Category: Filament

The solution to a lot of problems is to slow down your print speed. But, is there such a thing as too slow (spoiler alert, yes there is)?

If you think about what’s happening inside the nozzle, it makes sense. You are melting some plastic and pushing it through an orifice (the nozzle). If your speed is too high, you end up trying to push unmelted plastic. That’s a problem too, but the subject for a different post. This post is about the other extreme. When your temperature is high and your speed is low, the filament sits in the chamber for a long time.

However, if you raise your 3d printer temperature too high and go too slow, you are likely to encounter several issues. Some of them are:

  • Overheating: Printing with too high temperature can cause the filament to overheat and degrade. This can lead to clogging, jamming, or nozzle damage. It can also affect the color and appearance of the filament, making it darker or duller. Overheating can also cause thermal runaway, which is a dangerous situation where the temperature sensor fails and the heater keeps heating up uncontrollably.
  • Oozing: Printing with too high temperature and too slow speed can cause the filament to ooze out of the nozzle when it is not supposed to. This can create blobs, strings, or zits on the surface of your print, ruining its aesthetics and accuracy. Oozing can also waste filament and make it harder to clean your nozzle.
  • Warping: Printing with too high temperature and too slow speed can cause the filament to cool down unevenly on the print bed. This can create internal stresses that make the print warp or curl up at the edges or corners. Warping can affect the dimensional accuracy and stability of your print, as well as its adhesion to the print bed.
  • Cracking: Printing with too high temperature and too slow speed can cause the filament to shrink more than usual as it cools down. This can create gaps or cracks between the layers or within the walls of your print. Cracking can compromise the strength and durability of your print, as well as its appearance.
  • Jamming: Your filament is melted. When the gcode performs a retract function, it pulls melted plastic backwards, which subsequently starts to cool. It doesn’t take long for it to solidify enough to cause problems and will often get stuck.

The solution is often simple. You can either increase your speed or decrease your temperature.

Yesterday I wrote about working with TPU.

This material caused me so many problems in the beginning that I thought it might be worthwhile to talk about it in more detail today.

One of the pieces that I optimize is the tension put on the filament from my extruder. I use a dual gear extruder rather than an extruder with just a gear on one side. This increases the surface area that is in contact with the filament and allows me to put less of a “bite” on the filament, making it less likely to get deformed.

Additionally, I optimize the tension screw so that my gears just barely make marks on the filament.

The underlying issue that I’m trying to solve is that the material is soft. If I place too much pressure on the filament it can flatten out and then it won’t extrude properly or might even cause a clog.

Along the same lines, I optimize my retraction settings. If you have the option of using a direct drive extruder vs. a bowden extruder, you should do so. If you don’t, that’s ok. It’s not ideal, but we can make it work. With a bowden tube using normal PLA my retraction settings are normally around 6mm and 40mm/s. When I set up with TPU, however, I use 1-2mm retraction and no more than 20mm/s. Additionally, most slicers have a setting that limits the number of retractions in a section of filament. I typically limit the retraction to no more than 3 retractions per 10mm. This is to avoid grinding a flat spot onto the filament from repeated retractions as the part is being printed.

In my post yesterday I mentioned that I increase my temperature and reduce my speed, but I didn’t mention any specific values. It varies, but I normally like to run TPU or silk PLA that contains TPU at around 210-220 and I run it pretty slow, usually around 20-30 mm/s. These specific settings all require some testing and optimization, but this should give you a good starting point. The general idea is to make sure that the material is melted enough when it gets to the hotend that it won’t cause the filament to bind or bend. Same thing with the speed, if you try to push too much filament through the filament ends up bending and causing clogs.

Working with flexible filament, such as TPU, is challenging.

One of the main challenges of working with TPU filament is its high elasticity and low rigidity. This means that TPU filament can stretch and bend easily, which can cause problems with extrusion, retraction, and feeding. It can be similar to trying to push rope. It is advisable to reduce the retraction distance and speed, as well as the print speed, to prevent stringing and oozing.

Another challenge of working with TPU filament is its sensitivity to temperature and humidity. TPU filament can absorb moisture from the air, which can affect its print quality and performance. Moisture can cause bubbles, cracks, and warping in the printed objects, as well as increase the risk of nozzle clogging. To prevent these problems, it is essential to store TPU filament in a dry and cool place, preferably in a sealed bag with desiccants. Moreover, it is recommended to use a heated bed and an enclosed print chamber to maintain a stable temperature and avoid drafts.

