During FDM 3D printing, the printer extrudes filament and deposits molten material in a sequence of shapes. The printhead is always either depositing material — to lay down a section of the print — or holding back material in order to move from one area to another.In practice, however, the printhead isn’t always capable of holding back material. Because the nozzle of a printer contains an open aperture — it doesn’t “close up” in between extrusions — it is susceptible to an issue known as oozing. This is when small amounts of material accidentally leak out from the nozzle and onto the build area, negatively affecting print quality.Oozing can then lead to a related issue known as 3D printer stringing. 3D printer stringing occurs when an oozing printhead has to make lots of travel movements, skipping from one area of the build to another. When the oozing printhead travels a lot, the oozed material forms itself into many fine strands, creating what looks like cobwebs or whiskers over the surface of the printed parts. High-temperature materials like <a href="https://www.wevolver.com/article/petg-print-settings" target="_blank" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-redirect" rel="noopener noreferrer">PETG</a> are especially susceptible to 3D printer stringing, but different filaments like PLA and ABS can also experience it.This article looks at the most effective ways to stop 3D printer stringing. It covers simple preventative maintenance steps, as well as the best <a href="https://www.wevolver.com/article/ender-3-v2-max-speed" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-redirect">slicer settings</a>.<h2 dir="ltr">Material Considerations for Preventing Stringing</h2><h3>Filament Selection</h3>Different 3D printing materials have varying properties that can influence their propensity for 3D printer stringing. The quality of the filament can also impact stringing, with low-quality filaments potentially contributing to the issue due to inconsistent diameters, impurities, or poor adhesion properties.When choosing a filament, consider its properties and how they may affect stringing. For example, materials like PETG and TPU are more prone to stringing due to their higher viscosity and flexibility compared to PLA or ABS.<h3 dir="ltr">Filament Drying</h3>One way to prevent 3D printer stringing is to ensure the printing material is in good condition. Filament that has absorbed too much moisture can cause numerous problems, including <a href="https://www.wevolver.com/article/under-extrusion" target="_blank" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-redirect" rel="noopener noreferrer">under-extrusion</a>, blobs, nozzle jams, weak parts, and stringing.[1]Wet filament can cause stringing because the extra moisture absorbed by the material ends up evaporating within the printer nozzle, causing a buildup of pressure that forces out the molten plastic in unwanted places.To prevent this issue, filament should be stored in a sealed container with a desiccant. It can also be dried out with a dedicated filament dryer, a food dehydrator, or an oven.Recommended reading: <a href="https://www.wevolver.com/article/how-to-dry-filament" target="_blank" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-valid">How to dry filament</a><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUxMTQyMzU1MDAzLURlc2ljY2FudF9zaWxpY2FfZ2VsLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib" alt="Desiccant">Keeping filament dry can prevent stringing<h2 dir="ltr">Slicer Settings to Reduce Stringing</h2><h3 dir="ltr">Retraction Settings</h3>Printer maintenance is one way of troubleshooting 3D printer stringing, but another common problem that leads to stringing is incorrect slicer settings. These settings can be easily adjusted in slicing software like Cura or Simplify3D.<a href="https://www.wevolver.com/article/cura-retraction-settings" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-valid">Adjusting retraction settings</a> is one way to fix stringing during the FDM printing process.[2] Retraction is when the nozzle pulls back a small amount of filament before it travels (moves to another part of the build area without actively depositing material). By pulling the filament deeper inside the nozzle, the melted plastic is less likely to seep out. A common test print known as a stringing tower is one way to test out the effect of retraction settings.To prevent stringing, try adjusting the following retraction settings:<ul><li dir="ltr">Retraction distance: In increments of 1 mm, increase the amount of filament retracted into the nozzle</li><li dir="ltr">Retraction speed: In increment of 5 mm/s, increase the speed at which the nozzle retracts the filament</li><li dir="ltr">Minimum travel distance: In increments of 1 mm, decrease the minimum travel distance required to enable retraction</li><li dir="ltr">Vertical lift: This retraction setting, called "Z-Hop" in Cura slicer, instructs the printhead to move vertically during travel to avoid dragging along the surface of the part. Disabling this setting can reduce stringing.</li></ul><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUxMTQyNDA4MjQ1LWhvdGVuZF9ub3p6bGUuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib" alt="Printer nozzle">Some stringing issues can be solved via retraction<h3 dir="ltr">Print Temperature</h3>Runny filament is more likely to ooze out of the 3D printer nozzle than viscous filament, so using a lower temperature in the hotend (and melting the filament slightly less) is one way to tackle 3D printer stringing.[3]Of course, using a low temperature can lead to problems of its own, particularly under-extrusion, so it is important to attain a balance between good material flow and prevention of stringing. Try reducing the print temperature in increments of 5 °C in order to find the right temperature.Temperature TowersUsing a temperature tower — a 3D printable model designed to be printed at increasing or decreasing temperatures along the Z-axis in order to indicate the ideal printing temperature — is a practical method for reducing 3D print stringing.While you can design your own tower, there are plenty of downloadable models available for <a href="https://www.thingiverse.com/thing:2493504" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-link-highlighted atomseo-status-valid">download</a> that come with <a href="https://www.wevolver.com/article/your-guide-to-3d-printing-g-code" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-valid">g-code</a> for instructing the printer to gradually adjust the printing temperature while it prints.&nbsp;After the print is finished, carefully examine the temperature tower. Each section represents the filament's behavior at different temperatures, showcasing various levels of stringing and print quality. During your examination, identify the segment of the temperature tower where stringing is minimal and print quality is optimal. Adjust your 3D printer's nozzle temperature to match this value.Recommended reading: <a href="https://www.wevolver.com/article/petg-temperature-considerations-nozzle-temperature-heated-bed-cooling" target="_blank" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-valid">PETG temperature considerations: Nozzle temperature, heated bed &amp; cooling</a><h3 dir="ltr">Print Speed</h3>Adjusting printer speed settings is another way to prevent 3D printer stringing. The two key parameters here are print speed, which determines the speed at which the printhead moves while it deposits material, and travel speed, the speed at which the printhead moves over empty space while it is not depositing any material.Print speed does not have a huge impact on stringing. However, it is a parameter closely tied to print temperature: higher print speeds require higher temperatures in order to melt the material quickly enough. Since you may have already reduced your print temperature to prevent stringing, your maximum print speed may be reduced.A more relevant speed setting is travel speed. Slow travel speeds can cause stringing, because a slow-moving printhead has more time to dangle an oozing nozzle over the parts below. By increasing travel speed, the nozzle has less time moving through open space and fewer opportunities to drip excess material onto the printed parts.