MBX Structure

A.    Detailed description

This structure is a model of a printing company called “The Mail Box” (MBX) located in an industrial area of Dallas, Texas near the intersection of Westmoreland and IH 30.  This building is 760 feet by 320 feet exclusive of the octagonal “pods” at the east and west ends of the south facing building.  Approximately one-third of the building, the east end, is warehouse and not air-conditioned.  Most of the other two-thirds, the west end, is air-conditioned for printing, letter-stuffing and sorting equipment.  Also, the west end of the building is for administrative, service and computer personnel.  The east end is for sales, accounting and human resources.  The south and west walls have a number of truck docks and the north wall has railroad docks that a no long used and the siding, while still present, has been disconnected from the main line a few yards away.  The photos below will give a perspective of the prototype structure.

The scratch built, Z scale structure attempts to capture a fairly large prototype building.  The structure in not compressed and the model is approximately 45” x 20” x 2”.  This model is very closely modeled to the prototype.  The main departure is an outside light fixture and the corners of the building.  The structure is made from approximately 400 pieces of styrene, 50 digital photos, 57 pieces of paper stock, 12 molded ac units and one brass ladder with guard.

The walls are constructed with pre-painted styrene strips laminated to a styrene base.  The foundation is painted with “Concrete” Poly Scale, the main panels are spray painted with textured “Beige” Rust-Oleum and the accent stripes are painted “Conrail Blue” Poly Scale.  The dock doors are precut from to outside styrene laminate and the base laminate out later.

The pods are made from styrene and the exterior walls are digitally adjusted photos (Adobe Photoshop Elements 2.0) of the actual prototype glass walls.  The photos captured the reflections of trees, sky and other background scenery.  Exterior down lights and exterior wall lights are 1.5-volt rice lamps with six switches for control.

The roof is made of .080” styrene sheet cemented together with laminated support strips on the underside.  Textured “White” Rust-Oleum is used to create the rough surface of a pebbled roof.

Dock doors are configured as open, open with truck apron, closed and closed with apron.  The closed doors are digitally adjusted photographs of the prototype doors and are glued to a styrene backing which is glued to the inside of the walls.  Truck aprons are made of black paper stock and are glued to yellow painted styrene strips.

Personnel entries are configured as ground level steel doors, floor level steel doors and main entry doors with front steps.  These doors are from digitally adjusted photographs of the prototype doors.  Floor level doors are made by stair-stepping styrene strips with brass handrails.

Here is the model:

Click on the photo to see larger photo.  Click back to return.

B.     Scratch built features

Exterior Walls

Making tilt-up, pre-cast concrete walls for the MBX structure created several challenges.  One thing to do was to get the textured look of pre-cast and that was solved with "Rust-Oleum" Textured spray paint in the color beige.  The building walls had several blue bands running horizontally along the walls and I did not believe masking would solve the problem so I decided to laminate the walls.  I would have a thin piece of 0.015" backing and to that I would glue pre-painted strips of styrene.  This laminating technique also solved another problem of cutting very square dock doors.  Wherever there was to be a dock door I left out the laminate.  Using a Chopper permitted me to get very precise and square door edges.

The photo below shows all of the components that made up a wall.  

The next photo shows a piece of more the eight feet of stock wall material used in making the building.  

Exterior Wall Lights

In the first photo is a set of three fixtures in the making.  The first step was to cut 0.5" lengths of 0.010" square styrene tubing.  I used Plastruct instead of Evergreen because the inside dimensions were fit the rice lamp better.  I then put to coats of “Grimy Black” Polly Scale on the styrene pieces.  On one end I painted into the tube to darken the inside of the tube that might show and to prevent light from glowing through the tubing.  Next I slid the lamp into the tube so that lamp was not quite flush with the painted end of the tube.  I put a drop of CA glue on each end to secure the lamp.  Note how the wire leads are coiled to make a temporary stand to hold the light fixture upright.  

After the holding glue had set up I used a Superfine Mircobrush to apply very small drops of white glue into the tube over the lamp.  I let this dry and applied another drop, repeating this process until a small dome formed.  After the dried completely, I had a very nice looking light fixture that would serve for an exterior wall light.  

I cut 0.010' square hole in the exterior wall and the put the fixture in with just a slight protrusion on the external surface.  I used CA glued the fixture to the wall.  I have sense gone back and added a gusset beneath the fixture for reinforcement.  

The photo below shows how it will look when the structure is complete.  

Materials:

Plastruct #90621 square styrene tubing

Miniatronics Corp Incandescent Lamps - Clear 1.5 volt, 30ma, 1.2mm dia

Polly Scale Grimy Black paint

AC Units

The MBX building is large.  With two-thirds of a 350,00 square foot building air-conditioned, there were many AC units on the roof.  I could not find any Z scale ac units to purchase so I bought an N scale ac unit to get some ideas.  I determined I could build them myself but there would be too many to build.  I decided to make a master and use a latex mold.  The stuff I got a number of months ago had gone bad and took my original master with it.  The first master wasn't very good anyway.  I found out that molds would only last for about ten or fifteen molds and then you needed to make a new mold.  I decided to make four masters and I use some brass sprue to make the ac doors and some N scale brass Venetian blinds for the grills at each end.  I also used some small diameter styrene rod for the vent stack on top.  The body was made up of miscellaneous strip styrene.  

