Combating 3D Printing Problems: A Troubleshooting Guide

Finally a complete troubleshooting guide for the most common problems experienced with 3D printers.
As much as we would like for 3D printing to be plug and play with minimum issues, that day not quite reached us yet… though it is not that far way.
Therefore, in the meantime we need to settle with recognising potential problems and fixing them ourselves (many of which are created by us and not our printer)

Contents

3D Printing Issue #1: Warping / Curling

What is Warping & What Causes it?

The plastic used for generating your model will cool at different rates within different areas of your model. For example, plastic around the edges tend to cool faster than within the model as it is exposed to more air.
When cooling happens too quickly at some areas of the model, the model starts to curl or bend upwards to the point it is no longer level with the printer bed. As a result, the model’s shape is compromised and the bending effect also puts some stress creating cracks on the model.
Although PLA has a lower shrinking factor to ABS, they both can still warp. Please not that this does not necessarily mean that PLA is the solution to this problem, as both plastics have other advantages and disadvantages.

Plastic warping due to cooling too quickly
 Image credit: 3dprinting.com

How to Combat Warping Issues?

  1. Clean & dust free build surface:

    Impurities, debris, dust and old pieces of your print residing on your bed can assist with warping. PLA and ABS stick on cleaner surfaces better, which in turn holds your print in place restricting the effects of warping.

  2. Evenly Distributing Heat Within Your Print

    As mentioned, warping is caused by differences in temperature within the model. Traditionally when printing a 3D model, the layers are added from the bottom and work their way up, which means the bottom layers start to cool as the rest of the layers are being built up (causing the warping).
    By using a heated bed, the lower layers of the print stay warm, preventing greater differences in temperature which reduced the nasty effects of warping.

  3. Correct Z-endstop Calibration

    The first layers of your print are the foundations that provide strength and rigidity. The 3D printer’s Z-endstop needs to be set correctly, set it too high from the bed and the plastic will struggle to get a good bond to the platform and set it too close, the filament may start to clog up at the nozzle as there is no sufficient gap to allow the plastic to extrude at the correct rate (a clicking sound coming from the stepper motor indicates clogging)

    Tip: Test several first layers at different heights (increments of 0.05mm) until satisfied.

    Tip #2: It is best to level your bed / platform first before calculating the desired Z-endstop (to get an equal Z-endstop value, the bed needs to be entirely flat throughout its area)

  4. Bed Level Calibration

    This is simply the art of making sure your printing platform or bed is completely horizontal (or as horizontal as physically possible). A horizontal bed will allow for a more accurate print, with even added layers and improved structure strength… less chance of warping / curling.
    Doing this will depend on your printer’s make and model, however, if you are new to the world of 3D printing and require an explanation on how to do this generally.
    Here is an article on levelling your printing platform on the MakerGear M2

  5. Printing Resolution: The Speed At Which You Print

    A higher resolution print means thinner layer build up along the X-Y directions. This means better adhesion, more layers (therefore improved structural integrity) and slower cooling rates.
    Just like with normal printers, the higher the resolution, the slower the print, which means a slower moving printer head and therefore less movement of the printer itself. Such movement can effect the overall print quality (due to shake) that can assist with structural problems, making warping even more possible.

  6. applying Glue To Build Surface

    Making sure your print is firmly stuck to your platform is one way of preventing the base of your model from warping. However, there is a fine line regarding how firmly your print should be fixed against the platform.
    For example, blue double sided tape will hold your model firmly on the bed, however, this creates issues when removing your model from the bed once the print is finished (the adhesion is so strong, that by pulling your model free, you may end up damaging it).
    One alternative is Elmer’s Disappearing Purple School Glue Sticks which generally has enough adhesion to keep your model in place (depending on its size). It is also non toxic and can be easily cleaned off by simply applying hot water.

3D Printing Issue #2: Stringing / Oozing Effect

What is Stringing & What Causes it?

Stringing is when small thin strands of plastic protrude out from the model a little like strands of hair.
There are points where the nozzle needs to travels through open air (travel move) to get to an other point of the model to deposit plastic. During this ‘open air’ movement, the nozzle should not be depositing any plastic, however, if there is any leakage or oozing, the plastic will leak on parts of the model where it should, hence ‘stringing’

Common stringing issues look like this – Photo credit: 3dwithus.com

How to Combat Stringing Issues?

