As 3D printing technology advances, we're seeing an increase in the number of final models produced directly from 3D printers, not just prototypes, which also opens up new possibilities for designers.
This is partly due to the improved quality of 3D printers. But it's also because interesting techniques are being applied in the product design process, helping to enhance the ability to print complex shapes and rigid models.
I designed an example to demonstrate the best techniques I use daily to create complex models that are as good as manufactured parts.
The model design was done in SolidWorks, but the techniques used can be adapted to any design software.
Light fixture with all 3D printed parts
This decorative pulley light fixture I designed showcases the different techniques I use to create objects with difficult-to-print shapes, and enhances the joy of displaying it in my living room.
In this blog, I will introduce each part and show you where I made enhancements, where I created custom supports for difficult-to-print areas, and the Ultimaker features I used to achieve the standards I was looking for. So let's get started.
Making the Model Stronger
The body of the light fixture is an area that can be under significant stress, depending on what is hung from the pulley. This part will have to bear the weight of the pulley, the light bulb, and any lampshade you want to add.
During the design phase, I added two 4.5mm holes to the main strut.
These holes allowed me to slide two 4mm threaded rods in. Before sliding them in, I applied some super glue to the thread to secure the rods in place. This will increase the weight the strut can bear while keeping the threaded rods hidden inside the model.
Before sliding in the threaded rods, add glue
Change Your Infill Density
You can also increase the strength of a certain part of the model by increasing the infill density in Cura. For the main body, I increased the infill pattern to 40%. This means the internal body has 40% plastic and 60% air. The rest of the parts were reduced to 20% as they do not bear much stress.
However, increasing the infill density has two main drawbacks. It will increase your print time and the material used, so it's important to find an infill density that works best for your object.
40% infill 20% infill
Orientation
The fork part of the wheel can be printed in two orientations: Option A or Option B, as shown below.
I chose Option B because it allows the layers to run along the U-shape, following the length of the shape, rather than across it.
The reason is that I know in order to install this wheel, I will have to pull the fork open to insert the axle. If I chose to print Option A, where the layers run along the area that needs to bend, it might snap due to the fragile areas between layers.
When designing, consider the orientation of your printed object. Thinking about this early can prevent problems later.
Option A Option B
Adding the axle to the fork part
Material Selection
Material selection can also be an important factor when designing robust models. Each material has its own properties that can greatly benefit your project.
Since this is a broad topic, let's now look at the four most commonly used materials: PLA, ABS, Nylon, and CPE.
Ultimaker PLA: PLA is your standard 3D printing material. It is the most common and easiest to print, but it is brittle and prone to breaking when bent.
Furthermore, its chemical properties are not great and it has a low melting point. Immersing it in boiling water allows you to bend and shape it. So, if your design will be exposed to outdoor sunlight or in hot places, PLA might not be your choice.
Ultimaker ABS: ABS is another popular material choice, but like PLA, it has some drawbacks. While it is more flexible than PLA and can withstand higher temperatures and elements, it is harder to print.
It is more prone to warping if the printing environment is not enclosed and well-controlled, and it must be printed on a heated bed. It also releases unpleasant fumes that can cause irritation to some people, so you should print any material in a well-ventilated room and not sit directly next to the 3D printer.
Ultimaker Nylon: Nylon is a more advanced material. Its chemical composition makes it susceptible to moisture. So, if you are working in a humid environment, you will need to store it in a dry container or dry it in an oven. A large amount of moisture in the material can significantly reduce quality.
However, once you are happily printing with Nylon, it is an excellent material. With high impact resistance and lower abrasion sensitivity, it is the perfect material for mechanical fittings or parts that rub against each other. But like ABS, it can warp and requires a controlled ambient temperature!
Ultimaker CPE: CPE is an excellent industrial material with superior dimensional stability. This means it doesn't shrink as much as other plastics and will be more dimensionally accurate to the original 3D model. This is important for tolerances. CPE is also recommended to be printed on a heated bed.
Therefore, depending on the object you are making, choosing the right material is very important and should be considered in the early design stages.
Supports
Support material can be your best friend in 3D printing, but it can also cause some problems. It's great for helping you achieve complex shapes that can't be manufactured otherwise, but its drawback is that it can sometimes be difficult to remove (unless you use PVA on an Ultimaker 3). The trick is to avoid using support material as much as possible, but sometimes you need it to achieve your design.
In my design, the main body has a rotating axis that helps support the main rod and makes it look good.
The curled end and top clearly need support, but the support for the top is very thin. This is more concerning because the higher it gets, the more unstable it becomes, and this thin support needs to hold its own weight and the curl until it touches another support. This is very risky and likely to fail.
You can see how thin the support structure is
So I went back to SolidWorks and designed my own custom support structure. This can be done in any other design software as well.
This greatly increases the footprint on the platform and makes the supports generated by Cura more stable.
The support structures I designed are offset by 0.3mm from the top, so they can be easily separated.
This technique is very charming and makes difficult overhang designs feasible.
Adding support using SolidWorks
Before removing supports After removing supports
Inserting Screws
Sometimes, you might need to use more glue to combine your parts. Screws can be very helpful, but you might not want them to be easily visible.
You can hide them in various ways. You can hide screws and bolts so they are only visible from a certain angle, or you can create an insert to fully conceal them.
It is also possible to stop printing at a certain point, insert the bolt, and then continue, allowing the printer to close the hole in the model.
There are two ways to do this. First is to manually pause the print and insert the bolt, but this is not very precise.
Cura has an option that does exactly this. This feature is called "pause at height."
It's a bit hidden, but you can find it by going to the options at the top of the screen. Open "Extensions > Post Processing > Modify G-Code > >". Here, select "Add a Script" and then select "pause at height."
Here, you can set the exact height you want to pause at, where you want the print nozzle to move to when paused, and where the print bed should drop to. Make sure you tell the nozzle to stop somewhere that won't restrict your printing.
My advice is to test this feature by creating a small square with an insert, especially if this is your first time trying it.
Remember to turn off the "pause at height" option for your next print.
These are the basic techniques you can use to help you create custom supports for more difficult shapes, and reinforce areas that might need attention, making your design more robust.
This is not an absolute "do's and don'ts" tutorial, but rather a springboard to help inspire your own designs and creativity.
Use this knowledge to help you create excellent projects and develop and strengthen your own techniques.
I'm excited to see the community pushing the limits of 3D printing more than ever before. Even if it's just a simple insert job.
Someone will learn from it and appreciate it. Happy printing!
Completed 3D printed light fixture
3D Printed Light Fixture File Source: https://www.youmagine.com/designs/decorative-light-fixture
Kirby Downey is a designer from South Africa, living in London, who enjoys teaching people how to utilize 3D printing technology and how to push the boundaries of 3D printing.
With over eight years of knowledge and experience in FDM and SLS technologies, Kirby helps himself and others with everything needed on their 3D printing journey.
Article source: https://ultimaker.com/en/blog/51343-end-use-parts-3d-printing-a-decorative-light-fixture