<h3 dir="ltr">Wipe Distance</h3>To minimize stringing in 3D prints, adjusting the wipe distance is another option. In Cura, you can modify this through the Outer Wall Wipe Distance parameter.Typically used to conceal seams, the wipe distance setting also aids in reducing stringing. Wipe distance signifies how far the nozzle moves at a layer's end without extruding material. By setting it to 0.4 mm or higher, excess material is wiped off the wall, preventing oozing and stringing.<h3 dir="ltr" id="isPasted">Combing</h3>Combing mode can help reduce stringing in 3D prints. This setting, available in some slicers, alters the path of the print head during non-printing moves to minimize the need for retractions. Instead of retracting the filament and moving directly between two points, the print head follows the contours of the printed object, avoiding crossing over empty spaces where possible.By keeping the print head within the boundaries of the printed object, combing mode reduces the likelihood of oozing and stringing during non-printing moves. To enable and configure combing mode, consult your slicer software's documentation or settings menu. Some slicers offer different combing modes, such as "All," "No Skin," or "Within Infill," which provide varying levels of combing based on the specific needs of your print.<h2 dir="ltr">Other Ways to Reduce Stringing</h2><h3 dir="ltr" id="isPasted">Nozzle Maintenance</h3>Another common cause of 3D printer stringing is a clogged nozzle. Material passing through the FDM printer nozzle can occasionally get stuck or leave residue, and this residue must be regularly removed to ensure smooth operation of the hotend.There are several ways to unclog a nozzle. Suitable tools include a brass wire brush, a needle, a heat gun, or a dedicated cleaning filament. ABS residue can also be removed by immersing the nozzle in acetone.<h3 dir="ltr">Post-Processing</h3><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk2OTI3NzYwMjkyLWhlYXRfZ3VuLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib" alt="heat gun">Using a heat gun is a fast way to remove plastic residue caused by stringingPost-processing techniques such as sanding, polishing, and chemical smoothing can be used to remove the plastic residue left by stringing.Manual Stringing RemovalThe plastic residue stuck on the surface of a print can often be removed manually with a knife or pliers. Small bits of material that cannot be removed in this way can be removed later with a more precise method.SandingUsing sandpaper is another way to remove stringing residue, especially small protrusions that cannot easily be removed using a knife or pliers. Apply polish after sanding to achieve a smooth finish.HairdryerUsing a heat gun or a simple hairdryer is a fast and simple way to remove thin webs of plastic residue. Often, the heat will cause the strings to ball up, allowing them to be easily removed.Recommended reading: <a href="https://www.wevolver.com/article/3d-print-sanding" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-link-highlighted atomseo-status-redirect">3D print post-processing steps: supports, sanding, smoothing, more</a><h2 dir="ltr">Key Takeaways</h2>Like many common 3D printer problems, stringing can be prevented with a combination of proper 3D printer maintenance and fine-tuning of slicer settings.If you are struggling to identify the root cause of your 3D printer stringing, it is probably worth carrying out the physical maintenance — correctly storing filament and regularly cleaning the printer nozzle — before adjusting any slicer settings. Even if moist filament or a clogged nozzle is not the root cause of the stringing, carrying out these basic preventative measures is a good way to maintain print quality over future prints. Additionally, a slicer’s default settings are precisely optimized for individual print materials and typically do not require radical alteration in order to deliver good results.That being said, adjustment of print parameters within the slicing software gives total control over the print process and in many cases is necessary to fix stringing. In particular, retraction and temperature settings are often the key to unlocking successful prints without oozing or stringing issues.Finally, it is important to remember that stringing and other surface defects are not always critical and can often be mitigated via post-processing techniques like sanding.<h2 dir="ltr" id="isPasted">Frequently Asked Questions</h2>What is 3D printer stringing?&nbsp;3D printer stringing is a common issue that occurs when thin strands of filament are left behind between different parts of a printed object, creating an unwanted web-like appearance.How can I prevent stringing in my 3D prints?&nbsp;Preventing stringing involves adjusting print settings such as retraction, temperature, and print speed, as well as using high-quality filament, maintaining your printer, and storing filament properly.What is the role of retraction in preventing stringing?&nbsp;Retraction is the process of pulling the filament back slightly during non-printing moves to prevent oozing, which can cause stringing. Adjusting retraction settings can help reduce or eliminate stringing.How does printing temperature affect stringing?&nbsp;High printing temperatures can cause the filament to become more fluid, increasing the likelihood of oozing and stringing. Optimizing the printing temperature for your specific filament material can help reduce stringing.<h2 dir="ltr">References</h2>[1] Kwon S, Lee S, Kim Y, Oh Y, Lee S, Kim J, Kwon J. <a href="https://www.hindawi.com/journals/js/2020/8846466/" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-link-highlighted atomseo-status-redirect">A Filament supply system capable of remote monitoring and automatic humidity control for 3D printer</a>. Journal of Sensors. 2020 Jun 24;2020.[2] <a href="https://support.ultimaker.com/hc/en-us/articles/360012016280-How-to-fix-stringing" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-link-highlighted atomseo-status-redirect">How to fix stringing</a> [Internet]. Ultimaker Support. [cited 2022 Apr 25].[3] Paraskevoudis K, Karayannis P, Koumoulos EP. <a href="https://www.mdpi.com/2227-9717/8/11/1464" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-link-highlighted atomseo-status-valid">Real-time 3D printing remote defect detection (stringing) with computer vision and artificial intelligence</a>. Processes. 2020 Nov;8(11):1464.

3D printer stringing is a common problem in FDM printing

Prints covered in plastic cobwebs? Like many FDM users, you’re probably the victim of 3D printer stringing. Fortunately, stringing can be prevented via printer maintenance and adjustment of slicer settings.

