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Discussion Starter · #1 ·
In my Refit Insanity thread Gunstar1 posed the thought that the Nacelles were too wide. This got me off on some photo comparisons in Visio and Photoshop.
Everyone allready agrees that the kit nacelle bottom profile is a bit too wide, but what about the rest of it. Here is my comparison overlay.

The discrepancy in the horizontal band across the grill I believe is mostly photo ange and can be ignored.

Here are my conclusions:
1) Yes the bottom is too flat. The nose and bottom can be improved and made closer by sanding there is enougn kit material thickness.
2) The size and the shape of the grill and its borders are pretty close to right on with a little rounding of the bottom corners needed.
3) YES the overall nacelle profile is a bit too wide. See the delta between the outer edges highlighted in red and green.
4) No this extra width CANNOT be taken out just by removing some from the vertical center line. If you do then the grill and all of the top details become the wrong proportions.

Conclusion: The basic width can not be fixed in a practical fashion because the section that needs to be removed is a cut just behind the plane of the fluxchillers that then needs to angle inwards and continue all the way to the rear.

Please also note that this discrepancy in basic width is not very much. What looks like a lot in the photo above is in reality only about 0.60 on each side.

Note: If you refer to Thomas's correction photos for the prototype you see these same notes. Aparently the molders chose not to correct this like other items that Thomas wanted corrected.

Hope this helps,
Mark
 

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I think that the top details (bulges and front/top grill details) need to be corrected anyway (see pdf that was attached in the insanity thread). Lots o' putty would be needed to reconstruct the correct bulge dimensions, and the little box details as well (they are kinda oversized anyway). But what do you think about the BACK end of the warp engines? As shown in my pdf Photoshop/Illustrator overlay, it's wayyyy too fat. I probably will end up removing material down the long axis middle and resculpting the engine bulges (and adding those pesky little raised square details. Ok...maybe I'm getting obsessed...oops...too late.
 

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"Profile" would refer to a side view, btw. What you're concerned with is the cross-section.

-Pedantic John
 

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Marc111: Just a word of caution here about using photos to rectro-design a model. That is what I've been doing for the last few weeks, trying to reconstruct decent plans for an Excelsior. I'm sure I've got 80 or 100 Excelsior photos that I've downloaded, plus everything that I have in print (and, yes, after spending weeks struggling to finish in two dimensions, last night I found the photos I Thought That I had that would have made everything So much easier, and prompted a couple more hours of revisions), and I've been Photoshopping them all, trying to work out dimensions and details.
What I've discovered (accidentally) is that even the very same photo downloaded from 2 different sites can have completely different distortions. ???
And while I expected pictures to be skewed in one dimension relative to another - get the right length and you need to expand or narrow the area to get the right width, etc, I never expected that they could be distorted both long and shot along the same axis. But they can. They can stretch for a portion, then narrow, and even stretch again, and it doesn't matter which end is nearer the viewer??? And sometimes quite significantly. Sigh.
I think there's distortion from the original viewing angle, from the camera lens, from the original printing, from the scanning, from the posting, from the program, from the screen, from the printer, from the beer. Of from any combination.
You may very well be right about the narrowing of the nacelles. But looking at that one photo above, I'd say that that could as easily just be distortion in the image angle. Esp as it seems so symmetrical. From that one example, there's no way of saying that the bottom of the nacelle shouldn't actually be wider. What I've learned from all of this is that you need to measure from at least 3 different sources, preferably from as many different angles as you can find to work with. And then take an average or a guess as to what suits your artistic sensibilities best.
Working from photos, I don't think you can get better than 2% to 3% accuracy. You just cannot make it any more accurate. If an .060 is a difference within that range, then whether you want to fix it probably just depends on the eye of the beholder.
 

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Discussion Starter · #5 ·
Gunstar1:
Yes I think the cross section is a bit wide at the rear. Not sure if its enough to bother with.

Starseeker: You are right on. All it takes is one not fully proportional resizing some where in the process and all the carefull comparisons are faulty. Angle can be everything and it is very hard to match up.

For example I started looking at the heigth of the slot lights just below the bridge. I compared them to the dome heigth, the side wall heigth, the dome width and the full bridge width across 5 different photo views. I assumed that the kit dimension for the non slot dimension was correct and ran the math. The answer for slot heigth comnes out with a range of 0.055 to 0.70 with a mean of .060 depending on the element assumed to be correct and the picture view used. The kit by the way measures 0.040.

Thre may be some extra width in the nacelles but it is hard to be completely sure. I willl try a few more views.
 

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Discussion Starter · #6 ·
OK I took Starseekers advise and looked at 3 more views. The problem is that what you want is a nice clear top down orthoganal view. I found one abet dim with a screen cap from the E in the nebula during STTWOK. I examined the following proportions.

Rearmost width of impulse engines/ Saucer diameter

Nacelle width at the front horizontal bar detail/ Rearmost width of impulse engines

Distance between the linear top grills/Nacelle width at the front horizontal bar detail

Distance between the linear top grills/Rearmost width of impulse engines

I did this for the original black and white photo STNPent05 even though there is angular distortion the impuls eng are close to the same distance away as the front of the nacelles,

This ovrhead shot I found on the web

And what looks like a good orthoganl shot from STTWOK.