After the four masters were made I glued them to a styrene base and then built up walls to create cavity for the mold material.   The mold was very easy to use and I let it set up over night even though it was advertised as a 4-hour curing time.  It is sort of pretty; one part is white and the other is blue and when mixed it turns out beautiful blue.  The castings were made from clear polyester casting resin.  This stuff was messy to work with and smelled awful.  But once done the castings turned out ok.  I airbrushed them first with light gray then silver then gray again to get a combined silver-gray look.  

I made two four master molds and poured five castings for a total of forty units.  One mold held up fine and I can use it again if needed.  The mold, while still usable, is showing a few tear marks around the corners of the masters.  It should be noted that the mold turned out very good because of the extra thickness all around the masters.  Were that thickness not there, the mold would not remain true to the master and the castings would not be any good.

Materials:

Assorted styrene

Brass sprue

Brass Venetian Blinds

Castin' Craft Clear Polyester Casting Resin (two part)

Micro-Mark One-to-One Silicone Mold Rubber

Polly Scale Undercoat Lt Gray paint

Polly Scale ATSF Silver paint

Outdoor Ladder

This ladder and climbing guard were made from 1/16 square grid brass stock by K&S Engineering.  Neither styrene nor balsa seemed like it would do the job.  I wanted to get used to working with brass for my next project anyway.  To make the ladder I simply cut out a narrow but long singlewide set of blocks then cut away the excess brass with a sprue cutter.

The climbing guard was more complicated and tedious to build.  First, I marked what brass grid I wanted to retain with a "Sharpie Permanent Marker" with a Fine Point.  Doing this helped me not get lost and cut the wrong piece of grid strip.  Then, using the sprue cutter, I cut away the entire unmarked grid.  I made one mistake, so I may make another.  After getting the entire unmarked grid cut out, I wrapped the new grid around a 5/32" styrene tube leaving the ends on each side flat so they could be glued to the wall of my structure.

Next, I brush painted the ladder Grimy Black and the climbing guard Refer White before gluing to the wall.

Click on the photos to see larger photo.  Click back to return.  

Exhaust Vents

There are many exhaust vents on the roof of a larger building.  They are arranged in rows for gas heaters and they are clustered around bathrooms.  Styrene tubing (3/32" dia.) was cut into 0.010" lengths and slipped over 0.040" dia. styrene rod cut 0.375" long.  This is a very simple little project.  

Skylights

I tried to find a z scale skylight in the local hobby shop but had no luck.  Even the smallest HO scale skylight was not going to look right.  And if they had been the right size, it would have cost a fortune to buy all that would be needed for the MBX structure and I would still have to figure out how to finish them to like a real skylight.  One day while looking for something else, I found some page pebbles in squares, rectangles, circles and ovals.  They came in a variety of sizes as well.  Their dome shape spoke loudly of a skylight!  I got a pack of small rectangles (16 in a pack) for $2.00.  I brought them home and painted several white on the top and several white on the bottom, looking for the "skylight" look.  So then I tried sticking one to a piece of styrene and that was the solution.  I added some dark gray to the edge of the styrene to give it the look of the sides of a skylight.  

I stuck eight packages, 128 total to a sheet of 0.030" thick styrene sheet.  

I then cut the page pebble from the styrene, painted the edge and now I have 128 skylights.  

C.     List of commercial components

Miniatronics Corp Incandescent Lamps - Clear 1.5 volt, 30ma, 1.2mm dia.

Push-on, push-off electrical switches for lamps purchases at surplus store

Red-black lamp cord (zip cord)

D.    List of material

a.       Exterior walls

                                     i.      .015” sheet styrene cut into various widths

                                     ii.      .030” x .010” strip styrene

                                     iii.      “Concrete” Poly Scale

                                     iv.      “Conrail Blue” Poly Scale

                                     v.      Textured “Beige” Rust-Oleum

                                     vi.      Outdoor Ladder and guard detailed above

                                     vii.      Exterior Wall lights detailed above

                                     viii.      Dock doors detailed above

                            ix.      Personnel entries detailed above

                                     x.      Various photo derived signs

b.       Octagonal pods

                                        i.      Assorted styrene

                                        ii.      Kodak Premium Picture Paper

                                        iii.      Adobe Photoshop Elements 2.0

                                        iv.      “Concrete” Poly Scale

                                        v.      “Conrail Blue” Poly Scale

                                        vi.      Textured “Beige” Rust-Oleum

c.       Roof

                                          i.      .080” styrene sheet

                                           ii.      Textured “White” Rust-Oleum

                                           iii.      AC Units detailed above

                                          iv.      Exhaust vents detailed above

                                          v.      Skylights detailed above