The Model Railway Handbook

Build your own

Draw the train you want. Then go and make it.

Sketch it on the pad below with a finger, a mouse or a stylus — or trace over a photograph — then describe what it is, and the bench writes you a build sheet: the route in, the order of work, the parts to buy and the thing that most often goes wrong.

The design bench

Nothing here is uploaded anywhere. The drawing is stored in this browser only, so it is still here when you come back — and gone for good if you clear the page.

Draw it

Side elevation, left to right, wheels on the bottom line. The squares are there to keep the ends vertical and the roof level.

mm deep

The scale below the pad is prototype feet: a 60 ft coach fills the sheet, a four-wheel wagon takes about a sixth of it.

The STL is your outline filled in and extruded to the body width, in millimetres, at whatever scale the form on the right is set to — so it prints the size the real model would be. It is a solid block of your silhouette: ideal for checking proportions in the hand, or as a core to detail over, rather than a finished body shell.

Describe it

Six answers is enough. The sheet updates as you type.

Choose what you are building and how you want to build it, and the sheet writes itself — the sequence, the parts to buy, and the thing that most often goes wrong.

Five ways to build a train, easiest first

They are not a ladder. Plenty of people kitbash for thirty years and never touch a soldering iron, and the results can be superb.

Start here

Kitbash a ready-to-run model

Take a cheap running model, cut the body about, and put it back together as something else. Shorten a coach, splice two wagons, swap a cab. The chassis already works, which removes ninety per cent of what makes model building hard.

Most popular

Plastic kit

Injection-moulded parts on a sprue, designed to fit. A wagon kit is an evening's work and costs less than a ready-made one. This is where most people learn to prepare parts, glue properly and paint.

A real step up

Etched brass kit

Flat metal sheets, half-etched fold lines, and a soldering iron. Sharper and finer than plastic can ever be, tolerant of being unsoldered and redone, and the standard way to get an obscure prototype.

Ambitious

Scratchbuild

Sheet styrene or nickel silver, a drawing, and a scalpel. Slow, and the only way to own a model of the thing nobody makes. Start with a plain-sided goods van, not a streamlined pacific.

Modern

3D print the body

Draw it once, print it as many times as you like. Ideal for repeated parts, awkward compound curves, and anything you want in a rake of six. The work moves to the screen, and the finishing still happens at the bench.

All five

Mix them

A ready-to-run chassis, an etched cab, a scratchbuilt bunker and printed castings is a completely normal recipe. Nobody is marking you on method.

1

Preparation — the half nobody photographs

Every disappointing model was rushed at this stage. Parts are moulded or etched with surplus material on them, and paint shows up every trace of it.

  • Wash plastic parts in warm soapy water and let them dry. Mould release agent is invisible and paint will not stick to it.
  • Remove parts properly: sprue cutters for plastic, a piercing saw for etched frets. Twisting a part off leaves a crater that has to be filled.
  • File flush, then check by feel. Your fingertip finds a raised nub that your eye misses.
  • Dry-fit everything with masking tape and look at it from a metre away. That is the distance the model will be seen from, and errors that matter are visible there.
2

The chassis, until it runs sweetly

Build the running gear first and do not go near the body until the chassis crawls, hauls and does not stall. A beautiful body on a poor chassis is a shelf ornament.

  • Bearings square, axles free. The chassis should roll down a 1% slope on its own before a motor goes near it.
  • Quartering on steam: the crank pins on the two sides must be exactly 90° apart. Out by a few degrees and the mechanism binds once per revolution; out by more and it locks. Use a jig, or buy wheels ready-quartered on their axles.
  • Gearbox ratio: roughly 40:1 for a mixed-traffic engine, 30:1 for something fast, 60:1 or more for a shunter you want to creep.
  • Pickups on every wheel — phosphor-bronze wire bearing lightly on the back of the tyre. This single decision separates models that run from models that stutter.
  • Weight as much as the body will swallow, low down and over the driven axles.
Run it in before you judge it

Twenty minutes in each direction, unloaded, at half speed. Tight new gears free up noticeably, and a mechanism that sounded rough often turns quiet.

3

The body — square, and square again

  • Work off the footplate or floor. It is the reference surface; if it is bowed, everything above it is wrong.
  • Cut openings while the sheet is flat. Drill the corners, join the holes with a scalpel, then file to the line with a needle file.
  • Use internal formers — scrap strip glued inside corners — so a slab-sided body cannot lozenge as the glue sets.
  • Check with a square at every stage, and hold assemblies together with elastic bands, clothes pegs or a sheet of glass while they cure.
  • Overlays hide sins. A layer of thin sheet over a seam is faster and neater than filling and sanding, and prototypes are full of panelling to imitate.
4

