🔥 The definitive guide to solving 3D printing problems by Bitfab

🤬Having problems with your 3D printer? You’ve come to the right place.

In Bitfab we have prepared the definitive guide to solve all your 3D printing problems. Thousands of hours of professional 3D printing behind our back to help you with the setbacks you have with your printer.

And we not only give you the keys to diagnose your printing errors but also the best tips to prevent them from reappearing, fix your printer and calibrate. Pictures, videos and our best tips in a mega article.

👇 Enjoy the guide and use the index if you want to go to directly to the part that interests you.

🤬 The most common defects and problems in 3D printing

We have put together a collection of the most common problems that arise when using our 3D printer. They are the same problems that we commonly encounter in our online 3D printing service, and so we have quite a bit of experience dealing with and solving them.

A well calibrated printer, correct lamination and an experienced operator are key to avoiding these problems. By having that you will be able to solve any printing problem.

If you experience any of these issues, follow the instructions we give you and if you still can’t solve them, you have the comment box at the end of the article to tell us your doubts.

❌ Warping, the first layer peels off and the parts bend

Warping en impresión 3D

Warping is a decreasingly common problem, as the vast majority of modern printers have hot beds. In any case, warping can be caused by the following factors:

  • Lack of adhesion to the bed: this can occur due to incorrect height of the nozzle in relation to the base, or poor leveling; but also lack of adhesion to the printing surface.
  • Thermal contraction of the upper layers, which when “shrinking” pull on the lower layers. If this occurs, the print surface may even break if it is a BuildTak type, as the sticker will be torn off the bed. This can also happen with glass. This happens mostly with materials such as ABS or Nylon, and it is very difficult for it to happen when printing PLA.

Depending on our problem we can look for a solution accordingly:

For the lack of adhesion there are several solutions. If we are using a glass base, it is highly recommended to use some adhesive to increase the fixation of the part. Some known adhesives are the famous Nelly hairspray, or its more professional version 3Dlac. If we are using ABS we can apply a layer of the mixture known as ABS slurry which we can make ourselves by dissolving ABS in a container with acetone.

If your problem is related to thermal contraction, increasing the adhesion will not help you too much since, as we have said, the ABS when deformed can even break our printing base. To solve this problem we can simply cover the printer with whatever we have at home. A large box can work, as well as a more professional enclosure made in a closet.

The idea in this case is to enclose the heat generated by the bed, so that there is not much difference between the temperature of the first layers and the temperature of the upper layers, which are farther away from the heat of the bed.

Here’s an article that we made explaining this problem more in depth: How to avoid warping and cracking in my 3D prints.

❌ Cracking or delamination

Following on from the above problem is cracking or delamination. We talk about cracking when the layers of a part are not well joined, resulting in these layers being separated (hence the name delamination). This problem can be caused by two different reasons:

  • Poor adhesion between the layers: the layers do not stick properly to each other.
  • Thermal shrinkage: the layers stick together well, but a difference in temperature between different sections of the part causes it to deform, which can cause some layers to separate.

If the problem is lack of adhesion, it is usually due to low of temperature. Most filaments have a temperature range in which they can be printed.

Within this range, lower values will give us a better aesthetic appearance, since the deposition will be “cleaner”. Conversely, higher values will give us better layer adhesion. Printing materials such as ABS at less than the proper temperature often leads to cracking when trying to bond two layers without applying enough heat.

To check if our part is cracking due to lack of adhesion between the layers, we can try to raise the temperature and/or reduce the speed of the layer fan, as excessive cooling can also affect it negatively. Some materials, like ABS, will always be prone to cracking and will be more difficult to control; others like PLA are very easy to print without cracking.

On the other hand, if our problem is thermal contraction the solution is more complicated, as we must manage to create a warmer environment in our printing area. The optimal solution would be to cover our printer, as indicated in the previous point. This can result in some problems, since an excessive temperature can lead to failures in the electronics: missing steps or losing printing artifacts… it can also cause clogging, since there is not enough difference in temperature between the cold zone and the hot zone of the hotend.

In general, avoiding draughts (and the consequent temperature variations) and covering our printer will help, but we must be careful to avoid the problems mentioned.

