How to Design For 3D Printing
If you are already good at 3D modelling and are able to create 3D models, you should know that not all 3D models are printable. If you would like to turn your designs into physical products, you need to know the various designs for 3D printing strategies to help you produce 3D models that are ready to print.
Designing for 3D printing isn’t much different from general 3D modelling; the same process is used but there are a few additional things you need to put into consideration. Before we have a look at the various tips for designing models for 3D printing, you need to know that there is no one size that fits all. Though there are some basic things all designs meant for 3D printing have in common which we’re going to look at shortly, there is no specific rule for all models. Let’s now have a look at the ten tips for designing models for 3D printing.
Choose Appropriate tools for 3D Printing
Mobius Strup for Pen designed in SelfCAD Software
The first thing you need to do is choose the right tool that you will be using for designing models for 3D printing. The two most important tools you need are a 3D modelling software and a slicing program.
There are several 3D modelling softwares available. When you do a quick search, you will be able to get a lot of them, some free and some paid. When you are a beginner, you can be confused on which one you should consider or the factors that you need to consider before choosing the software to use.
Having the right 3D printing tool will help you bring your ideas to life easily without spending much time figuring out how the software works. When you are looking to settle for a 3D printing tool, you need to ensure that it’s easy to use and one can get started on it easily. It should also have both 3D modelling features as well as a slicing option if you don’t like switching to a separate program to prepare your models for 3D printing.
A few years ago, most 3D programs were not optimized for 3D printing. After designing the 3D models, one had to switch to another separate 3D slicing software in order to slice and generate the G-Code to send to the 3D printer. But presently we have programs that have made it easier for 3D designers to design their 3D models and prepare them for 3D printing all under a single program. An example is SelfCAD.
SelfCAD is the only 3D modelling software that has combined 3D modelling, rendering, and 3D printing features all under one program. After designing your models, you can use the magic fix tool to fix the meshes and use the in-built slicer to slice the model and generate the G-Code to send to your 3D printer.
There are also other programs that you can use for designing your 3D models like Blender, Onshape, TinkerCAD, etc. After designing on them you can switch to a slicing software like Meshmixer, cura, KiSSLicer and many others to prepare them for printing.
Choose an Appropriate 3D Printing Technology best for your specific project
There are several 3D printing technologies available and each of them can’t be used for every model. After choosing an appropriate software the next thing you need to do is choose an appropriate 3D printing technology.
When you know the material for the final design to be printed, it becomes easier to decide on which 3D printing technology to use. For example, if the model will be 3D printed with ABS, then Fusion Deposition Modelling is the best technology to use. FDM is also great when one wants to produce strong and durable parts.
Laser Sintering Technology is appropriate when you want to produce models that have rubber-like materials for example alumide and polyamide. Lost Wax Casting is good when printing a metal in 3D.
Consider the Size of the Model
When you have chosen the 3D modelling software to use, have the 3D printing technology to use in mind, and have started designing your model, you need to consider the size before anything else. Make sure that the size of the model is as per your requirements and that it will fit the 3D printer too.
Also, ensure that all the parts of the design are promotional. This is important especially for the models that fit together like puzzles or those that are worn together like rings.
Ensure your Model is Watertight
A 3D model that is watertight doesn’t leak when water is poured on it. There are several things you need to put into consideration to ensure that your design is watertight. Ensure that edges are closed and that all the normals on the model are facing outward because any flipped normal on the model will be detected as holes by the 3D printer.
You need to also ensure that any internal geometry that might have been left behind by accident during booleans operations on the model is cleaned.
Always Check on Shrinkage and Warping
One of the great challenges that usually occur after a model has been designed and 3D printed is shrinking and warping. This occurs mostly due to changes to the material during the heating and sintering process resulting in deformation and cracking of the model.
Heating and melting usually affect the parts that are long and flat and this leads to lengthwise contraction of the model. The stress concentration points like the sharp sections of the model are where deformations mostly occur. Both cracking and deformation can be fixed when the model is still in the design phase.
Sharp corners can be avoided by ensuring that you design the model in such a way that it has flat corners. And if you are using software like SelfCAD, you can fix the sharp corners using the round object tool. All you need to do is select those sharp edges and corners and apply the round object tool. Smoothening will ensure that the stress is evenly distributed and this reduces the risk of imperfections and cracking.
Overhangs are the geometric shapes that extend on the layers of the model but do not have direct attachment to the model. Overhangs are necessary evil, sometimes you can’t just avoid them.
Before 3D printing, there are key things you need to put into consideration. For example, if you can’t avoid overhangs, consider reorienting the model. This is because most 3D printers have an adjustment angle of around 45 degrees. You need to have this in mind and if it’s not possible to execute your task, you will need to use supports.
Not every 3D printer has been designed in a way that it can print overhangs. So before 3D printing, test your 3D printer using a test model to see if it will work successfully. If it’s successful you can go ahead and prepare your model but if not, you can choose to look for another one.
7. Consider Resolution of the Model
Resolution is the level or quality of details a 3D model should have when it’s being 3D printed. Always ensure that the resolution of the model is appropriate. The resolution settings are different for different 3D printing technologies and each of them have a specific way of determining how the resolution of the final design is determined. The resolution of the models being 3D printed is usually controlled by the nozzle of the 3D printer as well as the movement of the motor.
When designing your model, you need to keep resolution in mind especially during the slicing process. You need to avoid extreme levels of details as it can make 3D printing difficult. You should consider the settings of your 3D printer too.
8. Ensure Vulnerable Areas are Thickened
Ensure the vulnerable areas like the joining areas and the points of contact are strong and not too thin. When these points are too thin, there are chances of them breaking during or after 3D printing.
9. Consider the Strength of the Model
This is to ensure that your design is successfully 3D printed and is functioning as required. This is mostly handled during the 3D modelling process, but a slicer settings can be tweaked so that the 3D printed part will be strong.
The density of your design is one of the factors you need to consider to produce strong prints. Most 3D slicing software have the fill density option and you need to maintain the default settings, which is usually 20%. This amount ensures stability and reduces the printing time and cost too. The fill density settings can be increased if the structural integrity is of great importance.
Demonstration of the default settings of the infill of the SelfCAD software
The material you use also has a great impact on the strength of your model. ABS is one of such materials that will help produce strong parts, though you can’t use it on heavy tasks. An alternative to ABS is ABS Like. It's more expensive than general ABS, but can be used for heavy tasks.
Nylon is another great material that you can use for your designs. It’s very expensive, but can be used for producing 3D designs that can be used on heavy tasks.
Consider Escape Holes
Escape holes in 3D printing are created by hollowing the model. Each software has steps for hollowing an object. For example, in SelfCAD, you can hollow an object using the stitch and scoop tool, difference option.
An escape hole is useful for allowing excess materials in the model to be removed. This is important for models that are dyed because having trapped powder on the model won’t allow it to dye evenly. So it’s important that as you design your model you ensure that there are escape holes and they should be big enough that the support materials can escape easily too. Escape holes also help save on the expenses of 3D printing as the excess material is removed.
Having looked at the above design considerations for 3D printing, you might be wondering, wilI be able to achieve all these? You don’t need to worry or freak out because if you know the software and the material you are using very well, it won’t be much of a challenge. For the software, I would recommend using SelfCAD because its tools work directly on the mesh which takes a lot of time in other programs.
SelfCAD tools, just like magic fix, help prepare your 3D designs for 3D printing in real time while you’re still designing and you don’t need any additional software or to download any program. Everything can be done under a single platform.
Enjoy powerful modelling, rendering, and 3D printing tools without the steep learning curve.