Little Foundry Steam Locomotive
Original static miniature locomotive with an exact octagonal boiler net, open square chimney, window-cut cab and six chassis-mounted paper wheels.
Materials
- 180-220 gsm cardstock
- Scissors or craft knife
- Cutting mat
- Ruler and scoring tool
- PVA glue
Finished size: 110 x 44 x 78 mm
Steps
CutValley foldMountain foldGlue area
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Cut and score
Print at 100 percent; confirm the 50 mm ruler. Cut every outline and remove all five cab window openings. Score dashed lines. Use 180-220 gsm cardstock; wheels are fixed decorations.
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Close chassis beam
Fold C1 at 90 degrees around a 36 x 12 mm cross section. Glue the 4 mm long seam inside the first face. Fold the 3 mm end tabs inward 90 degrees and glue C2/C3 over them. Finished beam length is 110 mm; let dry.
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Form octagonal boiler
Fold B1 longitudinal creases 45 degrees in the same direction. Glue its 4 mm seam inside the first facet. Turn end tabs inward 90 degrees and glue B2/B3 onto them. Boiler length 64 mm, across flats 32 mm. Glue its bottom flat facet onto the chassis top, front end 8 mm behind the chassis front; rear end at 72 mm. Dry fully.
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Stand cab walls
Fold each A1-A4 bottom and top flange inward 90 degrees. Glue feet onto the chassis top: side walls from 72 to 106 mm behind front, flush with both chassis sides. Front/rear walls span the 36 mm width at 72/106 mm. Keep windows unobstructed; lightly glue vertical butt joints. Front twin small windows sit above the boiler.
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Fit cab roof
Glue A5 onto the four inward top flanges at height 62 mm. Roof overhang is 4 mm on every side. Flanges overlap at corners; apply thin glue and hold square until dry.
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Mount chimney
Fold F2 four flanges upward 90 degrees. Glue its 10 x 10 mm floor on the boiler top flat, centered 25 mm behind chassis front and across the width. Fold F1 corners 90 degrees, glue its 4 mm seam inside, and slide its bottom over F2 flanges. Glue the four 4 mm overlaps. Leave chimney top open.
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Attach stationary wheels
Glue the upper marked rectangle of each W wheel directly to the chassis side. Wheel centers are 22, 52 and 88 mm behind front and 12 mm above the table, exactly on the lower chassis edge. Align all six bottoms on a flat table and hold until dry. These full-face mounts require no axle, wire or hidden support; do not try to roll the train.
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Add hubs and dry
Center each H disk on the outward face of its matching W wheel. Glue flat and allow all joints to cure. The six stationary wheel disks support this miniature; handle by the chassis, not chimney or roof. Physical print/cut/assembly validation is deferred.
Notes
The 3D model shows each piece in its finished, idealized shape; the exploded view only spreads the pieces apart. It is not a paper-physics simulation: curved shapes are forming guides, not exact physical folding or proof of developability, and intermediate fold shapes are not supplied.
- Original miniature, not a scale replica. Decorative nonrolling wheels; no functioning engine or mechanism.
- Every shell facet and tab has an exact piecewise-rigid flat correspondence. Boiler is intentionally octagonal, not a smooth cylinder.
- All supports are supplied paper parts: closed chassis beam, glued wheel mounts, cab flanges and chimney foot. No hidden axles.
- Zero-thickness preview idealizes paper and glue thickness; hub faces offset 0.15 mm to show the paper layering. Flange overlaps are intentional.
- Generation only. Physical printing, cutting and assembly remain pending; screen review deferred.