❌ Layer shift

Layer shifting is a problem that occurs in the form of a displacement on some axis at a certain height. It can occur in the X-axis, the Y-axis or even both simultaneously. The most common causes of layer shifting are:

  • Excessive temperature in the motors, or drivers: the electronics in general are not designed to operate continuously at a very high temperature.
  • Lack of power in the motors, usually caused by a very low voltage value in the drivers.
  • Mechanical failure: it can happen that we have some of our belt’s teeth broken, or there is some debris on the shafts that can cause a jam in the movement of our printer. Sometimes a wrongly tightened component can also cause layer displacement defects when the whole shaft moves freely.

A general advice would be to put heatsinks, and if possible ventilation, to the drivers of our board. These components basically take care of sending all the necessary air flow to the motors, so they tend to heat up. Likewise, if our printer operates in very hot environments it would be appropriate to add some heatsink to the X and Y axis motors as well. If the drivers are very hot, you will usually hear a knock, knock, knock on the motors when the drivers are briefly disconnected to give them time to cool down.

Additionally, you can check if your printer has drivers with adjustable voltage, and if so, you can increase this voltage slightly by carefully turning the potentiometer on each driver. Be careful when doing this, and always do it with the printer turned off or using a ceramic screwdriver to avoid short-circuiting with a metal screwdriver. If you turn up the power on the motors too much you risk falling into the overheating problem again.

Finally, check that the shafts of your printer are clean and free from obstructions. Also check that the belts and bearings are not too tight (if the bearings are tightened with flanges or screws). Shafts that do not move well, over-tightened belts… cause motors to work harder and may lose steps.

❌ Z-wobble

This problem can be difficult to identify, as it is often not easy to distinguish it from a simple inconsistency in the extrusion. To identify it we must look at whether this inconsistency is repeated on a regular basis. If it seems random, or just noise in general, your problem is probably not z-wobble but an extrusion problem. Conversely, if there seems to be a pattern that repeats periodically such as waves on the surface, you may well have a problem with your Z-axis.

This problem is mostly due to structural failures in the construction of the machine, and is difficult to solve without making major modifications to our machine chassis. First of all check that all the parts are properly assembled, maintaining the perpendicularity and making sure that there are no loose screws.

Try to tighten all the screws on the couplers that connect the z-axis motors to the spindles. Also check that there is no wobble between the spindle and the trapezoid nut. It is complicated to give a correct solution, because the axis needs some freedom to move to compensate small errors in the chassis, such as corners that are not perfectly perpendicular.

A good solution that is not too expensive is to replace the motor-coupler-spindle assembly with a motor with a built-in spindle. We can also add reinforcements to our printer so that the frame of the printer does not wobble at the top.

❌ Stringing

Stringing is one of the most common problems in novice parts in the world of 3D printing, so if your parts have a lot of strings don’t worry, it’s totally normal and quite easy to solve.

Stringing appears when, as the hotend moves between two sections of our print, a small amount of plastic drips off and sticks to both sections, leaving a small thread in between.

This problem can be caused by the use of a bad quality hotend, but usually the machines have a hotendsn of sufficient quality, so the problem almost always comes from bad lamination in the slicer.

The most important parameters you should check in your slicer to minimize the stringing are the following:

  • Temperature
  • Retraction distance
  • Retraction speed

Temperature is a vital factor and probably one of the 5 most important settings in your profile. If you have a lot of stringing you are almost certainly melting at too high a temperature. Remember that all materials have a range of temperatures in which they can be printed, so try lowering the temperature and bringing it closer to the lower limit recommended by the manufacturer. If you are already using a very low temperature and still have stringing, check the following points.

While it is not possible to “suck” plastic out of the nozzle, as no negative pressure can be created, it is possible to minimize the pressure on the nozzle by pulling the filament out of the hot zone of our hotend. The shrinkage distance is very dependent on our printer, as both the melter and extruder and the type of extrusion (direct or bowden) must be considered. Most bowden printers perform well with a shrinkage value between 3mm and 6mm, and direct extrusion printers between 0.5mm and 2mm.

The speed of retraction is another important factor, as the higher the speed the lower the stringing. This speed will depend on the motor of our extruder and also on the type of extrusion (1:1 vs 3:1 like the Titan extruder). Generally values between 40 mm/s and 60 mm/s usually work, but if you have any doubt, please ask in a forum or group dedicated to your specific printer.