A third challenge of working with TPU filament is its adhesion to the print surface. TPU filament can stick very well to some surfaces, such as glass or PEI, but not so well to others, such as blue tape or BuildTak. This can result in either poor bed adhesion or difficulty in removing the printed objects. To solve this dilemma, it is helpful to use a thin layer of glue stick or hairspray on the print surface to improve the adhesion. Alternatively, it is possible to use a flexible or magnetic build plate that can be easily detached and bent to release the printed objects.

One final challenge that I’ve experienced is that some TPU (or filaments with TPU in them) tend to expand when heated up. I normally like to warm up my machine for a few minutes before beginning a print. This allows for any expansion and movement to happen while the machine is sitting idle, rather than while the machine is printing. However, I’ve found that some TPU based filaments will burn and end up leaving burnt pieces in the nozzle, which end up clogging it. For TPU based filaments, I prefer to retract the filament approximately 100mm, then warm up the nozzle, and include a line of code in the beginning of my file that feeds the filament back into the nozzle. For this same reason, I also like to do a cold pull after each part that I print with TPU based filament. I just cut off the last 25mm or so of the filament. I have far fewer issues that way.

These are some of the challenges of working with TPU filament that I have encountered and how I have overcome them. I hope this information was useful for you. If you have any questions or comments, please feel free to leave them below. Happy printing!

I see this question pop up sometimes in help forums and chatrooms. My experience with filament has been “you get what you pay for.” I’m all for lowering operating costs, but do it carefully.

Here are some of the risks you should be aware of:

  • Clogging: Cheap filament can contain foreign particles or impurities that can clog your nozzle or damage your extruder. This can result in poor print quality, failed prints, or even permanent damage to your printer. Clogging can also waste your time and filament as you try to fix the problem or reprint your model.
  • Fumes: Cheap filament can emit toxic fumes or volatile organic compounds (VOCs) that can harm your health or the environment. Some filaments, such as ABS, produce more fumes than others, such as PLA or PETG. Fumes can cause allergic reactions, respiratory irritation, headaches, nausea, or other symptoms. Fumes can also pollute the air and contribute to global warming.
  • Quality: Cheap filament can have inconsistent diameter, color, or strength. This can affect the accuracy, appearance, and durability of your prints. Cheap filament can also have poor adhesion, warping, or brittleness. Quality issues can compromise the functionality and aesthetics of your prints and make them unsuitable for certain applications.

To avoid these risks, you should use high-quality filament from reputable brands that have good reviews and ratings. You should also follow the recommended settings for your printer and filament, such as temperature, speed, and cooling. You should also print in a well-ventilated area or use a filter or enclosure to reduce the exposure to fumes.

If you are using silk PLA, you might have encountered a common problem: the extruder gear grinds a flat spot on your filament when you have retraction enabled. This can cause under-extrusion, clogging, and poor print quality. But if you disable retraction, you might get stringing and oozing. So how can you overcome this dilemma? Here are some tips that might help you.

  • Increase the extruder temperature. Silk PLA usually requires a higher temperature than regular PLA, around 210-230°C. This will reduce the resistance in the hot end and allow the filament to flow more easily.
  • I have also had success with reducing the extruder temperature to the very minimum temperature. When reducing the temperature the flow of PLA is slower, so a slower speed is also required to accommodate the lower temperature. This option allows me to disable retraction altogether.
  • Decrease the retraction distance and speed. Retraction pulls the filament back into the extruder to prevent oozing, but it also puts more stress on the filament. Try reducing the retraction distance to 2-3 mm and the speed to 20-30 mm/s. This will minimize the grinding and still prevent stringing.
  • Calibrate the extruder tension. The extruder tension is the force that the extruder gear applies on the filament to push it through the nozzle. If the tension is too high, it can cause grinding and flattening of the filament. If it is too low, it can cause slipping and under-extrusion. You can adjust the tension by turning a screw or a knob on your extruder. The ideal tension is when you can pull the filament out of the extruder with moderate force, but not too easily or too hard.
  • Use a high-quality filament. Silk PLA is a special type of PLA that has a shiny and smooth surface. However, not all silk PLA filaments are created equal. Some might have inconsistent diameter, impurities, or additives that can affect the print quality and performance. Make sure you buy from a reputable brand and store your filament in a dry and cool place.

I was printing a couple of things for my wife out of PLA+. Then my daughter wanted something printed in a silk PLA that contained some TPU. These are two very different filaments with very different properties. Just swapping filament spools and hitting “Print” would not have been successful. Here are the steps that I took to successfully swap between the two.