3D Printer Stringing: How To Fix It

It is always discouraging when a 3D print comes off the build platform with visible defects and imperfections. Whether it’s a 3D print that has become unstuck from the print bed and <a href="https://www.wevolver.com/article/3d-print-warping" target="_blank">suffered from warping</a>, or a <a href="https://www.wevolver.com/article/3d-printer-stringing" target="_blank">print with stringing</a> or other surface irregularities: a ruined print amounts to wasted time and material costs. We’ve already addressed <a href="https://www.wevolver.com/article/3d-print-not-sticking-to-print-bed-heres-the-solution" target="_blank">how to fix problems like poor first layer bed adhesion</a>—which can lead to 3D print warping—so in this article we’ll be focusing on another type of defect: 3D print blobs &amp; zits. Keep reading to understand what causes blobs and zits and how to prevent them from happening in the future.<h2 dir="ltr">Identifying Blobs &amp; Zits on a 3D Print</h2>In 3D printing, blobs (also known as zits) are extrusion irregularities that appear on the surface of a 3D printed part. Blobs and zits are distinguished from other surface defects, like <a href="https://www.wevolver.com/article/z-banding-rooting-out-the-cause-and-fixing-the-3d-printing-defect" target="_blank">Z-banding</a>, by their inconsistency. Whereas Z-banding produces a ribbed pattern on the 3D print, blobs are quite literally bits of oozed filament that stick out from the print’s surface.&nbsp;Blobs and zits can significantly degrade the quality of 3D prints, affecting both their appearance and functionality. These imperfections often create visible blemishes, detracting from the overall aesthetic value of the print. Furthermore, they can disrupt the fit and alignment of components, especially in cases where precision is essential, such as mechanical parts or modular designs. They key impacts of blobs and zits are:<ul><li dir="ltr">Weakened Structure:<ul><li dir="ltr">Blobs and zits can introduce inconsistencies in layer adhesion, reducing the strength and durability of the print.</li><li dir="ltr">They can also create stress points, making the print more prone to cracking or breaking under load.</li></ul></li><li dir="ltr">Poor Aesthetics:<ul><li dir="ltr">Surface imperfections like blobs and zits are especially noticeable on smooth or curved surfaces, diminishing the visual appeal.</li><li dir="ltr">These defects often require post-processing to correct, such as sanding, filling, or painting.</li></ul></li><li dir="ltr">Potential for Part Failure:<ul><li dir="ltr">Blobs and zits may interfere with moving parts, causing mechanical issues.</li><li dir="ltr">They can can disrupt tolerances, leading to misalignment or improper functioning of assembled pieces.</li></ul></li></ul><h2 dir="ltr">What causes 3D printing blobs and zits?</h2>There are a number of potential issues that can be causing blobs and zits, all of which can be fixed by fine tuning printer settings.[1] Below are the leading causes of 3D print blobs and zits.<h3 dir="ltr">Over-extrusion</h3>3D print blobs &amp; zits are primarily caused by <a href="https://www.wevolver.com/article/over-extrusion" target="_blank">over-extrusion</a> and the motion of the filament extruder. If, for example, you are printing a part with a circular perimeter, blobs can occur when the print head returns to its starting position. The material builds up at this point, which can result in the formation of a filament blob. Similarly, if the 3D printer extruder starts and stops several times over the course of a 3D print job, blobs and zits can also occur.&nbsp;<h3 dir="ltr">Retraction</h3>Blobs and zits can also be caused by 3D printer nozzle retraction. In the FDM 3D printing process, retraction is a technique in which the hot end briefly pulls filament back instead of extruding it out. This method is used to reduce unwanted material extrusion, like stringing, as the print head moves to a new print location. However, if the <a href="https://www.wevolver.com/article/cura-retraction-settings" target="_blank">retraction settings</a> on your 3D printer are not optimized, the process may actually have a negative effect, causing blobs or zits.<h3 dir="ltr">Nozzle Temperature</h3>Other 3D printer settings, such as nozzle temperature, can also increase the risk of blobs. For example, if the nozzle temperature is too high, filament can come oozing out too quickly and create defects on the print surface. (On the flip side, if nozzle temperatures are too low, it can cause other issues like clogs, poor layer bonding, poor dimensional accuracy, and structural weaknesses.)<h3 dir="ltr">Print Speed</h3>Printing speeds can also be a factor if they are too fast and don’t allow for sufficient cooling time between layers. In other words, if new layers are deposited before the underlying layer of filament has had time to adequately solidify, it can be squished and deformed by the weight of the layers above it.Recommended reading: <a href="https://www.wevolver.com/article/3d-print-warping" target="_blank">What Causes 3D Print Warping and How to Prevent It</a><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUwOTQ1OTQzOTE0LTNkX3ByaW50aW5nLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" width="624" height="459" class="fr-fic fr-dii" alt="3D printer nozzle extruding red filament" style="width: 690px;">If the 3D printer nozzle is too hot it can cause over-extrusion resulting in blobs and zits.<h2 dir="ltr" id="isPasted">What can you do to prevent 3D printing blobs?&nbsp;</h2>Fortunately, there are a number of ways to minimize the risk of blobs and zits in FDM 3D printing. Below are five key strategies you can try to prevent the 3D printing defects from occurring.<h3 dir="ltr">Adjust Retraction Settings</h3>In slicer software, you can adjust retraction settings to control how much filament is pulled back into the nozzle and at what point this happens. Finding the right retraction settings can minimize material buildup either at the beginning of the print head’s path along the part perimeter or as it completes a layer and rejoins its starting position (for this, see coasting settings below).In general, it is advisable to use a smaller retraction distance (this is the amount of filament pulled back into the nozzle). This is because if too much filament is retracted, air can also be pulled into the nozzle. When the printhead then goes to extrude filament, the air is heated along with the filament, which can cause extrusion inconsistencies, like blobs and bubbles on the print surface. Too little retraction, however, can lead to over-extrusion and defects like stringing and blobs and zits. It’s all about finding the sweet spot, so you might need to try out a few different retraction distance settings. The amount of retraction will also depend on the type of FDM 3D printer: systems with direct drive extruders only require a retraction distance between 0.5 mm to 2 mm. Bowden extruder systems, on the other hand, can require higher retraction values, as much as 15 mm.[2]Retraction speed is also worth mentioning. This setting controls how quickly the filament is pulled back into the nozzle. If the retraction speed is too slow, your print may suffer from oozing filament. A standard range for retraction speed is between 20 mm/second and 100 mm/second.<h3 dir="ltr">Activate Coasting Settings</h3>Coasting is a setting built in to most 3D printing slicer programs, including Simplify3D and Cura. Coasting is often found under retraction settings and controls if the print head stops extruding filament at the end of each layer perimeter. Coasting is therefore helpful in reducing blobs or zits that are caused by filament buildup when the extruder comes back to its starting point.When you activate coasting, the slicing program will essentially tell the 3D printer nozzle when to stop extruding filament—usually this will be triggered a fraction of a millimeter before the printhead completes the part’s perimeter. Coasting therefore anticipates that there will be over-extrusion when the printhead stops extruding and stops the buildup of material at these starting/ending locations. Coasting also helps to relieve pressure inside the nozzle that causes over-extrusion. It is advisable to begin with a smaller coasting distance, such as 0.2 mm, and increase the value incrementally until you no longer see blobs appearing on the part’s surface.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUwOTQ2MDg3MjYxLTNkX3ByaW50dGVyX3NldHRpbmdzLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" width="624" height="448" class="fr-fic fr-dii" alt="3D printer extruding yellow filament">Coasting and retraction settings can help to minimize blobs and zits if used properly.