steve/hobby-servo

Hobby servo: SG90, MG90S, Futaba S3003 and MG996R, with a single-arm horn.

v1.0.0 Latest STEVE MIT 0

Open in STEVE

Isometric

Parameters

Preset5 sizes

Servo

SG90MG90SS3003MG996R

Detail

fullsimple

full: with the horn, tab holes and output shaft. simple: case and tabs only.

Defaults built

part.py 50 lines · Python · STEVE runtime · checked

Download

"""Hobby servo with a single-arm horn. The case's underside is on the XY plane, centred on the origin, the case's long side along X, the output shaft up at the +X end.

Fit dimensions come from each maker's drawing in the README; the shaft's place, the tabs' thickness, the holes and the horn are proportions, for looks."""

from steve import Model

designation = "SG90" # Servo

detail = "full" # full: with the horn, tab holes and output shaft; simple: case and tabs only

# type: (case length, case width, length over the tabs, height to the tabs' top, height to the case's top, height overall)

# SG90: Luxorparts item 87897 sheet, update Nov 30, 2017: 22.8, 12.4, 32.0, 15.6, 26.7, 15.6 + 15.8 (horn included).

# S3003: Luxorparts item 87902 sheet, update Nov 30, 2017: 40.5, 20.2, 54.2, 29.5, 39.4, 29.5 + 19.0.

# MG90S and MG996R: Tower Pro drawings, https://www.electronicoscaldas.com/datasheet/MG90S_Tower-Pro.pdf and MG996R_Tower-Pro.pdf: MG90S 22.5, 12, 32.5, 21, 35.5; MG996R 40.3, 20, 53.6, 26.6, 36.6, 47.6.

# The MG90S drawing gives no case top: 0.75 of the way from the tabs to the top, for looks.

SERVOS = {

"SG90": (22.8, 12.4, 32.0, 15.6, 26.7, 31.4),

"S3003": (40.5, 20.2, 54.2, 29.5, 39.4, 48.5),

"MG90S": (22.5, 12.0, 32.5, 21.0, 31.9, 35.5),

"MG996R": (40.3, 20.0, 53.6, 26.6, 36.6, 47.6),

}

length, width, span, tab_top, case_top, overall = SERVOS[designation]

tab = 0.1 * width + 1

shaft_x = length / 2 - width / 2

model = Model()

with model.sketch("case_sketch", on="XY", name="Case") as sk:

sk.rect("case_rect", (-length / 2, -width / 2), (length / 2, width / 2))

model.extrude("case", "case_sketch", distance=case_top, name="Case")

model.plane("tab_plane", on="XY", offset=tab_top - tab, name="Tabs")

with model.sketch("tab_sketch", on="tab_plane", name="Tabs") as sk:

sk.rect("tab_rect", (-span / 2, -width / 2), (span / 2, width / 2))

model.extrude("tabs", "tab_sketch", distance=tab, name="Tabs")

if detail == "full":

with model.sketch("holes_sketch", on="tab_plane", name="Tab holes") as sk:

sk.circle("hole_left", (-(span + length) / 4, 0), 0.08 * width + 0.5)

sk.circle("hole_right", ((span + length) / 4, 0), 0.08 * width + 0.5)

model.extrude("holes", "holes_sketch", distance=tab, op="cut", name="Tab holes")

horn = 0.14 * (overall - case_top)

model.plane("boss_plane", on="XY", offset=case_top, name="Boss")

with model.sketch("boss_sketch", on="boss_plane", name="Boss") as sk:

sk.circle("boss_circle", (shaft_x, 0), 0.32 * width)

model.extrude("boss", "boss_sketch", distance=0.35 * (overall - case_top), name="Boss")

with model.sketch("shaft_sketch", on="boss_plane", name="Output shaft") as sk:

sk.circle("shaft_circle", (shaft_x, 0), 0.17 * width)

model.extrude("shaft", "shaft_sketch", distance=overall - case_top - horn, name="Output shaft")

model.plane("horn_plane", on="XY", offset=overall - horn, name="Horn")

with model.sketch("horn_sketch", on="horn_plane", name="Horn") as sk:

sk.slot("horn_slot", (shaft_x, 0), (shaft_x - 1.2 * width, 0), 0.25 * width)

model.extrude("horn", "horn_sketch", distance=horn, name="Horn")

model.material("abs", color="#26282b")

result = model.result()

"""Hobby servo with a single-arm horn. The case's underside is on the XY plane, centred on the origin, the case's long side along X, the output shaft up at the +X end.
Fit dimensions come from each maker's drawing in the README; the shaft's place, the tabs' thickness, the holes and the horn are proportions, for looks."""
from steve import Model

designation = "SG90"  # Servo
detail = "full"  # full: with the horn, tab holes and output shaft; simple: case and tabs only