Step 1: Clean the nozzle

The first step is to clean the nozzle of your 3D printer to remove any residue of the previous filament. This is especially important when switching from a lower temperature filament (such as PLA) to a higher temperature filament (such as ABS), because the leftover PLA may burn and clog the nozzle when heated to ABS temperatures.

To clean the nozzle, you can use one of the following methods:

  • Cold pull: This method involves heating the nozzle to the melting temperature of the previous filament, then letting it cool down slightly, and then pulling out the filament with a quick motion. This should remove most of the residue from the nozzle. You may need to repeat this process a few times until the filament comes out clean.
  • Nylon cleaning filament: This is a special type of filament that is designed to clean the nozzle by absorbing any impurities. You can load the nylon cleaning filament into your 3D printer and extrude it at a high temperature (around 250°C) until it comes out clean. You can also use the cold pull method with the nylon cleaning filament for better results.
  • Needle or wire: This method involves inserting a thin needle or wire into the nozzle and gently scraping out any debris. You can do this while the nozzle is hot or cold, but be careful not to damage the nozzle or burn yourself.

Step 2: Adjust the temperature

The second step is to adjust the temperature of your 3D printer to match the new filament. Different filaments have different optimal printing temperatures, which depend on various factors such as the brand, color, and quality of the filament. You can usually find the recommended temperature range on the spool label or on the manufacturer’s website.

Step 3: Adjust the bed temperature

The third step is to adjust the bed temperature of your 3D printer to match the new filament. The bed temperature affects how well the first layer of your print adheres to the build platform, which is crucial for preventing warping and curling. Different filaments have different optimal bed temperatures, which also depend on the type of build surface you are using.

Step 4: Adjust the speed and cooling

The fourth step is to adjust the speed and cooling settings of your 3D printer to match the new filament. The speed and cooling affect how fast and how well your filament solidifies after being extruded from the nozzle. Different filaments have different optimal speed and cooling settings, which depend on their viscosity, shrinkage rate, and strength.

If you are into 3D printing, you might have heard that it is important to make your wall thicknesses in multiples of your nozzle size. But why is that? And what are the benefits of doing so?

The nozzle size is the diameter of the hole that extrudes the melted filament onto the build plate. The most common nozzle sizes are 0.4 mm and 0.8 mm, but there are also other options available. The nozzle size determines how much material is deposited per layer and how fine the details of your print can be.

The wall thickness is the width of the outer shell of your print. It is usually measured in millimeters or number of perimeters (the number of lines that make up the wall). The wall thickness affects the strength, durability and appearance of your print.

Now, why should you make your wall thicknesses in multiples of your nozzle size? The main reason is to avoid gaps or overlaps between the perimeters. If your wall thickness is not a multiple of your nozzle size, the slicer software will have to either leave a small gap between the perimeters or squeeze them together to fill the space. This can result in poor adhesion, weak walls, uneven surfaces or blobs and zits on your print.

For example, if you have a 0.4 mm nozzle and you set your wall thickness to 1.2 mm, you will get three perimeters that fit perfectly next to each other. But if you set your wall thickness to 1.3 mm, you will get three perimeters plus a 0.1 mm gap that the slicer will try to fill with extra material or leave empty. Either way, you will not get a smooth and consistent wall.

By making your wall thicknesses in multiples of your nozzle size, you can ensure that your perimeters are aligned and evenly spaced. This will result in stronger and smoother walls, better layer adhesion and less material waste. It will also make your slicing and printing process faster and easier, as the slicer will not have to calculate how to fill or avoid gaps.

Of course, this rule is not absolute and there may be situations where you want to deviate from it. For example, if you are printing a very thin wall that cannot accommodate a multiple of your nozzle size, or if you are using a variable layer height feature that changes the nozzle size dynamically. In these cases, you may have to experiment with different settings and see what works best for your model.

But as a general guideline, making your wall thicknesses in multiples of your nozzle size is a good practice that can improve your 3D printing results. I hope this blog post was helpful and informative for you. Happy printing!

TPU is a flexible filament that can produce amazing prints, but it also requires some special settings and adjustments to print well. One of the most important factors is the tension of the extruder, which affects how well the filament is fed into the hotend and how much pressure is applied to it.

The tension knob is a small screw or dial that controls how tight or loose the spring that presses the idler bearing against the filament is. If the tension is too high, the filament can get crushed or deformed by the idler, causing jams, underextrusion, or poor quality prints. If the tension is too low, the filament can slip or skip in the extruder, causing overextrusion, stringing, or blobs.

