Sep 7, 2013

Tutorial on how to design gears for 3d printing

Tutorial from youtube user Sidnmd on how to design 3d printable gears.

From video description:
Here is one of the many approaches to designing gears for 3D printing.
1) use Gear template maker to design a gear
2) export to a jpg file
3) use freeware wintopo to vectorize and save vector as a 3D dxf file
4) use a CAD program to import the 3D dxf and extrude surfaces
5) clean up with free netfab or send directly to 3D printer 
This project explains how I go about making different types of gear profiles (different sizes, tooth number, addendum etc...).
The Gear Template Maker (GTM) shareware is a program that was designed for CNC or laser cutting of gear outlines but only generates a 2D dxf file. I wanted to get to a 3D dxf file that could be 3D printed on an Up!3D printer.
The steps that I use apply to sprocket gears, involute gears,rack and pinion gears.
The basic idea is to get from a jpeg image generated in GTM through freeware version of Wintopo to generate a 3D dxf file that you can extrude using any basic CAD program, then print on a 3D printer. The entire process should take under 3 minutes.

This video shows how to configure a sprocket gear that can be used with a Tamiya belt kit. See www/ project "Making gears".

Update (5.10.2014.):

Here is a different gear designing tutorial that was published on Instructables by user revrekad

From tutorial description:
3D models for gears can be created different ways - each way has pros and cons
Calculate parameters for gears manually - diameters of gear wheels, angles of teeth, etc. Create a 3D model in CAD software. Print models, test, correct, repeat...
  • Measure existing gears and use these parameters to create 3D model in CAD in the way as above. It's not easy to find gears similar to needed (even when they can be scaled)
  • Take the photo of existing gears (e.g from a toy car), print it scaled, put on the display and draw the 2D geometry in CAD - to reproduce gear's shape. This is more easy than in previous steps, but also required to find similar gears (or at least their picture)
  • Use graphics software with build in gear-generation features. E.g Inkscape (graphics editor with extension which renders a gears), FreeCAD (free CAD software), etc.
  • Use a program which generates geometry of gears by specified parameters - this way is describes in this video instruction.
Software used in this instruction:
  • Gear Generator - this is not free software. It allows to generate 2D geometry of gears and export it to dxf-file
  • PTC Creo Elements/Direct Modeling Express 6 - this is free software which allows to create quick and easy mechanical models for prototypes. This product allows to create models the way similar to solid modeling - but more simple. Version 6 has a great new feature - export 2D geometry on a workplane, this feature is used in the instruction.
  • Netfabb Basic - this is free software which allows to fix STL-geometry or rotate parts.
  • KISSliser - this is free software (with additional features available in purchased version). Prepare STL-geometry for 3D printing - slices and translates to G-codes.