Parts with features smaller than 1 cm could only be machined until recent innovations in 3D printing changed this. Regular sized parts can simply be prototyped using filament-based 3D printers, fused deposition modelling (FDM). They can also be designed with additional thickness to be sanded down during post-processing. However, smaller parts need to be prototyped using other techniques. Previously, it was just machining.
Now, newer techniques for 3D printing micro parts solve the problem. These are divided into two categories powder-based 3D printing and resin-based 3D printing. Both of these methods give an adequate surface finish while preserving details.
Filament 3D printing
FDM is short for fused deposition modelling. It melts material in string filament form and is currently the centre of the 3D printing revolution. It is started with open source projects such as RepRap project, followed by semi-opensource Ultimaker project, and the rest is history. The technology now is responsible for most of the desktop 3D printing market share and for good reasons.
FDM is easiest to operate, easily maintained, most affordable, and has the shortest order to deployment lead time, since there are distributors for it in all major cities. FDM printers almost do not require any setup time before each print. Some printers even offer continuous printing, using automatically replaceable print beds, or a moving conveyor print bed.
Powder 3D printing
Powder SLS (Selective Laser Sintering) machines usually cost €200k+, so the better option for in-house prototyping is usually the much cheaper resin. However, if one is just looking for a few prints to validate a one-off invention, SLS should be a great option. The service might cost the project budget only a few euros per part, but it is usually hassle-free and parts can be printed using a flexible material too, in addition to rigid ABS-like material (ABS stands for a type of plastics very common in consumer and industrial products).
Although Shapeways and similar online services have a simple order process, they usually have long turnaround times. So for frequent orders, a regional dedicated supplier should be a better option. Many can provide the service with 1 business day turnaround time, since multiple client parts could be printed simultaneously with minimal increase in the print time.
Resin 3D printing
SLA 3D printing
SLA printing stands for Stereolithography printing. It is a resin-based 3D printing process that utilises a laser to cure part of the resin according to a given design. It works similar to FDM (Fused Deposition Modelling) printing, only it is upside down. Instead of the FDM printing head, it utilises a laser module or mirror prism that redirects laser from a fixed module. This allows the machine to pin-point micro areas to be cured, while being able to re-create smooth curves.
The build plate of a resin printer moves upwards after each layer is completed. The final print is later placed under a UV light source to cure any remaining uncured resin. SLA machines cost around €10k and are usually used at an industrial level for prototyping. A new technology similar to SLA is LFS, which stands for Low Force Stereolithography. The technology is based on the incremental movement of a laser instead of a continuous movement. This reduces the print quality slightly, but reduces the price significantly. Today LFS machines can be found for around €3k.
SLA can provide a higher level of detail compared to SLS, but lacks strength and material options. SLA also requires a lot of manual intervention, which not only adds to cost of operation, but makes it extremely hard to scale for larger organisations and a headache for smaller ones. DLP is sort of low-end SLA, so it is only used within small economies that cannot justify the cost of SLS machines and do not require an additional level of detail provided by SLA.
Most SLA printers on the market today below €1k are actually DLP printers, which stands for Digital Light Processing. These printers utilise an LCD below the resin, instead of a laser. They feature less moving parts, so they are usually faster, but their resolution is much less than that of SLA printers.
DLP 3D printing
SLA machines tend to have a higher print resolution. They also have a moving laser point, which draws smooth curves compared to the pixel system in DLP machines. On the other hand, having a flashing LCD allows DLP printers to print one layer simultaneously, making it relatively faster than comparable SLA machines.
For working on micro products, DLP 3D printing machines should be sufficient for smaller parts. They are also usually a fraction of the cost of true SLA machines. Note that many DLP machines are advertised as SLA machines. However, most of these will have to mention somewhere in the description that there is an LCD involved.
Resin printing used to be dominated by relatively expensive €10k+ SLA (Stereolithography) machines, but it is much cheaper nowadays to get DLP (Digital Light Processing) machines. The difference between those is that SLA uses laser and DLP use led light from an LCD.
