3D Printing Trouble shooting

3D Print Problems and solutions (Pick SEO Japanese Friendly Title)


無断複製・転載・配布行為を禁止します



FFF式(FDM)プリンターで起こりうるトラブルと解決方法を提示する

プリントを開始したが、射出されない


頻度の高いトラブルではあるが簡単に解決することが可能である。まず以下の事項を確認するのがよい。


  1. エキスとルーダーがプライミング(射出準備)されていない
    1. 3Dプリンターを初めて導入される際、非常に頻繁にみられる事象であり心配のされるところになります。フィラメントを挿入して、比較的長距離をエキストルーダーモーターで移動させなければ射出されません。1目盛移動させるとすぐに材料がノズルの先から融けて射出出来る状態が3Dプリンターをプライミングさせた状態となります。これらを行うには幾つかの方法があります。一つはプリンター内臓コントロールかスライサーを直接プリンターにつないだ状態より射出する方法です。もう一つはスカート、ブリムやラフト機構を使い実際の造形物の一層目が始まる前にノズルが完全にプライミングされた状態にする方法です。

  1. Temperature for your filament is too low
    1. This can often happen if you are using new and different brands of filament. This can occur even if you are setting the printer to the correct temperature but your PID sensor is not functioning correctly, a common problem in 3D printers. The way you know this happens is if your hear your extruder motor clicking, this is indicating that it cannot push the plastic down and may also be caused by your nozzle being too close to the bed. Try raising temperatures by 3-5 degree increments. As a general rule, it is better for filament to be printed at the coolest possible temperature.
  2. Nozzle too close to the build plate
    1. If the nozzle is set so close to the build plate, filament will not be able to flow out the nozzle. Make sure you can fit a sheet of normal A4 paper in between your nozzle and build plate. If you cannot, your nozzle is too close.  Either adjust your Z-offset or mechanically raise the nozzle.
  3. Filament Stripped
    1. Check where your filament meets your extruder gear. If you see that the gear has eaten into the filament. It will not be able to provide the driving power to push the filament down, even under ideal printing settings. Cut the filament above the point where it has been eaten into and readd the filament.  
  4. Extruder Clogged
    1. When troubleshooting issues with no extrusion this is one of the last issues you should check. Extruder jams often occur for two reasons, bad extruder design causes plastic to be heated and cooled in the wrong areas. That is why some printers and people will have this as a constant issue. You probably already know how to troubleshoot your specific extruder. The other common way for jams to occur is through using filaments with certain additives. Cheap filaments will often try to ‘bulk-up’ their filament by adding things that you should not be running through your printer and those cool composite filaments like copper or steel, can cause a build up of debris that will impede flow and cause jams. There are a number of ways to solve a jamed extruder but it is advisable to start with the gentler methods first then move onto more extreme cases. Try heating up your extruder another 10 or 20C above where your filament prints and try printing again. Sometimes by increasing the flow, the filament itself can clean the extruder barrel slightly. This is especially true for filaments like nylon which will pick up debris in your extruder barrel and deposit them. Another good tool is a small steel rod which can be inserted directly into the extruder barrel and force out any debris.

Print doesn’t stick to build plate


The first layer of a print is generally the most important. An object that doesn’t stick to the build plate on the first layer will be unlikely to succeed and a print that sticks only marginally is likely to fail later in the print due to thermal stress or mechanical force such as nozzle drag. Getting the first layer perfect is one of the best things you can do to help your overall print quality.


  1. Nozzle is too high
    1. All else being equal, one of the most common reasons that a print does not stick to the build plate is because the nozzle is too high. Some build surfaces and filaments function better at different nozzle heights but generally the ideal height is about the thickness of one sheet of paper. Which is testable by sliding a piece of paper in between the nozzle and the buildplate; if you feel no resistance, the nozzle is too high, if you feel a slight drag but are still able to slide the paper, you have the correct height. New higher grade 3D printers often come with some automatic feature to adjust z height by use of sensor. If this is failing you, try adjusting the z-offset in your slicer or onboard controller.
  2. Bed Temperature too low
    1. This can occur in especially cold environments or when printing with a material such as ABS that requires a high bed temperature. PLA can be printed on surfaces as low as room temperature, although the ideal is usually around 50-60C whereas ABS is best printed at 100C+. Typically filament manufacturers will list their ideal conditions.
  3. Not enough surface contact
    1. Some prints, especially if they are tall and don’t have much surface area touching the build plate will have trouble sticking. Try using the skirt, brim, or raft options in your slicer to add extra surface area to the print.
  4. Cooling fan
    1. There are two types of fans on a 3D printer extruder. One type is for cooling the heatsink of the extruder to prevent heat from getting into the cool zone of the extruder and the other is designed to cool the part so that the plastic is sets in the correct position as soon as it is deposited. On the first layer, rapid cooling of the part could cause the print to peel away from the build plate. Try turning off the part cooling fan for the first layer.
  5. Non planer build surface
    1. What happens is that when building a object with a large surface area touching the build plate, one spot on the build surface may be at the perfect Z height whereas another part will be .5mm different. The perfect spot might stick well but if the other part at another spot doesn’t, it can cause the entire part to not stick. This can be a frustrating problem as the cause is often related to the design of the machine. If your printer has some way to adjust the bed level, follow the manufacturer's instructions. If that doesn’t work. Try using a gluestick and laying down a thicker layer on the problem part.
  6. A note on types of build surfaces
    1. Manufacturers have numerous types of build surfaces, metal, glass, perforated board, PEI, Kapton tape, Buildtech, painters tape ect. There are so many options partially because no one is perfect. Some will work better with specific materials and 3D Printer designs.

