3D Printing Tips: How to Fix Elephant Foot?

3D Printing Tips: How to Fix Elephant Foot?

3D Printing Tips: How to Fix Elephant Foot?

It’s often said that you need to get your first layer perfect in 3D printing so that the rest of the project prints smoothly. Unfortunately, getting that ideal first layer is easier said than done.

Elephant Foot is one of the more common issues when printing in the first layer. This error is easy to spot but also relatively easy to address.

Here are the main structure of contents.

What Is Elephant Foot?

what is 3d Elephant Foot

Source:Chitubox

The term ‘Elephant Foot’ aptly describes how this 3D printing defect looks like – the first layer that flares outside. However, subtler than most other 3D printing problems, Elephant Foot can still be visually unappealing.

It is most problematic if you are 3D printing model needs very tight tolerance. This is often the case for objects that are functional or meant to be together.

Although Elephant Foot manifests on the first layer, it’s not always immediately apparent. In some cases, the added pressure from the upper layers’ weight causes the Elephant Foot. It is more problematic as you have already wasted a lot of filament by detecting the problem.

Compared to other 3D printer troubleshoot, 3d printing Elephant Foot is considered to be minor. It does not detract heavily from the base model in terms of appearance and can remedy in post-processing. This does not mean that you could leave unaddressed, especially if you’re a stickler for details.

What Causes 3D Printing Elephant Foot?

As opposed to most first layer problems, Elephant Foot has nothing to do with warping. It can happen even with traditionally “easy” material such as PLA or PETG filament.

In most cases, the elephant foot is caused by improper 3D printer settings.

Excess Filament at First Layer

In some cases, the first layer bulging is simply a case of the layer having too much material.

When the nozzle extruders more filament than is needed for the first layer, some of this excess filament will push out of the extruder’s side. This is enough to create the characteristic appearance of the elephant foot.

Excess Compression from Top Layers

The Elephant Foot defect’s delayed onset can come about as more and more layers are printed. This puts more pressure on the base layer, making it more prone to deforming by flaring outside.

Even under normal circumstances, it is inevitable for the base layer to bear the whole model’s weight. However, the elephant foot becomes prominent when the base layer is not strong enough to support this weight. Naturally, the effects of weight compression are more pronounced in bigger or taller prints.

In some cases, the effect becomes unavoidable – you have to compensate for it in your design.

Excess Compression from Nozzle

Sometimes, the excess compression does not come from the top layers.

If the base layer is flaring out at the early stages, it is a good chance that the nozzle will press down the material due to improper Z-offset setting or bed that has poorly leveled.

Insufficient Cooling

Another way for the base layer to lack strength is to overheat. It is possible either with excess heat from the print bed or with insufficient cooling.

If the base layer fails to develop rigidity, it will almost certainly deform once it needs to support the upper-layer weight. The uncooled first layer will progressively get wider and create a prominent Elephant’s Foot.

How to Fix Elephant Foot 3D Printing?

There are two strategies to avoid elephant foot: to make the base layer as strong as possible or anticipate an unavoidable Elephant’s Foot effect.

The choice of which option is more viable depends on several factors. Types of 3d filament you are using, the model you are printing, and the ability to edit 3D models are all considerations.

Bed Leveling

bed leveling
Source:cults3d

The most straightforward action to 3d printing elephant foot is to level your bed. Something that you should be doing anyway as part of regular 3D printing practice.

The goal of bed leveling is to ensure that the nozzle and print bed distance is uniform at all points. This makes it a lot easier to dial in the proper Z-offset settings for the nozzle. Not only does this solution help prevent elephant foot, but it also results in more consistent bed adhesion and layer cooling.

Some 3D printers come with an automatic bed leveling feature. If this is the case for you, then there should be no reason not to run it every time you start a new 3D printing project.

If your 3D printer has no such feature, then you can do the bed leveling manually. You will involve setting the bed height by adjusting each of the four adjustment screws on the bottom.

A piece of paper or cardboard can serve as a makeshift “feeler gauge” that you can stick between the print bed and nozzle. This feeler gauge is inserted between the nozzle and print bed at various points, adjusting screws as necessary. It is an easy process and should not take more than five minutes.

Reduce Heated Bed Temperature

heated bed

Although heated bed massively helps with bed adhesion, it can also cause adverse effects if set improperly. It is a clear sign that the heated bed is set at too high temperature in the elephant foot.