<h3 dir="ltr">Wiping and Shell Settings</h3>Another group of <a href="https://www.wevolver.com/article/ender-3-v2-max-speed" target="_blank">slicer settings</a> that can help minimize blobs and zits are the wipe parameters. With wiping activated, the 3D printer will drag the nozzle at the end of every printed layer along the outer wall of the printed part to remove any material buildup. With this setting, it is common for retraction to happen simultaneously, which can help prevent blobs and zits. A typical wipe distance—the length that the nozzle will wipe along the outer wall—is 0.4 or 0.5 mm. Wiping can also help to reduce the appearance of the z-seam.Because 3D print blobs and zits are primarily an aesthetic issue on the outer shell of a part, tuning your 3D printer’s shell parameters can improve the overall print quality by preventing or covering up blobs and zits. For instance, simply activating the “outer before inner wall” setting in your slicer can improve the quality of the part’s outer shell. This setting tells the 3D printer to extrude the outer layers of a part before printing the inner structure and infill. Not only can this reduce the risk of blobs and blemishes, it can also improve the dimensional accuracy of your print.<h3 dir="ltr">Adjust Print Temperature and Speed</h3>As we saw, a too-hot print head can lead to over-extrusion, and rapid printing speeds can lead to defects like blobs and zits due to lack of cooling. Therefore, lowering the print temperature and print speed can help to reduce the risk of blobs and zits. The temperature of your nozzle will depend on the type of filament you are 3D printing. For example, PLA filament typically requires <a href="https://www.wevolver.com/article/pla-bed-temperature" target="_blank">a nozzle temperature of between 200-210 °C.</a>[3] If blobs are still occurring in this range, try lowering the nozzle temperature in 5°C increments.Reducing the print speed can also reduce the occurrence of blobs and zits. In general, a lower printing speed can improve print quality because the nozzle has more time to deposit the filament and the extruded layer has more time to cool before the next layer is applied. Try reducing your print speed by 5 to 10 mm/s to see if that helps minimize the appearance of blobs.Recommended reading: <a href="https://www.wevolver.com/article/abs-bed-temperature" target="_blank">ABS print temperature considerations: Nozzle, bed, enclosure</a><h3 dir="ltr">Adjust Fan Settings</h3>In addition to finding the right print head temperature, you can also reduce the risk of 3D print blobs and zits by increasing your 3D printer’s fan speeds. (Or, if your 3D printer doesn’t have a built-in fan, it can help to integrate one.) A fan helps to regulate the temperature of the 3D printing environment and can help prevent overheating.&nbsp;This, in turn, ensures that the layers of melted thermoplastic that are deposited onto the print bed are cooled and solidified at a controlled rate. Because over-extrusion and squished print layers are two potential causes of blobs and zits, increased cooling in the print chamber using fans can promote better quality prints. Of course, over-cooling your print environment can also impact layer adhesion—it’s all about finding a balance.Here’s a table summarizing the five aforementioned strategies:<div dir="ltr" align="left"><table><tbody><tr><td>Strategy</td><td>Description</td><td>Adjustment Range/Notes</td></tr><tr><td>Adjust Retraction Settings</td><td>Controls how much filament is pulled back into the nozzle to reduce material buildup.</td><td>Retraction distance: 0.5 mm to 2 mm for direct drive, and up to 15 mm for Bowden. Retraction speed: 20–100 mm/s.</td></tr><tr><td>Activate Coasting Settings</td><td>Stops filament extrusion slightly before the printhead completes a layer perimeter to reduce buildup.</td><td>Start with 0.2 mm coasting distance and adjust as needed.</td></tr><tr><td>Wiping &amp; Shell Settings</td><td>Wiping removes excess filament from the nozzle; shell settings help cover blemishes.</td><td>Wipe distance: 0.4–0.5 mm. Shell before infill for improved finish.</td></tr><tr><td>Adjust Print Temperature &amp; Speed</td><td>Lower temperatures and slower speeds reduce over-extrusion and give filament time to cool.</td><td>Lower nozzle temperature by 5°C increments. Speed: Reduce by 5–10 mm/s.</td></tr><tr><td>Adjust Fan Settings</td><td>Increased fan speed helps cool the print layers faster, preventing overheating and over-extrusion.</td><td>Increase fan speed but avoid over-cooling to maintain layer adhesion.</td></tr></tbody></table></div>Each of these strategies targets specific factors contributing to blobs and zits, improving overall print quality.<h2 dir="ltr">Conclusion</h2>In the end, the first step to preventing 3D printing defects like blobs and zits is to understand where they come from. Factors like temperature, calibration, and slicer settings can be the cause and solution to blobs and zits. So if you’re experiencing imperfections in your 3D print’s outer shell, be sure to play with your retraction, coasting, and wipe settings, as well as adjust your nozzle print temperature. It may take some time to find the right combination of settings for a given material, so start out with a small test print. The results will be worth it!&nbsp;<h2 dir="ltr">Frequently Asked Questions (FAQs)</h2>Q: How can I identify blobs and zits on a 3D print? A: Blobs and zits appear as small, raised lumps of excess filament on the print's surface, which are often irregular in shape. Look for uneven layers, especially around corners, edges, or smooth surfaces, where the extruder may have released too much material.Q: How do blobs and zits affect the quality of a 3D print? A: Blobs and zits can weaken the print’s structure by causing poor layer adhesion, making it more prone to cracking or breaking. They also reduce the visual appeal of the print and can interfere with part alignment, potentially leading to mechanical issues or misfit components in assembled designs.Q: What causes blobs and zits in 3D printing?A: Blobs and zits in 3D prints are often caused by over-extrusion, improper retraction settings, high nozzle temperature, or excessive print speed. These issues can lead to excess filament being deposited at certain points, causing raised lumps or irregularities on the surface of the print.Q: How does over-extrusion cause blobs and zits?A: Over-extrusion happens when too much filament is pushed out during printing, especially at start/stop points or circular perimeters. This results in material building up and forming blobs or zits, particularly when the print head returns to its starting position or moves over areas multiple times.Q: How do retraction settings affect blobs and zits in 3D prints? A: Incorrect retraction settings can lead to blobs and zits when the nozzle pulls filament back too much or not enough during travel moves. If retraction is not optimized, excess material may be extruded at the wrong time, causing unwanted surface defects.Q: What is coasting, and how can it help prevent blobs and zits?A: Coasting is a setting that stops filament extrusion just before the printhead completes a layer. This prevents excess material from building up at the start/stop points of a print, minimizing blobs or zits. Start with a small coasting distance, such as 0.2 mm, and increase it incrementally until the surface imperfections are reduced.Q: How can adjusting print temperature and speed reduce blobs and zits?A: Lowering the print temperature and speed can help prevent blobs and zits. If the nozzle is too hot, filament may ooze out too quickly, causing defects. Try reducing the temperature in 5°C increments if blobs persist. Slower print speeds allow the material to cool properly, reducing the risk of squished layers or over-extrusion, both of which contribute to blobs and zits.<h2 dir="ltr">References</h2>[1] MorCh N. Analysis of the Effects of Basic Printer Settings on PLA 3D Prints (Doctoral dissertation, Massachusetts Institute of Technology).[2] Simplify3D, 2022. “Stringing or Oozing.” [Internet] <a href="https://www.simplify3d.com/support/print-quality-troubleshooting/stringing-or-oozing/" target="_blank">https://www.simplify3d.com/support/print-quality-troubleshooting/stringing-or-oozing/</a> [Accessed April 20, 2022].[3] Ultimaker, May 28, 2021. “How to Print with Ultimaker PLA.” [Internet] <a href="https://support.ultimaker.com/hc/en-us/articles/360011952740-How-to-print-with-Ultimaker-PLA" target="_blank">https://support.ultimaker.com/hc/en-us/articles/360011952740-How-to-print-with-Ultimaker-PLA</a> [Accessed April 21, 2022]

Prevent 3D print blobs and zits by adjusting temperature and slicer settings.

Surface imperfections on a 3D print can be frustrating but they’re not insurmountable. Here is how to prevent and fix 3D print blobs and zits by adjusting 3D printer and slicer settings.

