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5 Reasons Why 3D Prints Fall Apart (Easy Solutions) 

Discover 5 common reasons why 3D prints fail & find easy solutions to improve print quality. Save time, materials & frustration with these expert tips!

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Whether you’re just getting into 3D printing or doing it for a while, there is nothing more frustrating than a print that ultimately falls apart. Thankfully, this is something that you can fix pretty quickly most of the time. So, let’s talk about why it may be happening and how you can get your prints to hold firm. 

Your 3D prints may fall apart if you use the wrong temperature, print too quickly, or set the layer height too high. 3D prints may also fall apart due to under-extrusion, an unlevel bed, or inadequate infill density. 

In the rest of this article, I’ll explain why your 3D prints might fall apart. Then, I’ll discuss the solutions to each issue so you can keep your models intact and durable. 

Why Your 3D Prints Fall Apart

3D prints can fall apart for many reasons, but some are more common than others. So, let’s talk about some of those common reasons and help you figure out what is causing your prints to fall apart. 

Under Extrusion

Under extrusion usually occurs when your hotend does not get hot enough to liquefy your filament. When this happens, the filament won’t be as sticky when it comes out of the nozzle, making for terrible layer adhesion and a print that will quickly fall apart.  

Another common cause of under-extrusion is a filament feeding issue. If your spool holder doesn’t offer smooth, easy feeding of your filament, there will be resistance, and the filament won’t make it through the hotend fast enough to keep up. 

And last but not least, a minor clog in the system can create under-extrusion. If a small glob of filament is stuck in your Bowden tube, the gears in your extruder, or the hotend, your filament won’t have an easy path through the nozzle. This resistance keeps your printer from creating a consistent flow of plastic. 

The severity of under-extrusion can vary, but it will be very noticeable, no matter the cause.

If the amount of plastic is close to the correct amount but just a little under, you may notice that the figure falls apart over time. If you see visible gaps in the print immediately, there is significant under-extrusion. 

Printing Speed

Another common reason that your prints may fall apart is printing speed. You must be careful about printing speed, as printing too fast or too slow can cause separate issues. 

But let’s talk about how printing speed can cause your 3D prints to fall apart. 

In most cases, slower is better when 3D printing – but as humans, we’re all pretty impatient. However, print your models too fast, and you’ll see stringing, under-extrusion, and lousy layer adhesion. All of these issues will make for a weak print. 

Speed interferes with the durability of your print because, if you’re printing too quickly, the filament may not get hot enough in the hotend. Thus, if you move too fast, your filament will never get up to the proper temperature, and it won’t be able to stick to itself. 

Likewise, high speeds may result in narrow layer widths, reducing the surface area of each wall’s thickness. These thin walls won’t be able to withstand pressure, and they might even fall apart while your print is still on the bed. 

Layer Height

When creating 3D prints, you should keep your layer height in mind, as it can significantly affect the final object’s strength. 

Because 3D printing works by placing one layer at a time, you need to specify how tall you want each layer. If you expect too high of a layer, this can cause delamination and make your print fall apart. 

This issue is pervasive in filaments like PETG and ABS, which are prone to warping. PLA is a bit forgiving, but it might also warp if you set the layer height too high – resulting in delamination. 

Infill Density

The infill density of your 3D print can either make or break your overall design. The infill density determines the amount of plastic used to fill the inner parts of the object. 

Too much infill density can be a waste of resources, but too little density can cause your print to be delicate and weak. 

Some sort of infill is usually necessary for every single print. There are some notable exceptions, but for the most part, if you are not adding even 1% of infill, you will probably end up with a weak, disfigured, or spaghetti-like model. 

Some Easy Solutions for Prints That Fall Apart

Now that we covered some of the major causes of a print that is falling apart, let’s go over some ways you can fix the problem. 

1. Change the Temperature

Fixing your printing temperature will be pretty straightforward. 

When selecting your print temp, go with the temperature recommended by your filament’s brand. You can usually find the ideal printing temperature on the product listing where you bought the filament or the packaging. 

This temperature will usually be a range, and I, along with most experts, recommend starting your print by using the temperature that falls right in the middle of this range. 

For example, if my PLA filament says to print it at 200 – 210° C (392 – 410° F), I recommend starting your print at 205° C (401° F). 

If you experience under-extrusion, increase the temperature one degree at a time until you are happy with the results. Over-extrusion requires a decrease in print temperature. 

The second way to fix an issue with the temperature is to change the cooling fan temperature. Even if your hot end temperature is just right, you may still notice problems with your parts if the fan speed is too high. 

This draftiness can cause a significant change in how well the parts of the print stick together, as it can cool the filament down before the parts can adhere. 