Additionally, almost all slicers or laminators have different more advanced settings that can help reduce the stringing, but these will only be of importance if the three previous ones are well adjusted. This is a very broad topic and we could make an exclusive guide about this problem, so if you want to see it, leave us a comment!

❌ Overheating, curling

One of the easiest problems to diagnose is overheating.

As we can see in the image, melting our plastic at an excessive temperature will cause the parts to look deformed, with the center of the layer sunken. This is because when melted at too high a temperature, the material does not have time to cool down, and that is why the layers can collapse or sag.

These deformations will be much more pronounced in small areas, such as small peaks of our part, where instead of a clean figure, a deformed churro will remain.

The solution to this problem is simple: lower the temperature. We must also play with the values of the layer fan, since a high temperature can favor a more fluid extrusion and we can compensate this temperature with a good cooling. In this way the material will be cooled down quickly and we will be able to obtain optimal results.

❌ Elephant’s foot

The elephant foot is a defect consisting of the expansion in the horizontal plane of the first layers of our part. It can occur due to two things or, normally, a combination of both: the nozzle is too close to the bed or the temperature of the bed is too high.

If the nozzle is too close to the bed, it is obvious that the first layers will be more flattened and therefore expand in the XY plane. To solve this problem we must correctly level our first layer, as indicated in a previous section of this article.

An excessive bed temperature (say, 90 or 100 degrees for PLA) can cause the newly deposited plastic to expand and deform, causing this very characteristic effect.

❌ Ghosting, ringing

The best article on this topic on the internet is the 3D Campy post by 3DSpana about ghosting, because he dedicated himself to try different combinations and components, taking pictures of the results, so you can see how decreasing the weight of the axes affects ghosting. If you prefer it on video, here’s the summary:

😍 Keys to print correctly with your printer

You’ve seen the list of problems we’ve collected. Now you have to know how to DO things.

Knowing your printer and laminator is the key to error and defect-free printing, so here are some tips to avoid problems and help you diagnose and fix them:

✅ Printing speeds

One of the most common mistakes we find on beginners is wanting to print too quickly on their first parts.

The printing speed is one of the most important printing parameters to obtain the best printing quality and an excess of speed affects the part very negatively for many reasons: vibration, extrusion problems, overheating, loss of steps…

One of the first things you have to do when you encounter a problem is to reduce the printing speed to see if it is solved. We usually print almost all parts between 40 and 60mm/s, no more is needed for most cases. In a printing service the most important thing is reliability and when you are looking for reliability it is best to print at reasonable speeds so you don’t have to throw the parts away.

It is not necessary to print your parts at 100mm/s, especially the first ones. Yes, we all know someone who does it and gets it done, but it’s not the best way to make sure they come out right.

✅ Bed adjustment and leveling

Learning to set the bed correctly level and the extruder at the right height is one of the first steps we take with a new 3D printer.

Here’s what a properly adjusted bed looks like: the height of the first layer has to be correct across the entire surface of the bed.

Problemas altura primera capa

First layer too close

If your first layer is too close to the printing surface, you can cause jams, scratches on the bed, parts with the wrong dimensions, elephant foot…

Correct first layer

When the first layer is correct, the threads deposited by the extruder touch each other and are not too flat against the bed.

First layer too separate

A very separate first layer can be noticed by the separate threads.

Parts printed in this way are usually detached from the bed or warp.

And how do you properly level a hot bed? Our preferred technique is paper in the corners. It is not necessary to have a printer with self-leveling, the best thing is to have a reliable and well calibrated printer to print with quality.

✅ How to prevent and fix extruder clogging

Extrusion jams are the number one cause of failure on a farm like ours. You may have mastered your printer but the jams are always going to be there, so it’s critical to understand them and be able to prevent and fix them.

If you don’t yet understand how a 3D printer extrusion works and what the common terms for referring to them are, you can first check out our guide to 3D extruders.

Causes for clogging

Clogs arise from many different causes, sometimes in conjunction with each other. I believe the best way to solve them is to first understand all those causes and then try a series of techniques that can help fix them.

