Can't find the part you need? Design it yourself! TinkerCAD is a free, browser-based 3D design tool that's perfect for creating custom model railroad parts. No software installation, no complex learning curve—just open a browser and start creating.
Getting Started with TinkerCAD
Setting Up Your Account
- Create a free Autodesk account
- Click "Create new design"
The TinkerCAD Interface
Workplane: The grid where you build
Shape panel: Basic shapes on the right side
Tools: Top toolbar for alignment, grouping, etc.
View cube: Rotate your view in the upper right
Navigation Controls
- **Rotate view:** Right-click and drag
- **Pan:** Middle-click and drag, or Shift+right-click
- **Zoom:** Scroll wheel
- **Reset view:** Click the home icon
Core Concepts
Primitive Shapes
TinkerCAD builds everything from basic shapes:
- **Box:** Rectangular solids
- **Cylinder:** Round columns
- **Sphere:** Balls
- **Roof:** Wedge shapes
- **Cone:** Tapered cylinders
- **Torus:** Donut shapes
The Magic of Holes
Holes are the secret to TinkerCAD. Any shape can become a "hole" that cuts into other shapes when grouped.
To make a hole:
- Click "Hole" in the shape panel (or press H)
- Group it with a solid shape—it subtracts!
Grouping Objects
Grouping combines multiple shapes (including holes) into a single object:
- Select all shapes (click and drag, or Ctrl+click)
- Click "Group" (or press Ctrl+G)
- Shapes merge, holes subtract
Important: Group only when you're done adjusting! You can ungroup with Ctrl+Shift+G.
Designing for 3D Printing
Scale and Measurements
TinkerCAD defaults to millimeters. For model railroad work, you'll need to think in scale:
| Scale | 1 real foot = | Common object sizes |
|-------|---------------|---------------------|
| Z (1:220) | 1.38mm | Person: 8mm tall |
| N (1:160) | 1.91mm | Person: 11mm tall |
| HO (1:87) | 3.51mm | Person: 20mm tall |
| O (1:48) | 6.35mm | Person: 37mm tall |
Tip: Create a "reference person" shape at the start to check your scale.
Minimum Wall Thickness
Thin walls fail during printing:
- **FDM minimum:** 0.8mm (two wall lines)
- **Resin minimum:** 0.5mm
- **Safe for both:** 1.0mm+
Minimum Detail Size
Details smaller than your printer can resolve will disappear:
- **FDM:** 0.4mm minimum feature size
- **Resin:** 0.1mm minimum feature size
Designing for Overhangs
FDM printers struggle with overhangs over 45°:
- Design with flat bottoms when possible
- Add chamfers instead of sharp overhangs
- Consider printing orientation during design
Model Railroad Project: Simple Structure
Let's design a small lineside shed, step by step.
Step 1: Main Walls
- Drag a **Box** onto the workplane
- Set dimensions: 25mm x 15mm x 15mm (HO scale ~8x5 ft)
- This is your basic building footprint
Step 2: Hollow It Out
- Drag another **Box** onto the workplane
- Set dimensions: 23mm x 13mm x 14mm (1mm walls)
- Lift it 1mm (for the floor) using the arrow tool
- Position it centered inside the first box
- Select both, click **Group**
Now you have a hollow building shell!
Step 3: Add a Door
- Drag a **Box** for the door opening
- Size: 4mm x 1mm x 8mm (a bit wider than person-width)
- Position it on one wall, sitting on the floor
Step 4: Add a Window
- Drag a **Box** for the window
- Position on a wall, raised off the floor
Step 5: Simple Roof
- Drag a **Roof** shape (wedge) onto the workplane
- Adjust size to cover the building plus overhang
- Group everything together
Step 6: Add Details (Optional)
- Use thin boxes for trim around doors/windows
- Add a cylinder for a chimney
- Use small boxes for foundation details
Advanced Techniques
Using the Align Tool
Keep things centered and positioned precisely:
- Click "Align" (or press L)
- Click the alignment points you need
Creating Patterns (Arrays)
For repeated elements like fence posts:
- Duplicate again—it repeats the same move!
Importing Shapes
You can import SVG files for custom outlines:
- Create a 2D shape in Inkscape (free) or Illustrator
- Extrude to desired height
Great for:
- Custom signs
- Logo shapes
- Complex outlines
Using Community Shapes
TinkerCAD has a "Shape Generators" library with useful premade shapes:
- Text for signs
- Gears and mechanical parts
- Architectural elements
- ISO threads for screws
Exporting Your Design
File Formats
STL - Most common, works with all slicers
OBJ - Includes color information
GLTF - For rendering and visualization
Export Steps
- Select your completed design
- Click "Export" (top right)
- Choose STL for 3D printing
Checking Your Design
Before printing:
- Import into your slicer software
- Check for errors (holes, non-manifold edges)
- Most slicers can auto-repair minor issues
- Preview the sliced result
Model Railroad Design Ideas
Structures You Can Design
- Lineside sheds and shanties
- Simple industrial buildings
- Signal towers and switch stands
- Station platform elements
- Loading docks and ramps
Detail Parts
- Custom signs (using text shape)
- Pallets and crates
- Barrels and drums
- Cable reels
- Air conditioning units
Tools and Jigs
- Track gauges for your scale
- Coupler height gauges
- Car spacing jigs
- Painting holders
- Storage trays
Tips for Success
Start Simple
- Begin with basic rectangular buildings
- Add complexity gradually
- Complete projects build confidence
Use References
- Prototype photos help with proportions
- Measure real objects when possible
- Scale calculators help convert dimensions
Test Print Early
- Print a test at low quality settings
- Check fit and proportions
- Adjust design before final print
Save Versions
- Duplicate designs before major changes
- Name files clearly with version numbers
- Keep successful designs for future reference
Moving Beyond TinkerCAD
When you're ready for more power:
Fusion 360 (free for hobbyists)
- Parametric modeling (dimensions update automatically)
- More precise measurements
- Better for mechanical parts
Blender (free)
- Organic shapes and sculpting
- Advanced modeling tools
- Steeper learning curve
OpenSCAD (free)
- Code-based modeling
- Perfect for parametric designs
- Very precise but requires programming mindset
Your First Project Challenge
Try designing a simple loading dock:
- Platform base (elevated box)
- Support posts (cylinders)
- Edge detail (thin strips)
This project uses multiple shapes, holes for cutting, and alignment tools—everything you need to know for most model railroad parts.
Start designing, start printing, and soon you'll be creating parts that no manufacturer offers!