How to Prevent 3D Print Blobs & Zits

When an FDM 3D printer works properly, it extrudes thermoplastic filament and deposits it in a sequence of two-dimensional layers. Sometimes, however, the 3D printer is unable to extrude the right amount of material, leading to noticeable issues like thin layers, missing layers, gaps, holes, and weakness of the printed part.The problem of a 3D printer failing to supply adequate material is called under extrusion, and it happens to all printer users from time to time. Generally, under-extrusion is not a sign of any major hardware problem with the 3D printer, but the phenomenon can have a range of causes, which makes it tricky to diagnose the underlying issue. Under-extrusion can usually be solved by printer maintenance — cleaning the nozzle, for instance — or by adjustment of print settings.This article examines what can cause under-extrusion and offers solutions for how to fix under-extrusion problems, both through physical maintenance of the 3D printer and adjustment of print parameters.<h1 dir="ltr" id="isPasted">Under-Extrusion or Over-Extrusion?</h1>In 3D printing, both over-extrusion and under-extrusion are problems related to the amount of filament extruded by the printer, but they manifest in different ways, affecting the print quality and structural integrity of the object being printed.Under-extrusion occurs when the 3D printer doesn't supply enough filament to create the intended layers of the object. This can result in gaps, weak structures, and a rough surface finish. Under-extrusion can happen due to various factors such as a partially clogged nozzle, improper slicing settings, insufficient filament tension, or a worn-out drive gear. It's akin to a pen running out of ink while drawing; the printer doesn't have enough material to complete the designated paths, leading to incomplete prints with visible defects.Over-extrusion, on the other hand, happens when the printer supplies more filament than necessary for the specified print. This excess material can cause issues like blobbing, <a href="https://www.wevolver.com/article/3d-printer-stringing" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted atomseo-status-valid">stringing</a> between printed parts, and a loss of fine details. Over-extrusion often occurs due to incorrect <a href="https://www.wevolver.com/article/ender-3-v2-max-speed" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted atomseo-status-valid">slicer settings</a>, where the printer is instructed to extrude more material than required. It can also be caused by a misaligned printer, incorrect nozzle diameter settings, or a too-high printing temperature. Over-extrusion is comparable to using a pen that leaks blotches of ink.Recommended reading: <a href="https://www.wevolver.com/article/over-extrusion" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted atomseo-status-valid">Dealing with Over Extrusion in 3D Printing</a><h1 dir="ltr">Fixing Under-Extrusion with Printer Maintenance</h1>There are several potential causes of under-extrusion, and many of these relate to the condition and cleanliness of the 3D printer. Clogs, dirtiness, and incorrect calibration can all lead to extrusion problems, so learning how to identify these basic issues is an easy way to prevent under-extrusion.<h2 dir="ltr">Nozzle&nbsp;</h2>FDM printers must feed a spool of thermoplastic filament through various parts of the machine, and there are a few areas where the material can leave a buildup of residue and cause clogging.If under-extrusion starts happening suddenly (and you haven’t made any changes to the print setup) then a clogged nozzle is a likely culprit. There are few ways to clean and remove blockages from a 3D printer nozzle, including:<ul><li dir="ltr">Using a brass wire brush (not steel) to remove debris</li><li dir="ltr">Using a needle to remove internal debris</li><li dir="ltr">Running a special cleaning filament through the printer and performing a cold pull (letting the filament cool while it is in the nozzle, then pulling it out)[1]</li><li dir="ltr">Removing the nozzle and immersing it in a chemical such as acetone (best for ABS)</li><li dir="ltr">Removing the nozzle and using a heat gun to melt any filament left inside</li></ul>Another hot end issue that can cause under-extrusion is a worn-out PTFE coupler — a component found on common FDM machines like the Creality Ender 3 and Ultimaker 2. The coupler should be replaced if it becomes deformed by heat.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUwNTIwNzQzNjEzLW5venpsZS5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 300px;" class="fr-fic fr-dib" alt="Clogged nozzle">Clogged nozzles can cause under-extrusion<h2 dir="ltr">Bowden tube</h2>The hot end isn’t the only place where clogs can occur. Bowden tubes can also get clogged up with filament, and this can equally cause under-extrusion, as not enough filament is able to pass through.A clogged Bowden tube is often the result of heat creep: when the tube gets hotter than it’s supposed to be and melts the filament before it reaches the hot end. To clean the tube, first remove it, then push a small piece of sponge or cloth through it using a piece of filament.<h2 dir="ltr">Drive gears and motor</h2>Drive gears are responsible for gripping the filament and pushing it into the hot end where it melts and forms the print layers. Over time, these gears can accumulate debris, such as dust or leftover filament particles, causing the grip on the filament to weaken. Regular cleaning and inspection of the drive gear can prevent this. Additionally, the gear's teeth might wear out, reducing their effectiveness. Replacing worn-out gears ensures a proper grip on the filament, enhancing the extrusion process.One reason why debris might accumulate in the extruder gears is incorrect tension on the filament. The tension must be great enough to cause small marks in the filament but not so great that the gears strip chunks out of the material, resulting in thin and weak layers.<h2 dir="ltr">Cooling fan</h2>Bowden tubes can get clogged when filament melts too early on its journey to the nozzle. This is sometimes caused by issues with the printer’s cooling apparatus: if the fan is not able to regulate temperature, the material can overheat, leading to under-extrusion. The cooling fan may cease to function properly if it is installed improperly or if jamming has occurred. Check it for stray pieces of filament or other debris, and remove these items with a brush.<h2 dir="ltr">Filament</h2>Problems with the 3D printing material can cause under-extrusion. These problems can include damp filament, knots in the filament, and incorrect material settings (discussed in the print settings section).Damp filament can indirectly cause under-extrusion. This is because filament expands when it absorbs too much moisture, and a bloated strand of filament can cause clogging within the nozzle. Fortunately, it is easy to keep filament dry by storing it correctly and, if necessary, drying it out thoroughly before use. The link between moist filament and under-extrusion is particularly noticeable with flexible filaments like TPU.[2]Filament can also become tangled or knotted, especially when it is regularly removed from the 3D printer and replaced. Using a filament clip can help to prevent this issue.Recommended reading: <a href="https://www.wevolver.com/article/how-to-dry-filament" target="_blank" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-valid atomseo-link-highlighted">How to dry filament</a><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUwNTIwNzk1MzY5LWZpbGFtZW50LmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 300px;" class="fr-fic fr-dib" alt="Tangled filament">Tangled filament can lead to under-extrusion<h2 dir="ltr">Firmware and software updates</h2>Under-extrusion and myriad other issues can be caused by minor technical bugs, which tend to pop up when using outdated 3D printer firmware and slicer software. Install updates when they become available.