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.

Print failure because of nozzle temperature error. Diagnose nozzle. PID tuning. Everything looks fine. I thought I had PID tuned but I must not have. Print a part. Print failure because of nozzle temperature error. Ugh, here we go again. Wash, rinse, repeat.

It turned out to be that my extruder JST connector was loose in the printhead. It was snug enough that the nozzle would be hold its temperature stable while it was sitting still. But, as soon as it started moving the connector would become disconnected at times and create problems for the nozzle to hold its temperature steady. What a pain.

Simple fix, though. Just push the connector back in place. Make checking your connections a part of your monthly maintenance routine.

A thermistor is a device that measures and controls the temperature of your 3D printer’s hot end and heated bed. It is a vital component for successful 3D printing, as it ensures that your printer operates at the optimal temperature for your chosen filament.

However, thermistors are also fragile and prone to damage or malfunction. A bad thermistor can cause a variety of problems, such as inaccurate temperature readings, thermal runaway, print errors, and poor print quality.

How to Diagnose a Bad Thermistor on a 3D Printer

There are several ways to check if your thermistor is working properly or not. Here are some of the most common methods:

  • Use a multimeter. A multimeter is a device that can measure the resistance of your thermistor. You can use it to compare the resistance value of your thermistor with the expected value from the manufacturer’s specifications or a resistance-temperature table. If the values are significantly different, your thermistor may be faulty.
  • Use a diagnostic test. Some 3D printers have built-in diagnostic tests that can check the functionality of your thermistor. You can access these tests from your printer’s menu or software. If the test fails or shows an error code, your thermistor may be faulty.
  • Look for symptoms. A bad thermistor can also cause some noticeable symptoms that affect your printing process. Some of these symptoms are:
  • Thermal runaway. This is when your printer’s temperature goes out of control and exceeds the safety limit. This can damage your printer or even cause a fire. Thermal runaway can happen if your thermistor is loose, broken, or shorted.
  • Higher than usual print temperatures. If your printer requires a higher temperature than the recommended one to extrude your filament, your thermistor may be faulty. This can result in over-extrusion, stringing, oozing, or blobbing.

What to Do About a Bad Thermistor on a 3D Printer

If you suspect that your thermistor is bad, you should replace it as soon as possible.Here are some general guidelines:

  • Replacing the thermistor on your hot end:
  • Turn off and unplug your printer.
  • Wait for the hot end to cool down completely.
  • Remove any filament from the extruder.
  • Remove any fan shrouds or covers that block access to the hot end.
  • Locate the thermistor on the hot end. It is usually a small cylinder with two wires attached to it.
  • Carefully disconnect the wires from the thermistor. You may need to cut them or use a screwdriver to loosen them.
  • Remove the old thermistor from the hot end. You may need to unscrew it or pull it out gently.
  • Insert the new thermistor into the hot end. Make sure it fits snugly and securely.
  • Connect the wires from the new thermistor to the wiring on your printer. Make sure they match the polarity and color coding of the old ones.
  • Reattach any fan shrouds or covers that you removed earlier.
  • Turn on and plug in your printer.
  • Calibrate your new thermistor using your printer’s menu or software.

3D printing is an amazing technology that allows you to create anything you can imagine. However, it is not always easy to get the perfect print. Sometimes, you may encounter problems such as stringing, warping, clogging, or under-extrusion. These problems can ruin your print quality and waste your time and filament.

Today, I would like to step out of the technical aspects of 3d printing and talk a little bit about more of a process. I want to demonstrate the process that I go through in taking a symptom, such as “my 3d print has a lot of stringing” or “my 3d print is coming off of the bed” and turn that into actionable troubleshooting steps. Granted, some of this is knowledge that comes with experience, and there just isn’t a way around that part of it.

Step 1: Identify the symptom

The first step is to identify the symptom that you are experiencing. For example, stringing is when thin strands of filament are left between different parts of your print. Warping is when the edges of your print curl up and detach from the bed. Clogging is when the nozzle gets blocked by melted filament and prevents extrusion. Under-extrusion is when the nozzle does not extrude enough filament and leaves gaps or holes in your print.

Step 2: Find the possible causes

The next step is to find the possible causes of your symptom. For example, stringing can be caused by high printing temperature, low retraction speed, or too much moisture in the filament. Warping can be caused by low bed temperature, poor bed adhesion, or large temperature differences between layers. Clogging can be caused by dirty nozzle, incompatible filament materials, or incorrect nozzle size. Under-extrusion can be caused by low printing temperature, low flow rate, or partial clogging. This step is done either by trial and error or research. I prefer research.

Step 3: Apply the solutions

The final step is to apply the solutions that can fix your problem. A solution is a method or action that can eliminate or reduce the cause of your symptom and improve your print quality. For example, to reduce stringing, you can lower your printing temperature, increase your retraction speed, or dry your filament before printing. To prevent warping, you can increase your bed temperature, use a raft or brim, or enclose your printer to maintain a stable temperature. To clear clogging, you can clean your nozzle with a needle or a wire brush, use compatible filament materials, or change your nozzle size. To avoid under-extrusion, you can increase your printing temperature, increase your flow rate, or check for partial clogging.

