Why Are My 3D Prints Brittle? Possible Causes and Solutions

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The many problems associated with 3D printing include brittle 3D prints.

Brittle 3D prints tend to be caused by a number of issues but primarily it is due to very old and or cheap filaments.

Many PLA filaments require a lot of attention when they are made and they have to be vacuum-sealed, preferably with silica gel to make sure that moisture does not seep into the filament.

This is the first step.

Why are my 3D prints brittle?


If they are shipped properly from the factory, but you don’t reseal the PLA spool roll after use, the odds are that your 3D builds will become progressively brittle with time.

Although the vast majority of filaments such as PLA roll or bag and its ABS counterpart roll do last a long time, storage plays a key role here.

Exposure to the air can make it difficult to save the PLA roll in time. For example, if your PLA roll and or other filament bag are kept in the wrong conditions such as being exposed to ultra violet radiation from direct sunlight then they can become brittle. Once that happens then once fed into the printer no amount of adjustment is going to help at all.

If you may have tried it multiple times it would result in the same thing. First and foremost you will have to figure out how to get rid of the moisture and keep it sealed from the air. This will save it for a long time. If you like you can put it in an air tight jar.

You may share this spool or bag with others, but it will still lead to the same result. Never use it again because it will simply get in the way of a good print. It cannot be stressed enough why using dry PLA is so imported.

Once it is open it must be consumed quickly because an open spool can attract moisture. This moisture can permeate into the main layer. The key layer at low temp settings can spoil the print. Here, where you place the printer is important. Too much heat in the area and it will spoil the build.

Then there is the issue of filament diameter that can also lead to brittle 3D prints. The diameter tends to vary through manufacturer and batch. Sometimes it so happens that the idler tensioner is a bit too tight then if the filament still has some life left in it, it will nonetheless come to snap under the pressure at worse, or lead to brittle prints at best.

In either case, it will create problems in the long run as your prints will either not come out at all or they will be too brittle to be useful.

There are various solutions to brittle 3D builds. Let us check out a few popular remedies:

How to fix brittle 3D prints

Reload Filament

If you consistently get brittle prints, it would be a good idea to reload your PLA filament. If the issue persists after reloading then try another filament brand or material in order to check and see and eliminate the filament part of the problem.

If the other filaments work just fine that means that you will have to dispose of the old brittle filament, post haste.

PLA filament must first be checked to see that it is dry. One of the best things you can do is to check size since the wrong size will create a problem. See what works by checking beforehand.

If you find that low temp is not good enough, maybe your printer wants more heat to set it in its place properly.

Loosen the Idler Tension

If the new filament also starts to snap than you should check that your 3D printer idler tensioner is not too tight. If this appears to be the case, you should consider loosening it bit by bit to all the way.

As the 3D printer starts to print, you should start to tighten it, until there is zero slippage of the filament. This will also aid a lot in creating that ideal non-brittle build.

When All Else Fails, try another Filament

If after reloading the filament the issue persists, then merely reloading the same thing won’t resolve the issue. If this happens you might consider switching from say PLA to an ABS filament spool to check and see if your 3D printer has problems with the old one. If that is the case, you may need to shift to the new material for the time being.

The Causes behind Brittle 3D Prints

If your PLA filament pack does not absorb moisture, you won’t be able to get a great print. Here silica gel can help since it can absorb moisture from your PLA filament spool.

Apart from that, supports are a vital part of 3D modeling. Many otherwise great models may avoid the need for supports completely. It could need a little adjustment of the model to so as to try and angle verticals.

You could also get an additional design integral support that could easily be used to decrease moisture of the spool and structure the model.

Just ensure that you buy something that absorbs moisture. If the spool is sealed properly, it can be set and last for months. The extruder head will be able to extrude easily without any fear of breaking issues, even hours after the print is complete.

You could also ensure to easily increase the heat or decrease temperature to get the ideal one. The quality of your machine would also play a part. If you have tried small extruder movement, you can tweak them to get great builds.

And even if you have not used them, you can still try new settings till you find a setting you like. You may also be surprised by the high quality and capabilities of your 3D printer. You would be able to try printing an amazing 3D print. In fact, many printers can print various angles without using any support at all.

Getting the right printing temperature is not difficult at all. Just ensure your filament is the right one. Otherwise, you will find it will be much the worse for wear for all of your printed objects.

Software solutions such as Cura and Simplify3D are capable of producing outstanding support structures, and for the most part these automatically generated supports will far exceed the quality of any home grown solution. But although auto-generated supports do the job, they can be difficult to remove.

Applying your own support structures is a neater solution, but you’ll need to delve into the settings of your software to tailor the supports to your models.


Printing even small objects is not difficult, but you will want to ensure that they work well. Just follow the above tips and you will be well on your way towards getting a great 3D printing experience.

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