OpenSCAD gear generator
This is a fork of this OpenSCAD gear generator, translated into English.
OpenSCAD Library for Gear Racks, Involute and Worm Gears
A library for the parametric creation of gear racks, spur-, ring-, bevel- and worm gears, as well as of assemblies.
Parametric Gear Rack
Creates a gear rack.
This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 20° helix angle, a pressure angle of 20° becomes a pressure angle of 21.17° in the transverse section.
Format
zahnstange(modul, laenge, hoehe, breite, eingriffswinkel=20, schraegungswinkel=0)
Parameters
modul= height of the tooth above the pitch linelaenge= length of the rackhoehe= height from bottom to the pitch linebreite= face widtheingriffswinkel= pressure angle, standard value = 20° according to DIN 867. Should not be greater than 45°.schraegungswinkel= bevel angle perpendicular to the rack's length; 0° = straight teeth
Parametric Involute Spur Gear
Creates an involute spur gear without profile displacement following DIN 867 / DIN 58400.
Two gears will mesh if their modules are the same and their helix angles opposite. The centre distance of two meshing gears A and B with module m and tooth numbers za and zb is m/2·(za + zb)
Helical gears run more smoothly than gears with straight teeth. However, they also create axial loads which the bearings must be designed to contain. Recommendations for the helix angle depending on the module can be found in DIN 3978.
This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 20° helix angle, a pressure angle of 20° becomes a pressure angle of 21.17° in the transverse section.
Format
stirnrad (modul, zahnzahl, breite, bohrung, eingriffswinkel=20, schraegungswinkel=0, optimiert=true)
Parameters
modul= gear module = height of the tooth above the pitch circle = 25.4 / diametrical pitch = circular pitch / πzahnzahl= number of teethbreite= face widthbohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle to the rotation axis; 0° = straight teethoptimiert= if true, create holes for material/weight reduction resp. surface increase, if geometry allows
Parametric Herringbone Involute Spur Gear
Creates a herringbone spur gear without profile displacement. Two gears will mesh if their modules are the same and their helix angles opposite. The centre distance of two meshing gears with module m and tooth numbers za and zb is m/2·(za + zb)
Herringbone gears run more smoothly than gears with straight teeth. They also do not create torque on the axis like helical gears do.
A helix angle, if used, should be set between between 30° and 45°. Recommendations for the helix angle depending on the module can be found in DIN 3978.
This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 30° helix angle, a pressure angle of 20° becomes a pressure angle of 22.80 in the transverse section.
Format
pfeilrad (modul, zahnzahl, breite, bohrung, eingriffswinkel=20, schraegungswinkel=0, optimiert=true)
Parameters
modul= gear module = height of the tooth above the pitch circle = 25.4 / diametrical pitch = circular pitch / πzahnzahl= number of teethbreite= face widthbohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle to the rotation axis; 0° = straight teethoptimiert= if true, create holes for material/weight reduction resp. surface increase, if geometry allows
Parametric Gear Rack and Pinion
Creates a gear rack and pinion.
Helical gears / bevelled racks run more smoothly than gears with straight teeth. However, they also create axial loads which the bearings must be designed to contain. Recommendations for the helix angle depending on the module can be found in DIN 3978.
With a given module m and zp teeth on the pinion, the distance between the pinion's axis and the rack's pitch line is m/2·zp
This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 20° helix angle, a pressure angle of 20° becomes a pressure angle of 21.17° in the transverse section.
Format
zahnstange(modul, laenge, hoehe, breite, eingriffswinkel=20, schraegungswinkel=0)
Parameters
modul= gear module = height of the tooth above the pitch line/pitch circle = 25.4 / diametrical pitch = circular pitch / πlaenge_stange= length of the rackzahnzahl_ritzel= number of teeth on the pinionhoehe_stange= height from bottom to the pitch linebohrung_ritzel= central bore diameter of the pinionbreite= face widtheingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= bevel angle perpendicular to the rack's length resp. helix angle to the rotation axis on the pinion; 0° = straight teethzusammen_gebaut= assembled (true) or disassembled for printing (false)
Parametric Involute Ring Gear
Creates a herringbone ring gear without profile displacement. Helical gears run more smoothly than gears with straight teeth. However, they also create axial loads which the bearings must be designed to contain. Recommendations for the helix angle depending on the module can be found in DIN 3978.
This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 20° helix angle, a pressure angle of 20° becomes a pressure angle of 21.17° in the transverse section.
