3DPrintedRailRoad - Rolling Stock

Introduction:

This is the complete Rolling Stock that was designed for my young grandson.  When he came for a visit after about age three, his first question was if we could print another rail-car.  The answer was “Of course, What kind of car, and What color”?

I decided to post the complete selection of Thomas® railroad rolling stock in one place instead of a separate design model for each car.  This eliminates listing the repetitive printing and assembly instructions for each model.  Note: trains composed of this assembled rolling stock have problems in navigating the wooden curved track with the smallest radius.

Click the desired link button in the “Files” section to download the STL file platter/card for your selection(s).  Don’t forget to download the wheels. 

Before constructing any of this rolling stock, you will need to acquire an assortment of M3x10mm cap screws, M3 nuts, 10x2mm rare earth magnets, a length of 1/8” (3mm) dowel for coupler pivots, and a length of  3/16” (try 5mm) dowel for axles.  Also, read the text file “Magnetic_Couplers.txt” in the other files section.  A hex driver for the M3x10mm cap screws will be more convenient than using “L” shaped Allen wrenches for assembly.

The rolling stock selection:

The Hopper Car was printed in black since this one is for carrying coal.  The body is printed in one piece with just a touch of clean-up needed around the coupling. The platter includes the trucks and sleeves.

The Freight Car was printed with body and roof pieces.  There are 2 trucks, 2 sleeves, 4 sliding doors, the roof, and the main body of the car.  The doors are held in a track when the roof is glued on.  A bit of clean-up may be needed on the roof track for the doors.

The Flat Car is a low profile car that’s useful for transporting Pocket Cars or maybe an extra container. The platter includes the car frame plus 2 trucks and 2 sleeves.

There are two versions of the Caboose.  The original version is listed in the design files. The 2 trucks are glued in place with pivoting magnet holders/couplers.  If there is sufficient interest I would be glad to post the design for the more recent version that contains red flashing warning lights in the rear.  In constructing that version a printed circuit board would need to be assembled.  The caboose roof of that version is attached using a screw so the 9 volt transistor battery may be changed.

The Gondola Car was one of the earliest designs.  It uses two trucks, two sleeves and a body.  This became the template for a number of other variations. This car is useful for transporting random printed scrap material, Pocket Cars or maybe the odd container.

The Container Car is the longest car in the set since the frame has to be recessed lower, below the trucks.  The containers have four bumps in the top and recesses in the bottom to maintain stacking alignment.  The containers are glued in place in the prototype but that’s not a requirement.  Note: This “Car Frame” is printed with support turned on but the “Trucks and Sleeves” can be printed without support.  You will also need to download the “Rail_Cars_Container.stl” file. You’ll probably need to print multiple copies of containers in different colors since your rail yard will need a stack of containers ready for shipping.

The Tank Car is short enough to not to need movable trucks.  The magnet holder pivots on a short 1/8″ dowel to allow the car to track around curves.

The Log Car has “logs” that are “chained” in place using cable ties so they don’t accidentally get lost during storage.  Logs may be fashioned from 5/8” (15mm) dowels, cut to length and “chained” in place.

The Lumber Car is empty of any cargo.  But is ready to receive pallets of stacked lumber or other cargo.

The Passenger Car was printed in silver but any color is suitable.  The top is glued into place after attaching the trucks.

The Auto Carrier is an improved automotive transporter complete with integral loading ramps.  Again, the ramps attach using a section of 1/8” (3mm) dowel.  A drop of glue on the ends after assembly holds them in place.

 The Car Carrier has to be printed in pieces and then assembled like many of the other cars.  An earlier version tried using “support” to print the body.  Removing the support material was tedious and ultimately unsuccessful.  This car is too tall to fit through the tunnels with automobiles “Pocket Cars” transported on the top level.   Obviously this was a major design flaw for the railroad. The ramps attach using a section of 1/8” (3mm) dowel.  A drop of glue on the ends after assembly holds them in place.

The Diesel Locomotive was a later addition to the rolling stock after the Thomas® railroad was modernized.  The locomotive assembles in a similar manner to the other cars.  The only caveat is that after the magnets are glued into the trucks (remember the north and south poles) pick the truck that is attracted to the rear of a Thomas engine.  That truck should be at the front of the diesel locomotive engine so you may connect multiple assorted engines.  The “diesel shell“ and “fuel tanks” glue onto the frame like the roof of the other cars after attaching the trucks.

Assembly Instructions

The rolling stock coupler design for the caboose and tank car has the coupling magnet attached to a pivot inside the trucks.   The following discussion describes the construction of a caboose but constructing the tank car proceeds in a similar manner.

Printing a caboose will require two STL file downloads.  The first is the printing “platter” for the car, the roof, the trucks, and the coupling magnet holders. Download the file containing the caboose components i.e.  "Rail_Cars_Caboose_Car.stl".   Next you will need to download the design for the wheels.  “Rail_Cars_Wheels.stl”   Note: there are 8 wheels in this file but you can use the extras for another car.

Generally I use a 0.25mm layer height and put about 1mm of plastic on the outside surfaces as a shell.  Since my printer has a 0.5mm nozzle I use 2 vertical shells and 4 horizontal top and bottom shells.  I set a honeycomb fill pattern with a 25% fill density.  I don’t use support when printing the caboose or the wheels although this will require some clean-up after printing.

The trucks will require the most post-printing clean-up.  These trucks don’t pivot like on the later car designs since the Caboose wheelbase is short enough to navigate the curves in the track.  However the magnet holders do pivot.  So, trim off the printing support disc on the bottom of the magnet holders and clean out the recess in the trucks.  The magnet holders need to fit into this recess and pivot without binding.