# type: (case length, case width, length over the tabs, height to the tabs' top, height to the case's top, height overall)
# SG90: Luxorparts item 87897 sheet, update Nov 30, 2017: 22.8, 12.4, 32.0, 15.6, 26.7, 15.6 + 15.8 (horn included).
# S3003: Luxorparts item 87902 sheet, update Nov 30, 2017: 40.5, 20.2, 54.2, 29.5, 39.4, 29.5 + 19.0.
# MG90S and MG996R: Tower Pro drawings, https://www.electronicoscaldas.com/datasheet/MG90S_Tower-Pro.pdf and MG996R_Tower-Pro.pdf: MG90S 22.5, 12, 32.5, 21, 35.5; MG996R 40.3, 20, 53.6, 26.6, 36.6, 47.6.
# The MG90S drawing gives no case top: 0.75 of the way from the tabs to the top, for looks.
SERVOS = {
    "SG90": (22.8, 12.4, 32.0, 15.6, 26.7, 31.4),
    "S3003": (40.5, 20.2, 54.2, 29.5, 39.4, 48.5),
    "MG90S": (22.5, 12.0, 32.5, 21.0, 31.9, 35.5),
    "MG996R": (40.3, 20.0, 53.6, 26.6, 36.6, 47.6),
}

length, width, span, tab_top, case_top, overall = SERVOS[designation]
tab = 0.1 * width + 1
shaft_x = length / 2 - width / 2
model = Model()
with model.sketch("case_sketch", on="XY", name="Case") as sk:
    sk.rect("case_rect", (-length / 2, -width / 2), (length / 2, width / 2))
model.extrude("case", "case_sketch", distance=case_top, name="Case")
model.plane("tab_plane", on="XY", offset=tab_top - tab, name="Tabs")
with model.sketch("tab_sketch", on="tab_plane", name="Tabs") as sk:
    sk.rect("tab_rect", (-span / 2, -width / 2), (span / 2, width / 2))
model.extrude("tabs", "tab_sketch", distance=tab, name="Tabs")
if detail == "full":
    with model.sketch("holes_sketch", on="tab_plane", name="Tab holes") as sk:
        sk.circle("hole_left", (-(span + length) / 4, 0), 0.08 * width + 0.5)
        sk.circle("hole_right", ((span + length) / 4, 0), 0.08 * width + 0.5)
    model.extrude("holes", "holes_sketch", distance=tab, op="cut", name="Tab holes")
    horn = 0.14 * (overall - case_top)
    model.plane("boss_plane", on="XY", offset=case_top, name="Boss")
    with model.sketch("boss_sketch", on="boss_plane", name="Boss") as sk:
        sk.circle("boss_circle", (shaft_x, 0), 0.32 * width)
    model.extrude("boss", "boss_sketch", distance=0.35 * (overall - case_top), name="Boss")
    with model.sketch("shaft_sketch", on="boss_plane", name="Output shaft") as sk:
        sk.circle("shaft_circle", (shaft_x, 0), 0.17 * width)
    model.extrude("shaft", "shaft_sketch", distance=overall - case_top - horn, name="Output shaft")
    model.plane("horn_plane", on="XY", offset=overall - horn, name="Horn")
    with model.sketch("horn_sketch", on="horn_plane", name="Horn") as sk:
        sk.slot("horn_slot", (shaft_x, 0), (shaft_x - 1.2 * width, 0), 0.25 * width)
    model.extrude("horn", "horn_sketch", distance=horn, name="Horn")
model.material("abs", color="#26282b")
result = model.result()

pypart.toml 56 lines · TOML

Download

name = "steve/hobby-servo"

version = "1.0.0"

runtime = "steve"

license = "MIT"

summary = "Hobby servo: SG90, MG90S, Futaba S3003 and MG996R, with a single-arm horn."

description = """Hobby servo as an assembly envelope: case, mounting tabs, output shaft and a single-arm horn. Case, tab and height dimensions from the makers' drawings; the shaft's place, holes and horn are proportions, for looks. See the README."""

tags = ["servo", "rc-servo", "sg90", "mg996r", "s3003", "mg90s", "actuator", "motor"]

[parameters.designation]

type = "choice"

default = "SG90"

choices = ["SG90", "MG90S", "S3003", "MG996R"]

label = "Servo"

[parameters.detail]

type = "choice"

default = "full"

choices = ["full", "simple"]

label = "Detail"

description = "full: with the horn, tab holes and output shaft. simple: case and tabs only."

