Additive Manufacturing, 3D Printing, Rapid Prototyping
Additive manufacturing is a strategic game changer for those courageous enough to embrace it.
Is additive manufacturing a process, a technology, or an enabler? To indirectly answer that question: it is all of them. And a very versatile tool when applied properly. Three-dimensional printing is one of the processes and basically another drawer in the tool box. According to ISO/ASTM we currently have seven processes for additively manufacturing products. Additive manufacturing is now a method of manufacturing and a strategic game changer for those courageous enough to embrace it. This includes a strategy to engage the transition from pattern making and low volume production to advanced manufacturing of functional products.
Originally additive manufacturing was a way to produce prototypes very fast, so we all called it rapid prototyping. Looking back on it, we built an entire industry on an application of a technology. Originally this technology was stereolithography (vat photopolymerization) which was shortly followed by fused deposition modeling (extrusion based) and also selective laser sintering (powder bed fusion). Being able to take the quickly advancing electronic representations of products from computer aided design (CAD) software directly to machines that could produce the part without tooling opened a whole new approach to product development. This led the way to getting models of a design in days or weeks versus weeks or months. Superior products could now be produced at rates faster than ever conceived before giving competitive advantages to manufacturers in technology advancement and market penetration.
This is the shifter model in process at a test fit evaluation point.
The models produced from these systems had limitations. If the resolution was good the materials probably weren’t. If the materials were good the accuracy might have been questionable. This was the battle for many of the systems on the bleeding edge, including those that only appeared for a short while and failed to become a viable technology. We still have limitations with all of these systems that need to be accepted.
These limitations are illustrated in things like layer thickness. When we add materials we have to add in set increments based on the amount of material becoming the part at one point or layer. This causes the need to consider bonding energy in the layer or point and the approximation of the exterior curvature of the layer. Directionally affected bonding can be seen as a complication when considering the strength of the material as it traverses the part and perpendicular to the build axis. The deposition method will also impact the part as the phase changes occurring affect the part once the build is completed. All of these are also impacted by the potential file conversion complications and the fact that the STL file is an approximation of the original data set.
This full scale model of an electric engine was originally for a Detroit auto show. The true makeup was only known by few. It ended up being used at auto shows around the world.
When I say multiple system options I’m not referring to strictly the additive manufactured systems and materials. The pattern shops before additive manufacturing had to be very resourceful just as any operation. They utilized every tool at their disposal and found many ways to solve the problem of the day. Many of these solutions were pattern based, thus the name ‘pattern shop.’ These patterns were created from almost any material or object. The end product could be the remains of material once a block is machined or a collection of pieces that are assembled into the desired geometry. These patterns then represent the end object that could be reproduced in a variety of materials.
Once you had a pattern, the key was to reproduce it in a material that would be suitable for testing. Many of the engineered production materials can only be created in the production process. Sometimes the production process is only good for low volume. When combining these processes to produce materials similar to the intended production material, we open up a way to get product for testing. This also enables preproduction product units for market demand definition, development, and focus group advancement. Being the first to market can be necessary and very lucrative depending on your market and application.
Here is an example of the part being removed from a silicone mold. Silicone molds originated during World War II and still are very common in low volume production. This part would be produced hollow for a blow molding application.
Understanding how to take advantage of these low volume applications is helpful but it does not always generate an end product like a highly finished production tool. Parts may need secondary operations for precision, functionality, and/or aesthetics. The beautiful and fun to watch 3D printers won’t be much help here (yet). At this point we still need the expertise of an artist, or at least a very skilled technician. With standard tools available like the ones used for finishing wood products, there is a lot that can be done to a part. Skilled professionals can generate a finished product that will probably look better than the production parts. With the application of paint and artistic techniques these can be achieved for most any finish needed.
Once these patterns are produced they can be replicated through a variety of techniques. Most of these techniques must follow the common rules of tooling technologies but can have some flexibility. For example, most room temperature vulcanizing (RTV) material will have some flexibility. Low durometer silicone tooling can produce parts with negative draft, urethane tooling will reproduce good surface finish but will need some draft consideration. Sand tools will need draft applied and post processing to get the intended part. All of these will produce parts far cheaper than fabricating. Proper application of these technologies does take experience and understanding. When applied properly these can be an amazing tool to help manufacturers get their products launched. With these applications the materials have been used for a long time and have solid data available.
Three-dimensional printers are now very common cost effective tools for design guidance and design validation. They provide quick models to communicate and evaluate the design intent. Within all of the processes we are seeing these systems yield better materials and even better finishes. These technology advancements combined with reducing costs are expanding the awareness and understanding of what 3D printers can do. While not totally new, the masses are now beginning to see and envision the power of what additive manufacturing can do. This means we are not limited to using these systems for prototyping, moreover it expands how we can choose to use these technologies.
This demonstration model was for a client to confirm and demonstrate a four position shifter. Its success incentivized us to make a copy for entry into the AMUG competition where we may have been the first ever to win first place for the technical and the finishing competition.
We first have to understand that all of these technologies are tools for us to use. These tools have specific strengths and must be respected for their limits. Market size or economies of scale are one of these that reminds us they are not free. Costs are marginally coming down for the systems while capabilities continue advancing. More importantly, the consumables are advanced materials but they are still not a match to production materials from production processes. As the limits of where we can apply current additive manufacturing systems and materials expand we may need less tooling based options. All of these expansions of applications will be driven by the ever present economic drivers.
With all of these changing dynamics it will be exciting to observe. The onset of advanced and additive manufacturing may lead to more ideas, products and applications. These will be applications that were never economically viable before. This may lead to more products finding their way to existence through utilization of these direct and low volume tooling technologies. As this happens we could see exponential growth of manufacturing options and technologies that perform where no other solution was viable or conceivable. When you think about it, these are some really interesting times we are living in so don’t hold back on your creativity.