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.
Build kits
Curated systems with verified mating parts — download the whole assembly at once.
iPhone Accessory & Case Design Kit
A practical iPhone accessory cluster for designing cases, charging stands, holders and fit-checking around real phone geometry.
250 mm FPV Drone Build Kit
A complete FPV quad build cluster covering frame, propulsion, camera, control electronics, battery housing and mounting hardware.
NEMA 17 Motion / Linear Actuator Kit
A motion-control cluster around a NEMA 17 stepper, bracket, coupler, GT2 belt, pulley, bearing and driver.
Metric Fasteners & Threaded Hardware Pack
A reusable ISO/metric fastener library cluster with screws, nuts, washers, inserts, standoffs and bolt assemblies.
3D Printer Motion & Extruder Upgrade Kit
A 3D-printer upgrade cluster combining hotend parts, filament handling, stepper drive and motion hardware.
Arduino / ESP32 Prototyping Kit
A maker electronics cluster with Arduino, ESP32, breadboard, shield, servo, battery holder and enclosure.
Robotic Arm + Gripper Kit
A robotic manipulator cluster with 6-DOF arm, gripper, wrist, servo mounts, actuator and linear guide components.
CNC Workholding & Tooling Kit
A CNC machining cluster covering table, clamping, vise, chuck, collet holder, spindle and ball-screw motion.
HVAC Ventilation Duct Assembly Kit
A ventilation product cluster with grille, damper, duct adapter, fan, filter, flange and duct clamp.
Hydraulic / Pneumatic Pump & Valve Manifold Kit
A fluid-power cluster combining pump, valves, pressure gauge, manifold block, pipe and coupling parts.
RC / Line-Follower Robot Chassis Kit
A small mobile-robot cluster with chassis, wheels, hubs, motors, motor mounts, controller, battery holder and damper.
Desk Cable + Phone Stand Workstation Kit
A desk-organization product cluster combining cable routing, phone holders, headphone stands and laptop/iMac stands.
Camera Gimbal & Mount Rig Kit
A camera-rig cluster with gimbal, camera modules, tripod, tilt head, GoPro mount and camera bracket parts.
1:10 RC Car Drivetrain & Suspension Kit
A 1:10 RC Car Drivetrain & Suspension Kit cluster covering related CAD components for Automotive & Mobility.
Arduino / ESP32 Prototyping Kit; CNC Workholding & Tooling Kit
A Arduino / ESP32 Prototyping Kit; CNC Workholding & Tooling Kit cluster covering related CAD components for Robotics & Mechatronics.
Arduino / ESP32 Prototyping Kit; RC / Line-Follower Robot Chassis Kit
A Arduino / ESP32 Prototyping Kit; RC / Line-Follower Robot Chassis Kit cluster covering related CAD components for Motors & Power Transmission.
Belt & Roller Conveyor Design Kit
A Belt & Roller Conveyor Design Kit cluster covering related CAD components for Hydraulics & Pneumatics.
Centrifugal Pump & Motor Skid Kit
A Centrifugal Pump & Motor Skid Kit cluster covering related CAD components for Pumps & Fluid Systems.
Honda C-Series Engine Parts Pack
A Honda C-Series Engine Parts Pack cluster covering related CAD components for General Engineering.
Hydraulic / Pneumatic Pump & Valve Manifold Kit; Industrial Valve & Actuation Pack
A Hydraulic / Pneumatic Pump & Valve Manifold Kit; Industrial Valve & Actuation Pack cluster covering related CAD components for Valves & Flow Control.
IP65/IP67 Electrical Enclosure & Control Panel Pack
A IP65/IP67 Electrical Enclosure & Control Panel Pack cluster covering related CAD components for Enclosures & Panels.
Industrial Gearmotor & Drive Kit
A Industrial Gearmotor & Drive Kit cluster covering related CAD components for General Engineering.
Industrial Valve & Actuation Pack
A Industrial Valve & Actuation Pack cluster covering related CAD components for Valves & Flow Control.
Peristaltic / Dosing Pump Prototyping Kit
A Peristaltic / Dosing Pump Prototyping Kit cluster covering related CAD components for Pumps & Fluid Systems.
Raspberry Pi Case & Display Kit
A Raspberry Pi Case & Display Kit cluster covering related CAD components for Robotics & Mechatronics.
Superquadro Engine Internals Kit
A Superquadro Engine Internals Kit cluster covering related CAD components for Engines & Powertrain.
Vacuum Pump System Pack
A Vacuum Pump System Pack cluster covering related CAD components for Pumps & Fluid Systems.
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