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3D printer starts printing in air


5 Ways How to Fix 3D Printer That Starts Too High – 3D Printerly

You’ve loaded up your 3D printing model, preheated your 3D printer, and started the print. Unfortunately, your 3D printer is printing in mid-air for some reason.

To fix a 3D printer that starts too high, you should look towards your Z-offset in your G-Code and check that it isn’t bringing your Z-axis too high without you knowing. You can change your Z-offset by directly changing the G-Code within software like Pronterface or OctoPrint or from your slicer.

This can happen to you for a number of reasons which will be simply explained in this article. I’ve had the problem and fixed it successfully, so keep reading to solve this once and for all.

Why is My 3D Printer Printing in Mid Air?

While using 3D printers, there may come some malfunctions that can cause problems and even can ruin your prints, wasting your all efforts.

You may have faced the problem when you set a height for the nozzle to move and print but when you start the printing process you may notice that the 3D prints start too high.

Printing on the right height is necessary because if the nozzle is too high the prints will not stick to the bed properly and may cause printing failures such as rough edges or lifted layers.

Well, this problem doesn’t often happen but there are some reasons that contribute to the occurrence of this issue.

It is not a difficult job to avoid this issue because there are plenty of solutions, but to get the job done perfectly you should have to know about the actual reasons that are causing the problem.

The major reasons behind this problem to occur include the following.

  • Z Offset too High
  • Bad First Layer Settings
  • Print Bed is Not Calibrated Accurately
  • Wrong Octoprint G Codes
  • Print Requires Support

How to Fix a 3D Printer That Starts Too High?

As you know that there is not a single problem in 3D printers that cannot be solved. You can get rid of any problem after you have found out the basic reason or cause behind it.

There are many solutions suggested by the 3D printing experts and manufacturers to get rid of the 3D printer printing in mid-air problem efficiently without any hassle.

Whenever you notice that the 3D printer nozzle is too high, it is recommended to stop your printing process immediately and first try to fix the problem to prevent your prints from damages.

If you set a different print height but still see that the 3D printer first layer is too high then you should consider implementing one of the following solutions.

Here we will discuss the simplest and easiest techniques and ways to solve the problem and enjoy a perfect printing experience.

  1. Check Your Cura G-Code & Settings for Z-Offset
  2. Check for the First Layer Prints Settings
  3. Level the Print Bed
  4. OctoPrint Settings and G Codes
  5. Add Supports to Your 3D Prints

1.

Check Your Cura G-Code & Settings for Z-Offset

Most people who experience their 3D printer printing in mid-air or starting too high usually fix it by altering their G-Code and settings to stop the print head from moving up more than necessary.

This isn’t a too well-known method so it confuses many people, but once you know how it works, you see how simple it really is.

In Cura, go to Settings > Manage Printers > Highlight your 3D printer > Machine Settings. This will bring up your starting G-Code within your sliced file. I would examine this code and check what is happening with the Z axis.

The following is what is shown in my G-Code:

; Ender 3 Custom Start G-code

G92 E0 ; Reset Extruder

G28 ; Home all axes

G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed

G1 X0.1 Y20 Z0.3 F5000.0 ; Move to start position

G1 X0.1 Y200.0 Z0.3 F1500.0 E15 ; Draw the first line

G1 X0. 4 Y200.0 Z0.3 F5000.0 ; Move to side a little

G1 X0.4 Y20 Z0.3 F1500.0 E30 ; Draw the second line

G92 E0 ; Reset Extruder

G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed

G1 X5 Y20 Z0.3 F5000.0 ; Move over to prevent blob squish

G1 simply refers to a linear move, then the corresponding Z after G1 means to move the Z axis that number of millimeters. G28 is the home position.

  • Check over your G-Code settings and make sure that Z movement isn’t out of the ordinary
  • If you see the Z movement is a little too large, you can alter it and run a test print.
  • Make sure not to do it too low so your nozzle doesn’t scrape into your build surface.
  • Reset your settings back to default or to a custom profile that is known to work well.
  • You can also adjust the Z offset by inputting it directly into the slicer.

