Cardboard BB 7200 Locomotive

I always found trains beautiful and fascinating. Indeed, from the steam locomotives of the Union Pacific to the French TGV and the Shinkansen in Japan, trains fascinate by their mechanics, their imposing size...

That's why I built this cardboard locomotive, the BB 7200 of the SNCF, not as imposing but just as nice. I wanted to make a locomotive both realistic and cute to go on wooden tracks for children.

So I will explain the steps to make one.

• Cardboard (1 mm thick or some dimensions of the pattern should be changed)
• A cutter that cuts well
• Glue (white or gel glue) and a glue gun (not essential but allows more solidity)
• Paint (white, black and primary colors)
• Thin metal wire
• 2 toothpicks

I use calendars for the cardboard that make thin and strong boards.

The shape of the locomotive is a right prism. So draw the first pattern twice for the bases of the prism, i.e. the sides of the locomotive. Then draw rectangles respecting the dimensions to make the side faces of the prism, so the front, back, top and bottom of the train.

You will need to cut four notches in the bottom for the wheels.

You can see the 3d model of the locomotive on Tinkercad here.

You can now cut out the patterns. Also cut out eight 20 mm diameter discs to make the wheels.

When everything is cut out remove the layer of glossy paper with a blade to remove the writings and make the paint stick. Then you can scrape the cardboard with the blade to remove the protruding cardboard fibres

Glue the two sides on the top face with and add hot glue to make it stronger. The top face must be glued between the two sides.

Then add the front and back faces. Cut the rectangles if they are a little big and don't forget to keep a small space to insert the bottom face.

Cut a 20 mm wide strip of paper to the width of an A4 sheet and divide its length by two. Then roll the two bands with a toothpick. The toothpick should turn easily in the rolled strip.

Glue the two paper pipes on the underside (inner face).

Glue the eight discs together in pairs to make them wider. Paint the four resulting wheels black. You can add a very thin layer of hot glue around the wheels to make them non-slip.

Drill holes in the center of the wheels and fit the axle with a toothpick into the paper tubes. Place a quartered iron bead between each wheel and tube to make the wheels turn better.

First draw the shapes on the cardboard with a pencil.

Start painting the light and dark gray parts. Then paint the orange band (I use paper tape so it doesn't stick out) and the black windows.

You can search for images of BB 7200 on the internet.

To make your locomotive more beautiful you can add a lot of details such as the ramp to enter the cabin or the pantographs.

I made the ramp and the pantograph with metal wire and I stuck the wire in the cardboard with hot glue or white glue. I also added windshield wipers with a small piece of wire, the buffers with small cardboard discs and the headlights with red and white paint. If you are motivated you can add leds to make the headlights or the interior of the cabin making windows with transparent paper.

All that remains is to fit or glue the body on the bottom side. You have to add a weight in the locomotive so that it runs with more inertia.