Union Pacific / Wooden locomotive
Big Boy 4014.
Build an 87 cm steam locomotive from laser-cut plywood. Around 600 parts, right down to the details inside the cab.
Digital laser-cut files · Advanced build
87 cm length at 3 mm thickness · Tender sold separately
01 /The locomotive
A long boiler. A lot to build.
The Big Boy’s long body sits above rows of spoked wheels and connecting rods. The plywood edges trace those shapes all the way from the front steps to the cab.
This is a project for makers who enjoy a detailed build over several sessions. At 870 mm long in 3 mm plywood, the finished locomotive needs a shelf of its own.
01. The full profileLocomotive only / Dimensions at 3 mm
02 /In the details
Worth a closer look.
Explore the open cab, the wheels and connecting rods, and the details along the boiler.
The open rear of the cab reveals the window frames and layered plywood walls. This angle shows how the cab sits above the rear wheels.
Inside the cab / Rear view
Wheels and connecting rods / Close-up
Front-end construction / A closer look
The complete locomotive / From above
Boiler and top detail / Layered plywood
Along the boiler
Panels, lines
and layers.
Fine panel lines run along the Big Boy’s boiler. Around the twin openings on top, stacked plywood pieces make the depth of the construction visible.
03 /At your workbench
Make room for the Big Boy.
Check the fit.
Measure the plywood and choose the matching material version. Make a small test cut to check the slots and kerf.
Cut the parts.
Check the layout against your laser’s work area. Segmented parts are approximately 260 mm or less.
Follow the guide.
Use the included PDF assembly instructions and work through the model over several sessions.
Advanced build / Approximately 600 parts
A project to spend some time with.
About 600 parts make this an advanced build. Set aside space to sort the pieces and keep the assembly guide close as you work.
The download is for making the locomotive yourself. You’ll need your own material and access to a suitable laser cutter.
View the model on EtsyBefore you start.
- Material
- Plywood
- Supplied versions
- 3 mm / 1/8 inch
- Finished size at 3 mm
- 870 × 109 × 170 mm
Length × width × height - Parts
- Approximately 600
- Largest segmented part
- Approximately 260 mm
- Build level
- Advanced
- Assembly guide
- PDF included
Which cutting formats are included?
The 3 mm version includes DXF and SVG files. The 1/8 inch version is supplied in DXF. Check that your laser software opens the format for your chosen material.
Can I change the model’s size?
Scale every part equally. Slots and tabs scale too, so the plywood thickness must change in the same proportion. For example, a 3 mm design enlarged to 150% needs approximately 4.5 mm actual material. The finished dimensions increase as well. Test the fit before cutting the full model.
Is the tender included?
The locomotive and tender are separate designs. The matching tender is available through the link below.
Can I sell finished models?
The files are for personal use. Contact 21CNCStudio before commercial use or selling finished models. Do not share or resell the digital files without permission.
AI visualizations based on 21CNCStudio model renders.
The companion model
Add the Union Pacific tender.
Continue the build with the matching tender. Its files are sold separately from the Big Boy locomotive.
Explore the tender04 /From my studio to your workbench
Your turn to build.
Get the Big Boy 4014 laser-cut files and PDF assembly guide from the 21CNCStudio Etsy shop.
Get Big Boy files on EtsyDigital download · Locomotive onlyNo physical model or materials are shipped.