This is a replacement engine design for Bandai's 1:144 Falcon model kit.
This is the engine and widely spaced (45 openings) grid design from TFA. The film companies have never, as far as I know, published detailed blueprints of this new design, so most people have replicated the look of the engine by poring over screengrabs, particularly the planet escape sequence.
I'm lucky enough to have a contact who supplied me with a hand-drawn engine block diagram, and this model is based on that. It's therefore not an official design, but should be reasonably close. Thank you, anonymous information benefactor!
You'll probably want to put a thin layer of translucent tracing paper or something behind each of the blocks, so any internal light source isn't visible. Note that some filing and building up gaps with styrene will probably be required to fit this part into the Bandai Falcon.
Falcon engine designs
There have been several different Falcon engine designs over the years. Your choices basically boil down to:
1) A blank white plastic wall. The OT models had simple white acrylic sheets over the back, producing a wall of light when lit. You never got to see the engine area powered off, so we have no idea what the engines were supposed to look like.
2) A finely-spaced backlit grid with no internal engine details. For the SE film, John Knoll and his team designed a finely spaced rectilinear grid for the back end. It featured a simple glow of light, going from red to blue to white as the ship took off. It was never shown powered off, so the internals are not known.
3) A finely spaced grid with internal eggcrate engine ports. When Japan's Fine Molds released a 1/72 Falcon kit in the mid 2000s, they supposedly asked ILM what the engines looked like when off. ILM's answer was to design a boxlike structure to sit behind the SE's narrow grid. This had a double row of rounded-rectangular holes, like an eggcrate, through which magic Falcon energy could shine.
4) A widely-spaced backlit grid with curved engine ports. The TFA Falcon introduced two new engine continuity problems. The CGI version of the ship has an engine grid - but with much wider spacing than the SE Falcon's! Behind this new grid was a complex curved box and rod structure, sort of like a blocky venturi nozzle for an imaginary energy jet system.
5) TFA curved engine ports; no grid. The physical TFA Falcon set (as seen on Greenham Common) appears to have the CGI model's internal engine structure but without the external grid, which makes no sense and is a strange continuity problem. The physical replica model on display at the Launch Bay exhibition looks like this as well.
Please read the following if you're interested in these items.
These accurizing parts are not mass-market commercial products. I made them for my own use, and have put them here in case they're of interest to someone else. Possibly you, since you’re reading this.
These are components for the serious model maker who wants to build a more accurate miniature. They require a lot of fiddling and careful installation. If you don't want to trim, file, sand, and glue, then these aren't the parts you're looking for!
The parts are tiny, and easily broken. They push the limits of today's 3D printers. The detail in the digital previews is all there, but it won't always be visible at the miniscule sizes that this scale requires!