steve/gear-rack

Straight gear rack, ISO 53 basic rack, modules 0.5 to 2, any length, with common lengths as presets.

v1.0.0 Latest STEVE MIT 0

Open in STEVE

Isometric

Parameters

Preset38 sizes

Module5 options

Length20–2000 mm

Defaults built

part.py 42 lines · Python · STEVE runtime · checked

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"""Straight-tooth gear rack, ISO 53 basic rack, section from KHK's SR steel racks. Length along X, centred on the origin;

width along Y; base on the XY plane and teeth up along +Z. As many whole teeth as fit the length, centred, with the

tooth roots' level running to both ends. Height H is the pitch-line height H0 plus one module."""

import math

from steve import Model

module = 1 # Module

length = 300 # mm Rack length

PRESSURE_ANGLE = 20 # degrees: ISO 53:1998 basic rack

DEDENDUM = 1.25 # x module: ISO 53

# module: (face width B, overall height H, height to the pitch line H0). KHK Gears catalogue 2025, Racks, SR steel racks

# table, https://khkgears.us/media/yzroimcg/catalog-2025-racks.pdf

RACKS = {0.5: (5, 12, 11.5), 0.8: (8, 12.3, 11.5), 1: (10, 12, 11), 1.5: (15, 20, 18.5), 2: (20, 25, 23)}

MAX_TEETH = 260 # more teeth than this take longer to build than a build is allowed

B, H, H0 = RACKS[module]

pitch = math.pi * module

count = int(length // pitch)

if count < 1:

raise ValueError(f"The rack must be at least one pitch ({pitch:.3f} mm) long.")

if count > MAX_TEETH:

raise ValueError(f"{count} teeth is too long to build: at most {MAX_TEETH} teeth ({MAX_TEETH * pitch:.0f} mm at this module).")

tan_a = math.tan(math.radians(PRESSURE_ANGLE))

root_z = H0 - DEDENDUM * module

crest_half = pitch / 4 - module * tan_a

root_half = pitch / 4 + DEDENDUM * module * tan_a

points = [(-length / 2, 0), (length / 2, 0), (length / 2, root_z)]

for i in reversed(range(count)):

x = (i - (count - 1) / 2) * pitch

points += [(x + root_half, root_z), (x + crest_half, H), (x - crest_half, H), (x - root_half, root_z)]

points.append((-length / 2, root_z))

model = Model()

with model.sketch("rack_sketch", on="XZ", name="Rack section") as sk:

sk.polyline("profile", points, closed=True)

model.extrude("rack", "rack_sketch", distance=B, both=True, name="Rack")

model.material("steel-generic", color="#b4b8bd")

result = model.result()

"""Straight-tooth gear rack, ISO 53 basic rack, section from KHK's SR steel racks. Length along X, centred on the origin;
width along Y; base on the XY plane and teeth up along +Z. As many whole teeth as fit the length, centred, with the
tooth roots' level running to both ends. Height H is the pitch-line height H0 plus one module."""
import math

from steve import Model

module = 1  # Module
length = 300  # mm Rack length

PRESSURE_ANGLE = 20  # degrees: ISO 53:1998 basic rack
DEDENDUM = 1.25  # x module: ISO 53
# module: (face width B, overall height H, height to the pitch line H0). KHK Gears catalogue 2025, Racks, SR steel racks
# table, https://khkgears.us/media/yzroimcg/catalog-2025-racks.pdf
RACKS = {0.5: (5, 12, 11.5), 0.8: (8, 12.3, 11.5), 1: (10, 12, 11), 1.5: (15, 20, 18.5), 2: (20, 25, 23)}

MAX_TEETH = 260  # more teeth than this take longer to build than a build is allowed

