How to Prevent 3D Print Failures: Reduce Stringing and Oozing in Your 3D Print

How to Reduce Stringing and Oozing in Your 3D Prints and Avoid 3D Print Failures

So frustrating! You've worked your design, you've optimized your infill, but as your print starts to build you see fine threads of material left where there shouldn't be any. It's likely filament that has oozed out of your print head, while it was moving.

It happens to everyone, and happily, there are some settings and adjustments you can make. You will need to try a few to find what works best for you and your 3D printer.

Optimize your 3D print settings to minimize 3d printing stringing and oozing

The first thing is to check your retraction settings and make sure it's turned on. Retraction is how the filament stops coming out of your extruder nozzle. The nozzle has to pull the filament back in, and if it isn't quick enough, it will leave that thin cobweb of material on your print.

Experiment to find the right distance for your 3D print retraction setting, and also the right speed. You'll need to balance this, though. If it's not fast enough you'll get the stringing we're talking about, but if you speed it up too much, you risk damaging the filament and setting yourself up for filament grinding.

Also worth considering is temperature. You may find that lowering the nozzle temperature help minimize the oozing. As a first step, check the manufacturer's recommended temperature range for your specific filament. You may find your 3D printer filament has recently been changed, and is running at the temperature of the previous roll.

Increase the print speed a little. If you make it travel just a little faster, you'll hopefully minimize the chances of filament leakage during non-print movements.

Physical causes of stringing and oozing in 3D prints

Check for moisture in the filament. This is a bit more rare than issues with print settings, but if your filament is moist it can create steam when it is in the nozzle, leading to uneven extrusion and stringing. If you live in a humid location, you may need to store your filament in a sealed container, with a desiccant.

Of course, clean your 3D printer nozzle regularly. You need to remove any residual filament or debris that can make oozing and stringing worse.

Create your designs to avoid stringing and oozing while 3D printing

Now moving backward into the design phase - should we have started with that? - there are design tips that are good to know as well.

Prints with multiple towers or separate components are more prone to stringing and oozing. For example, if you're printing a bedful of chess pieces, there will be a lot of non-print moves required. Each time the extruder stops and starts increases the likelihood of stringing.

Similar to that are designs with overhangs and bridges. Make sure you optimize the travel path with this in mind.

This is why prints with continuous upward spirals - like vases - typically have less stringing than other designs. The extruder is proceeding in a forward direction, not stopping and starting, and likely keeping an even speed. These are all conducive to a more evenly finished 3D print, with less stringing and oozing.

3D print materials can be more or less prone to stringing and oozing

The material you're printing with can make a difference too. 

Materials like TPU and PETG string because of their flexibility: retraction may not be as immediate or effective, and ends up leaving a small amount behind. 

Nylon is another flexible material, and has the further characteristic of absorbing moisture. This is a material that would benefit from being stored, as mentioned above, in a closed container with desiccant.

PLA is prone to stringing at high temperature. However, it has a low melting point, so you can set your temperature lower. And it does have good layer adhesion, which helps too.

And as long as your settings are correct, ABS can be a great option as far as stringing goes. Keep in mind, though, that ABS is somewhat heat-resistant, and subject to warping. You'll want to have the print bed heated before you start 3D printing.

Keep track of your iterations; remember what works

Finally, keep track of your changes. With software like 3DPrinterOS your print files are tracked, so you can look back and tell which iterations worked and which needed further adjusting. The online camera helps, too, as you can watch your 3D print from anywhere, and get notified if there are issues.

We'd love to be part of your 3D printing journey! Our 3D printer fleet management software connects multiple 3D printers, manages your workflows, and controls multiple users. Be free to book a demo to see it in action for yourself!

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