If the bed is too hot for the filament, it prevents the material from becoming more rigid and developing strength. This makes it more prone to deforming into an elephant foot as soon as it needs to bear the model’s upper layer weight. You may even see the elephant foot getting worse as the 3D printing proceeds.

The first thing to do is check the recommended bed temperature for the filament. Make sure that you are working within this range. If there’s some wiggle room, then lower the bed temperature by 5 °C increments. Even small reductions in temperature should significantly improve if this is the root cause of the problem.

You can even try and go below the recommended temperature range for your filament, as long as you don’t run into any bed adhesion or warping issues. If this still does not solve your elephant foot problem, you might need to look into other solutions.

Add Raft to The Model

raft in 3d printing

A more robust option to avoid elephant foot is to print with a raft. You can make it easily through slicer software.

Raft is another layer of filament printed right below the base layer of your model. It acts as a sacrificial layer, significantly reducing the chances of errors becoming visible in the actual first layer.

Among most 3d printing problems, printing with a raft is considered a last resort. Because raft can consume a significant amount of filament that goes to disposal after, it’s not very practical if you’re planning to 3D print many models.

Typically, the raft always uses to facilitate bed adhesion and avoid warping. In this case, the raft becomes a buffer to absorb a potential Elephant’s Foot error. After printing, you can remove the raft from the rest of the print. This preserves the appearance of the model’s base layer.

Printing with a raft does not precisely address the root cause of elephant foot defect. It is still a good option if you don’t have the time to tweak your printer’s settings. However, solutions that do not require printing with a raft are a lot more sustainable.

Use Chamfers for Your Print

Instead of printing the base layer of the model, you can consider adding a chamfer to it. It is one of the more unconventional solutions.

The chamfer is simply a 45-degree slope that you can add to the model’s first few layers. This effectively means that the base layer of the model becomes narrower. This strategy is that the base layer’s swelling will cause it to become the ideal size.

A 45-degree angle is particularly ideal for this technique as it prevents the print from collapsing even with narrower base layers. This is one of the most reliable methods used in printing overhanging features.

The advantage is that it does not consume any extra filament. Since you’re printing with smaller layers, you might even end up using less filament – although the savings are minimal.

However, it’s going to take a bit of trial and error to anticipate precisely how much the base layer will swell. The best practice is to limit the chamfer to a 1-millimeter height or about two to three layers.

Adjust Z-offset

adjust Z-offset
Source:softsolder

Sometimes, elephant foot is simply the result of the filament material being compressed too tightly on the base layer. This could cause the filament to flare out and form the classic elephant foot appearance.

If reducing the bed temperature does not solve the problem, you may need to increase your nozzle Z-offset. The Z-offset determines the nozzle’s height relative to the print bed and plays a massive role in deciding bed adhesion and extrusion quality.

Although a low Z-offset aids bed adhesion by pressing down on the filament, too much of this pressure can cause the filament to deform excessively. Try to increase the Z-offset setting by about 0.1-millimeter increments until improvement can be observed.

Take note that increasing the Z-offset can cause other problems to pop up, the most likely of poor bed adhesion. This can cause the base layer to lift off or become warped.

If this happens, then you may need to solve the bed adhesion problem differently. Printing at higher temperatures, using a different adhesive, or printing with a skirt can be good options. Sometimes this happens in 3d printing – solving one problem leads to worsening another.

“Elephant Foot Compensation” Settings

Elephant Foot Compensation

Some 3D printers or slicers come with an automatic ‘elephant foot compensation’ setting. It is a convenient solution if the option is available.

When activated, this option reduces the size of the first layer of the model. Think of it like an automatic horizontal size compensation that only applies to the first layer. In this regard, this strategy is similar to the chamfer method but does not rely as much on guesswork.

As the following layers print, they press down on the first layer and compress the filament outwards. Ideally, this will result in perfect alignment of the first layer with the rest of the print. The size of the model determines precisely how large the compressive force on the first layer will be.

Even if your finished print comes out with a prominent elephant foot, all is not lost. If you’re not up to starting over with your project, then you can sand or deburr the imperfections in your finished print. This will take a lot of time but not as much as starting from scratch.

Summary

Compared to other 3D printing defects, elephant foot is not so bad. It’s not going to cause a catastrophic failure and might even be rendered unnoticeable with some sanding.

However, knowing exactly how to solve 3d printing elephant foot will be crucial in getting that base layer just right.

How Long Is 1 kg of PLA Filament?

