Introduction: Make a Loco From Junk

About: Eldest of five, son of two doctors, 10 years in Graphic Design and marketing, then retrained as a Biomedical Materials Engineer, don't ask me why, I think it was because I had always wanted to design artificia…
When I was a kid, and later as a grown up I wanted a train set. Not one of those little ones (which are very nice I am sure) but a really big one with finely detailed engines and carriages. They cost thousands and I don't see any way that I could justify spending that much money (even if I had it) on a toy like that. However, instead I decided to make a train set out of Junk. Here is the locomotive. The key to the success of this model is the brainwave I had of making the wheels like a real train's wheels... with FIXED axles. the rotation (because these wheels actually do roll) is provided by the way they are simply fixed to the chassis. This method of making the wheels is good for all sorts of train carriages from Circus Box Cars, to Tenders and should give hours of making fun and subsequently heaps of playability. This project appears in my book, dadcando: Build make do... the best way to spend quality time with your kids, which can be bought on or soon (after 5th July) on

Once you have the idea of the wheels in mind, you will quickly see that you can make any type of train loco from diesel through electric to good old fashioned steam, using drinks cartons or cut down cereal boxes as the bodies.

As this is a model made from junk the exact components are open to what you have at hand, or can easily get, but ideally you will need:
  • Bottle caps
  • thick and thin cardboard
  • coat hanger wire
  • hot melt glue (ideally)
  • set of compasses
  • single serving
  • drinks bottle
  • black and one bright colour paint (ideally spray paint)
For all the rivet counters out there... this is only a model built for fun using junk and is NOT meant to be a replica of any particular engine ;-)

Step 1: Make the Wheels

For this Steam Engine you will need 4 large wheels and 4 small ones. For the large wheels use poly-bottle milk lids with diameter 40mm (or similar), for the small wheels, use soda bottle lids, diameter 30mm. Draw 4 circles at 50mm diameter and 4 at 38mm diameter, on some thick card (foam board is perfect) cut out and then glue  the lids centrally, one to each disc
(glue gun / hot melt is the best glue for this).

If you don't have any bottle caps, you can cut the middle disc of each wheel out of the same cardboard.

If you want to make a diesel or electric loco with a rectangular body, then you will probably only need four sets of large wheels, or 6 sets if you wand to make a mahoosive Union Pacific Locomotive (check out Google images for some reference). ON the other hand if you want to make a little siding shunter, maybe only small soda bottle top wheels are all you will need... scratch building - so many choices.

Step 2: Make the Wheel Assemblies

Like real train wheels, this project uses a fixed axle design. Actually this is the complete breakthrough of this project. Cut 4 lengths of straight coat hanger wire about 85mm long. To make each wheel pair, push one end of a wire length through the cardboard side of the wheel. Remove it and then put the nozzle of the glue gun up to the hole and squeeze in a little bit of hot melt glue. Push the wire axle in fully.

Do the same at the other end of the wire so that you have 2 wheels glued securely on the axle. Make sure that the wheels are at right angles to each other. Repeat for the other big and small wheels until you have 4 sets of wheels and axles.

Step 3: Make the Floorpan

To make the wheel trucks or bogies, cut 2 x 2 rectangular pieces of thick cardboard. The width of the cardboard should just fit between the wheels so that they don’t rub.

The width of the rectangles will depend on the size of lid you used and the thickness of your cardboard for the wheels. The floorpan has to fit between the wheels so that they don't wobble about too much, but still turn freely (i.e. don't foul on the side of the card).

In one of the small pieces and one of the large pieces make two crosswise channels (spaced apart as shown). Either cut a vee shaped groove or crush the cardboard in with the back of a dinner knife. Do no cut all the way through. Only make grooves in 1 set of the rectangles.

If you are making a diesel or electric loco using a rectangular body, you won't need the small wheels and you won't need the two stage floorpan. One large floopan with 4 grooves in for four wheels is all that you will want.

Step 4: Assemble the Bogies

Carefully glue round the parts with the grooves in, making sure NOT to get the glue in the grooves and then rest the wheel assemblies in the grooves and stick the matching bit of card over the top, trapping the wheel assemblies but still allowing them to rotate freely.

Step 5: Make the Chassis Part 1

Join the 2 wheel bogies together with thick vertical stepped cardboard strips, shaped as shown.

To do this nicely, cut 2 rectangles of thick cardboard about 250mm long and about 60mm wide. Rest the wheels on a level surface and cut a step in the card so that you can glue it to both sets of wheels, while they are both resting on a flat surface. Make sure that when the cardboard is glued to the base it stands higher than the big wheels. To do this, the width of the cardboard at the big wheel end should not be less than 30mm, although its actual size depends on the size of wheels that you have chosen.

