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
Robot Arm Attachment 1 | 3D CAD Engineering Model
ROBOTICS · ROBOT ARM ATTACHMENT 1

Robot Arm Attachment 1 | 3D CAD Engineering Model

.STEP
Free
Laptop Back Cover Screwing 1 | 3D CAD Engineering Model
INDUSTRIAL DESIGN · LAPTOP BACK COVER

Laptop Back Cover Screwing 1 | 3D CAD Engineering Model

.STEP
Free
Customised I Beam 1 | 3D CAD Engineering Model
CONSTRUCTION · I BEAM

Customised I Beam 1 | 3D CAD Engineering Model

.STEP
Free
Bearing Support 14 | 3D CAD Engineering Model
MACHINE DESIGN · BEARING SUPPORT 14

Bearing Support 14 | 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
Automotive Battery Tray 1 | 3D CAD Engineering Model
AUTOMOTIVE · BATTERY TRAY

Automotive Battery Tray 1 | 3D CAD Engineering Model

.STEP
Free
4 Cylinder Engine 15 | 3D CAD Engineering Model
AUTOMOTIVE · 4 CYLINDER ENGINE

4 Cylinder Engine 15 | 3D CAD Engineering Model

.STEP
Free
Car 5 | 3D CAD Engineering Model
AUTOMOTIVE · CAR 5

Car 5 | 3D CAD Engineering Model

.STEP
Free
Knuckle For Buggy 1 | 3D CAD Engineering Model
AUTOMOTIVE · KNUCKLE FOR BUGGY 1

Knuckle For Buggy 1 | 3D CAD Engineering Model

.STEP
Free
Test Sac Parca Sheet Metal 1 | 3D CAD Engineering Model
MACHINE DESIGN · SHEET METAL

Test Sac Parca Sheet Metal 1 | 3D CAD Engineering Model

.STEP
Free
Modern F1 Car F1 24 1 | 3D CAD Engineering Model
AUTOMOTIVE · F1 24 1

Modern F1 Car F1 24 1 | 3D CAD Engineering Model

.STEP
Free
Ac2 H Chain Conveyor B320 Lx For Pallet Conveyor System | 3D CAD Engineering Model
INDUSTRIAL DESIGN · CHAIN CONVEYOR

Ac2 H Chain Conveyor B320 Lx For Pallet Conveyor System | 3D CAD Engineering Model

.STEP
Free
33 Stradale Tribute 1 | 3D CAD Engineering Model
AUTOMOTIVE · 33 STRADALE TRIBUTE 1

33 Stradale Tribute 1 | 3D CAD Engineering Model

.STEP
Free
Positioning Unit B320 L320 For Pallet Conveyor System 1 | 3D CAD Engineering Model
MACHINE DESIGN · POSITIONING UNIT B320 L320

Positioning Unit B320 L320 For Pallet Conveyor System 1 | 3D CAD Engineering Model

.STEP
Free
Pallet For Conveyor System 1 | 3D CAD Engineering Model
INDUSTRIAL DESIGN · PALLET

Pallet For Conveyor System 1 | 3D CAD Engineering Model

.STEP
Free
Engine 4 Cylinder Inline 1 | 3D CAD Engineering Model
AUTOMOTIVE · ENGINE 4 CYLINDER INLINE 1

Engine 4 Cylinder Inline 1 | 3D CAD Engineering Model

.STEP
Free
Hex Flange Nut External 1 | 3D CAD Engineering Model
MACHINE DESIGN · HEX FLANGE NUT

Hex Flange Nut External 1 | 3D CAD Engineering Model

.STEP
Free
E Bike Frame 4 | 3D CAD Engineering Model
AUTOMOTIVE · E BIKE FRAME 4

E Bike Frame 4 | 3D CAD Engineering Model

.STEP
Free
Bicycle 48 | 3D CAD Engineering Model
AUTOMOTIVE · BICYCLE 48

Bicycle 48 | 3D CAD Engineering Model

.STEP
Free
Oil Fired Boiler Vertical Boiler Steam Locomotive Boiler 1 | 3D CAD Engineering Model
ENERGY AND POWER · OIL FIRED BOILER

Oil Fired Boiler Vertical Boiler Steam Locomotive Boiler 1 | 3D CAD Engineering Model

.STEP
Free
Knuckle Joint Assembly 25 | 3D CAD Engineering Model
MACHINE DESIGN · KNUCKLE JOINT ASSEMBLY 25

Knuckle Joint Assembly 25 | 3D CAD Engineering Model

.STEP
Free
Gd 80F 1 | 3D CAD Engineering Model
MACHINE DESIGN · GD 80F 1

Gd 80F 1 | 3D CAD Engineering Model

.STEP
Free
750 Mm 20X20 4T Slot Aluminium Extrusion Profile 1 | 3D CAD Engineering Model
MACHINE DESIGN · 750 MM 20X20 4T SLOT ALUMINIUM EXTRUSION PROFILE

750 Mm 20X20 4T Slot Aluminium Extrusion Profile 1 | 3D CAD Engineering Model

.STEP