Generate spur, helical, and herringbone gears with user-friendly inputs.
Existing gear libraries require parameters that, while inherent to gear design, make the design of gears that will properly mesh challenging for an unknowing user.
In order for general spur gears to mesh, they must have identical pressure angles and diametral pitches (as well as a few other conditions, but the library takes care of those). If you're not sure what you just read, this library may be right for you.
These modules interface with the core library involute_gears, hiding parameters that result in incompatible gears if set without proper background knowledge. Specifying the number of teeth sounds like a helpful setting, but it's actually not a very useful place to start, as it affects many other parameters that one wouldn't expect.
Generate three types of gears sitting on the xy plane, centered on the z-axis. All inputs are optional, and their meaning is explained in the comments of each module.
spur_gear(pitch_diameter,
bore_diameter,
thickness,
pressure_angle,
diametral_pitch
)
herringbone_gear(pitch_diameter,
bore_diameter,
helix_angle,
thickness,
pressure_angle,
diametral_pitch
)
helical_gear(pitch_diameter,
bore_diameter,
helix_angle,
thickness,
pressure_angle,
diametral_pitch
)
The core library allows more inputs, such as hub size, rim size, etc., which
allow you to make prettier and more functional gears.
These were left out for brevity of the input list, but can be exposed by
adding them to the modules below. To see the full list of input options,
go to ~\OpenSCAD\libraries\MCAD\involute_gears.scad and check the
argument list of the module gear.
As always user friendliness limits functionality. For more information on gear design, see Kinematics, Dynamics, and Design of Machinery by K. J. Waldron, Chapters 10 and 11.