One of the most important considerations when designing parts for 3D printing is the wall thickness. While 3D printing makes prototyping easier than ever—not only in terms of cost and speed, but also in regards to DFM (design for manufacturing), you can’t disregard DFM completely.
A design might be (barely) producible by 3D printing, but what happens when you move to the next iteration or the next stage in manufacturing?
And so enters our 3D printing wall thickness recommendations! Here are some guidelines to ensure your 3D print is, in fact, printable and structurally sound, so you can design prototypes that can be produced in quantities of 1 and then ultimately 100, or 10,000+.
Wall Thickness Recommendations
There’s a limit to how thin a part feature can be designed for 3D printing.
Below is a table of our recommended minimum thickness for each material, as well as the absolute minimum thickness, for those of you who like to live dangerously.
We have had success printing parts as thin as our absolute minimum, but we can only guarantee a successful print at or above our recommended minimum.
Under our recommended minimum, the thinner the part, the higher the chance something goes wrong in printing. Anything below our absolute minimum is unprintable in practice.
Why There are Limitations
There are a variety of limiting factors to consider, both during and after printing.
3D printers print parts one layer at a time. As a result, if a feature is too thin, there’s a risk of the resin deforming or detaching, which means there isn’t sufficient material contact to connect it with the remaining body.
Additionally, just like you need a strong base to build a stable structure, if a part is being printed and the wall is too thin, that feature would likely bend before the resin can dry or cure. As a result, the thin wall would buckle, causing warping in the part.
Even if a thin-walled part prints successfully, the fragile part still has to survive cleaning and removal of support material.
Cleaning methods include water jet and picking away the residue, so many thin components break at this stage. Additionally, in order to print such a thin wall, you often need extra support material. With the support material gone after cleaning, the component is even more fragile.
Minimum Wall Thickness vs Resolution
We often see some confusion around the difference between minimum wall thickness and resolution. Sometimes we’re asked, “If the resolution of a material is so high, why can’t the wall be that thin?”
Resolution comes into play in how detailed and precise a design can be, so long as there is enough thickness to provide structural support.
Think of resolution as how accurate the part can be designed for printing, very similar to dimensional tolerance. Take a hollow sphere, for example. Minimum wall thickness determines how thin the shell can be so it’s printable and doesn’t collapse under its own weight.
Resolution determines how smooth the curvature is: low resolution will show visible “stepping” and roughness, while high resolution will hide these aspects.
Of course, there are always exceptions to the rule! Some parts can be printed with features below our recommended minimum wall thickness. Ribbing, cross supports, flat and supported components (as opposed to curved features) sometimes allow parts to be thinner.
While we aim to provide guidelines and recommendations around what we are 100% certain is printable, there are so many variables and design factors that make one thin part printable and the next one not. Because of this, we can only fully guarantee successful prints of designs above our recommended minimum wall thickness.
Though you might want to push the limits of your design, we don’t recommend going thinner than our suggested thicknesses. Even if your print is successful, that design choice will likely run you into complications around manufacturability down the road.
How will your part, which managed to be 3D printed, be produced during the next phase, perhaps via RTV or Injection Molding? Those thin walls will likely make your part impossible to manufacture at scale.
So pay attention to the wall thickness of your parts, and if you choose to design a part thinner than our recommendations, be sure to carefully consider whether or not it will be manufacturable later on.