How Long Is 1 kg of PLA Filament?

How Long Is 1 kg of PLA Filament?

3D printing filament is always sell in spools classified by weight. They are often in 500-gram or 1-kilogram spools, although there are both bigger and smaller options. This is likely the most convenient unit of measurement in terms of sales and logistics.

Unfortunately, it’s easier to estimate how long a spool would last if you knew exactly how long the filament is. Here is a handy way to calculate the meters of filament in your spool given its weight.

How To Calculate?

Calculating the meters of filament in a spool requires only basic math. However, there are some values that you need to know beforehand. To make this demonstration easier to understand, let’s assign values based on a theoretical spool of 1.75 mm PLA filament.

Needed values:

Weight of the filament =1 kilogram or 1000 grams

Density of the filament = 1.24 grams / cm3 (for PLA)

Diameter of the filament =<1.75 mm or 0.175 cm

Calculations:

Cross-sectional area of the filament = Π * (Diameter/2)2

Volume of the filament = Weight / Density

Length of the filament = Volume / Cross-sectional

Based on our calculations, around 335 meters of filament in a 1-kilogram spool of PLA filament with a diameter of 1.75 millimeters. Please note that these calculations assume that the filament diameter is perfectly consistent throughout its length.

You can use this method for any spool. You can also estimate the length of leftover filament in a spool that is partially consumed. Suppose you have a weighing scale at home. Just make sure to account for the weight of the empty spool.

How Long Does PLA Prints Last?

How Long Does PLA Prints Last?

How Long Does PLA Prints Last?

PLA is well-known in 3D printing circles as biodegradable plastic. Although beneficial in most cases, this characteristic has also caused concerns over the longevity of PLA as a 3D printing material. How long does PLA 3d print part go bad?

The good news is that PLA objects should last several years under normal circumstances. However, certain conditions can accelerate the breakdown of PLA. Avoiding these conditions is the key to making your PLA print last longer.

Does PLA Have Shelf Life?

pla-granules
Source: bioplasticsnews

The concerns mainly stem from the fact that its filament form tends to degrade quickly. 3D printing professionals often advise storing PLA filament in a low-humidity environment. It would be best if it stayed away from sunlight to maintain its good printing performance. Then the prints will be more robust.

PLA prints kept and used indoors will last virtually forever if they are not used to sustain heavy mechanical loads. Based on anecdotal evidence, an object made of PLA will at least 15 years when kept indoors. Under these conditions, You should have no problem with gifts and decorative items printed with PLA.

However, things may be different if PLA exposes to outdoor conditions for sustained periods. Depending on the temperature, humidity, and exposure to sunlight, PLA may degrade to a state where it is no longer functional. How long this process takes can vary widely based on specific conditions. In most cases, a PLA object can last for about a year outdoors before deteriorating heavily.

Reasons For PLA Prints Go Bad

Whether indoors or outdoors, there are factors that can accelerate the breakdown of PLA. To make your PLA print last, make sure to avoid exposure to these conditions:

Moisture

The breakdown of PLA mostly happens in the process of hydrolysis. PLA polymer can react with water at a shallow speed, which breaks the long polymer into smaller chains. That is the same reason for PLA filament becoming brittle when exposed to moisture.

Naturally, one of the best ways to prevent hydrolysis is to limit PLA exposure to moisture. For this reason, We do not recommend use PLA for the long-term storage of food or drinks.

PLA prints tend to fare poorly in very humid environments. Having a PLA print sit outside under the rain is also a sure way to break down faster.

Sunshine

Photodegradation is the process by which the properties of polymers diminish when exposed to sunlight or UV radiation. PLA has no specific resistance to the effects of photodegradation. There are two signs of PLA degrading due to UV radiation – increased brittleness and bleached colors.

PLA develops brittleness through crosslinking reactions induced by UV radiation. Then PLA will be stiffer and prone to breaking apart. Moreover, the crosslinks are more vulnerable to oxidation which will deteriorate the polymer into smaller chains.

Plastic bleached by UV tends to take on a characteristic yellow color. This affects the stabilizing agents in the plastic, turning into free radicals upon exposure to UV radiation.

Any dyes in the PLA filament can also be broken down by UV radiation, resulting in a gradual fading of colors.

High Temperature

Exposing PLA to high temperatures is generally not recommended. PLA prints can show signs of warping with a relatively low glass transition temperature of only 60 to 65 °C when left outside on sweltering days. It is standard advice not to use PLA 3d printed parts in your car.

