More Nacelle Work
OK, now that the basic work on the nacelles (page 7) is done we need to clean up the details and take a look at the results. First off the rear of the nacelles. At the end of my nacelle update the rears of the nacelles were sanded down to the proper thinness (from left to right). After getting the PE parts that replace the plastic piece that outlines the rear vertical fin I found they would not work on the thinned down nacelle. So back to the original kit parts. There is a solution here.
1) Reverse the "U" pieces. To match up the bump details to best effect you need to use the right as the left and visa versa. To allow this you will need to file the indents that allow the U shaped piece to fit around the vertical fin to match the fit in their reversed positions.
2) The bumps are close but need some careful filing and cutting into multiple bumps in places to achieve a close match.
Just when I thought I was done I noticed that the top of the vertical fin just did not match the studio model. In the kit part the top is parallel with the top line of the nacelle to allow for easy plastic molding. In the studio model shot above you can see that the top edge is actually beveled. OK some filing will fix this.
Once this was filed to shape I was also forced to conclude that the raised center boss that runs up the rear surface of the fin just does not come up as far as it did on the studio model. To correct this I carefully fitted in some 0.010 stock to lengthen the boss. Finally a rear to the nacelle that looks right.
Below you can see the original part, the modified part and the studio model. I think this gets the rear of the nacelle acceptably close.
Reworked Kit Original Kit Studio Model
If you look carefully at the photos of the nacelle rear you also can see where the bumps are not quite the same from the left side to right side nacelle. In both cases it is possible to cut grooves and file away parts of the existing bumps to closely replicate the studio patterns.
Top of Nacelle
As was detailed in the previous nacelle page I redid the shape of the raised bump details along the top of the nacelle. To finish this off I still needed to add the actual top flat surface detail. This was made from some 0.020 stock. At the forward end a 5mm hole is drilled to allow the clear dome piece to fit through this strip. Note, as you do this this required me to add some thickness to the top of the grill pieces just below the dome so as to match this piece to the new heights I had created. Below you can see a detail of the buildup vs the original part and a side view of the studio model for comparison.
The increased height is especially noticeable at the front of the nacelle and the overall height of the middle section. This now closely matches the studio model.
The other change that is forced on us is the front grill of the nacelle. When you change the slant of the front of the nacelle to the correct angle you then find that the kit part for the front grill is too short and needs to be extended at the bottom. In order to do this I used the same part from my sacrificial kit and cut out a section of the grill to glue on to the original part for the added length. This worked well. Below you can see the front of the nacelle after the changes.
The Inner Grills
There has been a lot of discussion about how these are colored as well as what they look like on screen. I should first say that I want an onscreen look. If you look closely at the STTMP footage you will find several shots where with light from the proper direction the flats between the glowing blue grooves are definitely purple in color similar to the Christies shots although not as faded a shade. Just as importantly the flats change angle as they form the surface of a shallow cylinder and as they curve off the angle that shows purple the quickly transition to a deep black under the movie lighting.
The question was how to
1. light block the clear part
2. achieve the proper shade of purple and
3. get the quick fade to black as the angle changed.
So what to do?
First the light blocking. On the rear surface I carefully masked the length that would allow the blue lighting to show through including an oval end to the mask to conform to the rear shape of the glowing lines. After masking the rear of the grill was painted with a good coat of gloss black.
On the front you must mask the grooves as this is where the light must shine through. For this I used blue masking tape cut to a 0.60 width and carefully burnished into the grooves. There is a curved pattern to the ends of the lighted groovs at the rear of the nacelle that is symmetrical from top to bottom about the center line.
After looking at a lot of video footage I can only seem to find 3 views of the inner grills when at warp. All four are found in STTMP.
View 1 is looking upwards towards the rear from the front side of the engineering hull up past the pylon to the rear of the grill.
View 2 is looking from the rear upwards towards the nacellle
View 3 is from the rear with the camera just at the height of the nacelles right at the moment after the asteroid explodes and the Enterprise is framed in normal space against the explosion.
View 4 is a shot of the ship passing while at warp that had enough characteristics that I was able to set up the exact same camera shot.
After much analysis ( why is there never an orthographic movie shot when you want one?) and a bit of trial and error I arrived at the following measurements which are as close as I could get to the studio model. Using publicity shots from the studio spotlighting that have slightly better views, I analyzed both of these using the pictures imported into visio for accurate dimensioning yielding 2 different results. Adding measurement for the rear of the grill to nav light and for the pylon to end of the bottom bulge as checks only served to point out where the camera distortion was greatest rather than confirming numbers. In thinking about this and the discussion on Hobbytalk I noticed one other length clue that I had not paid enough attention to. That is the placement of the center tip vs the shape of the outer contour of the grill area. The grill both slopes outward and tapers in, in that ovaloid fashion as it approaches the rear tip. I have observed in most of the views excepting at least one where perspective is bad, that the center tip seems to be placed a small bit forward of where the taper stops and the slope of the grill flattens out. This then led to my final analysis and the following numbers.
Each measurement is from the tip of the grill on the clear plastic PL kit grill part. (The tip of the grill itself, NOT the tip of the overall part that includes the glue border.)
Marking the lines from top to bottom as A to E the dimensions to the start (tip) of the glowing line are the distance specified in from the tip:
OK one last view. I was looking for a view to confirm the rear contour of the grill outline and accidentally found this. It is a portion of one of the 1992 exhibit photos. It is close to an ortho in the necessary dimensions. I added reference lines and used visio to size the picture to match the kit part. What I noticed in this photo is that the grooves along most of their length match the color tones of the flats. However at the back the grooves show up distinctly dark. This might be light masking showing up. Hmmm.
When I match it to the kit nacelle piece the grill opening matches. If my masking conclusion is correct then it should show a pattern that can be compared to my previous numbers. I then overlaid my grill with the tape masking. Results:
1) The point of my center tape mask matches the forward end of the dark groove. Conclusion the pattern is starting at the proper place.
2) The middle two line tips then match the end of the dark line as well to within less than .01 in.
3) The outer line is less distinct so there is some question here. My distance seems ok but I cannot prove it from the photo.
I think these really are masking lines showing up. It also look likes if they are, they confirm my final pattern numbers remarkably closely.
On to the painting. With the grooves properly masked I painted the entire outside of the clear part with gloss black as a light block. My next thought was to paint silver over this and then use a translucent purple overcoat. I tried the food coloring and future mix and just could not get an even coat. So I did the following: I mixed MM Acrylic clear red and clear blue into some silver until I got the proper purple sheen. This was then airbrushed over the black. This came close but it was a little lacking in its quick fade to black when the light was off access. I found that a light coat of clear blue over everything altered the sheen just right and gave a nice fade to black while preserving the purple for the correct lighting angles.
To finish off I removed the masking from the rear and again used a mix of clear red and clear blue to do an even coating of translucent purple to the back side. Finally after removing the groove masks on the outside I hand brushed some clear flat acrylic into the grooves to match things up and control the glossiness. The results are below.
Unfortunately this comes out slightly more blueish to the camera than by eye. Next a shot with the light off axis where you can see how quickly it fades to a black tone as in the movie footage.
Next step light masking the main Nacelle and lighting