B, H, H0 = RACKS[module]
pitch = math.pi * module
count = int(length // pitch)
if count < 1:
    raise ValueError(f"The rack must be at least one pitch ({pitch:.3f} mm) long.")
if count > MAX_TEETH:
    raise ValueError(f"{count} teeth is too long to build: at most {MAX_TEETH} teeth ({MAX_TEETH * pitch:.0f} mm at this module).")
tan_a = math.tan(math.radians(PRESSURE_ANGLE))
root_z = H0 - DEDENDUM * module
crest_half = pitch / 4 - module * tan_a
root_half = pitch / 4 + DEDENDUM * module * tan_a
points = [(-length / 2, 0), (length / 2, 0), (length / 2, root_z)]
for i in reversed(range(count)):
    x = (i - (count - 1) / 2) * pitch
    points += [(x + root_half, root_z), (x + crest_half, H), (x - crest_half, H), (x - root_half, root_z)]
points.append((-length / 2, root_z))

model = Model()
with model.sketch("rack_sketch", on="XZ", name="Rack section") as sk:
    sk.polyline("profile", points, closed=True)
model.extrude("rack", "rack_sketch", distance=B, both=True, name="Rack")
model.material("steel-generic", color="#b4b8bd")
result = model.result()

presets.toml 268 lines · TOML

Download

# Presets of this part (factory/PRESETS.md). Written by factory/gen.py.

[[presets]]

id = "M0.5-L100"

title = "Module 0.5, 100 mm"

params = { module = 0.5, length = 100 }

aliases = ["gear rack M0.5 100", "rack module 0.5 100 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=100 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.5-L150"

title = "Module 0.5, 150 mm"

params = { module = 0.5, length = 150 }

aliases = ["gear rack M0.5 150", "rack module 0.5 150 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=150 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.5-L200"

title = "Module 0.5, 200 mm"

params = { module = 0.5, length = 200 }

aliases = ["gear rack M0.5 200", "rack module 0.5 200 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=200 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.5-L250"

title = "Module 0.5, 250 mm"

params = { module = 0.5, length = 250 }

aliases = ["gear rack M0.5 250", "rack module 0.5 250 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=250 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.5-L300"

title = "Module 0.5, 300 mm"

params = { module = 0.5, length = 300 }

aliases = ["gear rack M0.5 300", "rack module 0.5 300 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=300 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.5-L400"

title = "Module 0.5, 400 mm"

params = { module = 0.5, length = 400 }

aliases = ["gear rack M0.5 400", "rack module 0.5 400 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=400 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L100"

title = "Module 0.8, 100 mm"

params = { module = 0.8, length = 100 }

aliases = ["gear rack M0.8 100", "rack module 0.8 100 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=100 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L150"

title = "Module 0.8, 150 mm"

params = { module = 0.8, length = 150 }

aliases = ["gear rack M0.8 150", "rack module 0.8 150 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=150 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L200"

title = "Module 0.8, 200 mm"

params = { module = 0.8, length = 200 }

aliases = ["gear rack M0.8 200", "rack module 0.8 200 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=200 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L250"

title = "Module 0.8, 250 mm"

params = { module = 0.8, length = 250 }

aliases = ["gear rack M0.8 250", "rack module 0.8 250 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=250 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L300"

title = "Module 0.8, 300 mm"

params = { module = 0.8, length = 300 }

aliases = ["gear rack M0.8 300", "rack module 0.8 300 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=300 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L400"

title = "Module 0.8, 400 mm"

params = { module = 0.8, length = 400 }

aliases = ["gear rack M0.8 400", "rack module 0.8 400 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=400 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L500"

title = "Module 0.8, 500 mm"

params = { module = 0.8, length = 500 }

aliases = ["gear rack M0.8 500", "rack module 0.8 500 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=500 mm; width=8.0 mm"]

standard = "ISO 53"

[[presets]]

id = "M0.8-L600"

title = "Module 0.8, 600 mm"

params = { module = 0.8, length = 600 }

aliases = ["gear rack M0.8 600", "rack module 0.8 600 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=600 mm; width=8.0 mm"]

standard = "ISO 53"

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[[presets]]

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id = "M1-L100"

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title = "Module 1, 100 mm"

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params = { module = 1, length = 100 }

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aliases = ["gear rack M1 100", "rack module 1 100 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=100 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L150"

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title = "Module 1, 150 mm"

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params = { module = 1, length = 150 }