After comparing the kit proportions to all of these sources I am forced to conclude (starseeker was right on using multiple views)that I was wrong and the kit width is OK on nacelle width to within the accuracy we can achieve based on these photos. So rather than trying to alter the nacelle width we should go after the difference in leading edge angle which is verifable from multiple pictures.

Thanks for the feedback.
Regards,
Mark
 

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Here's a thought....
Anyone know who now owns the model? Let's all chip in and convince him to do a 3D scan, and CNC the ship.... and have someone mass-produce the model economically as well as perfectly. Then no more forums on how to accurize it. Until then, I must agree to disagree and alter the width of these warp engines.... and yes, even the back ends drive me crazy cause they are too fat - by quite a few mm. I think that if the aft of the dorsal gets corrected in thickness by a margin of a mm, then the warp engines deserve at least that much attention.
...(stepping down from my soap box)....(for the moment) :)
 

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Discussion Starter · #8 ·
Gunstar1,
Boy do I wish we could do that. It would settle a lot of questions. I have gone back over my proportion comparisons and as well done several on the back as well.

The basic problem with corrections based on photos is getting accurate information and small angle mistakes in viewpoint and near vs far distortions can really mess things up.

There are too styles of corrections we try based on photos. Style 1 is corrections to details that are wrong that can easilly be seen because an angle is off ot something that was uniform in width isn't etc.

Style 2 is the harder one where the size is off. The problem is that in order to correctly size the fix we must compare the suspect section to another area of the model and use the assumption that the other area is in fact correct. Small variations make for sizable errors.

In looking at the nacelle cross section I used comparisons to the impulse width, the saucer width and the grill width. What I got was conflicting results. The grill to nacelle width was the comparison least prone to error being in the same spot on the model. This comparison showed very close results in proportion kit to studio model.

comparisons to the impulse deck width and the saucer width showed conflicting results from picture to picture used. In 2 cases .08 too big and in 2 cases .08 too small. My problem which to believe.

At the rear of the nacelle I tried comparing the width of the vertical fin detail to the width of the nacelle and as another view to the space to each side of the center fin. What I found was interesting. In my available photos I have good rear shots of both nacelles. The left nacelle shot implied the rear nacelle width should be reduced by .07, while the right nacelle implied the kit should be widened by .01. If both of these are correct then the kit people picked something in the middle.

I will admit I am really frustrated by this analysis. In most of my other cases the detail corrections have ben straight forward to figure out. This one is very tough.

If anyone has any thoufghts I am open to them.

Mark
 

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Discussion Starter · #9 · (Edited)
One final look just to keep driving myself crazy. I also looked / compared the front vertical bar width on the nacelle grill against the width of the nacelle at the horizontal bar and the total grill width. If one assumes the vertical bar is correct then the total width of the grill effect comes out right on but the overall outside width of the nacelle comes up too wide by about .06". I checked Thomas's correction photos and this seems to correspond to a width reduction running vertically in the area between the grill outer edge and the outer surface of the nacelle that he wanted but might not have been done.

If I combine this thought with the impression that possibly the rear is too wide by a similar amount one might be close. The problem in fixing this is that one needs to remove a section on each side of the nacelle down the whole length of the nacelle terminating near the rear end of the nacelle. In addition one would sand the sides of the finial end thinner. I will try to add a picture later.

This would mean cutting each half of the nacelle into two pieces lengthwise and then gluing them back together and smoothing out any discontinuities in the curvature.

I've got to think long and hard about this before going to this kind of trouble.

Thoughts?

Mark
 

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Discussion Starter · #11 ·
As Promised a picture of the cut line that would be needed.

Steve: Sculpting might be harder than modifying the kit given my sculpting skills.
Mark
 

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Marc: I don't know if this is going to help or just muddy the waters even further. Out of the blue, while thinking about something totally unrelated to Trek, it popped into my mind that the nacelles on the Refit are still based on cylinders. At least according to Mr. Scott's Guide. And which makes sense, as the original 1701 was. So I enlarged Mr Scott to the proper size and started measuring and looking thru my files of photos.
The only conclusion I have right now from looking at photos of the nacelles is that something is wrong on the PL kit's. The nacelle bottoms are not nearly rounded enough. The photos imply that a cylinder might be the right overall shape.
Scaling up Mr Scotts shows that the flux housings/surrounds aren't nearly wide enough. The overall outer width of the flux surrounds at the top should be approx 1.53" and on the kit they are 1.44", a difference of nearly 1/10".
The little fins that extend from the top of the flux surrounds to near the front tip of the nacelles are not nearly wide enough, whatever the correct width of the thing is, as is confirmed in all photos. If you go with the Scott's size of 1.53" overall, the kit's are 1.32" wide, a difference of 1/5"!
I think the key to determining the nacelles' proper profile is to go back and work from it as being based on a spherical cylinder, with the grills inset into the sides, and then the front end partly laid over top and then partly inset into the cylinder. I'm suspecting strongly that the bottom of the front 3/4 of the nacelle is too flat, and that everything associated with the flux housing is too narrow.
Wonder if anyone makes a 1.5" OD styrene tube? Evergreen? The easiest way to fix the nacelle might be to get a couple feet of that and graft in the kit parts...
 
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