Format
hohlrad(modul, zahnzahl, breite, randbreite, eingriffswinkel=20, schraegungswinkel=0)
Parameters
modul= gear module = height of the tooth above the pitch circle = 25.4 / diametrical pitch = circular pitch / πzahnzahl= number of teethbreite= face widthrandbreite= width of the rim around the ring gear, measured from the root circlebohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle to the rotation axis; 0° = straight teeth
Parametric Herringbone Involute Ring Gear
Creates a herringbone ring gear without profile displacement. A ring and spur gear mesh if they have the same module and opposite helix angels. Herringbone gears run more smoothly than gear with straight teeth. They also do not create axial load like helical gears do.
A helix angle, if used, should be set between between 30° and 45°. Recommendations for the helix angle depending on the module can be found in DIN 3978. This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 30° helix angle, a pressure angle of 20° becomes a pressure angle of 22.80° in the transverse section.
Format
pfeilhohlrad(modul, zahnzahl, breite, randbreite, eingriffswinkel=20, schraegungswinkel=0)
Parameters
modul= gear module = height of the tooth above the pitch circle = 25.4 / diametrical pitch = circular pitch / πzahnzahl= number of teethbreite= face widthrandbreite= width of the rim around the ring gear, measured from the root circlebohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle to the rotation axis; 0° = straight teeth
Parametric Planetary Gear using Involute Tooth Geometry and Herringbone Shape
This script calculates both the ring gear as well as, if required, the number and geometry of the planetary gears from the number of teeth on the sun and planets. For a module of m, zs teeth for the sun and zp teeth for the planets, the centre distance will be m/2·(zs + zp)
If the number of planets is set to zero (anzahl_planeten = 0) then the module will try and calculate them.
For a module of m, zs teeth for the sun, zp teeth for the planets and a rim width of br, the outer diameter is m·(zs+2zp+2.333)+2br
The helix angle should be between between 30° and 45°. Recommendations for the helix angle depending on the module can be found in DIN 3978. This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 30° helix angle, a pressure angle 20° becomes a pressure angle of 22.80° in the transverse section.
If no number of gears is given (anzahl_planeten = 0), then the script will attempt to calculate the least number of planet gears.
To avoid the gears sticking in a 3D print, particularly sticking of the planet gears to the ring gear, the gears can be printed in disassembled layout (zusammen gebaut = false). In that case, please note that herringbone teeth complicate the re-assembly. Experience shows that reassembly is still possible at 30°; however in case of reassembly problems, a lesser helix angle should be selected. Of course, one could always choose straight teeth (Schraegungswinkel = 0).
The gears can also be kept from sticking by a sufficiently large clearance ("Spiel"); a sufficient clearance also avoids meshing problems. Clearance can be left smaller if the 3D printer offers good resolution, however experience shows that it should not be less than 5%.
Format
planetengetriebe(modul, zahnzahl_sonne, zahnzahl_planet, breite, randbreite, bohrung, eingriffswinkel=20, schraegungswinkel=0, zusammen_gebaut=true, optimiert=true)
Parameters
spiel= clearance between teeth as a fraction of their width (0 = no clearance)modul= gear module = height of the tooth above the pitch circle = 25.4 / diametrical pitch = circular pitch / πzahnzahl_sonne = number of teeth on the sun gearzahnzahl_planet = number of teeth per planet gearanzahl_planeten= number of planet gears; if set to zero, the script will attempt to calculate the least number of planet gearsbreite= face widthrandbreite= width of the rim around the ring gear, measured from the root circlebohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle to the rotation axis; 0° = straight teethzusammen_gebaut= components assembled for construction (true) or disassembled (false) for 3D printingoptimiert= if true, create holes for material/weight reduction resp. surface increase, if geometry allows
Parametric Herringbone Bevel Gear with Spherical Involute Geometry
This script creates a herringbone bevel gear with spherical involute teeth geometry. Two gears will mesh if their modules are the same and their helix angles opposite. Herringbone gears run more smoothly than gear with straight teeth. They also do not create axial load like helical gears do. Recommendations for the helix angle depending on the module can be found in DIN 3978.
This script adjusts the pressure angle in the transverse section to the helix angle: e.g. with a 30° helix angle, a pressure angle of 20° becomes a pressure angle of 22.80° in the transverse section.