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aliases = ["gear rack M1 150", "rack module 1 150 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=150 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L200"

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title = "Module 1, 200 mm"

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params = { module = 1, length = 200 }

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aliases = ["gear rack M1 200", "rack module 1 200 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=200 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L250"

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title = "Module 1, 250 mm"

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params = { module = 1, length = 250 }

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aliases = ["gear rack M1 250", "rack module 1 250 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=250 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L300"

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title = "Module 1, 300 mm"

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params = { module = 1, length = 300 }

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aliases = ["gear rack M1 300", "rack module 1 300 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=300 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L400"

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title = "Module 1, 400 mm"

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params = { module = 1, length = 400 }

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aliases = ["gear rack M1 400", "rack module 1 400 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=400 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L500"

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title = "Module 1, 500 mm"

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params = { module = 1, length = 500 }

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aliases = ["gear rack M1 500", "rack module 1 500 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=500 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1-L600"

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title = "Module 1, 600 mm"

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params = { module = 1, length = 600 }

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aliases = ["gear rack M1 600", "rack module 1 600 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=600 mm; width=10.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L100"

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title = "Module 1.5, 100 mm"

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params = { module = 1.5, length = 100 }

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aliases = ["gear rack M1.5 100", "rack module 1.5 100 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=100 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L150"

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title = "Module 1.5, 150 mm"

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params = { module = 1.5, length = 150 }

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aliases = ["gear rack M1.5 150", "rack module 1.5 150 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=150 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L200"

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title = "Module 1.5, 200 mm"

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params = { module = 1.5, length = 200 }

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aliases = ["gear rack M1.5 200", "rack module 1.5 200 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=200 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L250"

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title = "Module 1.5, 250 mm"

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params = { module = 1.5, length = 250 }

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aliases = ["gear rack M1.5 250", "rack module 1.5 250 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=250 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L300"

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title = "Module 1.5, 300 mm"

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params = { module = 1.5, length = 300 }

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aliases = ["gear rack M1.5 300", "rack module 1.5 300 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=300 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L400"

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title = "Module 1.5, 400 mm"

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params = { module = 1.5, length = 400 }

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aliases = ["gear rack M1.5 400", "rack module 1.5 400 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=400 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L500"

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title = "Module 1.5, 500 mm"

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params = { module = 1.5, length = 500 }

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aliases = ["gear rack M1.5 500", "rack module 1.5 500 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=500 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M1.5-L600"

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title = "Module 1.5, 600 mm"

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params = { module = 1.5, length = 600 }

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aliases = ["gear rack M1.5 600", "rack module 1.5 600 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=600 mm; width=15.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L100"

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title = "Module 2, 100 mm"

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params = { module = 2, length = 100 }

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aliases = ["gear rack M2 100", "rack module 2 100 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=100 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L150"

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title = "Module 2, 150 mm"

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params = { module = 2, length = 150 }

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aliases = ["gear rack M2 150", "rack module 2 150 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=150 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L200"

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title = "Module 2, 200 mm"

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params = { module = 2, length = 200 }

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aliases = ["gear rack M2 200", "rack module 2 200 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=200 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L250"

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title = "Module 2, 250 mm"

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params = { module = 2, length = 250 }

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aliases = ["gear rack M2 250", "rack module 2 250 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=250 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L300"

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title = "Module 2, 300 mm"

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params = { module = 2, length = 300 }

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aliases = ["gear rack M2 300", "rack module 2 300 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=300 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L400"

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title = "Module 2, 400 mm"

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params = { module = 2, length = 400 }

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aliases = ["gear rack M2 400", "rack module 2 400 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=400 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L500"

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title = "Module 2, 500 mm"

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params = { module = 2, length = 500 }

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aliases = ["gear rack M2 500", "rack module 2 500 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=500 mm; width=20.0 mm"]

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standard = "ISO 53"

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[[presets]]

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id = "M2-L600"

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title = "Module 2, 600 mm"

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params = { module = 2, length = 600 }

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aliases = ["gear rack M2 600", "rack module 2 600 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=600 mm; width=20.0 mm"]

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standard = "ISO 53"

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# Presets of this part (factory/PRESETS.md). Written by factory/gen.py.

