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
Emoji Anxious 1 | 3D CAD Engineering Model
3D PRINTING · EMOJI ANXIOUS 1

Emoji Anxious 1 | 3D CAD Engineering Model

.STEP
Free
Plastic Bottle 182 | 3D CAD Engineering Model
INDUSTRIAL DESIGN · PLASTIC BOTTLE 182

Plastic Bottle 182 | 3D CAD Engineering Model

.STEP
Free
Ripswitch V2 Ultra Racing Drone 1 | 3D CAD Engineering Model
ROBOTICS · RIPSWITCH V2 ULTRA RACING DRONE

Ripswitch V2 Ultra Racing Drone 1 | 3D CAD Engineering Model

.STEP
Free
Exercise 014 Chess Pieces The Queen 1 | 3D CAD Engineering Model
3D PRINTING · CHESSPIECE

Exercise 014 Chess Pieces The Queen 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
Hexagonal Spiral Vase For 3D Printing 1 | 3D CAD Engineering Model
3D PRINTING · HEXAGONAL SPIRAL VASE

Hexagonal Spiral Vase For 3D Printing 1 | 3D CAD Engineering Model

.STEP
Free
Exercise Freecad 017 Chess Pieces The Tower 1 | 3D CAD Engineering Model
3D PRINTING · CHESS PIECE

Exercise Freecad 017 Chess Pieces The Tower 1 | 3D CAD Engineering Model

.STEP
Free
Holder Er 25 1 | 3D CAD Engineering Model
MACHINE DESIGN · HOLDER ER 25 1

Holder Er 25 1 | 3D CAD Engineering Model

.STEP
Free
Drill Bit Holder 5 | 3D CAD Engineering Model
3D PRINTING · DRILL BIT HOLDER 5

Drill Bit Holder 5 | 3D CAD Engineering Model

.STEP
Free
Sample Pcba 1 | 3D CAD Engineering Model
ELECTRICAL · SAMPLE PCBA 1

Sample Pcba 1 | 3D CAD Engineering Model

.STEP
Free
Exercise Freecad 018 1 | 3D CAD Engineering Model
MACHINE DESIGN · EXERCISE FREECAD 018 1

Exercise Freecad 018 1 | 3D CAD Engineering Model

.STEP
Free
E Ingraham Co Rose Mantle Chime Clock Face 1 | 3D CAD Engineering Model
INDUSTRIAL DESIGN · E INGRAHAM CO ROSE MANTLE CHIME CLOCK FACE 1

E Ingraham Co Rose Mantle Chime Clock Face 1 | 3D CAD Engineering Model

.STEP
Free
Spool Holder Adapter 2 | 3D CAD Engineering Model
3D PRINTING · SPOOL HOLDER ADAPTER 2

Spool Holder Adapter 2 | 3D CAD Engineering Model

.STEP
Free
Beautiful Christmas Tree Star Easy To Print 1 | 3D CAD Engineering Model
3D PRINTING · CHRISTMAS TREE STAR

Beautiful Christmas Tree Star Easy To Print 1 | 3D CAD Engineering Model

.STEP
Free
Nano Sim To Mini Sim Card Adapter 1 | 3D CAD Engineering Model
ELECTRICAL · NANO SIM ADAPTER

Nano Sim To Mini Sim Card Adapter 1 | 3D CAD Engineering Model

.STEP
Free
Edge Lamp 1 | 3D CAD Engineering Model
3D PRINTING · EDGE LAMP 1

Edge Lamp 1 | 3D CAD Engineering Model

.STEP
Free
Frame For 4 X6 Photos Model For 3D Printing With | 3D CAD Engineering Model
3D PRINTING · FRAMEFOR4X6PHOTOS

Frame For 4 X6 Photos Model For 3D Printing With | 3D CAD Engineering Model

.STEP
Free
Truncated Decagonal Trapezohedron 1 | 3D CAD Engineering Model
3D PRINTING · TRUNCATED DECAGONAL TRAPEZOHEDRON

Truncated Decagonal Trapezohedron 1 | 3D CAD Engineering Model

.STEP
Free
Whirly 1 | 3D CAD Engineering Model
ROBOTICS · WHIRLY 1

Whirly 1 | 3D CAD Engineering Model

.STEP
Free
Tutorial Freecad Beginner 025 1 | 3D CAD Engineering Model
MACHINE DESIGN · FREECAD

Tutorial Freecad Beginner 025 1 | 3D CAD Engineering Model

.STEP
Free
Plastic Handle 14 | 3D CAD Engineering Model
INDUSTRIAL DESIGN · PLASTIC HANDLE 14

Plastic Handle 14 | 3D CAD Engineering Model

.STEP
Free
Tutorial Freecad Beginner 026 1 | 3D CAD Engineering Model
MACHINE DESIGN · FREECAD

Tutorial Freecad Beginner 026 1 | 3D CAD Engineering Model

.STEP
Free
Sheath For Global Gs 38 9Cm 1 | 3D CAD Engineering Model
3D PRINTING · SHEATH FOR GLOBAL GS 38 9CM 1

Sheath For Global Gs 38 9Cm 1 | 3D CAD Engineering Model

.STEP