 

Under Extrusion


Underextrusion is the phenonom in FFF printing where less than the optimal amount of filament is being extruded due to an incorrect software setting. The classic way to check this is to print a cube with three shells and check the top layer to see if there are gaps between each shell.

  1. Filament Diameter is wrong
    1. Not all 1.75mm and 2.85mm filament is as it says. Some cheaper brands might be off by as much as .1mm. This may not seem like a lot but if you consider that the 1.75mm filament is being pushed through a .4mm hole, even a small error in plastic amount results in big changes in overall print quality. The way to check filament diameter is to cut a meter length of filament from the spool, measure in a few places and take an average of your measurements. Input this as the filament diameter into your slicer. In theory, this is proper way to 3d print with every new spool of filament, even from the same brand and batch. In practice, you can make small adjustments using an extrusion multiplier in real-time on many newer 3D printers.
  2. Flowrate and Extrusion Multiplier
    1. This is the setting is often both on onboard controllers and slicing software. It is expressed as a % and often small changes make large impacts on the print. For example, under extrusion might be corrected with just a 1% or 2% increase in in flowrate or the extrusion multipler. Keep in this mind when troubleshooting under extrusion and test in small increments.

Over Extrusion

Over extrusion is just the opposite of under extrusion. It also occurs for the same reasons; incorrect filament diameter and too much flowrate and the solutions to fixing it are the same. Under


Bubbling and Holes on Top Layer


This can be a frustrating 3D printing problem because it often occurs at the end of a print of can cause a lot of wasted time and material. Understanding the reasons this occurs is key to avoiding this problem.


  1. Bubbling and top solid layers
  1. Bubbling happens because the filament is being cooled and will quickly exert some thermal stress causing small edges of plastic to lift up. This slight warping wouldn’t normally be a problem if it was occurring at the infill level because the top needs to be smooth for a nice looking print this can be a surprise problem. This also occurs more drastically on more shallow angle surfaces because of the higher degree of layer offset.  The solution is to add more solid top layers. Also keep in mind, when printing with a lower Z height, it might be necessary to add more solid top and bottom layers as each layer amounts to less plastic and more chance for bubbling.

2) More Infill

  1. The most common cause of holes on the top layer is insufficient infill. This is because as the material is attempting to bridge between infill, it will sag slightly causing the material above it to sag as well. Adding more infill prevents this by having small gaps for the filament to bridge preventing sagging. Also note that different materials bridge better, so for example, while 20% infill might be sufficient for your model when printing in PLA, with ABS it might it might cause holes or gaps to form.

3) Also see underextrusion section if there are unseemly gaps in the top layer.


Stringing or Oozing

Stringing is the problem where filament is still moving outside of the nozzle while the extruder is moving but not intending to print. That is why you often see it occurring near multiple tall slender objects such as pillars in a building.


  1. Overheating
    1. The most common reason to seeing oozing is due to overheating. This is because the filament flow rate is too high and the back pressure created inside the hotend will naturally push out the high flow material.

2)Retraction settings

  1. Retraction distance is too low
    1. This happens because retraction is designed to prevent flow of material into unwanted spaces by sucking up a small amount of the filament at the nozzle. Models with a lot of retraction movements will often see problems with oozing. This typically means your retraction setting is not correct. Try adding a small (.5mm) amount more reaction distance in your slicer settings,
    2. Retraction speed may be to slow to retract enough filament to prevent oozing. Try turning retraction speed up in increments of 10mm a second. Be careful because too high a speed will cause excessive force against the filament and may cause enough wear for your extruder geared teeth to chew through the filament.