Also, check your heated print bed temperature if you have one. The first layer can make or break your print, and you don’t want to deal with bed adhesion issues on top of weak walls!

2. Clean the Nozzle

Another possible solution for 3D prints falling apart is to clean the nozzle on the hot end. 

Cleaning the nozzle is simple, and there are a few different ways you can go about it, depending on the available tools, and how stuck the clog is. 

The easiest solution to this issue is to use a cleaning filament. This specially formulated filament feeds in just like a regular filament, where it runs through the printer, but it doesn’t create a print. Instead, it removes blockages and cleans the nozzle. 

If you don’t have a cleaner filament, there are other options. 

A wire brush can help you clean the outside of the nozzle to remove any residue that sticks to it. If you choose a wire brush, ensure you heat the nozzle first to melt the residue, making it easier to remove. Otherwise, you may have to scrub hard to remove it. 

Finally, you can remove clogs from your 3D printer nozzle by heating the nozzle and inserting a needle. After the nozzle is up to your filament’s required printing temperature, insert the needle into the nozzle. 

The needle should break up the leftover residue inside the nozzle and allow you to remove it. Ensure you are gentle when inserting it, as you don’t want to affect the nozzle. 

Then, purge that nozzle! Let the filament flow until the string coming from your extruder is even, smooth, and clump-less. 

3. Reduce Your Layer Height

As I discussed above, layer height can significantly affect the overall quality of your prints. One of the best ways to ensure each layer is complete and adheres properly is to lower the layer height. This adjustment will reduce the chances of warping and delamination. 

Smaller layers also allow you to use less filament per second during printing. This adjustment will help your printer nozzle work more easily around any clogs or residue that may have been left behind from another print. 

To find the perfect layer height, you will need to adjust your printer settings before you start printing your object. 

As a rule of thumb, ensure that your layer height is about half the diameter of your nozzle. For example, when using a 0.4 mm nozzle, you should make your layer height 0.2 mm. 

You may be able to get away with 0.3 mm, but start with 0.2mm and see how it goes first. 

If you already have a print falling apart, you will need to try the design again. Make changes to the temperature, nozzle, and layers for the best possible results. Otherwise, you may need to figure out if there is something else wrong with your 3D printer. 

4. Change Your Infill Density

Like layer height, you’ll have to change your infill density before slicing your model. 

Most experts recommend using at least 15% infill for every model. Even if you plan on removing the infill later, it’s a critical part of any print, so don’t skip it. 

However, if you plan to put any pressure on your model, you should aim for 20 to 40% infill. The more infill, the more durable your print will be. 

5. Level The Print Bed

You may need to check the bed if you have corrected the above issues and are still experiencing your pieces falling apart.

If the bed is not level, the layer heights will all be unequal in height and width, possibly introducing adhesion issues. 

To ensure the bed of your 3D printer is level, you will need an ABL or an Auto Bed Leveling Sensor. This device comes pre-installed on most 3D printers and ensures that the bed is level before you use it. 

Still, like any other program, it may not always work perfectly. So, even if your ABL program seems to be working, you may want to do a manual level check if your prints are falling apart. 

First, you should ensure that the bed and nozzle are clean before leveling. Any leftover residue can skew the results. Once the surface is clean, test the level of the bed by ensuring that the nozzle reaches it. The ideal level is when the nozzle touches each corner of the bed, but the touch should be light. You want the nozzle to tap the surface barely. 

It is essential to do this for each corner and the center of the bed to ensure that it is level. You may need to adjust the screws in the bed based on how to level the bed.

Make sure to test the bed again after messing with the screws to ensure it is level. Once you finish, try the printer with another model and see if this improves the print quality. 

6. Slow Down

If you run your 3D printer too quickly, your print’s quality will suffer. So, slow down, and be a bit more patient. 

Avoid using your slicer’s “speed” quality settings, and instead, opt for “detail” or “quality.” Using these features will make your print last much longer at the cost of an hour or two of print time. 

In addition, manually adjust the speed if you notice layer adhesion issues or under extrusion as you are printing. I usually take my Prusa down to about 80% of the preset speed when I see spaghetti-looking layers, and just that 20% difference significantly impacts the print’s strength.  

In addition, if you want your print to maintain structural integrity, keep taking that speed down. The layers will look smoother, and they will be much stronger. 

Final Thoughts

A 3D print that falls apart in your hands is not ideal, and there can be many reasons for this. 

3D printing is a delicate process that requires the right design, temperature, filament, and tools. Without everything working as it should, you may notice some delaminations. So, use some of these fixes and see if your printer works better and creates more reliable prints.

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.