Recent Posts



Allow 3D Printing for Prototyping but not Manufacturing

No 3D CAD, No 3D PrintingNo 3D CAD, No 3D Printinghttp://

No 3D CAD, No 3D Printing!

Nearly 456,000 3D printers will be shipped globally by the end of the year, doubling the 219,000 units that were shipped last year, according to Gartner. 44% of this growth is within the enterprise sector. The global 3D printing market is expected to grow from $4.98 Billion in 2015 to $30.19 Billion by 2022, at a CAGR of 28.5% between 2016 and 2022 according to this Markets and Markets report.The global 3D printer market is booming and the number of units shipped in 2020 is estimated to exceed 6.7 million. However, the whole ‘additive’ manufacturing trend depends on 3D CAD models as its starting point! Without a 3D CAD model you can’t 3D Print anything! With a 3D CAD model and a 3D Printer (or access to an online 3D Printing service) you can 3D Print to manufacture as many as you want.

How to Allow 3D Printing of your CAD Models but prevent Reverse Engineering and/or Manufacturing of your products from downloadable 3D CAD models?

As a manufacturer you are probably among the 81% worldwide using 3D CAD to design your products and using 3D Printing (aka Additive Manufacturing) in prototyping if not yet in production. You (and/or your distributors) may also be using 3D CAD models for inbound or content marketing of your products. If you are or if you are considering doing so you need to consider this key point: how do you let your customers use your 3D CAD models to specify your products within their CAD designs without also enabling them to reverse engineer or manufacture (by additive manufacturing or traditional ‘subtractive’ manufacturing) your products themselves?

There are three basic approaches to protecting your CAD intellectual property:

  • Digital Control – Specific things done to your product CAD models to help protect your Intellectual Property and prevent abuse of it.
  • Legal Control – Put your 3D CAD models online for anyone to download subject to accepting your legal terms and conditions (T&Cs).
  • No Control – Put your 3D CAD models online for anyone to download and use as they wish.

Digital Control

There are a number of specific limitations that can be applied to the downloadable 3D CAD models you put online depending what you want to prevent or discourage:

  • Hollow Out Models – wherever possible make the downloadable CAD models ‘outer envelope only’ and exclude the inner product details from the model. Keep your fully detailed CAD models in your engineering department and use a different set of models for marketing. These outer shell only models are usually all that customers need – the outer surfaces of the component including connection points to other components and and mounting block details. Dimensional precision and outer shell detail is all design engineers need to include in their CAD designs and the smaller the model the faster it downloads and can be manipulated within their CAD assemblies. With this approach your 3D CAD models are not complete enough to enable functional part manufacturing via 3D Printing though may enable prototyping.
  • Where Leaving Out Part of the Product is Not Possible – do something else such as model with extremely thin surfaces rather than solids or visa versa or come up with other ideas. For example if a product such as a door handle or draw knob have no internal detail and are hollow, model them as a solid.
  • Add indented Trademarks – for example add indented logos into the CAD model so if it is 3D Printed, the Trademarks are too. We think someone has to be a pretty committed forger to 3D Print someone else’s trademarks! Possibly introduce small un-obvious changes to Trademarks in the model so that if it is 3D Printed the forgery is obvious! Add Trademarks and or copyright notices into the CAD model metadata (and hidden signatures) into the CAD models to help with possible legal forensics.
  • Don’t Offer .STL File Format for Downloadable 3D CAD Models – most 3D Printing is done with CAD models in .STL file formats so don’t enable downloads in that file format. Of course most CAD systems can translate from other CAD file formats to .STL format so this may just involve an extra step for users.
  • Introduce Intentional Defects – you can legally state that your downloadable CAD models are approved for use in design documents but not approved for prototyping or manufacturing then back that up with intentional 3D CAD model defects. These intentional defects must not matter in a design document but could inhibit prototyping and manufacturing. For example:Bloomberg Graphic on 3D Priting Market Growth
    • It is possible to leave small gaps in 3D CAD models that are so small that they aren’t visible when viewing the model but their effect is that surfaces or solids of the model aren’t ‘closed’ or continuous. This leads to problems when trying to 3D Print the CAD model. Of course this can be overcome if the model is edited, in a CAD system or STL file editor, to close these gaps. However, as soon as the CAD model is changed it is no longer the manufacturer’s approved model so people may have less confidence in it in case anything else was accidentally changed.
    • Researchers from Ben-Gurion University of the Negev (BGU), the University of South Alabama and Singapore University of Technology and Design detail how to sabotage the quality of a 3D-printed functional part, which leads to the destruction of a device. This proof-of-concept video shows how the researchers destroyed a quadcopter UAV drone by hacking into the computer used to control the 3D printing of replacement propellers.
  • Digital Rights Management (DRM) for 3D Printing – is developing fast. For example the Authentise Sendshapes product described in this article enables 3D Printing of a single copy much like Netflix enables a single watching of a movie. Such a capability could enable a prototype to be 3D Printed but prevent functional part manufacturing.

Legal Control

We’re not lawyers so do not give legal advice. Please consult a lawyer for your legal advice!

As an hypothetical example, the T&Cs under which your 3D CAD models are downloaded could allow them to be used in customers’ design documents but not for 3D prototyping without extra permission and never for functional part manufacturing. Whatever legal constraints you apply, you will likely need to be prepared to enforce them so choose them carefully. At the same time, as with most emerging technologies, know that the law hasn’t kept pace with 3D Printing. For example see this Bloomberg article discussing product liability when products are 3D Printed.

No Control

By ‘No Control’ we mean simply putting your 3D CAD models online for anyone to download and use as they wish. This makes sense for some companies. For example, suppliers of 3D Printers or 3D Printing materials have an interest in providing free content to drive use of their products.

Here are our recommendations for industrial suppliers (manufacturers and distributors):

  • If you want to discourage all 3D Printing use both Digital and Legal Control on your 3D CAD models, though we recommend against introducing intentional defects into the models.
  • If you want to discourage 3D Printing for manufacture but enable it for producing prototypes then use just Legal Control on your 3D CAD models.
  • 3D printing is now available in materials as diverse as plastics, metals, chocolate, living cells, concrete and even drugs (the FDA in 2015 approved the first-ever 3-D printed prescription drug). Additive Manufacturing is being used by Manufacturing corporations and not just for prototyping! According to the Wohlers report, 32.5 percent of all Additive Manufacturing generated objects are already used as functional parts not prototypes. Industrial Manufacturers need to understand how Additive Manufacturing will affect their businesses and how it could be used for competitive advantage – before their competitors do!
  • Lastly, if you are not yet using 3D CAD models in your marketing consider doing so – see this blog post for an introduction.

As always, please let us know what you think by commenting below, or if you’d like to know more about or see the CAD technology in action click one of the buttons below.



Posted in