Choosing the Right Materials for Strong 3D Prints
Materials play a significant role in the strength of the 3D prints that you create, and you have plenty of filament options to choose from. It’s important to assess the filaments you pick based on the needs of the objects you are printing. For example, PLA is fine for ornamental models that will sit on a shelf, but you may need a material like nylon to print functional tools. You can find a range of filament options below alongside their best use-cases.
PLA: PLA, or polylactic acid, is the most common material used for FDM 3D printing. This material is rigid and hard, but it is also relatively brittle compared to other 3D printable materials. PLA is a good choice for those learning about 3D printing, as it is easy to print with and will almost always offer good results. ABS: ABS, or acrylonitrile butadiene styrene, is much stronger than PLA, but it is also harder to print with. The strength of ABS makes it ideal for functional parts, but it is inflexible and this has to be considered when you are choosing your filament. PETG: PETG, or polyethylene terephthalate, sits in a comfortable middle ground between ABS and PLA. It is stronger than PLA and more flexible than ABS, while also offering excellent chemical resistance. This makes PETG great for use outdoors and in other harsh environments. Nylon: Nylon is one of the strongest, most flexible, and most durable FDM materials on the market. Nylon 3D printer filament can be used to make functional parts and tools, as well as decorative items. Carbon-Infused Filaments: The inclusion of carbon fibers in filaments has become very popular. This rarely improves the strength of finished prints, but it can improve layer adhesion.
Choosing the right 3D printer filament material for any given project is difficult. You should explore all the available options when picking your filament, especially when you are working on objects that need to last.
Designing Strong 3D Models for 3D Printing
Much like the materials you choose for your 3D prints, the design of each print also has a dramatic impact on the strength of your 3D prints. Designing stronger 3D printable models takes some learning. While you can’t start creating the strongest prints right away, you can find some of the key considerations you need to make below. Your 3D model designs will improve as time goes by and you learn more about creating strong shapes.
Error-Free 3D Printable STL Files
Whether you use Blender, Fusion 360, or any other 3D design tool to create 3D printable models, errors are bound to crop up from time to time. Non-manifold models are a good example of this, where there are gaps in the outside of the model that can prevent it from slicing properly.
Solving this sort of issue is easier than ever before. Just about every slicer on the market, including Cura, can scan your models for errors when you load them for slicing, often offering repairs along the way. Of course, though, it is always best to learn and improve the quality of your 3D modeling to avoid errors in the first place.
Stress Distribution and 3D Printing
Predicting exactly where mechanical stress will most affect a 3D printed object is a challenge. Engineers perform complex mathematics to figure this out when working on large projects, but you can use your intuition to solve this problem when working on your own designs. You just have to ask yourself whether or not the shapes you create are going to be strong.
The image above is a good example of this. Without any form of bracing, the angled piece on the left would be very weak and prone to snapping if force were applied to either end. The angled piece on the right has a brace that will work to solve this problem. You can look at the work of professional engineers to get an idea of the strongest shapes and apply them to your designs.
Slicing Strong 3D Models for 3D Printing
The settings you choose in your slicer software are another factor that will impact the strength of your 3D prints. Slicer software can be daunting when you first get started, but we’ve broken down the most important settings to keep in mind when working to improve the strength of your 3D prints.
3D Print Infill Density and Patterns
It would be time-consuming and expensive for 3D printers to create solid objects, and most slicer software defaults to using infill on the inside of objects to save time and filament. An infill density between 20% and 30% is usually just as strong as a solid object, but dipping below this threshold can result in weaker prints.
Density isn’t the only factor to consider, though. Most slicers also provide the ability to choose different infill patterns for your 3D prints. Hexagonal infills are very common, but 3D or randomized infill options are often stronger. You should experiment with the infill options in your slicer to get the best results.
Suitable Inner and Outer Wall Thickness
While the inside of your 3D print isn’t solid, the outer and inner walls it features are. Adding additional walls to make them thicker will improve the strength of your 3D prints to a limit, making it worth experimenting with this option to get the best results. Most slicers will warn you if your wall thickness is too high.
Choosing the Right 3D Print Orientation
As you probably know, FDM 3D printers print in layers. Layers adhere to one another, but the bonds between each layer are usually the weakest part of a normal 3D printed object. You can think of this as being similar to woodworking: a skilled carpenter will always work with the grain to ensure that pieces are strong.
You can alter the orientation of your 3D prints in your slicer to improve their strength in the same way. By making sure that stress will follow the direction of layers, rather than going against them, you will lower the likelihood of splitting and other issues with your prints.
Finishing 3D Prints to Add Strength
Finally, as the last area to consider, it’s time to think about the finishing methods for 3D printing that can make your objects stronger. There are a number of ways to finish 3D printed objects, but only one will add strength to your models: epoxy resin coatings.
You can apply epoxy resin to your 3D printed objects once they are finished. This will add a hard layer to the outside of your prints, while also hiding the layer lines that formed during printing. Of course, though, this should be used alongside the other advice in this article, not as a replacement for it.
Making 3D Prints Stronger
Strength is an important aspect when making just about anything. FDM 3D printers have the capacity to make incredibly strong objects, but they rely on the user to achieve their full potential. In short, the techniques we’ve covered here are a great start for anyone looking to improve the strength of their 3D prints, but you also need to apply your own creativity to this problem to get the best results.
