3D printing is a fascinating technology that allows you to create physical objects from digital models. But how can you print complex and intricate shapes that have curves, angles, hollows, and overhangs? In this article, you will learn some tips and tricks to achieve high-quality prints of challenging geometries.
Not all 3D printers are created equal. Some are better suited for printing complex shapes than others. For example, FDM printers use a nozzle to deposit layers of melted plastic on a platform, while SLA printers use a laser to cure layers of liquid resin on a vat. FDM printers are more affordable and versatile, but they have limitations in resolution, accuracy, and support structures. SLA printers are more expensive and require more post-processing, but they can produce smoother, finer, and more detailed prints. Depending on your budget, design, and purpose, you should choose the printer that best matches your needs.
In my experience, it is about what you want to design and who is working around you. The FDM printers absolutely can do fine detail. You can use smaller nozzles and you can slow down the prints. You also have options with different types of filament. Decent printers can be purchases for $200.00 and up but you must learn to tinker with them to print well. The SLA or resin printers have issues with fumes and can be quite messy. They are able to do intricate detail as well but for me the mess and the fumes are two things I cannot adapt to in my printing environment. Again, as with FDM, price will be a factor. Cheap SLA printers can be purchased but you will have to learn the ins and outs to troubleshoot.
Before you print, you should optimize your design to make it more 3D printing friendly. This means avoiding features that are too thin, too small, or too intricate for your printer to handle. You should also consider the orientation, size, and scale of your model, as they affect the print quality and duration. You can use 3D modeling software or online tools to edit, repair, and simplify your design. You should also check for errors, gaps, or overlaps that could cause printing failures.
Designing small features in 3D printing requires careful consideration to ensure accuracy and structural integrity. If features are too small, they can lead to fragile or unusable parts. Specialized software tools like MeshLab or Netfabb help address this issue by enabling the creation of optimized designs specifically tailored for 3D printing.
One of the biggest challenges of printing complex shapes is dealing with overhangs and bridges. These are parts of your model that extend beyond the previous layer or span across a gap without any support. If you print them without support structures, they will sag, warp, or collapse. Support structures are additional material that hold up the overhanging or bridging parts until the print is finished. You can either design them manually or use your slicing software to generate them automatically. However, you should also be careful not to use too much or too little support, as they can affect the print quality and waste material.
I agree with Matthew; the purpose in design should be to use the least amount of supports as possible. Can you change the direction/orientation of your design to not need supports? Can you change the settings on your machines, such as the speed of the print, to not need supports? Questions to ponder before printing. Also, there are usually settings in slicers to achieve the support needed to get the design to print.
Despite challenging designs, build orientation minimizes the number of supports required. A key mentality to printing is the part is being grown. Each technology will have different stability ranges which require more care. Supports expand those limits beyond those unstable areas during the growth process. Optimal support structures are material and application specific. Designing supports should be thought of as a minimization problem. "What are the least number of supports to allow drawing compliance?" The upfront work minimizes the back end post processing work.
Another way to improve your print quality is to adjust your settings according to your model and printer. Some of the settings that can make a difference are layer height, infill, speed, temperature, and cooling. Layer height determines the resolution and smoothness of your print. Infill determines the density and strength of your print. Speed determines how fast your printer moves and extrudes material. Temperature determines how well your material melts and bonds. Cooling determines how quickly your material solidifies and shrinks. You should experiment with different settings to find the optimal balance between quality and efficiency.
Some additional considerations to take into account for your settings, in my experience, are choices related to what material you're working with. Whether SLA or FDM, different materials behave differently with different settings. PLA, for example, will need a print surface between 55 and 65 degrees to adhere to a PEI-covered sheet. On glass with tape you can even print cold. Having your print volume enclosed will also be necessary to avoid warping during the print process with ABS, Nylon or PolyPropylene. Another thing to consider is the ambient environment. A humid and warm room will need different settings than a cold and dry one. So if you have seasonal variations, your print settings need to adjust as well.
After your print is done, you should post-process it to remove any imperfections and enhance its appearance. This may involve removing the support structures, sanding, smoothing, trimming, gluing, painting, or coating your print. Depending on your printer and material, you may also need to wash, dry, or cure your print. Post-processing can be tedious and time-consuming, but it can also be rewarding and fun. You can use various tools and techniques to transform your print into a polished and professional-looking product.