Apollo Crawler

The center structure consists of a whole lot of I-beams and posts.  There are also walls containing windows and doors.  Within these walls is a computer room that is walled off from the engines and pumps.  I have glued in everything except the top two I-beam pieces.  These will be glued in later when the interior parts, engines and pumps are installed.  Once the top pieces are glued in, I can true up some of the misaligned posts. The entire structure is 3 dimensional except for where the truck arms will attach. At that point you can see sheets of styrene.  I wanted to get a really good attachment point for these arms.  Now that I think about it, if you mount the LUT and Saturn V on top of this model, all the weight is placed on top of the truck arms and goes straight through to the trucks.

There are two cabs mounted on opposite truck arms.  These cabs are where the drivers sit.  The one detail left to add is the big red wheel that steers the crawler.  

From the side you can see an A/C window unit that cools the cab.

On the underside I added wires.  It's the little details that add to the model.

The truck arms extend from the main structure and hold the trucks.  Again I added wire and small bits to simulate piping.  These small pieces are getting rather pixelated due to the resolution limitations of 3D printers.  If you have a resin printer you could get more detail in these pieces.  On the underside I added cable trays which will route the wires from the trucks over to the main structure.  

On top there are attachment points where the LUT sits.  Notice that each corner has a different configuration of hold downs.  The following drawing shows these.  One corner has four, one corner has none and the other two corners have two each that are in different directions.  I have added the other detail NASA drawings for this detail out on the website where I am documenting this build in more detail.  http://www.spacemodels-forum.com 

The end structures are open and contain the fuel tanks and some of the radiators.  I added vinyl decals to the fuel tanks.  

There are four trucks that move the crawler.  Each truck has a pair of tracks that are each driven by two electric motors.  I added wire to simulate the piping.  The tracks require 52 pieces each.  The pieces are attached together with a small piece of wire.

The main structure or chassis is the framework that consists of I-beams and columns.  Contained within this structure is a large room that contains the engines and generators that will not be modeled as they are not visible unless the top is removable.  The original model has STLs for the end portions that are exposed.  The remainder of the structure in the original model was a styrene box.  I have chosen to model the underside exposed I-beam structure.  Here is a picture I found of the underside.

And here is half of the underside parts printed up.  The other half is a mirror image.

I will glue a 0.030" thick styrene sheet on top of the center section and I have created mesh flooring for the exposed ends.

Here is a picture of the completed bottom I-beam structure.

I have glued the floor grating to the exposed ends and the center floor which is a sheet of 0.030" styrene.  You will need 3 - 1'x2' sheets.

I am going to print the model using Tamiya acrylic paint.  The vast majority of the model is a light gray.  I will use XF-19 Sky Gray.  Here are pictures of the four radiators that will be placed in the exposed ends of the structure.  After priming I painted the front a flat black, masked off the black and then painted the rest gray.

Here is the main structure with the flooring installed along with floor vents.