MachineBlocks
ToolsOnline building block editor optimized for 3D printing LEGO-compatible bricks. Generate customizable 3MF/STL models with precision fit, built-in calibration tools, and API for creating custom brick designs.
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MachineBlocks - 3D Print Your Own LEGO®-Compatible Bricks
MachineBlocks is a specialized online building block editor that generates customizable 3MF and STL models of LEGO®-compatible bricks optimized specifically for 3D printing. The platform addresses the unique challenges of printing functional building blocks that require precise tolerances and reliable interlocking mechanisms, making it accessible for makers to produce their own compatible brick collections on standard FDM printers.
Key Features
- Comprehensive Brick Library - Generate standard bricks (1×1 through 16×8), Technic bricks with holes, plates, slopes, corner pieces, brackets, containers, and specialized components
- Built-in Calibration Tool - Systematic tolerance testing to achieve perfect fit between studs and clutch power across different printer/material combinations
- Direct Customization Interface - Adjust dimensions, stud patterns, and structural parameters through an intuitive web interface without CAD knowledge
- API for Custom Designs - Developer API enables programmatic generation of entirely new brick geometries and parametric families
- Print-Optimized Geometry - Models feature proper draft angles, minimal overhangs, and structural reinforcement for reliable printing without supports in most cases
Technical Approach
The platform focuses on solving the precision requirements inherent to interlocking toy bricks:
- Tolerance Management - Calibration workflow helps users dial in the 0.1–0.2mm clearance needed for smooth assembly without loose connections
- Material Flexibility - Works with PLA, PETG, ABS, and engineering filaments; calibration compensates for shrinkage and layer adhesion characteristics
- Export Formats - 3MF files preserve color assignments for multi-material printing; STL available for universal slicer compatibility
- Community Examples - Gallery showcases functional prints from the user base, including custom molds, display sets, and mechanical assemblies
Use Cases
- Custom replacement parts for rare or discontinued brick sets
- Educational projects teaching CAD, tolerances, and mechanical design
- Oversized or miniature brick variants for specialized applications
- Prototyping modular systems that leverage the standardized LEGO® grid
- Production of bulk bricks in custom colors or materials not commercially available
Getting Started
- Visit machineblocks.com and browse the brick examples
- Print the calibration test set to determine your printer’s optimal tolerance value
- Select and customize brick types from the library
- Download 3MF or STL files and slice with recommended settings (0.2mm layers, 3+ walls, 30%+ infill)
- Join the Discord community for troubleshooting and design sharing
MachineBlocks bridges the gap between digital modeling and functional printed parts, enabling makers to expand their building block collections with geometries and colors impossible to source commercially.
Disclaimer
LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this site. MachineBlocks is an independent project and is not affiliated with the LEGO Group. Printer.tools is not affiliated with MachineBlocks.