I have seen good reviews for CREALITY DLP machine, but have not tested one myself. Although, I own multiple FDM printers from the company and they are exceptional. Other printers claim higher resolution, which might get them closer to true SLA printing quality, but I have not seen any reviews to suggest that. So I would stick with cheaper ones. Keep in mind that unlike FDM, resin printers materials usually require special safety measures and final prints require post-processing.
LFS 3D printing
Lately, there has been new technology that bridges the gap between SLA and DLP. This new technology is called LFS (Low Force Stereolithography). These machines also use laser but move in increments, similar to laser paper printers. This allows them to be much cheaper and possibly faster than original SLA printers.
3D Printing benefits
Compared to traditional methods of product development, 3D printing offers some major advantages compared to the other methods. Specifically, it overcomes some of the major roadblocks that have plagued the methods of the past, increasing the chance of getting a product manufactured. 3D printing has taken the world of product development by storm. And every company that wishes to ensure bringing an idea to life needs to know what it has to offer.
3D printing is fast becoming a vital component of product development and the continued existence of companies all over the world. It allows for great quality models and even products to be produced quickly and cheaply. On top of that, it streamlines the design process and allows for broader market and testing. To top that off, the technology is increasingly becoming accessible. Any company that wants to get its product manufactured can use it in various ways to produce a quality product that people will buy.
Reducing costs is a major component of doing business. Luckily, 3D printing offers massive savings in the following areas:
- Equipment: To get your product manufactured with 3D printing, all one needs is a 3D printer. This means product developers do not need to invest in any heavy equipment that needs many people to operate. This also allows companies to save on labour when undertaking a product development project.
- Components: A major part of product development is prototyping. With 3D printing, it is possible to create a high-quality and functioning prototype in a single step. This is much cheaper than securing each individual component and then assembling the product prototype, which is time-consuming.
- Storage space: Due to the cost of manufacturing, it is prudent for companies to manufacture products in large batches. But the downside of this is that they might need to pay for storage space while waiting for the units to be sold. With 3D printing, products can be manufactured and sold on a needs basis, without worrying about paying for warehousing.
- Fewer transportation expenses: 3D printers have the ability to make a product from start to finish. With traditional methods, a product prototype would travel from factory to factory until the final product was manufactured. With 3D printing, all the designers need to do is send designs to a single location to manufacture the product. This reduces the number of times to product has to travel, significantly cutting transportation costs, whether it is by ship, vehicle or plane.
Great for testing
3D printing produces product prototypes quicker and easier. Meanwhile, traditional methods would take weeks, maybe even months, for a product prototype to be complete. Now a functional prototype can be done in hours, allowing for fit testing on the target markets in the shortest amount of time. Once feedback is gathered from the consumers, it can be used to make improvements to a quality product.
Great product ideas can fail, if the execution was subpar. If a product is riddled with mistakes, it can be costly to fix the mistakes, depending on how far along the product development process is. 3D printing a real-life model can be produced and used to check usability, durability, manufacturing viability and more. This means mistakes can be caught and fixed before they become costly.
3D Printing future
There are many technologies and techniques used in prototyping. However, over recent years, 3D printing has been undeniably the fastest to grow and acquire market share. It is the fastest and most versatile, in addition to being reasonably priced in most cases. Competing technologies such as CNC or more niche vacuum casting can take days for simple parts that only take a few hours to manufacture using 3D printing. Although 3D printing is not the best when it comes to final parts strength, product prototypes usually do not need to feature full target strength. New 3D printing materials such as stupidly strong Nylons are also bridging the gap.
In China, SLS is now almost the golden standard for 3D printing and one can hardly find a service that relies on other technologies. Since capital is widely available in the country expensive SLS machines are easily justified. This is especially the case with the presence of a growing direction in the country to produce new products, which in turn requires a lot of prototyping. SLS main patents have now expired as well. This gave manufactures the ability to innovate more freely and create newer efficient SLS machines. The same happened with SLS materials which were also protected under various patented, and could now be manufactured by any expert manufacturer.
The future of 3D printing is now more about materials than anything else. Newer materials allow better bonding, smoother surfaces, and even come at more affordable prices. This is not to say that we will stop seeing innovations in machines themselves, however now machines’ year to year improvements are small and incremental, a far cry from the fast innovative pace it once employed. New thermoplastic materials used in 3D printing are heading towards metal strength and SLS metal printing.