Building the AMT Refit Enterprise by Don Matthys part 4

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NAVIGATIONAL DEFLECTOR and HOUSING

The Main Navigational Deflector dish on Enterprise Class Starships is the next task to tackle. The studio motion control model’s Deflector, when lit up, also includes a ring of dashed lights between the concave dish and the housing (kit part #15 ) AMT’s answer to this with the “Electronic Enterprise” was about as lame as you can get. The Lunar Models update kit featured a clear piece and a tan resin housing replacement.

My Lunar Model copy was kind of crusty on the edges (old overused RTV molds) and the clear Deflector also featured the light detail on the outer edge. A clear dish sample of theirs was badly warped and of uneven thickness. It was if the thing was pulled out of the RTV mold before curing and stuffed into the box it came in. If it was OK, the method of attachment would be to stick it on the outside front edge of the housing. I find both solutions to be useless. But I intend to try to do the same kind of thing but make it work this time. And this time the clear piece will fit into the housing slightly recessed in as it should be.

I cut the deflector dish away, at the second level from the housing with a thin razor saw. Then thinned housing evenly within 1 mm (36mm dia.) at the front edge where it was cut. I used a Sanding Drum on a Motor tool and smoothed out it by wet sanding.

I then glued the cut away dish onto and centered it on a ‘spindle’ of thick plastic sheet stock with a screw in the middle. This was mounted on a Sherline lathe and the outside ring was turned down to a diameter of 33mm ( As you might guess, I am using a electronic micrometer) I then turned the top ring to 31mm. Thus the dish is also now squared up without the bevel. I now have the difference for a ring of lights that will measure 3mm . For this I need to make art work.

Using Adobe Illustrator 5.5 I made the drawing of the light ring. 28 (14 each side) short dashed slots and two long slots located top and bottom. The image was drawn to full size and test fits were made on paper printouts. Not trusting the process camera I use for a precise sized shot I took the file to a graphic service for output to a film negative. This was necessary to control the precise fit I need to make this work.

The next step is to use a UV light photosensitive polymer to make a 3D etching of the ring. This light sensitive polymer is used a lot in the white metal casting industry to make a 3D relief of a line shot object. Ideal for making custom coins and specialty novelties of the like. The unexposed areas are washed away with with water. This leaving a raised areas with slots for the light ring in a precisely laid out depression. The 3D polymer was then adhered to a .40 in thick plastic sheet stock disc. After fine sanding in the tight spots the dish fits snugly into the housing piece, recessed in about 1mm from the front edge. On the inside of the housing a small strip of Evergreen plastic was adhered in place adjunct to the dish plate to act as a stop. The dish was then popped back out.

The last task is to prepare mold boxes and pour in silicon RTV as molds to make resin copies. The new deflector dish should be easy. It is a lot thicker on the back than the Lunar Model version and not tend to warp upon demolding. And though converting the kits plastic housing is relatively easy to trim to fit I shall try to copy it as well. My concerns are the 0.3% dimensional distortion for such a snug press fit into the housing.

I would not expect any other modeler to use these methods. I used technical assets not normally handy to the average model builder But this gives a good insight on the process of machining, computer generated graphics, and 3D polymer etchings to fabricate pattern parts.

The Main Navigational Deflector Dish and housing RTV mold (#15 replacement) worked out quite well. After removing the masters, a casting of it was made with Alumalite. After a 40 minute cure and demolding the two pieces fit together remarkably well. Next is to cast the Dish itself in a clear/blue resin. That is done. A 12 hour cure is required.

Warp Nacelle Struts

Warp Nacelle Struts (parts #17, 18, 19, 20)

Without modifications the Warp Nacelle Struts will be to thin and is missing fine grill detail on the front and back edges. The studio motion control model is a lot thicker, almost twice in relation to the kit. Here is how I modified it.

  1. Thinned the inside edged flush with the inside surface.
  2. Scribed two parallel lines on the top inboard pieces # 18 & 19 by planes
  3. With Evergreen sheet (#2020, N-scale car siding 3 1/4 .02″ thick.) a strip of four lines was cut and placed on its side and glued on the outboard sides inset slightly in .
  4. For strength, Evergreen strip (#8606 HO Scale 6×6) was cemented inside to the grill strips.
  5. With the leftover grill strip and a small size punch a concave cut was made into the strip. Turned around (smooth side out) and glued to the ends and the two breaks on the front Flush Intakes.
  6. After glue has set ant the new plastic was sanded smooth the other halves was glued on.

After this procedure the taps will be too wide to fit into the hull and the warp nacelle slots. These will have to be widened, and when installed a putty build up to correct contours as well. Also, I have not forgotten that wires must run through the pylon assemblies. The tabs at the ends are left open for the wires to run through.

WARP ENGINES

The kit that I am working with is the original “Star Trek: The Motion Picture” model, and “old smoothy” kit when AMT first brought it out in 1980. The Warp Nacelle Flux Chiller Grills are not molded onto this kit. Instead a stick on prismatic self-adhesive decal gimmick was used. On later issues of the movie Enterprise kit these grills where molded on along with the rest of that ‘panel garbage’ on the kit surface.

With the second kit that I bought I cut these grill details out. The edged was sanded as smooth and straight to the edges as possible. The inboard grills I intend to illuminate. Though the white styrene plastic will let the light from Lightsheet through like I did on my USS Reliant model, I want to try to cast this in a clear blue resin again for a even more brighter effect. After I get the molds made of the grills and cast I tackle their installation on to the smooth kit Warp Nacelles and further details after that.

Copies were cast with a clear two part resin called “Envirotex”. A blue dye was added to tint them blue. The Envirotex can be removed from the mold after about 12 hours. A good final cure take about 72 hours. So these pieces must remain flat for a while.

The outboard grills were cut out and replaced with the outboard grills cut from the second kit. Next the inboard grills was cut out and replaced with the new clear cast resin grills. These grills are just fit into place until lighting is installed and assembly.

The next step is to drill locater holes for the Thrusters or Spotlights on the bottom front of the Warp Nacelle. Then the location of the Navigational Strobes located aft on top.

The final lighting detail to make is the aft Thrusters located on the aft outboard nacelle parts (Final Stage Intercoolers) I drilled holes top to bottom first. Then two holes side by side on the outboard side. But not all the way. Then two holes side by side from the aft end all the way trough to the interior of the Nacelle. The slots where opened further with a motor tool burr. This will provide a light channel from a lamp located inside.

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