Elevated temperatures also increase the diffusion rate of moisture into PLA, making it even more prone to hydrolysis. The situation will be worse in hot and humid environments.

Microorganisms

We know that PLA is a biodegradable material. It can be broken down into its constituent monomers by biological matter. If you want PLA to last longer, then make sure to keep it away from any medium that is rich with microorganisms such as soil, plants, or water.

Other factors can also accelerate the breakdown of PLA due to microorganisms. Short-chain polymers resulting from hydrolysis or oxidation will be more vulnerable to biodegradation.

Even among all the 3D printing communities worldwide, understanding what makes PLA degrade is still somewhat flawed. Several other factors come into play here, such as the filament brand, additives, and the type of pigments used to impart color.

The environment will play a huge role in determining how well a PLA print stands up to the test of time.
Slowing down moisture degradation and keeping your PLA print away from direct sunlight are the two most important rules of thumb for making it last as long as possible.

How To Make PLA 3D Printed Parts Last Longer

In most cases, there is little thing you can do about the environment in which the 3D printed PLA objects will use. You can change 3D printer settings to make the finished product more resilient.

Some post-processing techniques can also help you in achieving this objective.

Interior Density

3d print infill
Increasing its infill density can make PLA print more robust. It increases mechanical strength and makes it more resilient against the elements. Your slicer software should allow you to adjust interior density from zero (completely hollow) to 100 (completely solid).

The advantage of a higher infill density is that it supports your finished print’s shell and allows for more even stress distribution. It also makes the patterns more premium because of the added heft. However, expect to use up significantly more filament and spend more time finishing your 3D printing project.

Composite Material

Composite filaments that use PLA as the polymer matrix are now ubiquitous. Such as wood, metal, or ceramics. Composite filaments allow you to create 3D printed objects that mimic the appearance of materials that are traditionally not used in 3D printing.

Some composite filaments can even contain solid materials such as carbon fiber. This material adds strength to PLA at the cost of reduced flexibility.

Just a word of warning – composite metal or carbon fiber is nowhere near as strong as the real thing. It should hold up to the elements better than standard PLA, but you can not expect it to act like real metal, wood, carbon fiber, or ceramics.

Orientation

3D printing technologies is based on building an object layer by layer. Unfortunately, the boundaries between these layers act as natural weak points of the final 3D printed product. In this regard, a 3D printed object’s strength is considered anisotropic or varying in different directions.

A strategy you can do is consider how stress will be applied to the object during its application. Make sure that the weak boundaries are closer to parallel to the direction of stress rather than perpendicular. With this in mind, you can alter the model’s orientation in your slicer so that the layer boundaries are more favorable to your purpose.

Injection

Being able to print hollow objects is one of the distinct advantages of 3D printing. This makes 3D-printed objects lighter, cheaper, and faster to manufacture. On the other hand, it also makes 3D printed items less durable and more prone to degradation by the elements.

A unique technique to strengthen 3D prints is to inject an adhesive material into the internal cavity. You can drill small holes on the shell to allow for injection. It is a quick and inexpensive method to strengthen a 3D print, although not considered fit for professional use.

Coating / Plating

A finished 3D print made of PLA can be post-processed to enhance its properties. Post-processing options can include coating with a water-resistant material or electroplating for improved strength.

Improving water resistance can be done by simply painting 3d prints outer walls. If the parts have been sanded smooth, Paining with epoxy will have more consistent application. This typically also imparts a glossy finish to the surface.

Electroplating is a process for coating 3D-printed parts with metals such as copper or nickel. Not only does this provide enhanced strength to the PLA print but also makes its surface electrically conductive.

Before the plating treatment, you should ensure that the PLA print surface is sanded and polished smooth.

This list highlights how different ways to make a PLA print last longer, ranging from changing a few settings in your slicer to more advanced post-processing techniques. The most prudent approach would be to consider precisely how your PLA print will be used and decide on a strategy accordingly.

Summary

PLA may be one of the most popular materials used in 3D printing, but users also recognize its resiliency deficiency.
PLA is the best option for items that are to be kept and used indoors. 3D printed parts made of PLA aren’t typically strong enough to support a large amount of stress.

Keeping PLA prints away from moisture, heat, or sunlight is the best way to make them last longer. Meanwhile, reinforcing PLA with denser infill or post-processing treatment can also be considered.

3D Printing Overhang: How to Deal With?

