June 20, 2022
So you returned to your printer, excited to see your finished print, only to find wispy strands of filament stuck to your print.
Stringing is a relatively common defect in 3D printing. While it’s often minor, it can be tedious to remove and can ruin the appearance of your print, sometimes forcing you to start over.
In this blog we’ll discuss what stringing is, why it happens, and how you can prevent it. Plus, we’ll go over how QuinlyVision, our multi-failure detection system that is able to detect and respond to 14 different 3D print failures and defects, is able to identify stringing.
Chances are you know what stringing looks like and are here to figure out how to fix it, but in case you’re just reading this for fun: strings are wispy strands of filament scattered across the build plate. They are no thicker than a couple of strands of hair, and they can be very difficult to remove from your print because they’re so thin.
Okay, now that we’re all on the same page about what stringing is, why does it happen? Stringing occurs when material oozes out of the nozzle while it travels from one place to another. It can come as a result of poor settings or from other failures that are occurring, such as over extrusion and under extrusion.
Some reasons you may be experiencing it are that you have the wrong retraction settings, incorrect nozzle or bed temperatures, or material that is retaining moisture. Each of these causes has a relatively simple fix which we will go over in the next section, along with some additional helpful settings to try.
As we mentioned earlier, stringing may be a minor defect in some cases, but in others it can ruin your print and there’s currently no system that detects it. QuinlyVision, however, can! So, how does it do this?
QuinlyVision goes through a similar process to you when identifying what happened to a failed print. First, it notices there is material where there shouldn’t be, then it assesses the appearance of that material. In the case of stringing, it can tell it’s not another failure (such as spaghetti) by the thickness of the strands, which are only about 1-2px wide.
Okay, this machine vision stuff is cool and all, but how does this help you? Well, there are two ways: QuinlyVision can determine the root cause of your stringing, making it easier for you to fix the problem, and in some cases it can prevent stringing entirely.
Let’s look at two scenarios:
Scenario 1: Your stringing occurs alongside under extrusion. This is because under extrusion happens when there’s not enough material in the print itself, which can be a result of material extruding where it shouldn't (e.g., during travel moves) rather than onto the print itself. You aren’t sure where to start when it comes to fixing this issue but QuinlyVision’s built-in Correction Wizard™ provides suggestions for how to fix your under extrusion (the underlying cause) rather than just fixing the stringing (what you notice first).
Scenario 2: Your stringing happens as a result of over extrusion because the excess material oozes out of the nozzle while it travels. If you have instructed QuinlyVision to pause your print when it identifies over extrusion, the minute that failure is detected, your print is paused, and no more stringing occurs. You can easily clean up a few wisps of filament and resume the print once you have fixed the problem, avoiding an outright failure.
Hopefully you found this blog helpful and have some new settings to try to fix your stringing! If you're interested in QuinlyVision, try our interactive demo during our livestream this Wednesday, June 22 from 4:30-6:30pm PST.