Engineering CAD Design Library

Browse quality-checked 3D CAD models for engineering, product design, prototyping and manufacturing. Preview models online and download files in STEP, STP, IGES, STL, OBJ, PLY, DWG, DXF and more.

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Build kits

Curated systems with verified mating parts — download the whole assembly at once.

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CONSUMER ELECTRONICS

iPhone Accessory & Case Design Kit

A practical iPhone accessory cluster for designing cases, charging stands, holders and fit-checking around real phone geometry.

6 partspairs verified
DRONES / UAV

250 mm FPV Drone Build Kit

A complete FPV quad build cluster covering frame, propulsion, camera, control electronics, battery housing and mounting hardware.

7 partspairs verified
MOTION CONTROL

NEMA 17 Motion / Linear Actuator Kit

A motion-control cluster around a NEMA 17 stepper, bracket, coupler, GT2 belt, pulley, bearing and driver.

5 partspairs verified
10,000+ models2D drawings
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Free
Universal Holder for Distance Sensors Compatible with Lego Bricks
ROBOTICS · UNIVERSAL HOLDER

Universal Holder for Distance Sensors Compatible with Lego Bricks

.STEP
Free
LEGO Minifigure Palette and Brush 3D Model
LEGO

LEGO Minifigure Palette and Brush 3D Model

.STEP
Free
4-Inch Hydrofoil Fin for Aquatone SUP Board - Low Water Level Performance
MARINE · HYDROFOIL

4-Inch Hydrofoil Fin for Aquatone SUP Board - Low Water Level Performance

.STEP
Free
DIN Rail Mountable Raspberry Pi 4 Enclosure with Expansion Space
INDUSTRIAL DESIGN · DIN RAIL MOUNT

DIN Rail Mountable Raspberry Pi 4 Enclosure with Expansion Space

.STEP

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Professional Automotive Interior and Exterior Structural Design Services
AUTOMOTIVE · AUTOMOTIVE INTERIOR DESIGN

Professional Automotive Interior and Exterior Structural Design Services

.STEP
Free
Engineering Practice Examples Collection
MACHINE DESIGN · ENGINEERING PRACTICE

Engineering Practice Examples Collection

.STEP
Free
DU 25 Single Union Joint
INDUSTRIAL DESIGN · DU 25

DU 25 Single Union Joint

.STEP
Free
Tray Slide Stand CAD Model for Industrial Applications
INDUSTRIAL DESIGN · TRAY SLIDE STAND

Tray Slide Stand CAD Model for Industrial Applications

.STEP
Free
Cat-Shaped Cookie Cutter CAD Model
COOKIE CUTTER

Cat-Shaped Cookie Cutter CAD Model

.STEP
Free
Advanced SolidWorks Techniques for Complex Shape Modeling
INDUSTRIAL DESIGN · COMPLEX SHAPE MODELING

Advanced SolidWorks Techniques for Complex Shape Modeling

.STEP
Free
PET Plastic Disposable Bowl for Serving Snacks and Fruits
INDUSTRIAL DESIGN · PET PLASTIC

PET Plastic Disposable Bowl for Serving Snacks and Fruits

.STEP
Free
XT90 Female Connector for Electrical Applications
ELECTRICAL · XT90

XT90 Female Connector for Electrical Applications

.STEP
Free
XT90 2+2 Male Plug Connector for Electrical Applications
ELECTRICAL · XT90

XT90 2+2 Male Plug Connector for Electrical Applications

.STEP
Free
2mm Thick Sheet Metal Part with Laser-Cut Design
MACHINE DESIGN · SHEET METAL

2mm Thick Sheet Metal Part with Laser-Cut Design

.STEP
Free
Linear Guide Rails and Sliders MGN9H for Y Axis Applications
MACHINE DESIGN · LINEAR GUIDE RAILS

Linear Guide Rails and Sliders MGN9H for Y Axis Applications

.STEP
Free
3D Printed Test Station for 80mm DMM Servo
ROBOTICS · 3D PRINTED TEST STATION

3D Printed Test Station for 80mm DMM Servo

.STEP
Free
Precision Cylindrical Component 14mm Diameter 34mm Length
MACHINE DESIGN · CYLINDRICAL COMPONENT

Precision Cylindrical Component 14mm Diameter 34mm Length

.STEP
Free
Professional Chessboard Design for Engineering Applications
INDUSTRIAL DESIGN · CHESSBOARD

Professional Chessboard Design for Engineering Applications

.STEP
Free
Snitch Assembly CAD Model for Engineering Applications
MACHINE DESIGN · SNITCH ASSEMBLY

Snitch Assembly CAD Model for Engineering Applications

.STEP
Free
Comprehensive Clutch Assembly with Springs and Friction Components
MACHINE DESIGN · CLUTCH ASSEMBLY

Comprehensive Clutch Assembly with Springs and Friction Components

.STEP
Free
Hand Basket with Unique Color and Design Features
INDUSTRIAL DESIGN · HAND BASKET

Hand Basket with Unique Color and Design Features

.STEP
Free
Micro Two-Cylinder Steam Engine Model for 3D Printing
3D PRINTING · MICRO TWO-CYLINDER STEAM ENGINE

Micro Two-Cylinder Steam Engine Model for 3D Printing

.STEP