[[presets]]
id = "M0.5-L100"
title = "Module 0.5, 100 mm"
params = { module = 0.5, length = 100 }
aliases = ["gear rack M0.5 100", "rack module 0.5 100 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=100 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.5-L150"
title = "Module 0.5, 150 mm"
params = { module = 0.5, length = 150 }
aliases = ["gear rack M0.5 150", "rack module 0.5 150 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=150 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.5-L200"
title = "Module 0.5, 200 mm"
params = { module = 0.5, length = 200 }
aliases = ["gear rack M0.5 200", "rack module 0.5 200 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=200 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.5-L250"
title = "Module 0.5, 250 mm"
params = { module = 0.5, length = 250 }
aliases = ["gear rack M0.5 250", "rack module 0.5 250 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=250 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.5-L300"
title = "Module 0.5, 300 mm"
params = { module = 0.5, length = 300 }
aliases = ["gear rack M0.5 300", "rack module 0.5 300 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=300 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.5-L400"
title = "Module 0.5, 400 mm"
params = { module = 0.5, length = 400 }
aliases = ["gear rack M0.5 400", "rack module 0.5 400 mm", "M0.5 rack", "module 0.5", "gear type=rack; module=0.5; length=400 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L100"
title = "Module 0.8, 100 mm"
params = { module = 0.8, length = 100 }
aliases = ["gear rack M0.8 100", "rack module 0.8 100 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=100 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L150"
title = "Module 0.8, 150 mm"
params = { module = 0.8, length = 150 }
aliases = ["gear rack M0.8 150", "rack module 0.8 150 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=150 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L200"
title = "Module 0.8, 200 mm"
params = { module = 0.8, length = 200 }
aliases = ["gear rack M0.8 200", "rack module 0.8 200 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=200 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L250"
title = "Module 0.8, 250 mm"
params = { module = 0.8, length = 250 }
aliases = ["gear rack M0.8 250", "rack module 0.8 250 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=250 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L300"
title = "Module 0.8, 300 mm"
params = { module = 0.8, length = 300 }
aliases = ["gear rack M0.8 300", "rack module 0.8 300 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=300 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L400"
title = "Module 0.8, 400 mm"
params = { module = 0.8, length = 400 }
aliases = ["gear rack M0.8 400", "rack module 0.8 400 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=400 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L500"
title = "Module 0.8, 500 mm"
params = { module = 0.8, length = 500 }
aliases = ["gear rack M0.8 500", "rack module 0.8 500 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=500 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M0.8-L600"
title = "Module 0.8, 600 mm"
params = { module = 0.8, length = 600 }
aliases = ["gear rack M0.8 600", "rack module 0.8 600 mm", "M0.8 rack", "module 0.8", "gear type=rack; module=0.8; length=600 mm; width=8.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L100"
title = "Module 1, 100 mm"
params = { module = 1, length = 100 }
aliases = ["gear rack M1 100", "rack module 1 100 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=100 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L150"
title = "Module 1, 150 mm"
params = { module = 1, length = 150 }
aliases = ["gear rack M1 150", "rack module 1 150 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=150 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L200"
title = "Module 1, 200 mm"
params = { module = 1, length = 200 }
aliases = ["gear rack M1 200", "rack module 1 200 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=200 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L250"
title = "Module 1, 250 mm"
params = { module = 1, length = 250 }
aliases = ["gear rack M1 250", "rack module 1 250 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=250 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L300"
title = "Module 1, 300 mm"
params = { module = 1, length = 300 }
aliases = ["gear rack M1 300", "rack module 1 300 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=300 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L400"
title = "Module 1, 400 mm"
params = { module = 1, length = 400 }
aliases = ["gear rack M1 400", "rack module 1 400 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=400 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L500"
title = "Module 1, 500 mm"
params = { module = 1, length = 500 }
aliases = ["gear rack M1 500", "rack module 1 500 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=500 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1-L600"
title = "Module 1, 600 mm"
params = { module = 1, length = 600 }
aliases = ["gear rack M1 600", "rack module 1 600 mm", "M1 rack", "module 1.0", "gear type=rack; module=1.0; length=600 mm; width=10.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L100"
title = "Module 1.5, 100 mm"
params = { module = 1.5, length = 100 }
aliases = ["gear rack M1.5 100", "rack module 1.5 100 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=100 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L150"
title = "Module 1.5, 150 mm"
params = { module = 1.5, length = 150 }
aliases = ["gear rack M1.5 150", "rack module 1.5 150 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=150 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L200"
title = "Module 1.5, 200 mm"
params = { module = 1.5, length = 200 }
aliases = ["gear rack M1.5 200", "rack module 1.5 200 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=200 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L250"
title = "Module 1.5, 250 mm"
params = { module = 1.5, length = 250 }
aliases = ["gear rack M1.5 250", "rack module 1.5 250 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=250 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L300"
title = "Module 1.5, 300 mm"
params = { module = 1.5, length = 300 }
aliases = ["gear rack M1.5 300", "rack module 1.5 300 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=300 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L400"
title = "Module 1.5, 400 mm"
params = { module = 1.5, length = 400 }
aliases = ["gear rack M1.5 400", "rack module 1.5 400 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=400 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L500"
title = "Module 1.5, 500 mm"
params = { module = 1.5, length = 500 }
aliases = ["gear rack M1.5 500", "rack module 1.5 500 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=500 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M1.5-L600"
title = "Module 1.5, 600 mm"
params = { module = 1.5, length = 600 }
aliases = ["gear rack M1.5 600", "rack module 1.5 600 mm", "M1.5 rack", "module 1.5", "gear type=rack; module=1.5; length=600 mm; width=15.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L100"
title = "Module 2, 100 mm"
params = { module = 2, length = 100 }
aliases = ["gear rack M2 100", "rack module 2 100 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=100 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L150"
title = "Module 2, 150 mm"
params = { module = 2, length = 150 }
aliases = ["gear rack M2 150", "rack module 2 150 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=150 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L200"
title = "Module 2, 200 mm"
params = { module = 2, length = 200 }
aliases = ["gear rack M2 200", "rack module 2 200 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=200 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L250"
title = "Module 2, 250 mm"
params = { module = 2, length = 250 }
aliases = ["gear rack M2 250", "rack module 2 250 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=250 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L300"
title = "Module 2, 300 mm"
params = { module = 2, length = 300 }
aliases = ["gear rack M2 300", "rack module 2 300 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=300 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L400"
title = "Module 2, 400 mm"
params = { module = 2, length = 400 }
aliases = ["gear rack M2 400", "rack module 2 400 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=400 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L500"
title = "Module 2, 500 mm"
params = { module = 2, length = 500 }
aliases = ["gear rack M2 500", "rack module 2 500 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=500 mm; width=20.0 mm"]
standard = "ISO 53"