There are six indentations in the bottom of the caboose for aligning the trucks.  Since these indents were printed against your printer platter they may have a rim of plastic around the edges.  Trim off any plastic “elephants-foot” burr that may have squeezed onto the edges of these indentations.  Also, the bottom of the roof has four alignment mark indentations that may need to be cleaned out.

Depending upon your printer accuracy you may need to clean out the inside of the magnet holder cups that fit into the trucks.  Does a 10x2mm magnet fit inside the magnet cup?  If not, use the point of a knife to ream out the inside edge of the cup until the magnet fits smoothly without forcing it.

Clean out the axle holes in the trucks by running a 13/64″ (5.2 mm) drill through them if needed.

Cut two 14mm lengths of 1/8″ (3mm) dowel and cut two 33mm lengths of 3/16″ (5mm) dowel.  All the parts are now ready for assembly.

With a truck positioned with the three alignment marks up, slide a magnet holder into the recess in the truck (flat side of the magnet holder down and align the pivot holes).  Press one of the 1/8″ dowels down through the truck and magnet holder holes.  It should be a snug fit with the plastic overfill burr on the bottom of the truck providing a stop.  Repeat with the other truck.  The magnet holders should pivot smoothly without binding and the top of the dowel shouldn’t protrude out from the top of the truck.

Now comes a bit of critical assembly.  When you glue the magnets into the magnet-holders/trucks you want a “north” pole sticking out of one and a “south” pole sticking out of the other.  This means your trains can be connected together in any configuration.  Apply “super glue” (cyanoacrylate adhesive) to the bottom and sides of the magnet holder cups on both trucks.  Using two magnets that are stuck together on a convenient metal surface, slide the top magnet off and press it into one of the magnet holder cups.  Place this truck at an arm’s length away from you on your table with the magnet up.  Take the other magnet and flip it over and press it into the magnet holder cup on the other truck.  Set this truck down a good distance away from the first truck with the magnet up until the glue dries.

Using the two 33mm lengths of 3/16″ dowel.  Apply a drop of super glue to one end of each dowel and press it into the axle hole of a wheel (flat side of the wheel up).  You’ll want the flat side of the wheels running against the trucks after assembly.

When the glue is dry that holds the magnets on the magnet-holder/trucks, slide a wheel and axle assembly through the axle hole in the truck.  Apply a drop of super glue around the end of the dowel that’s sticking out and press it into the axle hole of a wheel (flat side of the wheel toward the truck).  Make sure the wheels can turn freely, so, use a light touch with the glue

Check that the index bumps on the trucks fit smoothly into the alignment holes in the bottom of the caboose.  And, that the four index bumps on the caboose fit into the alignment marks on the roof.

Apply “super glue” (cyanoacrylate adhesive) to the top walls of the caboose and the tops of the trucks.  Press the trucks into the bottom of the caboose using the alignment marks and press the roof onto the top of the caboose using those alignment marks.  Put a weight on the caboose until the glue sets.

The remainder of the cars had the coupling magnets fixed to pivoting trucks.  Any special assembly instructions are presented in the car type listings.  The discussion will concentrate on assembling the gondola car.  The other cars are assembled in a similar fashion with the addition of a roof that’s glued on last. 

A gondola car is a useful piece of rolling stock, it can be used to carry imagined rocks, gravel, or sand depending on the needs of the construction project.  It also can carry two of the “pocket cars” should they happen to break down and need rail transportation. 

Printing a gondola car will require two STL file downloads.  The first is the printing “platter” for the car, the trucks, and the truck pivots/sleeves, the second is the wheels. Download the file containing the gondola car components i.e.   “Rail_Cars_Gondola_Car.stl”. 

Next you will need to download the design for the wheels “Rail_Cars_Wheels.stl” if you don’t already have that file.  There are eight wheels included in the wheels printing “platter”.  The multiple wheel content provides time for the plastic to cool while the other seven wheels receive a layer.  This reduces distortion due to printing on top of hot plastic.  Besides that, you always wanted some extra wheels for another rail car.

When slicing the file(s) use the same printer setup as for the caboose.

The trucks will require clean-up after printing.  There is an inside step in the vertical hole through the truck that holds the truck pivots/sleeves in place.  This will usually have a few plastic filaments hanging down since “support” was turned off.  Clean these out with a sharp knife and clean off any “burrs” on the truck pivots/sleeves.  The truck pivot should slide into the truck from the bottom (where the axle holes are) with about 0.5mm sticking out the top and rotate smoothly.

On the bottom of the gondola car frame are two arc indentions that form a rotation stop for the trucks.  Using a sharp knife cut out any “overflow” burr that may have formed as the first layer of plastic was deposited on the printing plate.

Start a M3 nut onto the end of an M3x10 mm screw.  Using the screw as a handle, push the nut into the nut trap in the inside of the gondola car.  Alternately, you can put the screw up through the bottom of the hole in the gondola car and start the M3 nut from the inside.  Then using a hex screw driver or Allen wrench you can pull the nut into the nut trap making sure the points are lined up.

Glue the magnets in the magnet holders using the same technique as for the caboose.  The reason you place the two trucks at arm’s length after gluing in the magnets is to avoid them snapping together while the glue is still wet.  After gluing the magnets into the truck magnet receptacles, install the wheels like with the caboose.

When the glue is dry for the magnets and wheels, put a screw up through the bottom of a truck pivot, put the truck pivot/sleeve up through the bottom of the truck and screw the assembly onto the bottom of the gondola car using the nut in the nut trap.  Make sure the rotation stops line up.  When you snug up the screws the trucks should rotate freely back and forth to the stops.

I’m sure your young engineer will enjoy operating this rolling stock selection.