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
9989 models2D drawings
Sort by:
Free
Traditional V8 Engine Prototype Model
AUTOMOTIVE · V8 ENGINE

Traditional V8 Engine Prototype Model

.STEP
Free
Steam Prototype Design Using NX CAD Software
INDUSTRIAL DESIGN · STEAM PROTOTYPE

Steam Prototype Design Using NX CAD Software

.STEP
Free
Car Hood Outer Panel Designed with CATIA
AUTOMOTIVE · CAR HOOD OUTER PANEL

Car Hood Outer Panel Designed with CATIA

.STEP
Free
Professional Bicycle Frame CAD Model
AUTOMOTIVE · BICYCLE FRAME

Professional Bicycle Frame CAD 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
Process Adaptor Design for Industrial Applications
INDUSTRIAL DESIGN · PROCESS ADAPTOR

Process Adaptor Design for Industrial Applications

.STEP
Free
Precision Gear Shaft CAD Model for Mechanical Applications
MACHINE DESIGN · GEAR SHAFT

Precision Gear Shaft CAD Model for Mechanical Applications

.STEP
Free
Autonomous Minibus Concept for Public Transportation
AUTOMOTIVE · AUTONOMOUS VEHICLE

Autonomous Minibus Concept for Public Transportation

.STEP
Free
Industrial Component Model for Engineering Applications
MACHINE DESIGN · INDUSTRIAL COMPONENT

Industrial Component Model for Engineering Applications

.STEP
Free
Crankshaft Assembly CAD Model for Engineering Practice
MACHINE DESIGN · CRANKSHAFT

Crankshaft Assembly CAD Model for Engineering Practice

.STEP
Free
Toyota 1NZ-FE Engine Control Unit (ECU) CAD Model
AUTOMOTIVE · TOYOTA 1NZ-FE

Toyota 1NZ-FE Engine Control Unit (ECU) CAD Model

.STEP
Free
Crankcase Ventilation Pipe Holder for Mazda Engines
AUTOMOTIVE · CRANKCASE VENTILATION

Crankcase Ventilation Pipe Holder for Mazda Engines

.STEP
Free
Spark Plug Wire Holder for Engine Management
AUTOMOTIVE · SPARK PLUG WIRE HOLDER

Spark Plug Wire Holder for Engine Management

.STEP
Free
Side Door Hinge for Industrial and Commercial Applications
INDUSTRIAL DESIGN · SIDE DOOR HINGE

Side Door Hinge for Industrial and Commercial Applications

.STEP
Free
Crankshaft CAD Model for Engine Component Design
AUTOMOTIVE · CRANKSHAFT

Crankshaft CAD Model for Engine Component Design

.STEP
Free
Robotic Hand Claw Driven by DC Motor and Lead Screw for Industrial Applications
ROBOTICS · ROBOTIC HAND CLAW

Robotic Hand Claw Driven by DC Motor and Lead Screw for Industrial Applications

.STEP
Free
2 Degree of Freedom Camera Stabilizer with Dual Axis Rotation
ROBOTICS · 2 DEGREE OF FREEDOM

2 Degree of Freedom Camera Stabilizer with Dual Axis Rotation

.STEP
Free
Automated Guided Vehicle (AGV) CAD Model
ROBOTICS · AUTOMATED GUIDED VEHICLE

Automated Guided Vehicle (AGV) CAD Model

.STEP
Free
Cam with Spring Mechanism CAD Model
MACHINE DESIGN · CAM

Cam with Spring Mechanism CAD Model

.STEP
Free
Three-Wire Spark Plug Holder for Automotive Applications
AUTOMOTIVE · SPARK PLUG HOLDER

Three-Wire Spark Plug Holder for Automotive Applications

.STEP
Free
Additive Manufacturing Platform with FDM Printing Features
3D PRINTING · ADDITIVE MANUFACTURING PLATFORM

Additive Manufacturing Platform with FDM Printing Features

.STEP
Free
Trailer Caravan Jockey Wheel Clamp 48mm 300kg Zinc Plated
AUTOMOTIVE · TRAILER CARAVAN

Trailer Caravan Jockey Wheel Clamp 48mm 300kg Zinc Plated

.STEP
Free
Precision Mechanical Component for Industrial Applications
MACHINE DESIGN · MECHANICAL COMPONENT

Precision Mechanical Component for Industrial Applications

.STEP