[[presets]]
id = "M2-L600"
title = "Module 2, 600 mm"
params = { module = 2, length = 600 }
aliases = ["gear rack M2 600", "rack module 2 600 mm", "M2 rack", "module 2.0", "gear type=rack; module=2.0; length=600 mm; width=20.0 mm"]
standard = "ISO 53"

README.md 28 lines · Markdown

Download

Gear rack

Straight-tooth rack. Length along X, centred on the origin; width along Y; base on the XY plane, teeth up along +Z.

Geometry

As many whole teeth as fit the length, centred, at pitch π m, with the root level running on to both ends. Tooth thickness π m / 2 on the pitch line, 20° flanks, addendum 1.0 m, dedendum 1.25 m.

Source

Teeth: ISO 53:1998, standard basic rack profile.
Section: KHK Gears, catalogue 2025, Racks, SR steel racks table, https://khkgears.us/media/yzroimcg/catalog-2025-racks.pdf:

Module	Face width B	Height H	Height to pitch line H0
0.5	5	12	11.5
0.8	8	12.3	11.5
1	10	12	11
1.5	15	20	18.5
2	20	25	23

Module 1.25 isn't in that table, so it isn't offered. A rack is limited to 260 teeth: longer ones take more than a build's time limit. The catalogue's preset widths differ for some modules: this part uses the KHK section. Maker names identify the source; this part isn't made by or affiliated with KHK.

