Discussion in 'Fan Art' started by Cary L. Brown, Apr 24, 2009.
^^ Lookin' good!
Nacelle Inset Annoyances...
I've seen a few of you guys deal with this in the past, but have never quite figured out what you did to supposedly "resolve" this situation. I was fully expecting to see what I'm seeing, which just proves that SOME piece of information out there is just plain wrong... possibly multiple piece of info.
The issue, of course, is the trailing end of the TOS Enterprise's nacelle inboard cutouts. Photos show that the base of the "groove" has a linear edge, not a rounded one, at this location (though the front seems to be rounded). The general assumption is that the back wall is flat, and extends from the "base" up to the point where it intersects the outer hull of the nacelle. The assumption I've normally seen tossed around is that this will form a curve - which is true - and that this was the curve we were seeing - which is false.
Here's what happens when you take that approach.
The blue lines represent the "target geometry." You can see that the curvature of this area is just entirely wrong.
My intent, at this point, is to do a simple "blend" between the flat surface of the "inside wall", or "base, and the curved area at the hull exterior. However, this isn't going to match what I've repeatedly heard people say the RIGHT answer to this problem was.
I'm very interested in how those of you who've built your own Enterprises have addressed this point.
I think this falls back to the question... are you attempting an idealize geometry or matching the physical model?
On the physical model this shape exists on only one place (as the trench feature doesn't exist on the other nacelle on the model), and starts out at the bottom as flat and starts bowing outwards as it progresses towards where it meets the cylindrical surface. That is how the 11 foot model was done, but the 33 inch model has an inward bowing and doesn't meet the base level of the trench in a straight line.
In either case, it isn't really flat, you end up with some version of a shoe horn shape on either model.
As for building this in a 3D application, I would suggest following Tallguy's lead in this area. He provided a beautiful tutorial here.
Oops. Not that it's terribly important, but the trench does exist in some fashion on the starboard nacelle:
Also, here's a nice shot of the aft end of the trench detail:
BTW, great job so far! I think you're well on your way to having one of the definitive builds of the 1701. I can't recall if you've mentioned this (and I'm too lazy to re-read the entire thread), but the Cloudster site linked above has some nice reference material. Perhaps most noteworthy are B&W pix of the E at a stage just prior to production. I say this because the lower saucer registry is still 180° from its final resting place. Also of note, these pix show a distinctive grid pattern on the lower saucer.
It is painted on, but there is not a trench... and there never was one.
This is a series of photos of the painted trench on that side from WNMHGB...
And the same area during the series when the grill work was added...
But there is no physical trench.
In fact during the 1974 restoration, the painted area was painted over leaving that part smooth (and the original grill was lost).
All the proof anyone should need for this exist in the series of photos at www.cloudster.com (I would suggest looking at ent05.jpg). This is very old news and shouldn't have to be shown again here.
...and a "painted trench" with added grill work is a trench of some fashion. Just as I said. Again, not terribly important, but there it is.
I'm very familiar with the site, having linked to it in my previous post.
FWIW, here's another shot showing, I think, the starboard nacelle wiring duct-taped to the model and running down the strut.
Wow. Well, next time I post something I'll be sure to check with you first.
Not a problem, I'm alway happy to help out.
Well played, sir. Well played indeed.
All I can say is that on MY model,
I do appreciate the various tips and pointers. Right now, the techniques I normally use don't seem to be lending themselves to making this feature (remember, this is solids-based CAD, not surface-based like Maya or Lightwave or Blender or whatever, where doing surface lofts are relatively simple). I've tried about a dozen different approaches, and so far all of them have left me with less than satisfactory results.
Of course, this is part of why I do this (besides the fact that I'm a huge freakin' geek, obviously!) - I learn new techniques this way and I can then apply them to my job, making me even more valuable to my employer... so it's "edutainment," really.
I assume the software has Boolean operations of some kind, right? Can you carve one volume out of another? Because, were I making this feature, I'd build a negative shape of the trench, then subtract it from the nacelle. It seems like that would give you the most control over the slope and how it changes shape as it meets the nacelle wall.
FYI, I'm going to be out for a while, and while I plan to bring my files along (on a portable HD) for my trip, I doubt I'll be able to get much accomplished on a laptop. Just don't want anyone thinking that my little "far east" trip really represents my getting discouraged or whatever.
Well, despite my last post... I'm not leaving quite yet (I'll be out of here later this week) and I got so sick of my attempts to learn "important phrases in Chinese" that I've jumped back into this.
Turns out that Pro/E DOES have the capacity to do what I want it to... but you have to buy an additional "module." Well, I broke down and did just that the other day (not too expensive when talking about your "personal use only, no commercial use" licensing, but quite a bit more... $1K+... for a commercial license. I'm talking about a feature called "advanced freeform surfacing," in case anyone's interested.
Well, with that, you can do surface-based features like lofts very easily, tweak surfaces and so forth, just like in 3DSMax or Maya or Lightwave (or, presumably, any of the other packages I've yet to really ever use). It's sort of separate from the main program... same UI but you're in a different mode... but it allows you to create the surface features, which you can then use in the main program once you leave that mode.
So, I've got some great, mathematically-precise NURBS-based surfaces whcih I can then merely "thicken" to create solid geometry. It doesn't quite mesh perfectly (some "wedge-shaped" gaps occur between the flat inset surface and the inset "walls") so I need to add additional geometry to fill those gaps, but that's trivial, and while it's visible on the inside of the nacelle, it's not visible on the outside... and I LIKE having it on the inside because that fits in remarkably well with what I want to do with my internal nacelle structure.
Here's an image of the port nacelle inboard region:
And a close-up of the aftmost region... yes, as Shaw suggested, and as Tallguy's "guide" indicated, it's got just a hint of a "shoehorn" effect, but it's almost unnoticable except when viewed in-section from directly above.
And for the first time, here's the nacelle in cross-section.
You can sort of see what I'm doing here. The pylon continues all the way through the nacelle, and is essentially an integral part of the nacelle structure (through the two heavy bulkheads making up the attachment region).
Forward of this is the bussard collector and a ring of tankage for storage of hydrogen collected by the bussards. This is not a "slush tank" (which is used for long-term storage of hydrogen at cryogenic temperatures, so there's no need for high-pressure)... no, this is a high-pressure storage "torroid."
In the region between the heavy bulkheads you see here is all of the control mechanisms and the principle user-serviceable hardware.
Running aft of this will be the primary power generation region, the antimatter-generation (aka "spin reversal") system, and at the very aft, the big sphere is the subspace field generator.
In case it's unclear to anyone where the pylon falls within those "heavy bulkheads"... it's not passing through the centerline of the nacelle, and for good reason... there's going to be what's essentially the equivalent of the TMP-style "horizontal intermix chamber" running the length of the nacelle. In the following image (which I created as a guide for making my inboard "trench" feature) you can see how this all relates.
Man, I just love those cutaways. Nice job!
Yeah, this all looks very spot on, Cary! I have little to offer besides and
Cary, there's an entry up on the blog of the National Air and Space Museum about the restoration of the Enterprise miniature. It's a light entry with few details, but it does have a fascinating x-ray that I thought you'd enjoy.
Whoa, Psion, that's cool. Is that the rear of the secondary hull? I wonder what that electrical stuff is...
Do you mean the inner workings of the energy efficient light bulb?
I knew it! They must have modified the Enterprise for an appearance in Hellraiser!
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