Step 6: Make the Chassis Part 2

Now you have the basic running gear assembly you can start to build up the locomotive parts. Cut 2 long thin rectangles of thick card that extend to just cover the big wheels and glue them on to the top of the chassis. Cut 4 small rectangles of thick card and glue them behind the big wheels (these will be the driver’s steps). Use two on each side. Finally cut a piece of thin card only as wide as the chassis and use it to box in the part over the small wheels.

Spray the whole assembly black. Don’t spray too thickly all at once, or you will gum up the wheels. Three or four light coats of spray from all angles should be enough, making sure that the wheels still turn after each coat.

Step 7: Cut Out the Boiler

Use a large, straight sided personal care or soap pump dispenser bottle for the boiler.

Mark round the bottle so that your cut will be at right angles to the axis of the bottle and neatly cut with strong scissors.

(Always mark before you cut, so that the result is neat and straight.)

If you don’t have the right containers at home, WHY NOT specially go out and buy a cheap one from a supermarket and decant the contents into another bottle. Actually when you look round the supermarket there are loads of lovely shapes in the bottles and containers. Most are made from good quality engineering materials (card and plastic) and they can form the basis for loads of models, dies and moulds.

Be creative, buying stuff to use the packaging after is actually much better (and much cheaper) than buying expensive model kits... and you get to use the product! Win - win, AND you get to use your brain to work out how all the bits fit together. Next time you walk around a supermarket look with new eyes at all the packaging imagining what cool stuff you could make from it.

Step 8: Make the Funnel

To make the funnel, mark then cut the top and base off a single serving drink bottle. At the top, cut slightly past the shoulder so that the top fits snugly in the base part. Turn over, apply glue to the cut rim of the top and glue inside the base. When set carefully cut a circular hole from the base part to make the funnel opening.

TAKE CARE, the base of a bottle is the toughest part of the plastic, and it is easy to slip and cut yourself if you are pressing hard with a knife. It is safer to cut the hole with a little hand held jig saw if you have one.

Step 9: Assemble the Boiler and Funnel

Rest the boiler onto the wheel chassis and position the funnel in the best place and carefully mark round it on the boiler.

Carefully cut out the hole for the funnel base. Check that the funnel fits and adjust the hole as necessary. You’ll see that the top of the original bottle that you used for the funnel has a flange round it, this will form the base of the funnel when it is inserted into the boiler and provides for a nice finish when the funnel is in place. Apply glue to the funnel and push into the hole in the top of the boiler.

Glue a smaller rounded bottle cap in place behind the funnel and then paint the boiler and funnel. Spray is best, and if you used clear bottles, spray inside for a lovely glossy finish.

Step 10: Make the Lamp

Make the lamp from 3 small rectangular pieces of thick cardboard glued together. For a neat finish, cover the edges with thin card or paper and paint or spray the finished block, black.

Cut a thin slice off the top of a white or clear, single serving drinks bottle and glue to the block to form the reflector and glass of the light itself.

Step 11: Make the Drive Pistons

Make 2 drive pistons, 1 for each side, using a rolled up piece of thin card or plastic glued at each end into a single serving drinks bottle cap. Paint or spray them the same colour as the boiler.

Step 12: Make the Cabin and Assemble the Engine

Glue the boiler and drive pistons in place, so that the pistons are level with the front of the boiler and rest up against the front of the walk-boards.

Glue the lamp in place.

Cut the cabin out of thick card using the template as a guide. For a neat finish, paint the cabin before you glue it to the locomotive assembly. Use a piece of thin card for the curved roof, cut out so that it overhangs by a small amount at the front and sides and as far as the back of the locomotive at the back.

I used a piece of card from a craft store that was corrugated on one side so that the card bent nicely, but also looked like a corrugated tin roof. I'm not sure that this was what real trains had, but the detail looked good to me.

Lastly use thin cardboard to make the cabin floor to fit inside the cabin, paint and glue in place.

Step 13: Put the Finishing Touches to Your Loco

Add detail and decorate as much as you want.

Stick black straws to the sides of the boiler as guide rails, and at the join between the boiler and chassis to hide any glue blobs. Stick thin pieces of card to the cabin side as trim and anything else you can think of.

Here are some ides of how you could personalise your locomotive, you could add:

A whistle make from drinking straws
Coat hanger wire sprayed silver to act as handrails along the side of the boiler
A cow catcher made of thin foil coated card (from a take out tray)
An Instrument binicle
A furnace door (inside the cabin)
A name plate with the locomotive's name on it

One of the things that you could do is make a tender and some carriages or trail cars for the loco to make it into a train. The model is satisfyingly large and will take medium sized plastic animals in proportion to it, so one really cool thing you could make is a Circus Train. I have started doing just that and you can see instructions for making carriages on, but you can see some of the photos here as well