Level the bed, print. Turn off the printer for the night. Try to print. Bed needs to be leveled. Level the bed. Print. Turn off the printer for the night. Repeat. If this is happening to you, your bed may be wobbly because the D rings are loose. A lot of times, the adjustments will be stable until the printer is turned off and turned back on. It will seem like your bed is constantly losing its level. This is because…well…it is. Most beds ride on a series of bearings that ride in a track or v-groove. To adjust the tightness of these bearings to the track many manufacturers use a D ring, which is a ring that fits in the middle of the bearing to hold it in place, but it has a hole that is off-center so that it can be adjusted.

The D rings are usually located on the four corners of the bed, and they have screws that can be tightened or loosened to adjust the tension of the bed. Here are the steps to adjust the D rings on a 3D printer bed that is loose:

  1. Turn off the printer and let the bed cool down completely. Do not touch the bed when it is hot, as you may burn yourself or damage the bed surface.
  2. Locate the D rings under the surface of the bed. You may need to remove the print surface or the glass plate to access them.
  3. Use a screwdriver or an Allen wrench to loosen the screws on the D rings slightly. Do not remove them completely, as you may lose them or damage the bed.
  4. Gently lift one corner of the bed and check if it is loose or tight. If needed, rotate the D rings to adjust the tightness against the track.
  5. At their proper tightness, the D rings will prevent the bed from wobbling, but will not inhibit the bed from moving back and forth.
  6. Replace the print surface or the glass plate and turn on the printer.
  7. Perform a bed leveling procedure to ensure that the bed is flat and even. You can use a piece of paper or a feeler gauge to check if there is a consistent gap between the nozzle and the bed on all four corners.
  8. Print a test model and check if the print quality has improved. If not, you may need to adjust the D rings again or check for other issues with your printer.

Adjusting the D rings on a 3D printer bed that is loose can help you improve your print quality and prevent your bed from wobbling or shifting during printing. It is a simple and quick fix that you can do yourself with some basic tools. However, if you are not comfortable with tinkering with your printer, you may want to consult a professional or contact your printer manufacturer for assistance.

A part cooling fan helps to cool down the extruded filament and improve the print quality. However, sometimes the fan may stop working or malfunction, causing various problems such as warping, stringing, or poor surface finish. I want to show you how to troubleshoot 3D printer part cooling fans and fix some common issues.

The first thing you need to do is to check if the fan is spinning at all. You can do this by turning on your 3D printer and looking at the fan. If the fan is not spinning, there may be a problem with the power supply, the wiring, or the fan itself. To test the power supply, you can use a multimeter to measure the voltage across the fan terminals. The voltage should be around 12V or 24V, depending on your printer model. If the voltage is too low or too high, you may need to replace the power supply or adjust the voltage regulator.

If the power supply is fine, you can check the wiring for any loose connections, broken wires, or short circuits. You can use a continuity tester to check if there is a complete circuit between the fan terminals and the power supply. If there is no continuity, you may need to solder or replace the wires. If there is continuity, but the fan still does not spin, you may have a faulty fan. You can try to spin the fan manually and see if it rotates smoothly. If it feels stiff or makes noise, you may need to lubricate or replace the fan.

If the fan is spinning, but not enough to cool down the part, you may have a problem with the fan speed, the fan duct, or the print settings. To test the fan speed, you can use a tachometer to measure the revolutions per minute (RPM) of the fan. The RPM should be around 3000 to 5000, depending on your printer model. If the RPM is too low, you may need to increase the fan speed in your slicer settings or replace the fan with a more powerful one.

If the fan speed is fine, you can check the fan duct for any blockages, cracks, or misalignments. The fan duct is the part that directs the airflow from the fan to the nozzle and the part. You can use a flashlight to inspect the inside of the duct and see if there is any dust, debris, or filament stuck inside. You can also check if the duct is cracked or broken and if it is aligned properly with the nozzle and the part. If there is any problem with the duct, you may need to clean, repair, or replace it.

Finally, you can check your print settings for any factors that may affect the cooling performance. Some of these factors are:

  • Layer height: A lower layer height means more layers and more time for cooling.
  • Print speed: A slower print speed means more time for cooling.
  • Fan speed: A higher fan speed means more airflow and more cooling.
  • Minimum layer time: A longer minimum layer time means more time for cooling.
  • Cooling threshold: A lower cooling threshold means more layers with full cooling.
  • Bridging settings: Bridging settings control how much cooling is applied when printing overhangs.

You can experiment with different combinations of these settings and see which one gives you the best results. You can also use some online tools or guides to help you optimize your settings for different materials and models.

If you are using the same settings on your 3D printer, but all of a sudden your prints start failing, you might be wondering what is going on. Here are some possible causes and solutions to troubleshoot your 3D printing problems.