Joining one thing to another

MaterialsUseHow
Styrene to styreneLiquid poly cementHold the joint closed and touch a loaded brush to the seam — it wicks in and welds the plastic. Strong in minutes, fully cured in a day.
Metal to metalSolder, 145°C or 188°CClean, flux, heat the work not the solder, and use the least that will flow. Two melting points let you add a part next to one already fitted without dropping it off.
Metal to plasticCyanoacrylate, or two-part epoxySuperglue for small fittings — a pin-head's worth. Epoxy where there will be strain, such as a chassis mount.
Whitemetal castingsEpoxy, or 70°C low-melt solderWhitemetal melts at soldering temperature. Either glue it, or use low-melt solder and a temperature-controlled iron turned right down.
GlazingCanopy glue or PVANever solvent cement or superglue near clear plastic: one fogs it, the other frosts it, and both are permanent.
FillingBody filler, or stretched sprueSprue softened into the joint with cement shrinks and sands like the surrounding plastic, which filler does not.
5

Detail, largest to smallest

Work down in scale: roof fittings, then handrails, then lamp irons, then pipework. Small parts fitted early get knocked off by the handling that fitting the large ones requires.

  • Handrails from 0.3 mm wire in drilled holes look immeasurably better than moulded ones. Drill with a pin vice, glue from inside.
  • Leave the fragile things off until after painting: whistles, lamp irons, buffer beam pipework, glazing. Keep them in a labelled box.
  • Add a crew. An empty cab is the loudest signal that something is a model, and a painted figure costs a pound.
6

Paint and transfers

  1. Wash the model again — this time to remove finger grease and sanding dust.
  2. Prime thinly. Grey primer on light colours, and it doubles as an inspection coat: every flaw you missed shows up immediately, while it is still fixable.
  3. Colour in several thin coats, letting each flash off. One thick coat drowns the detail you spent a fortnight building.
  4. Gloss varnish where the transfers go. Transfers silver on a matt surface because air is trapped under the film.
  5. Apply transfers with setting solution so they snuggle down over rivets and beading, then dab, don't rub.
  6. Seal with matt or satin varnish. It unifies the surfaces and gives weathering something to key to.
  7. Weather last, and stop earlier than feels right — see weathering.
7

Testing, which is part of building

  • Check it through your tightest curve and worst turnout before painting, with the body loose so you can see what fouls.
  • Check the coupler height against the gauge, loaded and unloaded.
  • Haul a real train with it up your steepest grade.
  • Leave it running for an hour and come back. Faults that appear when warm are real faults.
  • Anything wrong now is a repair. Anything wrong after painting is a repaint.

A worked example: a four-wheel wagon in one evening

first build

Every skill in this page appears in miniature here, and the whole thing costs less than a takeaway. If you have never built anything, build this.

  1. Wash the sprues and lay the parts out on a light-coloured tray so nothing escapes.
  2. Clean up the solebars and floor, and dry-fit the body sides to the floor.
  3. Glue the floor and sides square against a set square, using liquid cement wicked into the corners. Leave it under a weight.
  4. Fit the W-irons and bearings and check the wheels spin freely for several seconds when flicked. If not, ream the bearings.
  5. Add weight to the NMRA figure — for a 10 ft wheelbase wagon in OO, about 40 g. Self-adhesive strip inside the floor, over the axles.
  6. Fit couplers to your standard and check the height with the gauge.
  7. Test it on the layout, unpainted, in a train, over every turnout you own.
  8. Prime, paint, transfer, varnish — then a wash of dirty brown into the plank lines, and dry-brushed rust at the door hinges.
  9. Add a load — real coal, real slate, a tarpaulin of tissue soaked in dilute PVA. A loaded wagon tells a story; an empty one is a box.
Then build the same kit again

The second one takes half the time and comes out twice as well, and you will have learned more from the pair than from any amount of reading. Wagon kits are cheap for exactly this reason.

Tools and materials to start with

Buy firstWhy
Scalpel and spare bladesA blunt blade tears plastic and slips into fingers. Change them far more often than feels reasonable.
Sprue cuttersClean removal without stressing the part.
Needle filesA set of six. Flat, half-round and square do almost everything.
Liquid poly cement + a fine brushThe join method that makes plastic kits look built rather than assembled.
Engineer's square, smallThe difference between a body that looks right and one that is subtly, permanently wrong.
Pin vice and small drills0.3–1.0 mm, for handrails, lamp irons and every wire detail.
Styrene sheet and strip20, 30 and 40 thou sheet plus an assortment of strip covers most repairs and modifications.
Wet-and-dry paper400 to 1200 grit, used wet. Finishes surfaces that files leave rough.
Cutting mat and a steel ruleStraight cuts, and a bench that survives.
Soldering iron, 40–60 WOnly when you move to metal — but when you do, a proper iron with a temperature control is worth more than any other single purchase.

Not on the list, and often bought first: an airbrush. It is wonderful and it is not urgent — several thin coats from a rattle can, warmed in a bowl of hot water first, will get you a long way.