Format
pfeilkegelrad(modul, zahnzahl, teilkegelwinkel, zahnbreite, bohrung, eingriffswinkel=20, schraegungswinkel=0)
Parameters
modul= gear module = height of the gear teeth above the pitch cone = 25.4 / diametrical pitch = circular pitch / πzahnzahl= number of teethteilkegelwinkel= reference cone (half-)anglezahnbreite= width of teeth from the rim in direction of the reference cone tipbohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle between the teeth and the reference cone envelope line, 0° = straight teeth
Parametric Pair of Bevel Gears
This script calculates both the gear and the pinion of a bevel gear pair, using the gears' module and their numbers of teeth. The preset angle of 90° between the axes of both gears can be varied. It is possible to calculate the pair both assembled for design as well as disassembled for printing.
Format
kegelradpaar(modul, zahnzahl_rad, zahnzahl_ritzel, achsenwinkel=90, zahnbreite, bohrung, eingriffswinkel = 20, schraegungswinkel=0, zusammen_gebaut=true)
Parameters
modul= gear module = height of the gear teeth above the pitch cone = 25.4 / diametrical pitch = circular pitch / πzahnzahl_rad= number of teeth on the gearzahnzahl_ritzel= number of teeth on the pinionachsenwinkel= angle between the axes of pinion and gear, standard value = 90°zahnbreite= width of the teeth from the rim in direction of the cone tipbohrung_rad= central bore diameter of the gearbohrung_ritzel= central bore diameter of the pinioneingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle between the teeth and the reference cone envelope line, 0° = straight teethzusammen_gebaut= assembled (true) oder disassembled for printing (false)
Parametric Pair of Herringbone Bevel Gears
This script calculates both the gear and the pinion of a herringbone bevel gear pair, using the gears' module and their numbers of teeth. The preset angle of 90° between the axes of both gears can be varied. It is possible to calculate the pair both assembled for design as well as disassembled for printing.
Format
pfeilkegelradpaar(modul, zahnzahl_rad, zahnzsahl_ritzel, achsenwinkel=90, zahnbreite, bohrung, eingriffswinkel = 20, schraegungswinkel=0, zusammen_gebaut=true)
Parameters
modul= gear module = height of the gear teeth above the pitch cone = 25.4 / diametrical pitch = circular pitch / πzahnzahl_rad= number of teeth on the gearzahnzahl_ritzel= number of teeth on the pinionachsenwinkel= angle between the axes of pinion and gear, standard value = 90°zahnbreite= width of the teeth from the rim in direction of the cone tipbohrung_rad= central bore diameter of the gearbohrung_ritzel= central bore diameter of the pinioneingriffswinkel= pressure angle, standard value = 20° according to DIN 867schraegungswinkel= helix angle between the teeth and the reference cone envelope line, 0° = straight teethzusammen_gebaut= assembled (true) or disassembled for printing (false)
Parametric Worm
Creates a cylidrical worm (archimedean spiral) following DIN 3975.
The worm's pitch circle r can be calculated out of its module m, number of threads z and lead angle γ:
r = m·z·1/2sinγ
Format
schnecke(modul, gangzahl, laenge, bohrung, eingriffswinkel=20, steigungswinkel=10, zusammen_gebaut=true)
Parameters
modul= height of the thread above the pitch circlegangzahl= number of threadslaenge= length of the wormbohrung= central bore diametereingriffswinkel= pressure angle, standard value = 20° according to DIN 867steigungswinkel= lead angle of worm. Positive lead angle = clockwise thread rotationzusammen_gebaut= assembled (true) or disassembled for printing (false)
Worm Gear Set (Worm and Pinion)
Creates a set of one worm gear and a pinion. The pinion is a normal spur gear without globoid geometry.
Format
module schneckenradsatz(modul, zahnzahl, gangzahl, breite, laenge, bohrung_schnecke, bohrung_rad, eingriffswinkel=20, steigungswinkel, optimiert=true, zusammen_gebaut=true)
Parameter
modul= gear module = and height of the gear teeth above th pitch circle / of the thread above the pitch circlezahnzahl= number of teeth on the piniongangzahl= number of threadsbreite= face width on the pinionlaenge= length of the wormbohrung_schnecke= central bore diameter of the wormbohrung_rad= central bore diameter of the pinioneingriffswinkel= pressure angle, standard value = 20° according to DIN 867. Shouldn't be greater than 45°steigungswinkel= lead angle of worm. Positive lead angle = clockwise thread rotationoptimiert= if true, create holes for material/weight reduction resp. surface increase, if geometry allowszusammen_gebaut= assembled (true) or disassembled for printing (false)