2. Check for the First Layer Prints Settings

Sometimes the first layer height can also cause problems. With the change in the Z offset it is recommended to check for the first layer printing settings as well.

The first layer of the print is the most important factor of any 3D print and if it doesn’t adhere well, the print may not stick to the bed and can cause many problems.

Make sure that the first layer is not set to 0.5mm greater because the printer will have to print high to get the first layer done and this can cause problems.

  • Try to have a first layer around 0.2mm high
  • Experts suggest that the first layer should be set as an “even” value and not something “odd”.

3. Level the Print Bed

An unbalanced print bed can cause printing problem more than any other part of the 3D printer because all your prints are created directly on it.

If the print bed is not leveled correctly, there are possibilities that you face the problem of your 3D printer printing too high.

It is recommended to get a 3D printer that has an advanced auto-leveling system installed so it can account for the level differences in your print bed. It senses the position of the nozzle in comparison to the bed and adjusts accordingly.

If you don’t have the automatic bed-leveling system, you can still do a few things:

  • Check the settings and make sure that the print bed is leveled properly.
  • When you are sure about the level of the print bed then set the nozzle height accordingly.
  • If the unbalanced print bed is the real cause behind the problem then leveling it can help you out.
  • Check whether your print bed is warped, and if it is, replace it.

4. OctoPrint Settings and G Codes

OctoPrint is a software application that is well known for providing ease to the users of 3D printers.

This application provides its user with a web interface where you can input your G-Codes to control almost all the functioning of your 3D printer.

From setting heat temperature to leveling the bed, all the functions can be done just by adding G Codes in the OctoPrint application.

Sometimes even if you are using OctoPrint, there comes a problem that the OctoPrint nozzle is too high and is printing the first layer which is not sticking to the bed properly.

This can happen because of putting the wrong commands to the application.

  • The first thing you should do is to make sure that you have input the right G Codes to complete a print.
  • If the OctoPrint nozzle is too high, input the G Codes as “G0 Z0” to set the Z offset to “0”.
  • If you are unsure about the G Codes you can get built-in codes for your required object
  • G28 is a command for the print head to return to the ‘zero position’ or printer’s reference position.
  • Then implement G1 Z0.2 which is a linear move for the Z axis to move up to 0.2mm to start that first layer.

5. Add Supports to Your 3D Prints

Sometimes, you see your 3D printer printing in midair and just creating a mess. This can be down to your model having sections which require supports, so if you don’t have supports, those sections won’t print successfully.

  • Enable ‘Supports’ in your slicer

How to Fix Ender 3 Bed Too Far From Nozzle

To fix an Ender 3 (Pro or V2) bed that’s too far from the nozzle or too high, make sure your Z-endstop isn’t installed too high. This would cause the Z-axis to stop at a higher point, so you want to lower this down to the correct point where the nozzle is closer to the bed. 

Some users mentioned that they have to file down or cut off the nub on the edge of the Z-endstop bracket so you can lower it. There is a notch that has it sit in a certain place on the frame, but it can be a bit too high.

You can cut it off with your flush cutters or something similar, even nail clippers.

Make sure to lower your endstop gradually so the nozzle doesn’t crash into the bed.

Printer fails at remembering Z position: prints in air - 3D Printers - Talk Manufacturing

optimizer

#1

After a failed print where the printerhead dislodged itself, it seems the printer is having trouble keeping track of its own Z position.

Everytime I start a new print it starts printing a lot higher than the previous one, making it print completely in the air.

When I make the motor go all the way up untill it refuses to move further, and then start the print from that position it seems to be better, but still not great, forcing me to do both this and level the bed after every print, which is of course extremely tiresome.

