The advent of 3D printing has drastically changed how products and designs come to market. From rapid prototyping to personalized manufacturing, 3D printing offers endless possibilities. However, to harness its full potential, designers must understand the unique considerations and constraints associated with this transformative technology.
To get the most out of 3D printing there are multiple things to keep in mind when designing an eventual print, which we will outline in this blog post.
Choosing a Style of 3D Printer
There are multiple 3D printer styles available. They all use slightly different technologies and methods to produce the finished part. If you have the freedom to choose amongst multiple printer styles, take the time to pick what type of printer you wish to use. This will impact the design constraints of your model as well as the physical properties of your product.
Example of a 3D printer in-action.
For plastic 3D printing, there are 3 main styles of printers:
- Filament-based printers: These are the most common hobbyist printers. They are also a powerful tool for designers during prototyping and fixture design. They use a spool of plastic filament that is fed through a heating element and then deposited onto a build plate one layer at a time. These are the simplest of printers and are typically very cheap to operate.
- Resin-base printers: These printers use a vat of photosensitive resin that is selectively cured onto an inverted build plate one layer at a time. Just the fact that objects are printed “upside down” means things like overhang orientation and drain holes are more important. Resin printing is getting cheaper and cheaper every day. The main constraints with resin printing are that the parts typically remain photosensitive, build volumes are on the smaller end, and there is significant post-processing. On the positive side, you can print highly detailed objects such as miniatures with minimal layer line visibility, and print times are dependent on the z-axis dimensions. This means you can print as many units as possible that will fit on a build plate at once in the same amount of time.
- Powder-base printers: Technologies such as selective laser sintering (SLS) and multi-jet use a bed of powder that is then fused together by either a binding material or heat. This process is then repeated layer by layer. One major benefit of powder-based printing is that it is self-supporting. This means that you do not have to worry about the same support considerations you have with the other styles of printers. This style of printer is currently very expensive and special consideration is needed to handle the used powder during post-processing.
Designing for 3D Printing Efficiency
The main advantage of using 3D printers is the ability to iterate designs with a low turnaround time. To maximize this time savings there are multiple methods to implement. There are two main components to optimize when 3D printing: print time and post-processing time.
Print Time
Print times can be reduced in several ways. For filament printing, reducing the infill is an easy way to reduce the print time of the part. It is best to reduce the infill percentage to as low as the design is required to have. Eliminating the need for support material is another great way to reduce print times on filament-style printers. This can be achieved by changing the orientation of a model or changing the model to smoothly transition into overhangs. Resin printing time can be reduced by orientating the model in a way that reduces the height of the object.
Post-Processing Time
Post-processing is any work that needs to be done to a print after it comes off the printer. This includes sanding, removal of supports, washing, and curing of resin prints, cleaning of powder-based prints, etc. The amount of post-processing is dependent on the style of printer used and the desired surface finish of the part.
Filament printers have the least amount of inherent post-processing needed with only support material removal being potentially necessary but have the most obvious layer lines present on the surface finish which can take a lot of sanding to achieve a smoother finish. Resin printers have the required wash and cure steps that can be messy but result in a surface finish that can reach glass-like smoothness in some instances. Powder-based prints require the messy process of cleaning excess powder from the finished print, but the surface finish is better than filament printing and is closer to a matte or rough matte finish.
Designing for Effectiveness
A 3D print is only valuable if the purpose of the finished product is understood ahead of time. The physical properties of 3D-printed objects are typically different than that of a mass-produced object. For prototyping purposes, it is important to understand what those differences are and what it is you are looking to achieve with a prototype. 3D printing can be used for fit checks, strength and failure analysis, ergonomics, aesthetics, etc.
Know Your Materials
3D printing offers a wide range of materials, each with its specific properties and applications. Designers must have a deep understanding of the materials they intend to use. From thermoplastics like PLA and ABS to more advanced materials like nylon, carbon fiber composites, and even metal, the choice of material greatly impacts the design's structural integrity, durability, and aesthetic qualities.
Pay Attention to Tolerances
Overlooking tolerances can lead to parts that are either too loose or too tight, negatively affecting the final product's functionality. Accurate design specifications are crucial for successful 3D printing. Considering the layer-by-layer nature of additive manufacturing, it's essential to be mindful of tolerances to ensure that parts fit together as intended.
Optimize for Printing Orientation
Print orientation significantly influences the quality, strength, and appearance of 3D-printed parts. Designers should strategically orient parts to minimize the number of support structures needed, reduce printing time, and enhance surface finishes. Orienting parts to maximize layer adhesion can also improve the overall strength of the final product. Filament-style printers are typically the weakest between layers. This information can be used to decide on print orientation.
Test, Iterate, and Refine
The iterative design process is a cornerstone of successful 3D printing projects. Due to the relative ease of creating prototypes, designers can quickly test and refine their designs. This iterative approach helps identify potential flaws and areas for improvement, ultimately leading to better final products.
Summary
Designing for 3D printing creates many opportunities for engineers and designers. By understanding the principles of Design for Additive Manufacturing, choosing the right materials, optimizing orientations, and embracing the iterative process, designers can unlock the full potential of this transformative technology. As this technology grows and advances, so will the options that designers have and the products they create.
Watch Our Video on 3D Printing
Here at Epec, we use 3D printing to get design concepts and prototypes quickly to customers to reduce their costs and to build tooling fixtures to help build the product faster. Rapid prototyping is a game-changer. With 3D printing, digital designs swiftly transform into physical prototypes. This accelerates the product development cycle, allowing faster iterations and shorter time-to-market.