    1. Easy Pressure on Nozzle Through Retraction Settings

      Though this would be the first thing most 3D printer users would think about, it still could be something that is simply overlooked.
      The nozzle needs to provide some pressure so that the plastic can come out at a specific rate when building up the print, however, it is important to tell the nozzle to ease off the pressure during non-print moves (travel moves) to prevent any plastic from leaking out onto your model.
      Every 3D Slicer software will have a ‘retraction’ settings where you can adjust set pressures on your nozzle.
      Some experimenting will be in order to determine what best retraction settings suit your printer and filament being used. Setting retraction too high is one reason for clogging up your nozzle, and setting it too low will, well, cause oozing and result in stringing.

      What Determines Retraction Settings For Fixing Stringing
      • Bowden Extruders: have more distance between the nozzle and driver and therefore requires higher retraction settings
      • Direct Drive Extruders: have a closer distance between the nozzle and driver and therefore requires a lesser retraction settings.
      • Filament Type: PLA and ABS for example have different property characteristics and therefore require different retraction settings.
      • Same Filament Type: Even having the same filament type bought from the same manufacturer can mean adjusting your retraction settings, due to differences in characteristics.
    2. Moisture in Filament

      You may have heard that keeping your filaments moisture free is a much recommended practise, particularly with PLA, as they tend to absorb more moisture than ABS.
      As the plastic feeds through, it is heated up to melting point and passes through the nozzle. The issue with moisture is the water turns into steam which effectively interferes / mixes with the plastic making it easier to ooze out during non printing stages (creating the stringing effect)

      Check out this guide on how to prevent your filaments from moisture damage

    3. Calibrating correct hot-end temperature

      Calibration at this point is very important. Each filament manufacturer will give you a specific temperature to set depending on the type of filament you are using.
      However, please note, these temperatures are very close guides, but it is always recommended to calibrate the temperature to near perfection.
      Some people calibrate for each filament, even if it is the same material & model coming from the same manufacturer (there are always some differences).
      A good starting point on how to calibrate your hot-end temperature is to watch the below video. In this case calibrating for PLA 1.75mm filament.

      Temperature Hot-End Settings: How To Calibrate

    4. Increasing printer speeds during non-print moves

      The concept here is that if your nozzle is likely to ooze out some plastic, the slower it moves during non-print moves (the distance the nozzle needs to travel from point A to point B through the air before starting to add new layers), the more time the plastic has to leak onto your model. However, increase that speed, and the plastic will not have enough time to drip.
      The beauty here is that slicer packages have a setting to speed up the nozzle for non-printing movement which is independently to print speed. This way you can have slower print speeds for quality prints and higher non-print speeds for elimination / reduction in oozing.

      3D Printing Issue #3: Blocked Nozzle (Bowden)

      What is Nozzle Blockage & What Causes it?

      There are several reasons as to what causes blockages, but they can come in two forms, complete blockage where no plastic is coming out of the nozzle and partial blockage where plastic does come out but is somewhat restricted.
      While a complete block is easy to determine, sometimes a partial one is not. A good indication is when the filament does not come out linearly, but rather takes a bit of a bend when existing the nozzle.

      Checking printer nozzle for clogging – Photo credit: Thomas Sanladerer

      Tip: A good indication that your are building up plastic within your nozzle is when you start to hear a clicking sound. These are the gears in the extruder motor slipping as they are not able to push the filament through.

      Tip2: To clear out a complete nozzle block you can check out this video… it is really easy to, but a great tip is to have an extra nozzle at hand, you will see why in the video.

      For more details clearing out your nozzle this amazing video

      How to Prevent Nozzle Blockage Issues?

  1. Differences in Filament Diameter

    Going cheaper does not necessarily mean saving money and the same can be true when purchasing filament spools for your prints. Although not always the case, cheaper end filaments are more likely to have variations in diameter throughout its length. This effects a steady extrusion flow and may cause a build up of filament in the nozzle which ultimately blocks it.

    Sourcing filament manufactures that produce high end products with a constant diameter throughout will assist or prevent blockages.

    Alternatively, if sourcing quality filaments is not an option, you can learn how to calibrate your extrusion to compensate for filament diameter discrepancies. 

  2. Setting Nozzle to close From Bed

    It is important that your nozzle is set at the correct height from your bed (printer surface) to achieve a successful print.
    Set the nozzle too high and the melted plastic needs to travel further to reach the surface. This added distance means more time for the plastic to cool and therefore result in adhering issues.
    However, set the nozzle too low and not only will the plastic most likely smear all over the place, but it will also begin to back up in the nozzle, ultimately causing it to clog up.

