Is GearDXF free for commercial projects?

Yes, GearDXF is 100% free for both personal and commercial use. You can export DXF, SVG, and PDF files with zero watermarks and no subscription required.

What is the difference between Metric Module and Imperial Diametral Pitch?

Metric Module (m) is the pitch diameter in millimeters divided by the number of teeth (m = D / N). Diametral Pitch (DP) is the number of teeth per inch of pitch diameter (DP = N / D). They convert directly using the formula m = 25.4 / DP.

How do I calculate the center distance for two meshing spur gears?

For standard external spur gears, add their tooth counts together, multiply by the module, and divide by 2: Center Distance C = (m * (N1 + N2)) / 2.

How much backlash should I add for laser-cut or 3D printed gears?

For laser-cut acrylic or plywood, add 0.15 to 0.30 mm of backlash to absorb beam kerf and wood expansion. For FDM 3D printing with PLA or PETG, add 0.25 to 0.40 mm of backlash to prevent binding from nozzle over-extrusion.

Can I import GearDXF files directly into Fusion 360, SolidWorks, or LightBurn?

Yes. GearDXF creates clean, closed-loop AutoCAD R12/R14 DXF polylines with dedicated layers for outer profile, interior holes, keyways, labels, and center crosshairs.

GearDXF Working Manual: Technical Reference and Workshop Guide

A practical, friendly manual for engineers, machinists, and makers who cut, 3D print, or machine precision gears with GearDXF.

1. Quick Start: Build Your First Working Gearbox in 5 Minutes

Open the app. A single 20-tooth, module 6 spur gear is the root driver. Add a meshed gear, set teeth to 40 for a 2:1 ratio. Orbit using connection angle, run the kinematic simulation, and export to DXF, SVG, or PDF.

2. Connecting Gears: Mesh, Axle Shafts, and Compound Reductions

The gear train is a hierarchical tree. Mesh connections reverse rotation direction and share module. Axle connections lock gears onto the same physical shaft line with 1:1 speed, allowing stage 2 to introduce a new module.

3. Spur Gears: Tooth Geometry, Pressure Angles, and Involute Profiles

True mathematical involute gear flanks based on the standard 20 degree rack generator. Equations for pitch diameter, base circle, tip addendum, root dedendum, and bottom clearance.

4. Internal Ring Gears: Annular Geometry and Pinion Clearances

Annular ring gears with inward-facing concave involute teeth. Automatic rim thickness safety walls and clearance rules to prevent tip collision during assembly.

5. Rack and Pinion: Linear Motion and Travel Calculations

Straight gear bars converting rotary shaft torque into linear feed force. Linear travel speed formulas and solid backing bar body depths.

6. Mounting and Weight: Center Bores, DIN 6885 Keyways, and 11 Spoke Styles

Axle center bores, standard DIN 6885 / ISO 773 metric parallel keyway charts, and 11 parametric lightening spoke cutouts including circular holes, slots, trusses, hexagons, and cast spoke arms.

7. Backlash and Machine Tolerances: Real-World Fit for Lasers, 3D Printers, and CNC

Circumferential tooth thinning equations. Recommended backlash values: 0.15 to 0.25 mm for acrylic laser cutting, 0.20 to 0.35 mm for plywood laser cutting, 0.25 to 0.45 mm for FDM 3D printing, and 0.04 to 0.08 mm for CNC milling.

8. Exporting to CAD and CAM: DXF Layers, SVG Vectors, and Fabrication Layouts

AutoCAD DXF R12/R14 layer structure: profile (Red, ACI 1) for outer cut, holes (Blue, ACI 5) for inner cutouts, labels (Green, ACI 3) for text etching, construction (Gray) for pitch circles, and center_marks for crosshairs. True 1:1 scale printable PDF templates.

9. Step-by-Step Software Guide: LightBurn, Fusion 360, SolidWorks, and Slicers

Clear import walkthroughs for LightBurn laser software, Autodesk Fusion 360 sketch extrusions, SolidWorks 2D sketch importing, and direct SVG 3D printing in Bambu Studio and PrusaSlicer.

10. 1:1 Scale PDF Drilling Templates and Calibration Checks

Printable workshop drawings with true 1:1 scale verification, custom title blocks, and a 100 mm calibration check box to eliminate printer scaling distortion.

11. Canvas Controls, Shortcuts, and Cloud Project Saving

Viewport navigation controls, Spacebar animation toggle, H hotkey for manual access, and automatic Firestore cloud project syncing.

12. Tried-and-Tested Workshop Recipes: Real Projects Ready to Cut

Tested parameters for robotics multi-stage gearboxes, acrylic clockwork trains, and heavy-duty CNC aluminum rack and pinion assemblies.

13. Shop Troubleshooting: Fixing Binding, Scale Errors, and Undercutting

Practical diagnostic solutions for tooth undercutting on small pinions, ring gear tip collisions, laser kerf binding, and CAD unit import scaling issues.

14. Engineering Formulas and Quick Reference Table

Complete formula reference sheet for pitch diameters, center distances, tooth thickness, and CAD layer color mappings.

15. Frequently Asked Questions (FAQ) for Makers and Engineers

Answers to common questions regarding commercial usage rights, module vs diametral pitch conversion, center distance calculation, and laser cutting toolpath ordering.

16. About GearDXF: Core Tools, Privacy, and Workshop Workflows

Why GearDXF was created, the four integrated tools in one (spur gear calculator, gear ratio calculator, visual gear builder, and kinematic mesh simulator), 100% client-side privacy with zero server uploads, and craft workflows for laser cutting, 3D printing, CNC milling, woodworking, and robotics.