Challenges in Part Identification for 3D Printing
Updated: Sep 30, 2020
3D Printing has been around for the last 30 years. It started even before the worldwide web, also known as the internet, has been formed. Yet, while the internet has been invading every part of our lives, the adoption of 3D printing technology did not evolve in the same manner. Even to date, manufacturers find it difficult to fully utilize the advantages and capabilities of 3D printing. In general, prototyping and proof of concept development are still the major applications where this technology is being massively used.
Recent industry reports, however, indicate that a shift in this old paradigm is beginning to happen and that the digital transformation for industrial manufacturing is here. In fact, 80% of enterprises say 3D printing is enabling them to innovate faster, according to State of 3D Printing report (by Sculpteo). Also, most manufacturers (52%) understand the benefits of implementing 3D printing technologies beyond prototyping and are exploring use of this technology in production (for example, in 3D printing for tooling applications).
Yet it is still visible that most manufacturers struggle with identifying exactly if, when and in where to apply additive manufacturing for the benefit of their business.
So why is it happening? 51% of manufacturers believe that the knowledge gap in additive manufacturing is the major reason for its limited growth. The main problem for most companies is not having enough information and in-house expertise to use 3D printing to generate cost-savings. Manufacturers wish to reduce the risks associated with altering their production methods and to verify that their decision, at minimum, does not harm their products’ properties. Equally important for them is to assure this shift to additive, lowers production costs and makes financial sense. Thus, determining whether a part is a good candidate for additive manufacturing, requires extensive knowledge of the different technologies, materials and other factors of production.
Here are some of the important factors and certain challenges that needs to be considered in part identification for 3D printing - focusing on three aspects: geometry, materials, and economics.
While 3D printing allows the production of more complex, perhaps “organic” geometrical designs, some limitations still exist in the set of technologies. There are size and geometric restrictions that have to be considered when validating the 3D printability of a part. Clearly, the size of the part matters, since each printer has different limitations based on its tray dimensions. Also, parts of exceedingly small size might just not be cost effective to 3D print versus producing it in traditional methods.
There are additional, more complex factors to be considered. For instance, the minimum wall thickness threshold. This refers to the minimum distance between one surface of the part and the opposite sheer surface. Different materials and technologies require different minimum wall thickness thresholds. If one decides to 3D print a part with plastic, he can set the minimum wall thickness threshold required for the part at approximately 0.8 mm. However, if she decides to 3D print using binder jetting technology, then it is recommended that she uses a minimum wall thickness of 2 mm. Parts that are too thin will be very fragile to the point that they could not be printed properly.
Some software solutions feature heat maps that warn the engineer from areas that are below the thickness threshold and therefore do not comply with the requirements for 3D production. However, it is especially important to consider the aspect ratio of the printer - i.e., the ratio between height, depth and thickness. Most conventional heat maps do not take that into consideration.
2) Material and Mechanical properties:
Mechanical properties determine how a material will react to certain forces or stress that it is subjected to. Each manufactured part requires different levels of ductility, density, elasticity and resistance, for maintaining its functionality. For example, Young modulus is a mechanical property that measures the stiffness vs. flexibility of a material – in other words, the degree in which a material changes its shape under elastic loads. Elongation is a property that measures the ductility of a material, meaning- the amount of strain it can experience before failing when subjected to tensile load in tensile testing.
In some cases, the part must endure exposure to extreme temperatures, for example, when used in aerospace applications. Other parts have to be food safe or bio-compatible, as common in the medical device industry. A material analysis should review the 3D printed model and identify the 3D printable material that best matches the specified material and the required mechanical properties of the original part. It is important to evaluate the compromises that the engineer is willing to take, in terms of price vs. strength, and to examine the subsitute material according to that.
It is important to note that switching a part’s production from traditional manufacturing to 3D printing would most likely result in change the mechanical properties of the part. However, in many cases, there will be certain compromises that could be tolerated and will generate remarkable savings in lead time or costs. That was the case for Stanley Black and Decker, when they used CASTOR to find their first 3D printed metal part.
Calculating the cost for 3D printing of manufactured parts is certainly complex and may be affected by hundreds of parameters like the expected volume of production, cost of raw material etc.
Traditional manufacturing technologies like Injection molding, are very cost-effective for parts produced in high quantities of thousands and above. Some of these methods, will include high initial investment and a very low cost of per-unit manufacturing. This financial model might not be cost-effective for low volumes. On the other hand, additive manufacturing in these cases is ideal, especially for highly complex parts. Just by eliminating the costs of initial investment or tooling, it can already save thousands of dollars, and lower the cost per part significantly.
There is always a financial break-even point for 3D printing versus traditional manufacturing methods. The break-even point analysis is obviously compiled from many different parameters. To get to a practical conclusion, the cost estimations of both additive manufacturing and conventional manufacturing processes must be clear and compared to each other. 3D printing service bureaus’ usually estimate production costs automatically by the same manner, but many of operational expenses vary from one manufacturer to another. If one considers in-house 3D printing, then cost customization is very much needed to get to a definitive economic conclusion which reflects the specific case.
Finally, these are only some of the decision factors and challenges in choosing whether to transition from traditional manufacturing to additive manufacturing. The lack of knowledge often requires companies to hire additive manufacturing experts to identify opportunities for 3D printing. The process of screening hundreds or thousands of parts and analyzing all that data is usually done manually and is a very time-consuming process. When reliable data exists, software can be utilized to automate this process and to allow the user to set geometrical, mechanical and economic configurations that best suit the application. This automation results in a much more cost-effective and time-efficient 3D printable part identification. The process of part identification is the stepping stone to becoming one step closer to solving the challenges of transitioning to additive manufacturing.
CASTOR is a decision support software which conducts a technical and economic analysis, informs manufacturers when it is beneficial to use 3D printing instead of traditional manufacturing methods and provides feedback on each part. It recommends the suitable technology and material for the 3D printing, estimates the cost and lead-time for each part and connects the manufacturer to a service bureau that can print and supply the part according to the requirements.
CASTOR's easy-to-customize software recommendation, helps engineers to unlock the full benefits industrial 3D printing and helps them focus on the right parts that can make a difference.
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