Any idea about what could cause and fix this would be greatly appreciated.

bkjones

#2

What do you mean by the printer head dislodged itself? I would start by checking the Z axis stop switch and make sure it hasn’t been bumped. The next thing would be to manually turn the Z axis to the top and make sure both sides are even. Engage the stepper motors and then check again at 100 mm or so. After that make sure the X axis and Z axis are square. I think you will find the problem by doing the above steps. If not let me know and I will see if there is something else I can think of.

Inventreneur

#3

I also had the same problem and found that the stl file is corrupt. Try printing another file that worked previously.

horsj

#4

I would concur with bkjones analysis and approach, which should be your first steps, but would add that I had similar problems; constantly having to re-level the bed. After spending some time trying to work out was happening, I changed the Z axis microswitch for a higher quality Omron switch and have since had no problems. I found these work really well for aligning the Z axis: http://www.thingiverse.com/thing:1138928

BrimstoneE

#5

My printer had this issue which could only be resolved by unplugging the printer power cable and USB cables. This seamed to reset everything. I have a Wanhao DS5 Mini.

optimizer

#6

Manually screwing it all the way to the top seems to have done the trick, as bkjones suggested. I unfortunately only tried it with the motor before.

And with dislodging I meant that the printer actually pushed one of the horizontal bars out with the pressure of the PLA.

Anyway, thanks a lot for all your input, you guys are awesome.

Stephen_Jones

#7

you can manually reset the hiegth by including an auto ref stop check in the g code at say 100 and then disengaging the screws and manually adjusting to q00mm, but if unsure you can force dropout by screwing to the top. if you have altered the bottom ref limit switch don’t forget to include in your calculation.

Stephen_Jones

#8

you can check for lamination abnormalities this way as well, if you work backwards you can find the area that is delaminating and check things like srew claelyness, ball race freeness, etc at that location. first look for the source code call online for the operation you want to do and supply a numerical distance. simple, g-code is, its been around well before the 8086. StevetheBuddistXXX

3d printer defects: errors, main problems

Causes of Defects in 3D Printing and How to Fix Them

Buying a 3D printer is only half the battle. A beginner printer has a lot to go through. First, he will learn how to set up the device, calibrate the print head, set the necessary parameters, and test different types of filaments. But that's not all. The most unpleasant thing that can appear during operation is printing defects. And they need to be eliminated.

  • What are 3D printing defects?
  • Classification of defects

What are 3D printing defects?

After the printing process is completed, various defects can be found on the finished model. Most often they are associated with improper distribution of plastic. Defects appear for various reasons. But the main result is always the same - the model is damaged, you need to do the project on a new one. Printing defects cause downtime. Lost time and meters of filament.

Important! Within the framework of this article, defects that occur on FDM printers will be described. These are models of printing devices operating on the technology of hot deposition of plastic.

Sometimes mistakes can be seen right from the start. For example, when printing the first layer of a model. In these and other cases, it is necessary to prevent the defect in time. However, the press all the same should be stopped. But this way you can save material and time. This article will discuss the most common defects, as well as ways to eliminate them. At the end of the article, a comparative classification of faults will be given.

Layer displacement

The second name of this defect is skew. There are several options for the development of events at once. The skew can be slightly noticeable, with a slight deviation along the Z axis. The second option is a strong offset, the model is printed in pieces. In all these cases, the reason lies in the mechanical part of the printer.

Solutions:

  1. Check tension belts. They should be clearly in the grooves. It is not allowed to fray or stretch the belt. Sometimes it is easier to replace the entire set of belts with a new one.
  2. Sometimes small misalignments are caused by an incorrectly set pulley. Make a mark with a black marker before printing, after the end of the process, check the result. Calculate the difference. Tighten the problem area if necessary.
  3. The printer's Y and X axes are not properly aligned. They are not perpendicular to each other. They need to be set at 90°.

Attention! In rare cases, the problem is electrical. This option must be disassembled separately, armed with a multimeter.

The first layer does not stick

The initial layer acts as a foundation. If it "floats", then the whole model will get the wrong geometry. The second and subsequent layers may slightly shift the entire workpiece. The most unpleasant thing is that this defect can be found at the very end of the print.