  • Contamination at the tip and print canal. Impurities that are deposited in the print canal or at the tip of the nozzle and hinder or completely block the flow of the filament.
  • PTFE/teflon degraded. Teflon hotends in the hot zone require maintenance of the Teflon, which when degraded clogs the filament flow.
  • Extruder problems. Maybe your extruder is not working properly:
    • Too much tension or too little tension in the dock
    • Low voltage in the driver that does not give enough power to the motor
    • Dirty thrust wheel, with teeth covered with filament debris
    • Any loose or broken parts
  • Scratching the filament. This is very, very important to understand. When we see the scratched filament, nibbled by the extruder wheel, it is not always the cause of the clogging. All printing clogs, whatever the cause, end up scratching of the filament. And only those clogs that are due to spring tension and excessive shrinkage are the root cause of the clog itself.
  • Tip scratching the base. If the first layer is too low, it can interrupt the flow of the melted plastic and quickly cause a clog in the extrusion system.
  • Watch out for shrinkage. A part with a lot of very fast retractions can end up scratching the filament. And long, slow retractions can overheat the cold zone of the extruder and cause clogging as well. In general, retractions won’t cause your clogs, but you should always keep an eye on them.
  • Poor cooling. Cooling is a fundamental variable in all-metal hotends. If your extruder is 100% metal like the E3D V6 you have to be very careful with this and with excessive shrinkage.

Unclog the nozzle with acupuncture needles

Aguja acupuntura atasco impresora 3D

The technique of passing an acupuncture needle through the printhead is most useful if the real cause of your clog is an impurity. The nozzles themselves last many hundreds or even thousands of hours of use, so you will almost never have to change them.

Most likely a particle has been deposited in the nozzle and you should be able to get it out with the needle. We heat the head and stick the needle while hot, and then pull out the filament with the particles that might be causing the clogging embedded in the molten filament.

Repeat this process until the plastic comes out of the nozzle again easily.

Hot and cold pulling

The pulling takes a little longer to do than using the acupuncture needle, but it cleans the impurities better and also takes away the filth not only from the tip, but from the whole interior of the hotend.

They are easier to explain with a video like the one below:

Teflon switching

In hotends with Teflon liner it is necessary to change this component, in general, every several hundred hours. The Teflon or PTFE liner is a small tube that goes in the hot zone of your hotend to guide the filament in the last centimeters of run, and that is degraded due to the temperature it reaches. Changing it is a job that you will have to learn to do to properly maintain your printer.

Before the tube degrades completely, you will notice that your printer is having more and more trouble printing, the filament thread that comes out is thinner and it’s harder for it to deposit material on the parts that you print faster.

In every printer the change of Teflon is different, but here is the example of the Hephestos 2 from BQ to help you understand it better.

Adjusting the printing parameters

There are clogs that can occur because our laminate is not well adapted to the type of part and printer we are going to use.

To allow your printer to extrude more easily you can try:

  • Printing slower
  • Printing at a higher temperature
  • Printing thinner layers
  • Reducing the flow rate if you have more than 100%

These are all tricks that reduce the requirements on the extruder and melter because they require less flow through the hotend and heat the plastic to make it more fluid.

Retractions can also influence extrusion problems:

  • Too many or too fast retractions can result in scratching of the filament in the extruder.
  • Too long or too slow retractions can cause cooling problems in your melter (especially if it is all-metal) or end up clogging the plastic in the cold zone of the melter.

If you don’t know how to fix it, dissasemble the extruder and hotend

The best way to attack a mechanical problem that you don’t know how to solve is to proceed to disassemble what you want to fix. Taking apart a hotend and an extruder is quite simple and will allow you to see inside what is happening and reflect on the problem.

When you dismantle your extruder you will notice that there are some broken parts, dirt somewhere, some loose screws…

If you disassemble the hotend you will be able to see the state of the Teflon, the tension of the hotend threads and if there is print residue deposited in the filament canal.

In either case, take the opportunity to clean the parts to prevent errors in the future.

👋 That’s it for the 3D printing troubleshooting guide by Bitfab

Thank you so much for getting this far.

If you have any doubt or a different problem just put it in the comments and we will help you solve it, or maybe even add it to the rest of the problems 😁

👋 Greetings and thanks again!

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