed through about 64 stringers this morning before I had to tend to some adult stuff.  Won't be long before I can start working on the forward skirt interiors ... 



More and more ...


S-IC Forward Skirt Interiors  - more planning and more 3D modeling

Still working out the interior structures and detail plan. Started work on the LOX vent assemblies. Still looking for some detailed photos or diagrams, but I think I've got the general shape down.



A series of tubes.



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Strange.  I went in and relinked the image and it looks like it's showing as it did before.  All big like.


S-IC Forward Skirt Interiors - the kit tank parts are rubbish. Go figure.

Still working on the forward skirt interiors and, of course, that means a 1:1 drawing of the kit parts and their relation to the parts I wanted to produce.  Measured out the skirt and it's a few millimeters longer than it should have been. I could have trimmed it down to the correct size but I didn't bother.  Interestingly, and I think it's been covered elsewhere, the skirt cylinders are slightly tapered.  Probably to help with part removal during the injection process.  It's very slight but does add a bit of complication.


The other thing that was sort of a surprise is how "off" the kit provided tank dome parts are.  If you look at the drawing below you can see that the original bulkhead shape (dashed line) is much more bulbous and is considerably wider. The kit's parts ... not so much.


I'll be proceeding with the kit parts but will have to make some adjustments and tweaks to get it to look presentable.


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So these kits come with stringers section that wide? And we have to add them? Are these parts included in kit, or is it Evergreen you have bought to add. Great job on the access panals. This build is gunna be big.


So another question, hehe. On the LV from Apollo 15 on, the interstage has no rockets. I've never found out the reason, had they been unnecessary. Apollo 4/6 had 8, Apollo 8 through 14 had 4.



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Thanks ApolloMan. Indeed, those are Evergreen strips. The application is rather tedious, but I think the end result is worth the effort. If only Dragon had taken the time to get it correct in the first place.


As far as the separation motors around the interstage. I understand that they discovered that the rate of separation at staging was higher, or sufficient enough, where they were considered to not be absolutely necessary.  The resulting weight savings allowed for things like more fuel for the LM descent stage, SIM bay experiments in the Service Module and Lunar Rovers and such.


Hotdog - I reconnected the images, can you see them now?

Edited by johnlove_mk_II
I can't spell.
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This is sort of a housekeeping post.  I've been working on tying down details and how to proceed with construction ... so fair warning, there's not a lot to see here.


All planning and no construction make Jack a dull boy.


S-IC Forward Skirt Interiors - The interior plan is set ... Shapeways parts are ordered 

I think I've got my forward skirt research pretty much squared away. I tell ya, there's nothing like piecing together details from close-up photos, that darn stage lifting fixture is always in the fricken' way. The structure of the forward skirt is pretty interesting from a engineering standpoint. It is made up of three circumferential support rings attached to 12 skin panels.  That assembly is further reenforced by the 216 external stringers. The stringers transmit the longitudinal loads, via the upper most support ring to the interstage and then on to the S-II. Cool.



Here's one of my "working" drawings showing tank and skirt detail locations 


I was hatching this grand plan to have the three support rings and the internal stiffeners laser cut. But thinking on it further I've decided that I didn't want to deal with the down-time waiting on those parts to arrive. Given that the models will be stacked 99% of the time I've just decided to use styrene strips and rod. I'm finalizing the pattern for the layout and start on that on that part of assembly shortly. Oh yeah, I also already had the uppermost support rings cut when I had the umbilical details cut ... so I do already have those.


I had already completed considerable research on the LOX tank bulkhead from my previous endeavors.  I just had to adjust the drawing to the weird Dragon part.  I'm debating on whether to remove the molded "weld" lines then add my own ... or just to roll with it. I'm leaning towards just using them as they are and adding detail. That seems to be inline with the spirit of this build.


I also sent off the equipment box and LOX valve parts to Shapeways for printing.  I hope to see those within the next few weeks.

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S-IC Forward Skirt Interiors - LOX tank bulkhead 



The weld lines look low ...  but with the weird "Dragon" parts, I'm afraid thats as good as it gets.



Here's one of the Marshal built S-ICs bulkheads for comparison. 


Started adding the "weld" details to the tank bulkheads yesterday evening. The original bulkheads were made up of 16 gore sections, 8 base sections and 8 apex sections. The "Dragon" parts only represent the welds that go from apex to base so I used styrene strip to add the missing horizontal welds. As I was adding them it wasn't looking quite correct.  I'm guessing that the since the 'Dragon" dome was a little off shape-wise, it was causing it to look a little off to my eyes. I think I'll just continue adding detail and see if it doesn't start looking more "right" ... or at least acceptable. I may also sand down all the "welds" to about half they're current height as they're a little too proud of the surface. At that scale the welds would be as big around as a beer can.



Just for fun I stacked up one of the S-ICs on the Apogee Motors.  These things are going to be huge.

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Just from what I can tell John, it doesn't look like the real welds are done as straight lines but rather a slight arc upward. Yours look too straight. I think it should be more of a spider web kind of shape, which might be tricky getting that evenly done from section to section. But even though, this is coming along great.

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I can see what you mean.  They do curve, just not nearly as much as they should ... and at the angle the photo was taken, which is almost straight on, they do look really wack-a-do.  I think that since the dragon part is not so much ellipsoidal as it is spherical,  that's what makes the weld curvature less pronounced.


But yeah, I'm already thinking of creating a balsa plug and vac-forming properly shaped parts.

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Just decided to proceed with the LOX bulkheads as they are.  They look a little off, but with the added details they don’t look too bad.  Besides, they’ll be tucked away out of sight for most of the rest of their existence.



Adding the various access ports and whatnot.



The bulkhead placed inside the skirt with the interface ring.  Not horrible.

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