<h1 dir="ltr">Fixing Under-Extrusion with Print Settings</h1>Cleaning, maintenance, calibration, and firmware updates can all help to prevent under-extrusion and related issues. Sometimes, however, adjustment of print settings (in slicer software like Cura, for example) is all it takes to fix under-extrusion.<h2 dir="ltr">Nozzle temperature</h2>A common and easily resolvable cause of under-extrusion is insufficient nozzle temperature. If the hot end does not melt the material enough, it can struggle to push enough of it through the nozzle.Slicers usually have default printing profiles for certain filaments. But it may be necessary to adjust the printing temperature by 5 or 10 °C to achieve the best results. Also note that non-brass nozzles such as hardened steel nozzles require higher temperatures, as they do not retain heat well.<h2 dir="ltr">Flow rate</h2>Flow rate, the amount of plastic extruded per second, can be a cause of under-extrusion. When the set flow rate is higher than the actual capabilities of the printer, parts may come out under-extruded. Flow rate is defined by <a href="https://www.wevolver.com/article/3d-printer-nozzle-size" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-valid atomseo-link-highlighted">layer height, nozzle diameter</a>, and printing speed.In slicers such as Cura and Simplify3D, flow rate can be most easily adjusted via the extrusion multiplier parameter, which is usually set at around 90% (or 0.9) for PLA and 100% (or 1.0) for ABS.[3] When under-extrusion occurs, this value can be increased in small increments until the problem goes away.&nbsp;Note that the default flow rate will be incorrect if the filament diameter has not been set properly. For example, if you are using 2.85 mm filament but the slicer thinks you are using 1.75 mm, the printer will not feed through enough material at once. For the highest level of accuracy, you can use calipers to measure the exact diameter of your material.<h2 dir="ltr">First-layer calibration</h2><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjk4MzkwNDQ3ODk1LTNEX3ByaW50ZXIuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 300px;" class="fr-fic fr-dib" alt="first layer">Printing the first layer too close to the bed can cause under-extrusionUnder-extrusion can be caused by printing the first layer too close to the build surface. Users sometimes calibrate the first layer very close to the build surface in order to improve adhesion, but this can have the negative effect of actually obstructing the nozzle and preventing the natural flow of filament [4]First-layer calibration should strike a balance between adhesion and flow. If the print does not stick to the print bed, then a change in build surface material or use of an adhesive should be considered instead.Recommended reading: <a href="https://www.wevolver.com/article/how-to-clean-3d-printer-beds-glass-pei-adhesive" target="_blank" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-valid atomseo-link-highlighted">How to clean 3D printer beds: Glass, PEI, adhesive</a><h2 dir="ltr">Retraction</h2>Retraction is when the printer nozzle pulls back a bit of filament before it travels. Retraction can prevent issues like oozing and stringing, but incorrect <a href="https://www.wevolver.com/article/cura-retraction-settings" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-valid atomseo-link-highlighted">retraction settings&nbsp;</a>can cause under-extrusion issues.When using significant retraction, under-extrusion may occur immediately after travel (when the printhead hops from one part of the print to another without depositing material), as the interruption of material deposition causes a loss of pressure. Under-extrusion may be mitigated by increasing the retraction extra prime amount, which increases pressure in the nozzle after retraction.<h1 dir="ltr">Troubleshooting Under-Extrusion Checklist</h1>Although under-extrusion is difficult to stamp out altogether, carrying out regular maintenance can help to prevent the issue in most cases. And even if the problem turns out to be a slicer-related issue rather than a hardware issue, it never hurts to clean your nozzle and other hardware components anyway.If under-extrusion occurs, attempt the following:<ul><li dir="ltr">Check nozzle and Bowden tube for clogs</li><li dir="ltr">Clean gears, motor, and cooling fan</li><li dir="ltr">Store filament in a secure, dry place and check the spool for knots and overlap</li><li dir="ltr">Update printer firmware</li><li dir="ltr">Try increasing nozzle temperature</li><li dir="ltr">Try increasing flow rate</li><li dir="ltr">Try printing first layer further from print surface</li><li dir="ltr">Try adjusting retraction settings</li></ul><h1 dir="ltr" id="isPasted">Conclusion</h1>In summary, resolving under-extrusion issues in 3D printing demands a multi-faceted approach. Regular nozzle maintenance, involving clearing clogs and debris, ensures a consistent filament flow. Proper filament drying, especially for moisture-sensitive materials, preserves filament integrity and prevents irregular extrusion. And adjusting settings like printing temperature according to the filament type can prevent overheating and nozzle jams. By performing the necessary maintenance and adjustments, enthusiasts and professionals can significantly enhance the quality of their prints.<h1 dir="ltr" id="isPasted">Frequently Asked Questions</h1>What is under-extrusion?Under-extrusion is a <a href="https://www.wevolver.com/article/3d-printing-problems" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-internal atomseo-link-follow atomseo-status-valid atomseo-link-highlighted">3D printing issue</a> where the printer doesn't supply enough filament, resulting in incomplete layers, weak structures, and rough surface finishes in printed objects.How can I diagnose under-extrusion?Diagnosing under-extrusion involves examining the print for gaps between lines, inconsistent layer adhesion, or a visibly weak structure. It often manifests as visible spaces or irregular patterns in the printed layers.How does flow rate affect under-extrusion?Flow rate, which determines the amount of filament extruded per second, directly influences under-extrusion. If the flow rate is too low, insufficient filament is supplied, leading to under-extruded prints; if it's too high, it can cause over-extrusion issues.Why does wet filament cause under-extrusion?Wet filament absorbs moisture from the air, leading to its physical properties changing. When this filament is extruded, the moisture turns into steam, causing irregular flow and nozzle blockages, resulting in under-extrusion during printing.<h1 dir="ltr">References</h1>[1] <a href="https://support.ultimaker.com/hc/en-us/articles/360011620800-How-to-perform-a-hot-and-cold-pull" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted">How to perform a hot and cold pull</a> [Internet]. Ultimaker. 2020 [cited 2022 Apr 19].[2] Bruère VM, Lion A, Holtmannspoetter J, Johlitz M. <a href="https://link.springer.com/article/10.1007/s40964-022-00300-y" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted">Under-extrusion challenges for elastic filaments: The influence of moisture on additive manufacturing</a>. Progress in Additive Manufacturing. 2022 Jun;7(3):445-52.[3] <a href="https://www.simplify3d.com/support/print-quality-troubleshooting/under-extrusion/" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted">Under-Extrusion</a> [Internet]. Simplify3D. 2019 [cited 2022 Apr 19].[4] <a href="https://help.prusa3d.com/en/article/under-extrusion_2007/" target="_blank" rel="noopener noreferrer" class="atomseo-link atomseo-link-external atomseo-link-follow atomseo-status-redirect atomseo-link-highlighted">Under-extrusion</a> [Internet]. Prusa Knowledge Base. 2021 [cited 2022 Apr 19].

Under-extrusion can be fixed with maintenance and optimized print settings

One of the most common issues with FDM 3D printing is under-extrusion, which manifests itself as thin or missing layers or visible holes in the structure of the part.