[[presets]]

id = "SG90"

title = "SG90 servo"

params = { designation = "SG90" }

aliases = ["SG-90", "Servo-sg90", "SG90 servo", "9g servo", "9g micro servo", "micro servo"]

standard = "maker's drawing"

[[presets]]

id = "MG90S"

title = "MG90S servo"

params = { designation = "MG90S" }

aliases = ["MG90S servo", "MG90", "metal gear micro servo"]

standard = "maker's drawing"

[[presets]]

id = "S3003"

title = "S3003 servo"

params = { designation = "S3003" }

aliases = ["Futaba3003", "Futaba 3003", "S3003 servo", "Futaba S3003", "standard servo"]

standard = "maker's drawing"

[[presets]]

id = "MG996R"

title = "MG996R servo"

params = { designation = "MG996R" }

aliases = ["MG996R servo", "MG996", "MG995", "high torque servo"]

standard = "maker's drawing"

[[presets]]

id = "SG90-simple"

title = "SG90, simple"

params = { designation = "SG90", detail = "simple" }

aliases = ["SG90 simple"]

standard = "maker's drawing"

name = "steve/hobby-servo"
version = "1.0.0"
runtime = "steve"
license = "MIT"
summary = "Hobby servo: SG90, MG90S, Futaba S3003 and MG996R, with a single-arm horn."
description = """Hobby servo as an assembly envelope: case, mounting tabs, output shaft and a single-arm horn. Case, tab and height dimensions from the makers' drawings; the shaft's place, holes and horn are proportions, for looks. See the README."""
tags = ["servo", "rc-servo", "sg90", "mg996r", "s3003", "mg90s", "actuator", "motor"]

[parameters.designation]
type = "choice"
default = "SG90"
choices = ["SG90", "MG90S", "S3003", "MG996R"]
label = "Servo"

[parameters.detail]
type = "choice"
default = "full"
choices = ["full", "simple"]
label = "Detail"
description = "full: with the horn, tab holes and output shaft. simple: case and tabs only."

[[presets]]
id = "SG90"
title = "SG90 servo"
params = { designation = "SG90" }
aliases = ["SG-90", "Servo-sg90", "SG90 servo", "9g servo", "9g micro servo", "micro servo"]
standard = "maker's drawing"

[[presets]]
id = "MG90S"
title = "MG90S servo"
params = { designation = "MG90S" }
aliases = ["MG90S servo", "MG90", "metal gear micro servo"]
standard = "maker's drawing"

[[presets]]
id = "S3003"
title = "S3003 servo"
params = { designation = "S3003" }
aliases = ["Futaba3003", "Futaba 3003", "S3003 servo", "Futaba S3003", "standard servo"]
standard = "maker's drawing"

[[presets]]
id = "MG996R"
title = "MG996R servo"
params = { designation = "MG996R" }
aliases = ["MG996R servo", "MG996", "MG995", "high torque servo"]
standard = "maker's drawing"

[[presets]]
id = "SG90-simple"
title = "SG90, simple"
params = { designation = "SG90", detail = "simple" }
aliases = ["SG90 simple"]
standard = "maker's drawing"

README.md 17 lines · Markdown

Download

Hobby servo

A hobby servo as an assembly envelope. The case's underside is on the XY plane, centred on the origin, the long side along X, and the output shaft points up at the +X end.

Source

Servo	Case	Over the tabs	To the tabs' top	Case top	Overall	Source
SG90	22.8 x 12.4	32.0	15.6	26.7	31.4	Luxorparts item 87897 sheet, Nov 30, 2017, https://www.kjell.com/globalassets/mediaassets/701916_87897_datasheet_en.pdf
S3003	40.5 x 20.2	54.2	29.5	39.4	48.5	Luxorparts item 87902 sheet, Nov 30, 2017, https://naylampmechatronics.com/img/cms/Datasheets/000219_servo_s3003.pdf
MG90S	22.5 x 12	32.5	21	not given	35.5	Tower Pro drawing, https://www.electronicoscaldas.com/datasheet/MG90S_Tower-Pro.pdf
MG996R	40.3 x 20	53.6	26.6	36.6	47.6	Tower Pro drawing, https://www.electronicoscaldas.com/datasheet/MG996R_Tower-Pro.pdf

Proportions, for looks only: the output shaft's place and size, the boss, the tab thickness, the tab holes and the horn. S3003's sheet gives a tab hole pitch of 48.3 and a row of 10, which aren't modelled, so don't drill from this model: take the holes from your servo's drawing. The MG90S case top isn't on its drawing, so it's 0.75 of the way from the tabs to the top.

Clones of these servos vary. The cable isn't modelled.