Solution methods:

  1. Platform calibration. If the print bed is skewed, there is a good chance that the first layer will not stick. It is best to check platform calibration before starting printing. Many 3D printing programs help to go through this setting in a semi-automatic mode.
  2. Wrong print nozzle height. Another point worth considering. Most often, the extruder height setting is set through the printer parameters: Edit Process Settings → G-Code. They are located in the main menu of the device.
  3. The first layer was printed too quickly. The plastic just didn't cure. This setting must be found in the menu of the printing device. Approximate location: Settings → First Layer Speed. It is worth setting the print speed of the first layer 50% lower than the rest.
  4. Plastic cooling temperature. This option can be found on printers with a cold platform. The filament hits a cold surface, quickly hardens and rebounds. Here you need to experiment with the settings for the melting temperature of the filament or initially take a printer with a heated surface.

Important! Poor adhesion can be caused by covering material placed over the platform. Different glue, tape, adhesive tape - all this can repel plastic.

Pimples on the model

This also includes such defects as “snot”, swelling, sagging. All these faults are of approximately the same nature. They are related to the operation of the extruder. As it moves, it should stop, then start working again. Not all devices can lay even layers without defects. This is how the irregularities described above appear.

Solving methods:

  1. Retract and coast setting. The first parameter is responsible for starting the extruder. In this case, you need to configure the retraction through the device menu: Edit Process Settings → Extruders. Here you need to find the parameter Extra Restart Distance. Try reducing the fill length. When unevenness occurs when the nozzle stops, you need to tighten the roll-on stroke (roll-up movement). This setting is referred to as Coasting. It is in the same section where the retraction is set.
  2. It is better to avoid retraction and coasting altogether. That is, the filament must be flush with the edge of the nozzle. This parameter is especially critical for Bowden printheads. Another option is to set up retraction. You need to find the Advanced tab. It contains the Ooze Control Behavior setting. This option controls filament leakage and retraction start time.

If minor defects are still present, it is worth pointing out the entry points to the printer. This setting is found in the Edit Process Settings menu on the Layer tab. For example, you can leave small flaws inside the shape, starting printing from the inner layers.

3D printer won't print

This is one of the scariest things for a beginner 3D maker. The device appears to be broken. However, in most cases this is not the case. The printer turned on, but did not start to push through the plastic? There are four reasons for this.

Solutions:

  1. Plastic does not come out of the extruder due to leakage. This can often be seen in some cheap Chinese models. The filament is preheated in the extruder, it can seep through the hot end. The same effect can be observed after the end of the work. In this case, printing starts 3–4 seconds after the start. Automatic broken geometry of the first layer. To avoid this defect, experienced printers make the so-called skirt. This is a thin circle of filament around the future model. It is printed to bring the printer to life and fill the nozzle with plastic.
  2. The extruder is too close to the platform. The plastic just gets stuck inside the nozzle. The situation continues on the second layer. Only by the 3rd or 4th layer does the plastic begin to come out. The solution is to adjust the Z-axis height through the G-Code command.
  3. Sometimes the filament is simply chewed off by the drive gear. This is the part that pushes the thread forward. If a small amount of filament shavings is visible near the printer, it is likely that the gear has worn off the filament. You need to calibrate this node.
  4. Clogged extruder. There may be several reasons: ordinary dirt or rubbish, plastic coked inside the extruder, poor cooling of the filament. Mechanical cleaning of the nozzle with special needles or drills will help. They are sold in specialized stores.

Important! Just do not need to clean the nozzle with a screwdriver or other improvised tools. You can completely ruin the extruder.

Prints in the air

Various users are experiencing the same problem. The reasons for printing by air are related to setting new plastic settings in the slicer. Sometimes a defect appears due to incorrect setting of the Z axis.

