If you have ever need to create a gear to 3d print you may have been frustrated as I was. Turns out you can with only free tools.
Inkscape is a Vector Image creation and editor tool that is free and it happens to have a GEAR extension built in. But it's only 2d so how do we create a printable 3d gear?
Step 1: Inkscape
In Inkscape you click on extensions and find GEAR, then a dialog will pop up. The options are:
1) Number of teeth
This should be the same for all gears that you want to mesh
3) Pressure Angle
This one is the most important for getting gears to mesh with each other. They must have the same Pressure Angle
For more information about gears and they properties I suggest Gears
When you have your gear outline, Select it and then Save as SVG
Step 2: Tinker Cad
Tinker Cad is a free online CAD program that is very easy to lean to use and is a great starting point for making things you wish to 3d print. You do need to create an Adobe ID before you can use it.
In TinkerCad there is an Import file option, this will allow you to import your gear SVG file, and will automatically extrude it into 3d.
From there you can modify it, make a hole in it etc then export it as an STL and 3d print it.