    Learning how to calibrate your Z-Endstop through this guide. However, depending on the printer you have, there may be some differences… the guide

  3. Prevent Dust particles Entering Nozzle

    Ahh good old dust, it seems no matter how clean you try and keep a room it is only a matter of time before dust particles start to settle everywhere, even on your filament spools that are either stored away somewhere or the one that you are currently using attached to your printer.

    Consider your filament as a conveyer belt carrying dust particles, working its way to your nozzle. Now imagine dust impurities mixing into your melted plastic, what do you think is going to happen? Eventually there will be a build up of impurities resulting in a blocked nozzle.

    As a preventative measure, you could make your own DIY dust trap using lint-free cloth or alternatively purchase products such as the Universal 3D-print Filament Filter

  4. Low Hot-End Temperature

    It should be obvious that for your filament to flow through the nozzle uniformly and at a desired rate, the plastic must be melted at the correct temperature.
    Setting your hot-end incorrectly (in this case not high enough) means your plastic is not viscous enough to push freely through the nozzle. This makes it harder for the motor to push it through, where the gears will most likely grind away at the filament (damaging it) causing even more extrusion difficulties due.

    [TOC]

    Always check the temperature specification of your filament. Note, that these specifications may not work perfectly, so be sure to do a little testing by increasing / decreasing the temperature by 2-3 degrees until you get the perfect print (remember not to go about the max temperature of your hot-end).
    Finally when switching between filaments, be sure to remove all previous material is fully removed before changing temperature

    PLA & ABS Temperature Guide

    Material DescriptionExtruder TemperatureTemperature Tolerance
    PLAMost commonly used plastic, eco friendly (made form corn-starch), ideal for 3D prototyping.200 °C±10 °C
    Flexible PLAhttps://www.matterhackers.com/3d-printer-filament-compare±10 °C
    ABSMost commonly used plastic, durable, ductile, withstands high temperautes.230 °C±10 °C
    NylonIncredibly strong, durable and versatile. Often used for strong functional parts, such as hinges.255 °C±15 °C
    NylonXReinforced nylon by adding micro carbon. For tough, stiff and impact resistant parts.260 °C±10 °C
    PRO Series Nylon±10 °C
    ASAAlternative to ABS with improved weathering and yellowing from UV light. Ideal for out door prints250 °C±10 °C
    TPE±10 °C
    TPU±10 °C

    Check this awesome guide for more on temperature specifications on different filament types

    3D Printing Issue #4: Lack Of Bed Adhesion

    What is Bed Adhesion & What Causes It?

    The main issue is getting your print’s base layer to stick to the bed in order to form a good foundation for the additional layers that build up on top to create the final product. Failure of your model to adhere to the bed will undoubtedly result in a failed print.

    Remember warping issues? Well one of the issues that may occur is warping due to lack of force keeping the print held against the bed.

    Remember the nozzle is a moving part that effectively comes into contact with your print and with some printers having moving beds, this will result in a print that is not sturdy with layers of plastic not going on evenly.

    The trick is to have just enough adhesion to keep your model sturdy during the print, but not too sticky that you require great force to remove the print from the bed (resulting in damaging your model).

    Issues of printing through lack of adhesion – Photo credit: 3dhubs.com

    Note: Some people do not experience adhesion problems whereas some do and this can happen between people using the same machine. This leads me to believe that environmental factors can play a part on how well your print will stick to the bed, such as humidity and dust particles in the air, but apart from that, below are other common reasons for your print not sticking to the bed.

    It is believed that the greatest reason for print failures is the first layer either not being laid down well or not sticking to the bed platform properly....If that first layer of plastic doesn't stick to your print bed, it's almost inevitable that the print will fail

    How to Prevent Bed Adhesion Issues?

    xxxx mention differences between ABS & PLA

    3D Printing Issue #5: Over Extrusion

    What is Over Extrusion & What Causes It?

    As the name suggests, this is when the printer supplies more material than is required. This excess material compromises bonding and integrity of the model and results in excess material on the outside of the model printed.

    Typically the cause for over extrusion is due to the way the slicer software has been set to extrude the plastic. There are a few things that can be tried in order to get the perfect flow of plastic.

    Signs that your printer is over extruding – Photo credit: Hackaday

    How to Prevent Over Extrusion Issues?

    • Check your slicer’s extrusion multiplier settings
    • xxxxx
  5. Extrusion Multiplier Settings

    3D Printing Issue #x: Under Extrusion 

    3D Printing Issue #x: Layer Shifts

    3D Printing Issue #x: Snapped Filament

    3D Printing Issue #x: Stripped Filament

xxxxxx