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3D Customization is a powerful method by which the combination of design tools, software and 3D printing lets people design exactly what they want while letting this design be manufactured through 3D printing.
3D printing is a number of technologies that all manufacture things layer by layer. 3D printing is a quick way from an idea to a file and then onto an object. When something has to be made that day or if it is unique 3D printing will be one of the most cost effective technologies to produce that thing. Famously with 3D printing complexity is free. In this article we will look at some of the most prevalent 3D printing technologies in order to then understand what we mean with this.
Complex structures – Made by Twikit Design Studio
3D Printing Technologies
There are a number of 3D printing technologies that work very differently albeit according to the same general principle. The correct official term for all 3D printing technologies is Additive Manufacturing. The media and public however almost exclusively use 3D printing.
Stereolithography: The ISO ASTM name for this technology is Vat Photopolymerization. We’ve never actually heard anyone refer to it by this name however. It is more commonly referred to as SLA. With SLA a photopolymer is hardened by a laser in a bath of resin. Examples of stereolithography 3D printers are 3D Systems ProX 950 industrial systems or desktop systems such as the Formlabs Form 2.
SLA is very good at making highly detailed smooth objects. SLA is used for molds, casting, lost wax casting for jewelry, molds for dental aligners, concept cars and highly detailed prototypes. If something has to look incredible, be painted or be very smooth SLA is the technology of choice.
When parts need high strength, high UV resistance, high temperature resistance or to be very tough SLA is less suited as a technology and FDM and SLS are generally better. DLP is a similar technology. The key differentiator is that SLA is capable of making large parts, 30 CM to 1m and DLP is not.
The technology 3D prints supports to support the object and these must be removed manually. For a high end prototype or mold these supports also have to be sanded down. Objects also have to be UV flashed to cure completely before use. The manual processing required for SLA and the high material cost does make SLA parts relatively expensive.
DLP: Also falling under the vat polymerization technologies is DLP or Digital Light Processing. This technology uses a DLP DMD (Digital Mirror Device) chip also used in DLP projectors or some rear projection televisions to harden a photopolymer in a vat. Envisiontec is the main vendor in this space.
The drawbacks and advantages are the same as SLA. Depending on the part or application and the form factor of the device needed as well as its throughput either SLA or DLP could be better. Depending on part geometry your part could work better in SLA or DLP. DLP is very good for small individual parts 5 CM or so.
DLP is used for lost wax casting for jewelry, casting for dental and unique In The Ear hearing aids. DLP has supplanted mass manufacturing and handmade as the predominant technology in making ITE hearing aids.
Selective Laser Sintering is also called SLS or Laser Sintering or LS while its official ASTM ISO name is powder bed fusion. With this technology a laser sinters a bed of powder. Loose unsintered powder supports the part, a new layer is added and this repeats until a block of loose powder has been formed and the parts can be removed. EOS and 3D Systems are the main vendors in this space.
SLS is very good at in a highly productive relatively low cost way producing many unique parts at high volume. The detail level and mechanical properties of parts are good although FDM parts are generally rougher but tougher. SLS is used for surgical guides, aircraft parts, automotive applications as well as form and fit prototypes. The most popular SLS material by far is PA (polyamide) with PA 12 being the most popular variant.
SLS parts are porous however and have a relatively open surface texture. This may make them ill suited for some applications. SLA and DLP parts are smoother and generally have higher levels of detail.
Manual post processing for SLS is relatively simple with parts being vacuumed, taken out and blown clean. If color has to be applied or if the parts must have a closed and smooth surface then additional techniques such as tumbling or coating will have to be applied.
FDM also called Fused Deposition Modeling, Material Extrusion or Fast Filament Fabrication (Don’t ever use this in a conversation) is a technology whereby a filament is extruded onto a build platform. The technology was invented by Stratasys and is now the most widely spread 3D printing technology being used by most of the desktop 3D printing systems as well.
FDM makes tough, strong parts very well. It is good at producing single large parts. From file to print FDM is often quicker than SLS because there is no warm up and cool down time required. FDM parts are however rather rough with a lower surface and detail quality when compared to SLS, DLP and SLA. Since so many open systems run FDM the range of materials is far more widespread than with other technologies ranging from ABS to PLA with many colors and filled grades available. Depending on the part SLS is more often a more productive technology and SLA and DLP are better for molds and casting.
FDM is mainly used for tooling, jigs, B side parts, prototypes, form and fit prototypes and anything that needs to be strong and durable. For parts that do not need support structures post processing is minimal. If there are support structures then these can be washed away by hand or put in a support removal station that washes them. If parts need to be smooth then vapor processing can be used.
