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
Siren | 3D CAD Engineering Model
INDUSTRIAL DESIGN · SIREN

Siren | 3D CAD Engineering Model

.STEP
Free
Circular Lift | 3D CAD Engineering Model
MACHINE DESIGN · CIRCULAR LIFT

Circular Lift | 3D CAD Engineering Model

.STEP
Free
Turbine Watch Case | 3D CAD Engineering Model
JEWELLERY · TURBINE WATCH CASE

Turbine Watch Case | 3D CAD Engineering Model

.STEP
Free
Divers Watch | 3D CAD Engineering Model
JEWELLERY · DIVERS WATCH

Divers Watch | 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
Ship Crane | 3D CAD Engineering Model
MARINE · SHIP CRANE

Ship Crane | 3D CAD Engineering Model

.STEP
Free
Magnetic Storm 1 | 3D CAD Engineering Model
3D PRINTING · MAGNETIC STORM 1

Magnetic Storm 1 | 3D CAD Engineering Model

.STEP
Free
Kaplan Turbine Runner | 3D CAD Engineering Model
ENERGY AND POWER · KAPLAN TURBINE RUNNER

Kaplan Turbine Runner | 3D CAD Engineering Model

.STEP
Free
One Of Seven | 3D CAD Engineering Model
3D PRINTING · ONE OF SEVEN

One Of Seven | 3D CAD Engineering Model

.STEP
Free
Lurssen Wind Breaker Rotary Oil Damper | 3D CAD Engineering Model
MARINE · LURSSEN WIND BREAKER

Lurssen Wind Breaker Rotary Oil Damper | 3D CAD Engineering Model

.STEP
Free
Pump Impeller D 2 04M | 3D CAD Engineering Model
MACHINE DESIGN · PUMP IMPELLER

Pump Impeller D 2 04M | 3D CAD Engineering Model

.STEP
Free
Ansi Slip On Pipe Flange | 3D CAD Engineering Model
INDUSTRIAL DESIGN · ANSI SLIP ON PIPE FLANGE

Ansi Slip On Pipe Flange | 3D CAD Engineering Model

.STEP
Free
Asian Inspired Door | 3D CAD Engineering Model
ARCHITECTURE · ASIAN INSPIRED DOOR

Asian Inspired Door | 3D CAD Engineering Model

.STEP
Free
Asian Inspired Cannon Barrel | 3D CAD Engineering Model
3D PRINTING · CANNON BARREL

Asian Inspired Cannon Barrel | 3D CAD Engineering Model

.STEP
Free
Pump Housing Lower Part | 3D CAD Engineering Model
MACHINE DESIGN · PUMP HOUSING

Pump Housing Lower Part | 3D CAD Engineering Model

.STEP
Free
Smal Thruster | 3D CAD Engineering Model
AEROSPACE · SMAL THRUSTER

Smal Thruster | 3D CAD Engineering Model

.STEP
Free
Piston And Connecting Rod 1 | 3D CAD Engineering Model
AUTOMOTIVE · PISTON

Piston And Connecting Rod 1 | 3D CAD Engineering Model

.STEP
Free
Butterfly Valve 8 0 Keystone Wafer | 3D CAD Engineering Model
INDUSTRIAL DESIGN · BUTTERFLY VALVE

Butterfly Valve 8 0 Keystone Wafer | 3D CAD Engineering Model

.STEP
Free
Butterfly Valve 14 0 Keystone Wafer | 3D CAD Engineering Model
INDUSTRIAL DESIGN · BUTTERFLY VALVE

Butterfly Valve 14 0 Keystone Wafer | 3D CAD Engineering Model

.STEP
Free
Sit On Top Fishing Ski Seat | 3D CAD Engineering Model
MARINE · SIT ON TOP FISHING SKI SEAT

Sit On Top Fishing Ski Seat | 3D CAD Engineering Model

.STEP
Free
Cummins Vt 903 M Engine 1 | 3D CAD Engineering Model
MACHINE DESIGN · CUMMINS VT 903 M

Cummins Vt 903 M Engine 1 | 3D CAD Engineering Model

.STEP
Free
Ship 3 | 3D CAD Engineering Model
MARINE · SHIP 3

Ship 3 | 3D CAD Engineering Model

.STEP
Free
Centrifugal Pump Impeller With Video Tutorial | 3D CAD Engineering Model
INDUSTRIAL DESIGN · CENTRIFUGAL PUMP IMPELLER

Centrifugal Pump Impeller With Video Tutorial | 3D CAD Engineering Model

.STEP