How to Fix Under Extrusion: Maintenance and Print Settings

First-layer adhesion is critical to ensuring that your 3D print will be a success. But achieving good bed adhesion can be easier said than done. Corners unstick from the 3D printer’s build surface, <a href="https://www.wevolver.com/article/3d-print-warping" target="_blank">warping occurs</a>, and ultimately parts fail. Moreover, adhesion problems can be caused by a number of factors or any combination of issues, including bed leveling, bed temperature, extruder temperature, build plate deficiencies, <a href="https://www.wevolver.com/article/ender-3-v2-max-speed" target="_blank" rel="noopener noreferrer">slicer settings</a>, and more. Fortunately, there are several steps you can take to resolve the problem of a 3D print not sticking to print bed. In this article, we’re looking at the importance of bed adhesion when 3D printing as well as several different methods you can use to improve adhesion and, ultimately, print results.<h2>The Importance of Bed Adhesion</h2>Bed adhesion plays a crucial role in the success of a 3D print. When the first layer of a print adheres well to the bed, it provides a solid foundation for the rest of the print. This foundation is essential for ensuring a print's structural integrity and dimensional accuracy as well as minimizing the risk of defects.If good bed adhesion is not achieved, it can lead to a variety of issues, such as warping, curling, or part detachment of the print from the bed. In some cases, poor adhesion can even damage the printer itself, as detached prints may collide with the nozzle or other components. By understanding what factors influence bed adhesion, you can significantly improve the success rate of your 3D prints and minimize the risk of print failures due to poor bed adhesion.<h2>Method #1: Level the Bed</h2>One of the main reasons a 3D print may not stick to the print bed is poor bed leveling. If one side of your printer bed is even marginally higher or lower than the other side, it will affect the quality of your 3D print and how well the first layers of the print adhere to the build surface. In short, this is because the nozzle will be further away from part of the print bed and filament won’t be deposited evenly. When the nozzle is too close, it can cause the filament to be squished and spread out, resulting in thin layers and poor adhesion. Conversely, when the nozzle is too far away, the filament may not make sufficient contact with the bed, leading to weak adhesion.<a href="https://www.wevolver.com/article/filament-maker-two-3devos-industrial-grade-extruder-for-rd-and-material-innovation" target="_blank" rel="noopener noreferrer"><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1758709027722-SEO+ARTICLE+EMBED.png" style="width:100%px" class="fr-fic fr-dib" /></a>Ensuring your 3D printed bed is level can solve adhesion problems. Depending on the 3D printer hardware you have, you might be able to level the bed automatically or you may have to do it manually. If you are adjusting the bed level manually, one of the most popular methods for leveling a print bed is to use a piece of paper.  <iframe id="687fce2deed32030e1657d55" width="250" height="440" src="https://wevolver.com/iframe/specs/filament-maker-two?iframe=true" frameborder="0" scrolling="no"></iframe>Simply bring your 3D printer nozzle very close to the print surface and place a sheet of paper in between the nozzle and the build plate. Gradually raise the corner of the print bed using your machine’s leveling knobs until there is a bit of resistance when pulling the paper out. Repeat this on all corners of the print bed. You can also print a test <a href="https://www.wevolver.com/article/brim-vs-raft" target="_blank" rel="noopener noreferrer">skirt</a> after using the paper method to check the evenness of the first print layers. This is also a good idea because it allows you to check the level of the print bed while the machine is hot.<h2>Method #2: Change the Z-Offset</h2>The distance between the 3D printer nozzle and the build platform, known as the <a href="https://www.wevolver.com/article/z-offset" target="_blank" rel="noopener noreferrer">Z-offset</a>, may also be causing adhesion problems. In other words, if the nozzle is too close to the build surface, the first layer will be squished and won’t be evenly extruded; if it’s too far away, the filament extrusion also won’t stick to the build platform properly. The good news is that you can encourage good adhesion by positioning the 3D printer nozzle at the right distance.The z-offset can be adjusted in slicing software by changing the measurement values. Once the value is set, the z-axis will align itself accordingly to the print bed. If you are having adhesion problems, changing the z-offset should be used as a last resort. Where this method is most helpful is in situations where you are working with a thick build plate or if you are printing on a substrate. When experimenting with nozzle distance, make small adjustments and observe the results on test prints. Look for signs of proper adhesion, such as a smooth and even first layer, and adjust the nozzle distance accordingly until the desired adhesion is achieved.<h2>Method #3: Clean the Print Bed</h2>It is imperative that your print surface be clean before you start 3D printing. If there are any inconsistencies, like leftover glue or filament stuck to the print surface area, it can cause first layer adhesion problems. The <a href="https://www.wevolver.com/article/how-to-clean-3d-printer-beds-glass-pei-adhesive" target="_blank">best cleaning technique for a print bed</a> depends entirely on the build plate material. If you are working with a glass print bed that has filament or adhesive residue on it, start by removing the glass bed from the 3D printer and scraping the residue off using a dry scraper. From there, you can wash the plate with soapy water or window cleaner. It is also a good idea to give your glass build plate a final wipe using Isopropyl alcohol (IPA) or acetone. These cleaning products will help to remove any remnants of grease without damaging the glass surface. You can also follow these cleaning steps with a removable borosilicate glass print bed.A PEI build plate can also be cleaned with water and soap or IPA to remove residue. To ensure the thermoplastic bed surface remains smooth in the long-term, you can also wipe it down with acetone once a month or so. It is important not to use acetone on a thermoplastic build surface too often as it can erode the material. Ultimately, a clean, smooth print surface can help the critical initial layer of a print to adhere.Recommended reading: <a href="https://www.wevolver.com/article/how-to-clean-3d-printer-beds-glass-pei-adhesive" target="_blank" rel="noopener noreferrer">How to clean 3D printer beds: Glass, PEI, Adhesive</a><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjUwMjg3NDIzNjcwLTNkX3ByaW50ZXJfbm96emxlLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" width="624" height="437" class="fr-fic fr-dii" alt="3D printer nozzle and print bed" />A clean build surface will help to promote good 3D printing bed adhesion.<h2 id="isPasted">Method #4: Increase Bed &amp; Nozzle Temperature</h2>Temperature settings play a big part in the final quality of a 3D print. Thermoplastic filaments like ABS and PETG harden as they cool, but if printed layers cool too quickly, the materials can also shrink, which causes layers to pull away from the print bed and warp. Using a heated bed, especially for higher temperature materials, can therefore help to improve bed adhesion. More than that, choosing the right bed temperature and nozzle temperature for different types of filament can also improve print outcomes. For example, ABS filament prints best with a build surface heated to between 90°C and 110°C and a nozzle temperature between 230°C and 260°C.[1] PLA, for its part, prints best with a heated bed of between 60°C and 80°C and with a nozzle temperature of 190°C and 210°C.[2]Keep in mind that the optimal bed temperature may vary depending on factors such as the specific filament brand, bed surface material, and ambient room temperature. Therefore, it may be necessary to experiment with different bed temperatures within the recommended range to find the best setting for your specific setup. Another helpful tip to improve adhesion is to print the first few layers at a slightly higher temperature to ensure that they will stick. After those first layers, you can lower the bed temperature back to the recommended degree for the rest of the print. <h2>Method #5: Use a Bed Adhesive</h2>Another reliable way to improve your 3D printer bed adhesion is to apply an adhesive directly to the build platform before you start printing. There are a number of adhesive products developed specifically for 3D printing, such as Magigoo and Stick Stick. Some of these dedicated adhesives are even designed with specific materials in mind. For example, Magigoo sells adhesive sticks tailored to polycarbonate (PC) and nylon (PA).