All solutions come down to the fact that the user needs to carefully study the G-code of the printer. Sometimes the reason lies in the lowered Z-axis height settings. You can also see the print step here, perhaps it exceeds the required parameter. In the slicer, you need to check the plastic installation parameters. View the heating temperature of the nozzle and platform. All settings must be checked manually. When importing a profile, the left parameters can be picked up.

Prints in reverse: how to fix

A rare defect that is not always visible at the start of printing. That is, the model comes out normal, but mirrored. Such malfunctions are often found in Chinese kits or noname devices. There are two solutions. One is simple, the other is more difficult.

Methods of solution:

  1. It is necessary to invert one of the axes: X or Y - it does not matter. But only one. This can be done by flipping the contacts on the power board or on the motor itself.
  2. Invert axis via device firmware. This method is suitable for advanced users who are familiar with programming skills.

In any case, it's better to first check all the settings in the slicer again, only then go into the electronics of the device.

Layers skipped

The finished model shows that one or more layers have been skipped. This is eloquently evidenced by the gaps in the finished model. In rare cases, this defect is associated with insufficient extrusion. Perhaps there are problems with the capture and supply of the filament. Sometimes the reason lies in the wedging of the Z axis.

Solution methods:

  1. Check the mechanical part of the printer. If gaps began to appear frequently, you need to arrange an unscheduled maintenance of the device. Examine all shafts. Check that they are level and not misaligned. Power off the printer, try moving the head with your fingers. If resistance is felt, then one of the shafts is not installed correctly.
  2. Bearing wear. This element may simply wear out. You can see that the printer vibrates slightly. There is an unusual sound when printing. Diagnose a breakdown in the same way as the shaft. Turn off the power and move the extruder with your hands to find the problem part.

Attention! Remember to maintain your printer regularly. Lubricate the shafts with special oil. For example, for sewing machines. Before lubricating, clean the moving parts from dirt and plastic residues. Just don't overdo the oil. A large amount of lubricant can lead to the opposite effect.

Doesn't print in the center of the bed

Some users are having trouble printing on one side of the bed instead of the center. At the same time, in the slicer, the model is clearly in the center. There may be several solutions here.

Methods of solution:

  1. Slicer settings are down or incorrectly set. It is necessary to change the characteristics of the kinematics. Set the Delta robot parameter instead of the Cartesian robot. You also need to set the size of the table, equal to the square inscribed in the specified print area. In this case, set the Origin Offset parameter to half the side of the square.
  2. Try to adjust the position of the X-axis limit switch. In some cases, it is moved a little to the right.

What are the problems with the 3D printer test cube?

This figure is used to check the print quality. Naturally, during the test, she can clearly demonstrate where there are problems. It can be completely different defects. Most often, the test shows bulges and dents on the model.

Such defects result from overheating and shrinkage. To find out for sure the cause and eliminate these factors, you need to print four cubes in different angles. For some ABS plastics, you need to reduce the temperature, as well as turn on the blower by 5-10%.

3D printing echo

This problem can be described as thin stripes that form when printing layer by layer. That is, the final model does not have a formed and even surface. There is waviness (echo) on the edges. This defect is also called ringing on the walls. Typically, two factors are the cause: print speed and vibration.

Solutions:

  1. Reduce vibration. Make sure the printer is on a level and stable surface. Assess the condition of the bearings. Replace them if necessary.
  2. Inspect the shafts. Clean them of dirt and dust, lubricate with oil.
  3. Reduce the print speed through the printer settings.

Try changing the typing speed first, then check the mechanics.

Interesting! Even a single loose bolt can cause strong vibrations. Check all fasteners. Pull the bolts.

Salmon leather

This defect is somewhat similar to the previous one. Only there are no obvious waves or ripples. The defect manifests itself in the form of a pattern. It is similar to the representation of heights on topographic maps or the structure of salmon skin that is drawn on the walls of the model. In English resources it is called salmon skin. The defect appears due to two reasons: vibrations and incorrect characteristics of the current coming to the motors.