  • Check the filament. Sometimes the filament can get tangled, kinked, or broken, which can affect the quality of your prints. Make sure the filament is feeding smoothly and evenly into the extruder. If the filament is brittle or has moisture in it, you might need to replace it or dry it out.
  • Check the nozzle. The nozzle is the part that melts and deposits the filament onto the print bed. If the nozzle is clogged, dirty, or damaged, it can cause under-extrusion, blobs, stringing, or other issues. You can try to clean the nozzle with a needle or a wire brush, or replace it if it is worn out.
  • Check the bed leveling. The bed leveling is the process of adjusting the distance between the nozzle and the print bed. If the bed is not level, it can cause the first layer to be uneven, which can affect the adhesion and accuracy of your prints. You can use a piece of paper or a feeler gauge to check the gap between the nozzle and the bed at different points, and adjust the screws or knobs accordingly.
  • Check the temperature. The temperature is one of the most important factors that affect the quality of your prints. If the temperature is too high or too low, it can cause warping, cracking, stringing, or other issues. You can use a thermometer or a thermal camera to check the temperature of the nozzle and the bed, and adjust them according to the recommended settings for your filament type and model.
  • Check the speed. The speed is another factor that affects the quality of your prints. If the speed is too fast or too slow, it can cause over-extrusion, under-extrusion, ringing, or other issues. You can use a stopwatch or a software to check the speed of your printer, and adjust it according to the complexity and size of your model.

Have you ever wondered why your 3D prints sometimes don’t stick to the bed or have warped edges? One possible reason is that your bed is not properly warmed up before you start printing. Sometimes, you need to let your bed “soak” for a little while before you begin printing.

The bed of a 3D printer is usually made of metal, glass, or plastic, and it is heated by a heating element underneath. The purpose of heating the bed is to provide a stable and smooth surface for the first layer of the print to adhere to, and to prevent thermal contraction of the material as it cools down. However, heating the bed also causes it to expand and contract slightly, which can affect its shape and flatness.

Depending on the material and thickness of the bed, it can take some time for the bed to reach a uniform temperature and stabilize its shape. If you start printing too soon, the bed may still be flexing and adjusting its shape as it warms up, which can cause uneven adhesion, gaps, or curling of the first layer. This can ruin the quality of your print or even make it fail completely.

To avoid this problem, you should always preheat your bed before you start printing. You can do this by setting the bed temperature in your slicer software or on your printer’s LCD screen, and waiting for a few minutes until the temperature is reached and stable. I’ve found it very helpful to set my hotend and bed temperatures, and then go get a cup of coffee. I’ve found that the time it takes me to do this is good enough for the bed to be thoroughly heated, not just heated where the sensor itself is. If you want a more technical answer you can use a thermometer or an infrared camera to check the temperature distribution on the bed surface and make sure it is consistent.

By preheating your bed properly, you can ensure that your first layer sticks well and that your print has a solid foundation. This will improve the quality and reliability of your 3D prints and save you time and frustration. So next time you are ready to print something, don’t forget to get a cup of coffee!

I love that 3d printing allows you to create physical objects from digital models. Despite what I thought when I got my first 3d printer, it is not as simple as pressing a button and watching your design come to life. There are many factors that affect the quality and outcome of your 3D prints, and one of the most important ones is the configuration settings.

Configuration settings are the parameters that control how your 3D printer operates, such as the temperature, speed, layer height, infill, retraction, and more. These settings can vary depending on the type of printer, filament, model, and desired result. They can also interact with each other in complex ways, so changing one setting can affect another.

One of the most common problems that 3D printing enthusiasts face is poor bed adhesion. This means that the first layer of your print does not stick to the print bed, causing it to warp, curl, or detach. This can ruin your entire print and waste time and material. There are many possible causes for poor bed adhesion, such as incorrect bed temperature, nozzle height, leveling, or surface preparation. However, even if you have all these factors right, you may still encounter this issue if your other configuration settings are not optimal.

For example, if your print speed is too high, your extruder may not be able to keep up with the demand and under-extrude filament. This can result in gaps or thin spots in your first layer, which can compromise its adhesion. Similarly, if your retraction settings are too aggressive, you may experience oozing or stringing, which can interfere with the smoothness and consistency of your first layer. If your layer height is too large or your infill is too sparse, you may not have enough material to form a solid base for your print.

It is essential to understand how all of your configuration settings work together and how they affect the quality of your 3D prints. You should always test and calibrate your printer before starting a new project, and adjust your settings according to the specific requirements of your model and filament. You should also use slicing software that allows you to preview and fine-tune your settings before sending them to your printer. By doing so, you can avoid common pitfalls and achieve successful 3D prints every time.

Calibration – Check

Go to print – big goopy mess

Change nozzle – Check

Calibration – Check

repeat

After a lot of frustration I saw the wires for my part cooling fan pop out of the connector and I immediately knew what the problem was. Ugh. I had spent so much time diagnosing the wrong issue. The wires were in enough that they looked like they were secure, but out enough that they intermittently got disconnected. So, when I would print I would sometimes end up with heat creep or a big goopy mess of filament.

Bought 500 JST connectors on Amazon for $8.99 and my problem is solved.

Lessons learned (or relearned):

  • the root cause isn’t always immediately obvious
  • check everything
  • if you’ve replaced the nozzle 3 times and you still have the same problem, the problem likely isn’t the nozzle