To adjust the tension knob properly for TPU, you need to find a balance between enough grip and enough flexibility. Here are some steps to follow:

  1. Load the TPU filament into the extruder and preheat the hotend to the recommended temperature for your brand of TPU.
  2. Start with a low tension setting, such as turning the knob counterclockwise until it stops or loosening the screw until it is barely touching the spring.
  3. Print a test cube or a calibration pattern and observe how the filament behaves in the extruder. Look for signs of slipping, skipping, or grinding.
  4. If you notice any of these problems, increase the tension slightly by turning the knob clockwise or tightening the screw a bit. Repeat step 3 until you find a setting that eliminates these issues.
  5. Check the quality of your print and look for signs of overextrusion, underextrusion, stringing, or blobs. Adjust the tension accordingly until you get a smooth and consistent extrusion.
  6. Remember that different brands and colors of TPU may require different tension settings, so you may need to tweak them for each spool you use.

Silk PLA is a type of PLA filament that has been blended with additional polymers to give it a glossy, matte-like look. It is also more flexible than standard PLA, which can affect its printability and performance. Here are some considerations and adjustments you need to make when switching to silk PLA filament that contains TPU, such as silk PLA.

Print Temperature

Silk PLA filaments usually have a similar print temperature range as regular PLA, which is around 180 to 220°C. However, the exact temperature may vary depending on the brand and the amount of polymer added to the blend. You may need to experiment with different temperatures to find the optimal one for your silk PLA filament. A good way to do this is to print a temperature tower and see which layer has the best quality and adhesion.

Print Speed

Silk PLA filaments can be printed at a similar speed as regular PLA, which is around 30 to 80 mm/s. However, you may want to slow down your print speed if you encounter clogging or stringing issues, as silk PLA can be more prone to these problems due to its flexibility and glossiness. You may also want to reduce your retraction distance and speed, as too much retraction can cause jamming or under-extrusion.

Heated Bed Temperature

Silk PLA filaments do not require a heated bed, as they have good adhesion to most surfaces. However, if you have a heated bed, you can use it at a low temperature of around 60 to 80°C to improve the first layer adhesion and prevent warping. You may also want to use a glue stick, hairspray, or blue tape to increase the bed adhesion and make it easier to remove the print.

Cooling Fan

Silk PLA filaments benefit from using a cooling fan, as it helps to improve the layer cooling and prevent sagging or drooping of the overhangs and bridges. You can use your cooling fan at full speed or adjust it according to your print quality and settings. However, you may want to turn off your cooling fan for the first few layers to ensure good bed adhesion.

Post-Processing

Silk PLA filaments produce prints that have a shiny and smooth surface, which makes them ideal for decorative items or models. You may not need any post-processing for your silk PLA prints, as they already look polished and attractive. However, if you want to improve the appearance or durability of your prints, you can use some post-processing methods such as sanding, painting, or coating. You can also use a heat gun or a hair dryer to smooth out any imperfections or stringing on your prints.

Hey, what’s up, fellow 3D printing enthusiasts? Today I want to talk to you about something very important: filament. You know, the stuff that makes your prints come to life. But did you know that not all filament is created equal? In fact, the characteristics of filament can vary significantly, and hence the settings that are used must also be updated. Let me explain.

Filament is made of different materials, such as PLA, ABS, PETG, etc. Each material has its own properties, such as melting point, strength, flexibility, etc. Depending on the material you use, you need to adjust your printer settings accordingly. For example, PLA usually prints well at around 200°C, while ABS needs a higher temperature of around 230°C. If you use the wrong temperature, you might end up with a print that is under-extruded, over-extruded, or warped.

But even within the same material, there can be variations in quality and consistency. For example, some filament brands might have more additives or impurities than others, which can affect the flow and adhesion of the filament. Some filament spools might have more moisture or dust than others, which can cause bubbles or clogs in the nozzle. Some filament colors might require different temperatures than others, due to the pigments used. All these factors can affect the quality of your prints.

So how do you deal with these variations? Well, the best way is to test your filament before you start printing. You can use a calibration cube or a temperature tower to find the optimal settings for your filament. You can also measure the diameter of your filament with a caliper and enter it in your slicer software. This will ensure that you get the right amount of extrusion and avoid under- or over-extrusion.

Another thing you can do is to store your filament properly. You should keep your filament in a dry and cool place, away from sunlight and moisture. You can also use a desiccant or a vacuum sealer to keep your filament dry. This will prevent your filament from absorbing moisture and degrading over time.

You can make sure that you get great results from your filament. Remember, filament is not just a consumable, it’s an essential part of your 3D printing process. So treat it well and it will treat you well too. Happy printing!