Cut lists by scale
A T-TRAK single straight is the foundation piece — every other shape (double, corner, junction) is a permutation of the same idea. The numbers below are for one single straight in each scale, the right place to start your first module. Sheet stock is given so you can buy enough to allow a sensible kerf and a few square cuts off-cut.
N — single straight
The default for most Australian clubs. 6 mm MDF or B-bond ply.
- Base300 × 308 mm×1
- Side308 × 70 mm×2
- End288 × 70 mm×2
- Glue block32 × 32 × 64 mm hardwood×4
- Skyboard308 × 250 mm×1
Sheet stock to buy: one 300 × 900 × 6 mm panel for the box, plus one 450 × 600 × 6 mm panel for the skyboard. The off-cuts will go a long way toward a second module.
HO / OO — single straight
Larger footprint, two pine stays bracing the long sides.
- Base490 × 490 mm×1
- Side490 × 70 mm×2
- End478 × 70 mm×2
- Skyboard490 × 410 mm×1
- StayDAR pine 42 × 19 mm, length 408 mm×2
Sheet stock to buy: one 600 × 900 × 6 mm panel covers the base, sides, ends and skyboard with sensible off-cuts. The pine stays come from the timber rack at any hardware store.
Mini-T — single
A different beast: tiny, light, and stress-loaded at the joints. Use 12 mm hardwood ply for all three pieces.
- Base150 × 62n mm (n = unit count)×1
- Side / endcut to base perimeter, height as variant×2
- Backboardto base length, height as variant×1
Material rule: 12 mm hardwood ply only. Pine and MDF are not recommended at this size — pine warps, MDF snaps at the screws. See Mini-T variant for the full geometry table.
Hardware
A small bag of metalwork. Buy a few extra of each — you will drop one tee nut into the workshop floor and never see it again, and the M6 bolts come in packs of ten anyway.
- Tee nutM6, four-prong, hammer-in×4
- Carriage boltM6 × 50 mm, full thread (not part-thread)×4
- Hobby screwNo. 00 Phillips, black; 6 mm for N, 12 mm for HO/OOas needed
- Pilot drill⌀ 1.6 mm (1/16″)×1
- Hole saw⌀ 19 mm for RCA feeder ports×1
On the carriage bolts. Full-thread is non-negotiable. A part-thread M6 will run smoothly until you wind it up to the height your neighbour's module needs, and then the unthreaded shank will jam in the tee nut and refuse to move another half-turn. Either you bottom out short or you bottom out tall — neither helps you set up at 90 mm. Pay the extra two dollars for full-thread and the problem disappears.
On the hobby screws. The 6 mm N-scale length is what holds Kato Unitrack down without poking through your 6 mm base into the bolt heads underneath. Drive them by hand from a small Phillips driver — a power driver will spin the head off, and the head is the only thing keeping the track in place.
Tools
A short kit. If you already build anything in wood you almost certainly own most of it. The two items most builders forget are the 19 mm hole saw and the Kato re-railer — neither expensive, both painful to do without.
- SawHand saw or drop saw — square cuts are essential, not optional×1
- DriverSmall Phillips screwdriver, hand-driven×1
- ClampsOr weights — anything to hold the box square while glue sets×4+
- Steel ruler300 mm — also our recommended track separating tool×1
- DrillCordless or corded, with 1.6 mm and 19 mm bits×1
- Re-railerKato #24-000 — notched sides gauge the 33 mm spacing when laying track×1
The Kato re-railer is the single cheapest tool that matters most. The notches on its long edges aren't there for decoration — they are exactly the spacing the standard wants between the inside rails of the front and rear tracks. Slot two re-railers between the tracks while you screw them down and the geometry sorts itself out.
Build sequence
Six steps, in order. Do not skip ahead — the levelling feet need to be set before you fix track, because you can't reach the underside of the box once the track is in. Every problem we see at meets traces back to one of these steps being done out of order.
1. Cut square
The whole system depends on right angles. A drop saw, a circular saw against a track, or a tradesman's mate with a panel saw is your friend here. Freehand jigsaw cuts will haunt you for the life of the module — sides won't sit flush, ends won't sit flush, and the box will wobble the moment you trust it to stand on its own.
Sand the edges flush after cutting. A sanding block on a flat surface, four passes per edge, is enough to lose the saw burr without rounding the corner. If you can rock a side panel on a flat bench, it isn't square enough yet.
If you can't cut square, get the timber yard to do the rip. Most will do it for the cost of a coffee.
