Limitations of AM

Limitations of Additive Manufacturing / 3D Printing Compared to Conventional Manufacturing Processes

In our previous blog, we discussed the benefits of additive manufacturing (AM) but it is essential to note that additive manufacturing is not a universal solution for all manufacturing challenges. To get a deeper understanding of any technology the limitations should also be considered. Similarly, the AM approach has its fair share of process, productivity, and economic limitations that must be considered when evaluating its suitability for a particular application. So let’s dive deeper into the drawbacks associated with 3d printing.

Productivity can be low

Compared to established production methods, AM processes may have lower production rates. For instance, while an injection molding machine can produce a plastic component in less than a minute, creating an equivalent part using AM could take hours. Similarly, a CNC milling machine may take less than an hour to produce a finished part, but the same part made using metal AM technology could take more than a day.

Economics does not always prefer AM

High-end AM machines can cost several thousand and even millions of euros, and the material feedstock used by these machines can be significantly more expensive per tonne than the material used in traditional methods like molding, casting, or machining. The low productivity of these machines, combined with their high cost and raw materials, can lead to high-cost components.

Nevertheless, using AM can eliminate the need for toolings such as injection molds, die-casts, or investment casts, which may take several months to produce. Additionally, AM can reduce the number of manufacturing and assembly steps necessary to bring a product to market. Therefore, in any AM business case, it is crucial to take into account the total cost of production of parts, not just the cost of the 3D printing step.

Process capability is limited

Although AM can produce parts in the same or similar materials and sizes as conventional methods, it may not achieve the same level of accuracy, resolution, or surface finish without additional post-processing. As a result, the overall cost of the part may increase.

Physical and mechanical properties are weak in some cases

Material options for AM are not as wide as for traditional methods. Due to this fact and the anisotropic nature of some 3D printing technologies, AM can struggle to produce parts with the required physical properties and mechanical strength. This problem is continuously being addressed with new AM technologies, machines, and materials.

Product testing and certification are costly

AM can provide several benefits when a product or part is specifically redesigned for the AM process. However, this approach may involve making a new product using a new technique and material with distinct mechanical properties. In such a situation, testing may be necessary to certify the product’s capabilities.

For example, aerospace and medical parts have strict safety regulations and require extensive certification, which can lead to an increase in both the time and cost of adopting AM.

Process validation is not straightforward

When AM is employed to produce certified products or critical products, it is essential to track and control the process. Each AM machine is a factory in itself, and the quality of parts produced with AM can vary significantly due to small changes in the process environment such as temperature, gas flow, or contamination. Controlling the process environment can require costly equipment.

It is not easy to find AM specialists and the learning curve can be steep

Adopting AM requires skilled and well-trained personnel such as designers, operators, technicians, and engineers. Some high-end machines require multiple dedicated specialists, who are difficult to find and replace. Training and keeping the staff, therefore, adds to the costs and risks of adopting AM. There is, however, a trend toward automation and software-supported decision-making.

The verdict

Additive manufacturing offers numerous benefits, such as increased design flexibility, reduced waste, and cost-effective low-volume production. However, it is essential to consider the limitations of the technology, including material restrictions, limited scalability, and higher per-part production costs.

When deciding whether to use AM for a particular application, it is important to weigh the benefits against the limitations and evaluate the suitability of the technology for your specific needs. In our next blog article, we will delve deeper into the different types of 3d printing categories, followed by when to use additive manufacturing and when not to, providing insights to help you make better decisions.

Regarding better decisions, you might want to try our AI-supported tool 3D Spark. 3D Spark suggests the lowest-cost, fastest, and most sustainable manufacturing technology and material for each part, based on 3D CAD data and 2D technical drawings. Industrial 3D printing and common traditional processes can be compared automatically in terms of cost, carbon footprint, and delivery time.

Therefore, the best manufacturing approach can be identified even by non-experts. Beyond technical decisions, commercial processes related to manufacturing, such as sending out or responding to RFQs (Requests for Quotations), can be automated to a great extent.

Further reading
BSI PAS 6001:2020, The 3-D Printing Revolution, Harvard Business Review, Resource library | GE Additive