Solutions:

  1. Remove any vibrations that may occur in the device. Tighten the bolts and check the frame geometry. You can also slightly reduce the print speed.
  2. Installation of a special impulse reducer (TL-Smoother) in the circuit between the driver and the axle motor. This solution balances the current indicators. The edges are more even.

Salmon skin defect is common on DRV8825 stepper motor drivers.

Ripple

In this case, we are talking about the partial impact of waves on some parts of the model. The ripples are often of the same nature as the echo. It is also tied to vibrations and the speed of the extruder. However, unlike waves, ripples are especially pronounced at sharp corners, when the nozzle abruptly changes direction.

Methods of solution:

  1. Reduce the print speed. You need to find the Edit Process Settings menu in the printer settings, and then open the Other tab. Change two settings: Default Printing Speed ​​and X/Y Axis Movement Speed. The first is responsible for the speed of all movements of the nozzle, the second - the speed in the absence of plastic supply. Sometimes the reason lies in the factory firmware. It initially indicates increased extruder acceleration.
  2. We remove vibrations. Check the geometry of the device, stretch all the bolts, assess the condition of the shafts and bearings. Lubricate the device if necessary.

We recommend checking the print speed settings first.

Poor filling

If the figure is not filled enough, this means that it will not receive sufficient strength. The model may simply break or crack. Usually the causes of poor coverage lie in the slicer settings or print speed settings.

Solutions:

  1. Try changing the fill pattern. It is indicated by the Internal Fill Pattern parameter. There are presets in the settings with complicated filling options that give more strength to the finished model: Grid, Triangular and Solid Honeycomb. The printing time will increase, but the strength will also increase.
  2. Reduce print speed. The fast movement of the print head results in less infill. You need to tweak this parameter through the settings of the device itself or through the slicer parameters.
  3. Change extrusion width parameter. Some 3D printing programs allow you to set different infill values ​​for individual elements. For example, for the outer layers, set the size to 0.4 mm, for the inner layers - 0.8 mm. These settings can be viewed in the menu Edit Process Settings → Infill. In it you need to find the parameter Infill Extrusion Width. It is shown as a percentage. The higher the number, the thicker the layer.

Attention! When setting the Infill Extrusion Width parameter, make sure that the set value (in percent) is supported by the printing program (slicer).

Plastic is leaking from the extruder threads

This fault can be attributed to local printer failures, although they can create a number of defects in the form of “snot” on the model. Plastic oozes through various slots, flows down the extruder thread, exits the opening of the heating element. There may be several options for solving the problem.

Solutions:

  1. Check all screw connections. Sometimes a caked piece of plastic gets stuck between them. It creates a gap, the filament flows out.
  2. Clean and polish the surfaces of the thermal barrier tube and nozzle. Installing a fluoroplastic washer or winding a fum tape can also help.
  3. Reinforced cold drawing of threaded connections.

Attention! Sometimes the reason lies in a manufacturing defect. Nothing can be done here. Just completely change the extruder.

Plastic does not come out of the nozzle

For some reason, the printer stopped feeding filament. The device continues to make noise with the engines, but the plastic does not come out of the nozzle. There may be several reasons and solutions for this.

Solving methods:

  1. The plastic is out. For some printers, the filament spool is covered with a casing. Therefore, it is impossible to immediately understand that the thread is over. Check for material in the spool.
  2. The thread has broken. There was a gap between the hot end and the extruder. A common cause is with Bowden printheads. Perhaps the problem is with the filament itself. You need to try other material.
  3. Low plastic melting point set. The thick filament cannot pass through the narrow nozzle opening. Recommended temperature parameters for different types of plastic: PLA - heating t 180 °C, table heating t 60–80 °C; ABS - heating t 240 °C, table heating t 110 °C.

Interesting! Sometimes a clogged nozzle is causing the print to stop. This can happen even during work.

Model delamination

Visually, this defect looks like an accordion. In some places, the layers move away from each other. At the same time, it is clear that this is not a pass, but the absence of sticking of plastic. Layer separation occurs due to incorrect setting of the filament thickness or its melting temperature.