2. Glue the box
Sides go outside the ends, not the other way around — that is what makes the front face 300 mm wide instead of 288 mm. Glue blocks slot into the four inside corners; they are what your levelling-foot tee nuts will eventually anchor into.
Run a bead along each mating face, assemble on a flat surface, and weight or clamp until cured. Yellow PVA, aliphatic resin, or an MDF-specific adhesive (Selleys MDF or similar) all work; contact cement does not. Contact cement gives a rubbery joint that creeps under load and the corners will rack out of square within a year.
6 mm MDF is the recommended default — flat, cheap, takes paint beautifully. Plywood works too: B-bond exterior or A-bond marine grade only. Avoid C/D structural ply (knots, voids). Whichever you pick, seal MDF cut edges with thinned PVA before paint.
3. Set the levelling feet
Drill a clearance hole in each corner from below — 7 mm through the glue block is plenty. Hammer a tee nut into the underside of the block from inside the box; the four prongs should bite into the timber and sit flush. Run the M6 carriage bolt up through from underneath.
Turning the bolt by hand from inside the box now lifts the module. Wind it all the way down and the module sits at 70 mm; wind it all the way up and it reaches 100 mm. The standard target is somewhere in the middle — 90 mm at the rail head — which gives you headroom to compensate for a sloping table.
4. Drill feeder ports
Two 19 mm holes per module, drilled through the underside of the base, accept the standard RCA-bushing power feeders. Position them 45 mm and 78 mm in from the front face for N scale; 96 mm and 156 mm for HO/OO.
Drill them now even if you don't intend to wire on the day you build. It is a great deal easier to drill into a bare box than into a box that already has track, ballast and a half-finished cement works on top of it. Cover the ports with a strip of masking tape until you fit the bushings.
Drill out the moulding hole in the Unitrack base to 1.6 mm, then drive a small black No. 00 hobby screw by hand. Black blends into the ballast and the screw heads disappear. Silicone, contact adhesives and most construction glues are not recommended — Kato's plastic base sheds them within a season.
5. Lay the track
Set the Kato re-railer on the base between where the front and rear tracks will sit and you have your 33 mm centre-to-centre spacing for free. Two re-railers, one near each end, stop the tracks from creeping inward as you screw them down.
Pin or screw — both are valid. Pins go through the existing post holes in the Unitrack base. Screws go into 1.6 mm pilot holes drilled through that same hole. Most adhesives won't hold the Kato base under any sort of mechanical load, so the rule is mechanical fixings only. If you need to lift the track later for a wiring fix, you will be glad you didn't glue it down.
The track must overhang the module ends by exactly 1 mm. Not 0.5 mm. Not 1.5 mm. Exactly 1 mm. A strip of 0.040″ (1 mm) styrene held against the end face as a setback gauge takes all the guesswork out — push the track up against the styrene strip, screw down, remove styrene.
6. Skyboard
The skyboard goes on last, and it must come off again — modules go in and out of cars, and a fixed skyboard makes packing a nightmare. Two M6 bolts through the back face into tee nuts in the skyboard, or four self-adhesive Velcro pads, are both acceptable. Test the lift-off before you paint.
Paint the skyboard a sky tone — soft mid-blue, slightly grey, reading as "fair weather mid-morning." Resist the temptation to paint clouds; a row of three modules with three different cloud styles is more distracting than helpful.
Checking before paint
Five questions. If every answer is yes, prime and paint. If any answer is no, stop and fix — paint over a problem is a problem in a prettier coat.
- Track ends protrude from the module ends by exactly 1 mm?
- Levelling bolts move freely through their full 70 → 100 mm range, no binding?
- With all four bolts wound to minimum, does the module sit flat on a level surface — no rocking?
- Does the skyboard fit, sit square, and lift off cleanly for transport?
- Have both feeder ports been drilled at the correct offsets?
If all five are yes, you have a structurally sound module. Prime with a grey or brown undercoat, paint inside the box matt black (light spill kills the illusion of a tunnel mouth), and you are ready for scenery and electrical.
Where to buy the bits
Australian retailers stock every item on the lists above between them — sheet stock from the timber yard, hardware from any decent fastener shop, the Kato re-railer and Unitrack from any of the model railway suppliers. We maintain a comprehensive list with current stockists, postage notes and useful substitutes on the tools page.
The very short version: Bunnings or your local timber yard for the sheet and pine, Mitre 10 or a fastener specialist for the M6 hardware, and any model railway shop or hobby store for the Kato re-railer and the small black hobby screws. None of it should cost more than a hundred dollars to outfit your first module.