# Hobby servo

A hobby servo as an assembly envelope. The case's underside is on the XY plane, centred on the origin, the long side along X, and the output shaft points up at the +X end.

## Source

| Servo | Case | Over the tabs | To the tabs' top | Case top | Overall | Source |
|---|---|---|---|---|---|---|
| SG90 | 22.8 x 12.4 | 32.0 | 15.6 | 26.7 | 31.4 | Luxorparts item 87897 sheet, Nov 30, 2017, <https://www.kjell.com/globalassets/mediaassets/701916_87897_datasheet_en.pdf> |
| S3003 | 40.5 x 20.2 | 54.2 | 29.5 | 39.4 | 48.5 | Luxorparts item 87902 sheet, Nov 30, 2017, <https://naylampmechatronics.com/img/cms/Datasheets/000219_servo_s3003.pdf> |
| MG90S | 22.5 x 12 | 32.5 | 21 | not given | 35.5 | Tower Pro drawing, <https://www.electronicoscaldas.com/datasheet/MG90S_Tower-Pro.pdf> |
| MG996R | 40.3 x 20 | 53.6 | 26.6 | 36.6 | 47.6 | Tower Pro drawing, <https://www.electronicoscaldas.com/datasheet/MG996R_Tower-Pro.pdf> |

**Proportions, for looks only:** the output shaft's place and size, the boss, the tab thickness, the tab holes and the horn. S3003's sheet gives a tab hole pitch of 48.3 and a row of 10, which aren't modelled, so **don't drill from this model: take the holes from your servo's drawing.** The MG90S case top isn't on its drawing, so it's 0.75 of the way from the tabs to the top.

Clones of these servos vary. The cable isn't modelled.

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/hobby-servo/v/1.0.0/raw/part.py"

Raw files, bundle and API

part.py
pypart.toml
README.md
bundle.tar.gzthe package, as published

curl "https://pythonparts.org/api/v1/parts/steve/hobby-servo/1.0.0"

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

About this part

steve96 parts

Profile

ABSPlastics · Custom finish · 1.06 g/cm³

Mass: 8.45 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: cf480acd9ce1…

#servo #rc-servo #sg90 #mg996r #s3003 #mg90s #actuator #motor

Checks

PassedImports: 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

Hobby servo as an assembly envelope: case, mounting tabs, output shaft and a single-arm horn. Case, tab and height dimensions from the makers' drawings; the shaft's place, holes and horn are proportions, for looks. See the README.

Hobby servo

A hobby servo as an assembly envelope. The case's underside is on the XY plane, centred on the origin, the long side along X, and the output shaft points up at the +X end.

Source

Servo	Case	Over the tabs	To the tabs' top	Case top	Overall	Source
SG90	22.8 x 12.4	32.0	15.6	26.7	31.4	Luxorparts item 87897 sheet, Nov 30, 2017, https://www.kjell.com/globalassets/mediaassets/701916_87897_datasheet_en.pdf
S3003	40.5 x 20.2	54.2	29.5	39.4	48.5	Luxorparts item 87902 sheet, Nov 30, 2017, https://naylampmechatronics.com/img/cms/Datasheets/000219_servo_s3003.pdf
MG90S	22.5 x 12	32.5	21	not given	35.5	Tower Pro drawing, https://www.electronicoscaldas.com/datasheet/MG90S_Tower-Pro.pdf
MG996R	40.3 x 20	53.6	26.6	36.6	47.6	Tower Pro drawing, https://www.electronicoscaldas.com/datasheet/MG996R_Tower-Pro.pdf

Clones of these servos vary. The cable isn't modelled.

1.0.0 Latest Nov 5, 2026 · 1 hour ago

More #servo

STEVEMIT

steve/nema-stepper-motor

NEMA stepper motor envelope: frames 8, 11, 14, 17, 23 and 34, with common models such as 17HS4401 as presets.

0 32 sizes 0 17 hours ago v1.1.0

STEVEMIT

steve/hex-head-screw

Hexagon head screw, fully threaded, ISO 4017 / DIN 933, M1.6 to M36, any length, with catalogue sizes as presets.

20 86 sizes 0 2 hours ago v2.4.2

STEVEMIT

steve/button-head-screw

Hexagon socket button head screw, ISO 7380-1, M3 to M16, any length, with catalogue sizes as presets.

12 66 sizes 0 2 hours ago v2.2.2

STEVEMIT

steve/hex-nut

Hex nut, ISO 4032, M2 to M12.

9 9 variants 0 4 days ago v1.1.0

steve/hobby-servo

Hobby servo

Source

Hobby servo

Source

Related parts

steve/nema-stepper-motor

steve/hex-head-screw

steve/button-head-screw

steve/hex-nut