3D Printing Overhang: How to Deal With?

3D Printing Overhang: How to Deal With?

3D printing is described as being able to turn any digital model into a real-world object. However, it also has some limitations in structure. Such as 3d printing overhang and bridge.

If your model has crucial overhang elements, then don’t worry too much. Successful 3d prints with overhang is possible by following a few rules.

What Is Overhang In 3D Printing?

3d print with overhang curling

3D printing is a process that relies on building an object layer by layer based on the slices of a digital model. As each layer cools down and solidifies, it supports the weight of the back layer. It is a reasonably simple mechanism with a few fundamental limitations.

Overhang is the feature in the 3D printing model that extends outward from the previous layer. This structure does not directly support by any system underneath. Overhangs can be problematic as they can collapse under their weight when printing not in ideal conditions.

In some cases, overhangs do not collapse entirely but end up sagging or curling. Although less catastrophic, this can still ruin your 3D print visually and reduce its mechanical integrity.

Rules For Overhangs

Although overhangs can be a challenge in 3d printing, they are necessary for a lot of projects. If trying to print a complex design, overhangs are practically unavoidable. You will need to work around them to prevent them from collapsing or sagging.

The basic rule to follow is that it should not exceed an angle of 45 degrees from the vertical. At precisely the 45-degree point, an overhang still has a 50% support from the preceding layer and should not yet collapse. It is not an absolute rule as different types of filaments and printer settings can result in variations in the point of failure.

Beyond 45 degrees, you will have to resort to more creative solutions to prevent an overhang’s failure. These measures can range from adding support structures to your model or altering your model entirely.

How to Improve 3D Printing Overhang

If your model contains overhangs, it is prudent to make corrections or adjustments before 3D printing starts. After all, an overhang’s collapse is not the type of 3D printing error that you can recover.

Here are some precautions you can make to avoid wasting your time and filament.

Revise The Model

Maybe it is the most drastic thing you can do to improve your overhangs – make changes to your model.

While you change the orientation in slice software, the print performance will be much different.

Model Rotation

rotate 3d model

If the overhang features go beyond the 45-degree threshold, Rotating to a different orientation may be enough to make these overhangs more vertical. You can make them less prone to collapsing or sagging.

Some slicer software, such as Cura, comes with an auto-orientation feature that can rotate your model to minimize supports. This function essentially reduces overhangs. In most cases, the optimal solution is a combination of both – reorientation of the models and limited use of supports.

Angle Deforming

Angle Deforming

Suppose you are familiar with some 3d design software, such as Solidworks, Sketchup. You could revise the angle of overhangs.

This will save you the effort of tweaking with slicer settings to make sure that the prints do not collapse.

Use Support Structures

support structure

A model with overhangs will need support structures. These are pieces of filament printed with the sole purpose of providing mechanical support to overhanging features. Supports can be auto-generated by slicer software and may have different shapes, including linear, accordion, or tree-like.

Using too many supports has a significant downside. Supports consume a lot of extra 3d filament, which you will need to dispose of later. They can also be tough to remove, especially if they are rigid material like PETG or Nylon. For these reasons, it is good practice to use as few supports as possible.

The best way is to use soluble filaments such as PVA (Polyvinyl Alcohol) or HIPS (High-Impact Polystyrene). These filaments can be submerged in the appropriate solvent after 3D printing to remove them effortlessly. PVA dissolves entirely in water, while HIPS requires a limonene solvent.

Tuning the 3D Printer

Overhangs can be challenging for any 3D printer. To make sure that it is up to the task, do a general fine-tuning of your 3D printer before printing a model with lots of overhangs.

To maximize the performance of your 3D printer. Doing a bed calibration, cleaning your nozzle, relubricating motors and shafts, using a new build plate can be a huge help.

Tuning your 3D printer isn’t specifically useful for 3d print overhang but is generally good practice for any challenging job.

Print in Multiple Pieces

Split the model

In some complex models, overhangs cannot be addressed by simply changing the model’s orientation. Another solution is to break down an overly complicated model into smaller and simpler parts.

Working with smaller parts gives you more freedom to play around with the models and reduce overhangs. This is also a great strategy if you’re anticipating complicated models to fail during printing. Dividing them into smaller parts makes the challenges more manageable and lowers the stakes in potentially wasted time and filament.

