Production-Ready CAD Designs for Engineering Teams

Discover, buy, and sell professional 3D CAD models on a global engineering marketplace.

CAD outsourcing

Can't find the file you need?
We'll build it in 24 hours.

Send your requirements — we match you with a vetted CAD specialist and deliver production‑ready files. No hiring, no overhead.

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Typical kickoff in 24–72 hrs

Marathon-OS Design Hub

Everything you need to design faster, smarter, and with more impact.

Melth 99 Aircraft Design Project

Elongated Pentagonal Gyrobirotunda 1 | 3D CAD Engineering Model

Ender 3 Max Neo Direct Drive 1 | 3D CAD Engineering Model

3D Printed Push Up Bar 1 | 3D CAD Engineering Model

Replacement Fan Blade Design for 3D Printing

Fysetc Ucan Case 1 | 3D CAD Engineering Model

Hanuman Gadaa 1 | 3D CAD Engineering Model

Fidget Keychain | 3D Engineering Design File

Edge Lamp 1 | 3D CAD Engineering Model

Vignesan - Professional CAD Model

Exercise 014 Chess Pieces The Queen 1 | 3D CAD Engineering Model

Shuffler Pod Not Functional 1 | 3D CAD Engineering Model

Xmas Tree For 3D Printing 1 | Professional CAD Design

Kaffeefilterhalter 1 | 3D CAD Engineering Model

Multi-Filament Spool Holder for Organized Storage

GB-22 .22LR Ammunition Firearm 3D Printing Model

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Recently added / Trending

Everything you need to design faster, smarter, and with more impact.

12-24V Underwater Thruster Brushless Motor 4 Blade Propeller Design | High-Quality CAD Model

Blow Bar - Standard Mechanical Component

Jewellery Piece 6 - Downloadable CAD Representation

Chemical Bath 1 | CAD Model for Chemical Industry

Magnetic Choked Flow - Cryo Valve - Downloadable CAD Representation

3D Tesla Valve 1 | 3D CAD Engineering Model

Drone Storage Box with Sliding Acrylic Panel and Magnetic Closure

Central Drill Tool | 3D Engineering Design File

Unique Bracelet 3 - Standard Mechanical Component

Stepper Motor Driver For Nema17 1 | 3D CAD Engineering Model

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Why Marathon-OS?

For people who need CAD files they can actually trust and use.

No blind downloads

Preview CAD files online using Marathon previewer before you pay.

Quality-checked designs

Every CAD file is manually reviewed before listing.

Built for engineering use

Focused on real engineering, manufacturing, and production needs.

Marathon-OS free to use tools

Use powerful engineering tools without installing any software

CAD Viewer

Preview 3D CAD files online to inspect geometry and structure (powered by the Marathon-OS proprietary CAD viewer)

Supported file formats:STEP (.step, .stp)IGES (.igs, .iges)STL (.stl)PLY (.ply)OFF (.off)BREP (.brp, .brep)OBJ (.obj)

Preview CAD files →

CAD Converter

Drag, drop, and convert directly in your browser (with no local CAD tools needed)

Supported file formats:STEP (.step, .stp)IGES (.igs, .iges)STL (.stl)PLY (.ply)OFF (.off)BREP (.brp, .brep)OBJ (.obj)

Convert CAD files →

Become a creator on Marathon-OS

Publish your CAD designs, reach engineering teams, and monetize your work on a platform built for real engineering use.

Create your profile

Set up your creator profile with your expertise and portfolio.

Upload CAD files

Upload your CAD files in supported formats to the platform.

Add details

Add title, description, and tags so engineers can discover your designs.

Set pricing & publish

Choose to share for free or set a price, then publish your design.

Designed for Security

Capturing everything you see, say, and hear means trust and privacy is more important than anything else.

Encryption at rest

Encryption in transit

Single-sign on

Role-based access controls

Logging, auditing and monitoring features

Features to enhance privacy of personal data

Frequently Asked Questions

What is MarathonOS?

MarathonOS is a marketplace where CAD designers sell CAD designs to engineers, agencies, and organizations. Buyers can discover designs, purchase securely, and download instantly.

How do I publish a CAD file?

Go to your dashboard and click "Upload CAD File." Upload your file, add a title, description, previews, and pricing, then click "Publish" to list it on the marketplace.

How do I buy and download a design?

Open the design page and click "Buy/Download." After checkout, your file will appear in your Purchases/Downloads section, where you can download it anytime based on the license.

How do licensing and usage rights work?

All designs come with a Standard Usage License, allowing you to use, modify, remix, and commercially use the asset in your own products, client work, marketing, and team projects—royalty-free. Reselling or redistributing the original CAD file itself is not permitted.

How do creators earn money and get paid?

Creators set their own prices when publishing. When a buyer purchases a design, creators earn the sale amount minus a 10% commission, with earnings visible in the dashboard.

Can I collaborate with other creators or share with my team?

Yes. Collaboration is supported through your dashboard. You can work with other creators on shared projects, and teams can manage access to designs based on the license or plan.

What if there's a problem with a file or I need help?

If a file is broken, incorrect, or you need support, contact us via the Contact Us page or email [email protected] with the listing link or order details, and we'll help resolve it.