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.

Browse by part & function

The axis engineers actually search on — pick a part type to filter the catalog.

See all parts

Build kits

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

All collections
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
HARDWARE

Metric Fasteners & Threaded Hardware Pack

A reusable ISO/metric fastener library cluster with screws, nuts, washers, inserts, standoffs and bolt assemblies.

2 partspairs verified
3D PRINTING

3D Printer Motion & Extruder Upgrade Kit

A 3D-printer upgrade cluster combining hotend parts, filament handling, stepper drive and motion hardware.

7 partspairs verified
ELECTRONICS PROTOTYPING

Arduino / ESP32 Prototyping Kit

A maker electronics cluster with Arduino, ESP32, breadboard, shield, servo, battery holder and enclosure.

7 partspairs verified
ROBOTICS

Robotic Arm + Gripper Kit

A robotic manipulator cluster with 6-DOF arm, gripper, wrist, servo mounts, actuator and linear guide components.

7 partspairs verified
CNC MACHINING

CNC Workholding & Tooling Kit

A CNC machining cluster covering table, clamping, vise, chuck, collet holder, spindle and ball-screw motion.

6 partspairs verified
HVAC / DUCTING

HVAC Ventilation Duct Assembly Kit

A ventilation product cluster with grille, damper, duct adapter, fan, filter, flange and duct clamp.

6 partspairs verified
FLUID POWER

Hydraulic / Pneumatic Pump & Valve Manifold Kit

A fluid-power cluster combining pump, valves, pressure gauge, manifold block, pipe and coupling parts.

8 partspairs verified
MOBILE ROBOTICS

RC / Line-Follower Robot Chassis Kit

A small mobile-robot cluster with chassis, wheels, hubs, motors, motor mounts, controller, battery holder and damper.

9 partspairs verified
WORKSPACE ACCESSORIES

Desk Cable + Phone Stand Workstation Kit

A desk-organization product cluster combining cable routing, phone holders, headphone stands and laptop/iMac stands.

7 partspairs verified
CAMERA / IMAGING RIGS

Camera Gimbal & Mount Rig Kit

A camera-rig cluster with gimbal, camera modules, tripod, tilt head, GoPro mount and camera bracket parts.

5 partspairs verified
10,000+ models2D drawings
Sort by:
Free
Light Shield 1 | 3D CAD Engineering Model
3D PRINTING · LIGHT SHIELD 1

Light Shield 1 | 3D CAD Engineering Model

.STEP
Free
Thermal Shield 2 | 3D CAD Engineering Model
ENERGY AND POWER · THERMAL SHIELD 2

Thermal Shield 2 | 3D CAD Engineering Model

.STEP
Free
Uart Shield 1 | 3D CAD Engineering Model
ELECTRICAL · UART SHIELD 1

Uart Shield 1 | 3D CAD Engineering Model

.STEP
Free
Swd Shield 1 | 3D CAD Engineering Model
ROBOTICS · SWD SHIELD 1

Swd Shield 1 | 3D CAD Engineering Model

.STEP

Need a CAD file that is not in the library?

Share your requirement and Marathon OS will match you with a vetted CAD designer for production-ready CAD files, edits and manufacturing documentation.

Get it Built
500+Projects Done
24 hrResponse
15+CAD Tools
Free
Four Legged Mechanical Dog Robot 1 | 3D CAD Engineering Model
ROBOTICS · FOUR LEGGED MECHANICAL DOG ROBOT 1

Four Legged Mechanical Dog Robot 1 | 3D CAD Engineering Model

.STEP
Free
Poe Shield 2 | 3D CAD Engineering Model
ELECTRICAL · POE SHIELD 2

Poe Shield 2 | 3D CAD Engineering Model

.STEP
Free
Relay Shield 2 | 3D CAD Engineering Model
ELECTRICAL · RELAY SHIELD 2

Relay Shield 2 | 3D CAD Engineering Model

.STEP
Free
Can Rs232 Shield 2 | 3D CAD Engineering Model
ELECTRICAL · RS232

Can Rs232 Shield 2 | 3D CAD Engineering Model

.STEP
Free
Servo Shield V2 1 | 3D CAD Engineering Model
ROBOTICS · SERVO SHIELD V2 1

Servo Shield V2 1 | 3D CAD Engineering Model

.STEP
Free
Microstep Driver Tb6600 1 | 3D CAD Engineering Model
ROBOTICS · MICROSTEP DRIVER TB6600

Microstep Driver Tb6600 1 | 3D CAD Engineering Model

.STEP
Free
Openmv Cam H7 R2 1 | 3D CAD Engineering Model
ROBOTICS · OPENMV CAM H7 R2 1

Openmv Cam H7 R2 1 | 3D CAD Engineering Model

.STEP
Free
Openmv Cam M4 Ov7725 1 | 3D CAD Engineering Model
ROBOTICS · OPENMV CAM M4

Openmv Cam M4 Ov7725 1 | 3D CAD Engineering Model

.STEP
Free
Gripper Sets Using Parallel Cylinder 1 | 3D CAD Engineering Model
ROBOTICS · GRIPPER SETS

Gripper Sets Using Parallel Cylinder 1 | 3D CAD Engineering Model

.STEP
Free
Lens Mount 3 | 3D CAD Engineering Model
MACHINE DESIGN · LENS MOUNT 3

Lens Mount 3 | 3D CAD Engineering Model

.STEP
Free
6 Wheel Drive Rover 1 | 3D CAD Engineering Model
ROBOTICS · 6 WHEEL DRIVE ROVER

6 Wheel Drive Rover 1 | 3D CAD Engineering Model

.STEP
Free
Sino Ka 200 120Mm Dro 1 | 3D CAD Engineering Model
MACHINE DESIGN · SINO KA 200 120MM DRO 1

Sino Ka 200 120Mm Dro 1 | 3D CAD Engineering Model

.STEP
Free
2024 Crescendo Team 4639 Robot Cadenza 1 | 3D CAD Engineering Model
ROBOTICS · 2024 CRESCENDO TEAM 4639

2024 Crescendo Team 4639 Robot Cadenza 1 | 3D CAD Engineering Model

.STEP
Free
Weldling Mig Torch 1 | 3D CAD Engineering Model
INDUSTRIAL DESIGN · WELDLING MIG TORCH 1

Weldling Mig Torch 1 | 3D CAD Engineering Model

.STEP
Free
N20 11 | 3D CAD Engineering Model
ROBOTICS · N20 11

N20 11 | 3D CAD Engineering Model

.STEP
Free
Picomini 1 | 3D CAD Engineering Model
ROBOTICS · PICOMINI 1

Picomini 1 | 3D CAD Engineering Model

.STEP
Free
Simple Swerve Pods V2 Rev 1 | 3D CAD Engineering Model
ROBOTICS · SWERVE POD

Simple Swerve Pods V2 Rev 1 | 3D CAD Engineering Model

.STEP
Free
Simple Swerve V2 Gobilda 1 | 3D CAD Engineering Model
ROBOTICS · SIMPLE SWERVE V2

Simple Swerve V2 Gobilda 1 | 3D CAD Engineering Model

.STEP