Just keep in mind that you will inevitably need more post-processing work when splitting models up into several parts. You will have to glue the pieces together and sand the seams to be so visible. It may take a bit of practice to develop the crafting and post-processing skills needed to pull this off.

Use chamfers

Introduce chamfer

A chamfer is a way to create overhangs that seem to defy the 45-degree rule. Dividing the overhang into smaller segments, each one angled less than or equal to 45 degrees from the vertical. The angle then tapers off closer to being horizontal.

The downside of using chamfer is that it can drastically alter the appearance of a model. This may not be acceptable for your project, depending on its application.

Tweaking The Slicer Settings

If you’re still having problems with curling overhangs despite following the 45-degree rule, then your slicer settings may need some work.

Increase Fan Cooling

Cooling is your most powerful tool to keep your overhangs from collapsing.

Cooling the filament as quickly as possible helps it develop the strength to support its weight. Try to print with the cooling fan at maximum setting and without an enclosure. You can even try augmenting your cooling fan with a separate desk fan.

Decrease Layer Height

Collapsing overhangs happen when the filament cannot support its weight. An excellent approach to solving this problem is to make the layers as light as possible by reducing the layer height settings. This reduces the likelihood of the layers collapsing.

The drawback of this solution is that it will undoubtedly increase the printing time of your project.

Reduce Printing Speed

Reducing the printing speed gives filament more time to cool down and develop rigidity. Before it gets weighed down by succeeding layers on top of it, this strategy goes perfectly with a cooling fan set at maximum to strengthen your layers as quickly as possible.

As with reducing layer height, you are slowing down the printing speed will increase your model’s printing time.

Lower Printing Temperature

If you’re having a hard time keeping your overhangs up, then you may try reducing the printing temperature by increments of 5 °C. Make sure to stay within the recommended temperature range for your filament.

By printing at lower temperatures, you can help the filament establish rigidity faster after exiting the nozzle. This makes it more capable of supporting its weight and less prone to collapse. Please take note that it may be necessary to reduce the printing speed accordingly to ensure consistent extrusion.

The optimal slicer settings can vary widely based on the filament you are using and the dimensions of the overhangs that you are printing. It will likely take some trial and error before figuring out the perfect settings for your application.

Summary

If you want to get quality 3d prints, dealing with 3d printing overhang curling is essential you need to know.

Preparation is a crucial component in avoiding catastrophic failures because of overhangs. Depending on your circumstances, you may have to make a few changes to either your model or printer settings.

As with most 3D printing issues, expect a healthy amount of trial and error before you achieve success.

3D Printing Pillowing: Causes, Solutions, and How to Avoid It!

3D Printing Pillowing: Causes, Solutions, and How to Avoid It!

3D Printing Pillowing: Causes, Solutions, and How to Avoid It!

3D printing is rarely a perfect process, especially when dealing with an unfamiliar machine or filament.  One of the problems is the pillowing. Because it only comes up when printing the top layer – or when 3d prints will be finished.

As with most 3D printing problems, pillowing can be fixed by tweaking your printer settings. Check out our guide on pillowing and how you can avoid it.

What is 3D Printing Pillowing?

what is 3d printing pillowing

Pillowing is a typical 3D printing problem characterized by the top layer having an uneven surface. This feature can manifest as a series of small bumps, a very rough surface, or even small gaps and holes.

What makes pillowing particularly frustrating is that it comes up only when a print is almost done. By the time the top layer is printing, you would have already spent a lot of time and filament material. It leads to a lot of waste and the need to start over with the entire project.

Pillowing can happen regardless of the type of 3D printer or filament you are using. The silver lining in this is that solving it also does not require any fancy equipment or accessories.

Considering the stakes, it is in your best interest to avoid pillowing at the start of 3d printing. You will save a lot of time, effort, and filament.

Causes for 3D Printing Pillowing

To put it briefly, pillowing happens when the top of object fails to cool properly. Several factors can cause this issue.

Identifying each one of them is the key to addressing the problem even before it happens.

Filaments with High Melting Point

Thermoplastic printing filament has a different performance from 3d printers. They have a different print temperature, particularly those that tend to warp, also have an increased tendency to exhibit pillowing.

Warping of the top layer happens as the filament cools down. The stress generated by thermal contraction pulls the material towards the infill pattern directly below the top layer. If the top layer isn’t strong enough, this effect will create prominent holes or an uneven surface.

Improper Cooling

3d printer cooling fan

The Pillowing also happens when the top layer is not strong enough to resist thermal stress or support its weight.