Preset lengths: step.parts catalogue metadata (MIT, library/NOTICE.md).

# Gear rack

Straight-tooth rack. Length along X, centred on the origin; width along Y; base on the XY plane, teeth up along +Z.

## Geometry

As many whole teeth as fit the length, centred, at pitch π m, with the root level running on to both ends. Tooth
thickness π m / 2 on the pitch line, 20° flanks, addendum 1.0 m, dedendum 1.25 m.

## Source

- **Teeth:** ISO 53:1998, standard basic rack profile.
- **Section:** KHK Gears, catalogue 2025, Racks, SR steel racks table,
  <https://khkgears.us/media/yzroimcg/catalog-2025-racks.pdf>:

| Module | Face width B | Height H | Height to pitch line H0 |
|---|---|---|---|
| 0.5 | 5 | 12 | 11.5 |
| 0.8 | 8 | 12.3 | 11.5 |
| 1 | 10 | 12 | 11 |
| 1.5 | 15 | 20 | 18.5 |
| 2 | 20 | 25 | 23 |

Module 1.25 isn't in that table, so it isn't offered. A rack is limited to 260 teeth: longer ones take more than a build's time limit. The catalogue's preset widths differ for some modules: this part
uses the KHK section. Maker names identify the source; this part isn't made by or affiliated with KHK.

Preset lengths: step.parts catalogue metadata (MIT, `library/NOTICE.md`).

Use this part

STEVE

Open in STEVE

Open it in STEVE The STEVE runtime runs in STEVE: open the part there, or download the code and bundle.

Get the code

curl -o part.py "https://pythonparts.org/p/steve/gear-rack/v/1.0.0/raw/part.py"

Raw files, bundle and API

curl "https://pythonparts.org/api/v1/parts/steve/gear-rack/1.0.0"

The version's JSON (parameters, presets, files); add /build?name=value for a build at other values.

About this part

steve72 parts

Profile

Steel (generic)Carbon & alloy steels · Custom finish · 7.9 g/cm³

Mass: 259 g

At the parameters shown in the viewer.

License: MIT

Permissive: use, change and sell it; keep the copyright notice.

Runtime: STEVE
Requirements: None stated in the code
Built with: CadQuery 2.9.0.dev0
Published: Nov 5, 2026
Downloads: 0
Builds: 0
Stars: 0
Bundle: ad37c1c9f6cd…

#gear #rack #gear-rack #iso-53 #metric #power-transmission

Checks

PassedImports: math, steve

Every published part passes our checks before it’s listed. It is still code: read it before you use it.

Request a removal A copyright notice, or a trademark, confidential design, safety, malicious code or other problem. Report an illegal or prohibited item

Straight-tooth rack with teeth cut from the ISO 53 basic rack and a section from a maker's public catalogue. Length along X, centred on the origin; teeth up along +Z. See the README; not affiliated with any maker.

Gear rack

Straight-tooth rack. Length along X, centred on the origin; width along Y; base on the XY plane, teeth up along +Z.

Geometry

As many whole teeth as fit the length, centred, at pitch π m, with the root level running on to both ends. Tooth thickness π m / 2 on the pitch line, 20° flanks, addendum 1.0 m, dedendum 1.25 m.

Source

Teeth: ISO 53:1998, standard basic rack profile.
Section: KHK Gears, catalogue 2025, Racks, SR steel racks table, https://khkgears.us/media/yzroimcg/catalog-2025-racks.pdf:

Module	Face width B	Height H	Height to pitch line H0
0.5	5	12	11.5
0.8	8	12.3	11.5
1	10	12	11
1.5	15	20	18.5
2	20	25	23

Preset lengths: step.parts catalogue metadata (MIT, library/NOTICE.md).

1.0.0 Latest Nov 5, 2026 · 1 hour ago

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