There are other technologies such as Polyjet, other Binder Jetting technologies, Sheet Lamination, Directed Energy Deposition and Powder Bed Fusion for metals. Generally however the above technologies are the most prevalent.
Complexity and individuality is free
Complexity is free is kind of a 3D printing mantra and people have been repeating it for many years. What do we mean by this term however? 3D printers produce objects directly from a digital file. If you would like a million copies of an object then other technologies could also do the trick. If you require a million unique things however 3D printing is very cost effective. Whereas molding technologies are great at spitting out a million copies, 3D printing is good at spitting out a million unique parts. Pricing 3D printed parts is actually quite complex. Pricing variables can depend on individual geometry and the type of technology. Generally however we can say that pricing depends on the the time in the machine that the part requires, the amount of material that is used, the file preparation time that may be needed, the post processing that may be required and the number of other objects that are 3D printed simultaneously. Depending on how parts are nested inside the machine and what orientation they have they could cost more or less. We can say however that in general the 3D printer doesn’t differentiate between Aaron, Carol, Sally, Homer or Irene. If we 3D print a name tag it doesn’t really matter what’s on the name tag or what letters will be 3D printed. In this sense there are no tooling or start up costs with an individual file in 3D printing.
Complex structures are also made in a similar vein. A vase could be simple or it could consist of many different leaf shapes, generally this does not deter the 3D printer. We can make an incredibly complex vase with very many elements or design elements and the cost will be the same. The printer does not care what it prints it just layer by layer manufactures an object. Something could have many skins or a lot of differentiation throughout the design and the items cost will be the same. With 3D printing we have much greater design freedom but also a greater ability to iterate and completely change designs or parts.
Patterns and textures
Patterns and textures will be free as well. So a pattern can be added to an object with (essentially) no extra cost. That could be one pattern added to one object or a 100 unique patterns added to a 100 objects. This pattern could be a simple line or a intricate texture consisting of thousands of lines, the cost will be the same. Again, each vase could have this complex pattern or each one could have a variant of it that is completely unique. Patterns or textures can be used to individualize an object or to increase its functionality. Think of the golf ball pattern, similar patterns could be added to objects to increase their performance.
Integrating extra functionality into an existing part is also free. A conformal cooling channel could be 3D printed as a part of a mold for example. Or a spigot could be produced with letters on it denoting how it is to be used or inside of it the standard shape could be made to give a vortex to change the water’s direction. A pen holder could be added to an Iphone case without incurring extra cost. Or an industrial part could at the same time be engineered to be a housing and a heat sink. Companies are often not ready to fully take advantage of truly designing and making integrated parts using 3D printing. The mindset is currently just not there and often parts are designed with previous manufacturing paradigms in mind.
Less parts and integrated parts
Rather than have one complex part made up of five different molded components that have to be glued together 3D printing can produce that part in one production step with one manufacturing process. This means that as well as much lower start up costs there will be much lower legacy costs associated with that part. The reason 3D printing can do this is because it builds up objects layer by layer and in so doing can make more complex parts without the same constraints that traditional machining processes have. Fasteners, bolts and brackets can also be eliminated by 3D printing a design that does not need them. NASA and Directed Manufacturing 3D printed a rocket engine that previously had 115 conventionally manufactured parts. The 3D printed version had only two parts. In terms of storage, mold making and assembly cost, the savings are enormous.
Many companies are now experimenting with trying to get the parts that they are making 3D printed. By designing a part for 3D printing companies can unlock value through redesigning this part so that it is the same strength but less weight. Especially in aerospace this and the integrated/component reduction and iterative capability of 3D printing that is driving this industry’s adoption of the technology. Outside of aerospace however saving part weight will have significant impacts on part costs and distribution costs. Truck and automotive companies are also now looking to save weight on 3D printed parts in order to save on mileage of their vehicles. Just saving on material, energy and shipping costs could however make saving weight on parts a key reason to adopt 3D printing. Again this redesignability of the part and the ensuing complexity, is free. Airbus Defense and Space redesigned the brackets on one if its satellites to save the company one Kilogram of weight on the bracket.
Phone covers – made by Twikit design studio
Free complexity for you?
If we look at the possibilities that free complexity gives us they can be quite daunting. What does this mean for our business or our parts? Generally however it means that key parts can benefit from being redesigned for 3D printing. Additionally 3D printing can add complexity or variability or individuality to many things without additional cost. If this capability is then coupled with the ability to easily design a thing that you wish to have you can unlock the power of 3D customization. Call or contact us to find out more.