An easy way to avoid this is rapid cooling. Cooling makes the material rigid faster, giving it strength to hold its form.

Not Enough Support Material

3d printing support
In some cases, the top layer develops holes simply because the filament material falls through the gaps.

There is not enough infill to support the top layer, the filament with poor bridging performance will more likely suffer pillowing because of this reason.

Soft Filament

Flexible filament 3d printing

Soft or flexible filament, like TPU, are more prone to pillowing.

They lack the rigidity to hold their shape during cooling, especially when sparse support materials anchor them. When working with soft filament, cooling the molten material as quickly as possible becomes even more critical.

How to Avoid it? Try These Solutions

To avoid pillowing, we need to address its root causes. This involving reinforcing the top layer, either by providing it support underneath or helping it become rigid as quickly as possible.

If you’re still encountering issues with pillowing, here are some solutions you can try out.

Increase Top Layer Thickness

Building a thicker top layer makes it more mechanically robust. Hopefully, this will be enough to counteract the thermal stresses that can lead to warping.

A good rule of thumb to follow is to build the top layer about five or six times thicker than the other layers in the project.

Increase Infill Percentage

Another option to consider is the infill structure. The benefit of this is two-fold. Not only do you provide more support for the top layer, but your prints generally get more robust and heftier. A minimum of 25% infill is usually accepted to prevent pillowing. For the flexible filament, you need a higher setting.

While this is a reasonably effective solution to pillowing, increasing the infill percentage has a significant consequence. It also heavily increases the amount of filament going into any print – even more so than improving the top layer thickness. If you’re offering this service commercially, make sure to adjust your prices not to end up short-changed.

Decrease Speed of Printing

Slow and steady wins the race – keep this in mind when trying to prevent pillowing.

Slowing down the print speed can give the filament more time to cool down and develop rigidity. This allows it to better support its weight and the weight of the succeeding layers.

Take note that reducing the printing speed goes in tandem with lowering the printing temperature. We will go into more detail on that later on.

Improve Cooling

One of the most straightforward solutions to prevent pillowing is to maximize cooling for your project’s top layer. This action can develop strength and rigidity quickly before it becomes deformed because of warping or buckling.

In some cases, even setting the cooling fan to maximum might not be enough to prevent pillowing. If you find yourself in such a situation, then even a standard desk fan could help. Make sure to print in an area with good ventilation – cold fresh air from outdoors can speed up the filament’s cooling.

Lower Printing Temperature

If cooling is the problem, then why heat the filament in the first place? A smart strategy is to reduce the printing temperature for the top layer of your print. It helps to reduce thermal stress during cooling and relieves the filament’s develop rigidity earlier.

As mentioned, reducing the printing temperature goes hand-in-hand with lowering the printing speed. Make sure to adjust both these parameters simultaneously, so you do not run into an extrusion problem.

Be careful only to do this when the top layer has started printing. Layer adhesion tends to suffer when reducing printing temperature. However, layer adhesion is no longer as important in the top layer of a print.

Increase the Distance Between Print Head and Build Plate

A subtle solution to pillowing is to increase the z-offset of the print head while printing the top layers.

The heat emanating from the nozzle itself tends to slow down the filament’s cooling process that has already extruded. Just adjusting to 0.05 to 0.1 millimeters can profoundly affect reducing the effects of pillowing.

Just as with printing temperature, you are increasing the print head z-offset can also compromise layer adhesion.

Keep this in mind with every preventive measure that you take. You do not want to reduce layer adhesion to the point that the layers start splitting.

Change Filament Size

If you’ve done all the above measures but still suffer from pillowing, then consider changing over to another filament size. This is admittedly almost a shot in the dark, but it has worked in some situations.

Specifically, changing over from 2.85 millimeters from 1.75 millimeters may be the solution to your pillowing problem.

This method works because a larger-diameter filament can more reliably deliver the filament mass needed for consistent extrusion. That is particularly true when you’re using a wide-diameter nozzle.

This solution is worth exploring if you can observe signs of poor extrusion along with your issues with pillowing.

Summary

As far as 3D printing problems go, pillowing isn’t precisely one of the most complexes. However, it can be very disheartening because pillowing happens when a printing job is just about to finish.

Fortunately, pillowing also have relatively simple solutions. Just be ready to jump in as your print approaches the top layer. You may have to play it by ear, but the solution should not be too complex as long as you understand the fundamentals of how filament behaves as it cools.