[3] However, there are also several DIY solutions for bed adhesives: many makers have found glue sticks to be a reliable option, while others use hairspray or blue painter’s tape (best for PLA filament) or Kapton tape (best for ABS filament) to create a grippier print surface. If you do decide to use an adhesive coating on your 3D printer’s build plate, it is important to apply them evenly and in moderation to avoid excessive buildup and to always clean your build surface after the print is complete, otherwise you risk glue buildup and an uneven print surface.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjYxNDM1NTE2NTQyLWhhaXJzcHJheS5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" width="624" height="459" class="fr-fic fr-dii" alt="Hairspray can " />Hairspray, glue sticks, or dedicated 3D printer adhesives can improve first layer adhesion.<h2 id="isPasted">Method #6: Adjust Speed and Cooling Settings</h2>If your 3D print isn’t sticking to the print bed, tweaking your print speed or cooling settings in slicer software can often help fix the issue. For example, setting the print speed for the first layer of your print to be slower than the rest of the build can promote better adhesion. A slower deposition rate for the first thin layer of a 3D print will help the filament to bond with the build surface.Cooling settings can also influence print bed adhesion and are particularly important for materials that are sensitive to temperature changes, such as PLA. Proper cooling can help prevent the material from warping or curling as it cools, which can lead to poor adhesion. However, excessive cooling can cause the material to cool too quickly, resulting in weak bonding between layers. For PLA, it is generally recommended to use a cooling fan at 100% speed after the first few layers have been printed. For materials like ABS, which are more sensitive to shrinking, a lower fan speed or no cooling may be more appropriate.For the best results, feel free to experiment with different settings and observe the results on test prints, making incremental adjustments until the desired adhesion is achieved. Keep in mind that the optimal settings may vary depending on factors such as the specific filament brand, printer model, and ambient room temperature. <h2>Method #7: Use a Raft or Brim</h2>There are also other slicer settings that can be implemented to <a href="https://www.wevolver.com/article/3d-print-not-sticking-to-print-bed-heres-the-solution" target="_blank" rel="noopener noreferrer">improve bed adhesion</a>, such as <a href="https://www.wevolver.com/article/brim-vs-raft" target="_blank">rafts and brims</a>. Rafts and brims are features 3D printed alongside your part to improve stability and reduce the chance of warping. They increase the footprint of the printed model to encourage adhesion, which is particularly valuable when printing parts with a smaller base. A raft essentially acts as a base to your 3D printed part and ensures that your print adheres to its surface, rather than the build platform directly. A brim, for its part, consists of a 3D printed border that connects to and extends from the edges of a 3D printed component. Brims are effective at anchoring the edges of a build to the 3D printed bed and are typically easier to remove than rafts. Most slicer programs, like Cura and Simplify3D, offer automated raft and brim features.If you are using a raft or brim, it’s important to keep in mind that these 3D print features do require additional post-processing for removal. In some cases, the removal process is easy and can be done by hand, in other cases, you might need additional tools like cutters to remove the part from the structure.Recommended reading: <a href="https://www.wevolver.com/article/brim-vs-raft" target="_blank">3D Printing Rafts vs Brims vs Skirts: How to Get Started</a><h2>Method #8: Change the Build Plate</h2>Another method for improving first layer adhesion is to change your 3D printer build surface. Some desktop FDM 3D printers have a removable plate meaning that you can swap out the build plate for a new one should the original be damaged. But even if your print bed is in fine condition, it could be worthwhile to think about using different build surfaces depending on the material you are printing with.A glass bed is a popular choice for 3D printer bed surfaces due to its smooth, flat surface and excellent thermal conductivity. The smooth surface allows for easy removal of prints once cooled and can result in a glossy, mirror-like finish on the bottom layer of the print. However, glass beds can sometimes struggle with adhesion, especially with materials like ABS, which are prone to warping. For this reason, many makers also use additional build surfaces like PEI sheets or Buildtak to improve first layer bonding. These can be applied directly to the existing build plate and are particularly effective for high-temperature filaments like ABS and PETG. Both PEI and Buildtak sheets provide a textured surface that promotes strong bonding between the filament and the bed, reducing the likelihood of print failures due to poor adhesion.To maintain BuildTak and PEI sheets, clean them regularly with isopropyl alcohol or a similar cleaning solution to remove any residue or adhesive buildup. Inspect the sheets for signs of wear or damage, such as scratches, gouges, or delamination, and replace them as needed to maintain optimal print adhesion. When removing prints from the bed, use a spatula or a putty knife to gently lift the print without damaging the sheet.Recommended reading: <a href="https://www.wevolver.com/article/3d-print-stuck-to-bed" target="_blank" rel="noopener noreferrer">3D Print Stuck to Bed: What to do?</a><h2>Conclusion </h2>These eight methods can help you with troubleshooting your 3D printer adhesion problems. Sometimes a single method—like adding a layer of glue to your print surface—will do the trick. In most cases, however, making various adjustments will result in the best adhesion and high-quality prints. In sum, ensuring a level 3D printer bed and a clean build surface, as well as using adhesive aids, and having the right print settings and printing temperature will have the best print results.<h2>Frequently Asked Questions (FAQs)</h2>Q: What is the best bed surface material for 3D printing? A: There is no one-size-fits-all answer to this question: the best print bed material depends on the type of filament being used and the specific printer setup. Common bed surface materials include glass, BuildTak, and PEI sheets. Glass works well with most filaments but can benefit from additional adhesives. PEI sheets and BuildTak are also compatible with most filaments and can offer superior adhesion for common materials like ABS.Q: How often should I level my 3D printer bed? A: The frequency of bed leveling depends on your printer's usage and the stability of its components. It is recommended to check and adjust the bed level regularly, especially before starting a new print or after making any adjustments to the printer's components.Q: Can I use household items as adhesive solutions for bed adhesion? A: Yes, some household items, such as glue sticks and hairspray, can be used as adhesive solutions to improve bed adhesion. However, it is essential to apply them evenly and in moderation to avoid excessive buildup or uneven adhesion.Q: How can I prevent prints from warping or curling during printing? A: To prevent prints from warping or curling, ensure proper bed adhesion by optimizing bed leveling, bed temperature, nozzle distance, print speed, and cooling settings. Additionally, using appropriate bed surface materials and adhesive solutions can help minimize warping and curling. For materials that are more sensitive to temperature fluctuations, such as ABS, consider using a heated enclosure to maintain a consistent printing environment.<h2>References</h2>[1] Tractus 3D, 2020. “ABS Filament” [Internet] <a href="https://tractus3d.com/materials/abs/" target="_blank">https://tractus3d.com/materials/abs/</a> [Accessed April 13, 2022][2] Tractus 3D, 2020. “PLA Filament” [Internet] <a href="https://tractus3d.com/materials/pla/" target="_blank">https://tractus3d.com/materials/pla/</a> [Accessed April 13, 2022][3] Magigoo, 2022. “Magigoo Pro PA (Nylon)” [Internet] <a href="https://magigoo.com/products/magigoo-pa/" target="_blank">https://magigoo.com/products/magigoo-pa/</a> [Accessed April 14, 2022]

Good first layer adhesion is critical to ensuring a successful 3D print.

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