Solving methods:

  1. Reduce layer thickness (height). Here you need to follow the rule: the maximum layer thickness should be no more than 80% of the nozzle diameter. Otherwise, the layers will not stick to each other.
  2. Raise the melting point of plastic. If the height parameter is in order, then you need to look at the temperature settings. For example, the optimum melting temperature of ABS plastic is 220–240 °C, but some users set it to only 190 °C. You can increase the melting temperature in the slicer settings: Edit Process Settings → Temperature.

If standard temperatures are not suitable, try raising the setting by 10 °C. See if the adhesion of the layers improves or not.

3D printer extruder does not heat up

At the same time, the device shows 100% heating power, the set temperature is on the display, but the extruder is cold. In most cases, the cause lies in a break in the wires or in the heating element itself. Ring all circuit elements after the controller. To cut off problems on the heating element, apply 12 V to it. It should start to heat up.

Attention! Newer printers may encounter factory extruder defects. This element needs to be changed. There is no point in repairing the item.

Plastic falls in waves

Another name for this defect is “elephant foot”. In this case, the upper layers of the model are pushing against the lower parts, causing a wave effect. It sort of descends from top to bottom, forming a thick layer at the base of the model. This problem is especially common on models of printers with a heated bed.

Methods of solution:

  1. Find the optimal temperature regime between heating the table and blowing the model. Lower the heating temperature in steps of 5 °C. It is important to find a balance here, when the lower layers have already gained strength, but still retain adhesive properties for the following layers.
  2. Calibrate the table. Try applying the default settings. If the problem persists, slightly change the Z-axis height settings. Calibrate the new settings on the test cube. This is the base shape that clearly shows how the layers are laid down.
  3. Chamfer the base. The option is suitable for homemade devices. You need to start with a bevel of 5 mm and 45 °, after which you can make small adjustments.

Wall gaps

Such defects can be found when printing rather thin walls in the model. For example, when the extruder nozzle prints strips up to 0.4 mm thick, and the user needs to make a 1 mm edge. In such places, cracks may appear at the joints of the two layers. Typically, the defect is eliminated through the adjustment of the slicer.

Solution methods:

  1. We need to find the setting that is responsible for the wall thickness. Usually they are in the menu: Edit Process Settings → Advanced. Here you need to find the Gap Fil parameter. He is just responsible for overlapping areas and filling the gaps between thin walls. Check the box next to Allow gap fill when necessary. There is also an alternative. Go to the Infill tab and tweak the Outline Overlap parameter.
  2. Simply adjust the extrusion width. Increase the parameter value if possible. The strip width can be set on the Extruders tab via the Edit Process Settings menu.

Try and experiment to get the best fit.

Web

A special case of filament leakage, when sloppy plastic threads remain between the parts. This happens for the same reasons as influxes. The solution methods are exactly the same:

  1. Changing the speed and distance of thread retraction. Full instructions are listed above.
  2. Lower print temperature. Try tweaking this setting to reduce the fluidity of the plastic. Here you need to be careful. Excessive decrease in temperature can lead to a delamination defect.
  3. A separate solution is to set a parameter in the slicer that launches the print head in a long and winding path over empty space. The web falls near the model without sticking to its walls. No bridge is formed between the layers. To enable this option, go to the advanced settings of the slicer (Advanced). Check the box next to the Avoid crossing outline for travel movement option.

Interesting! Some 3D makers do not consider a web defect as something serious. They simply cut off the excess filament with a knife after the print is finished.

Extruder does not feed plastic

This problem is in the filament feed mechanism. Or the nozzle is too close to the table.

Solution methods:

  1. Check the plastic filament. It may have burrs on it. The feed gear has slipped. Check the condition of the thread, you may need to tweak the gear settings a little. Or change the plastic.
  2. Calibrate the table position. Raise the Z-axis slightly.

Sometimes the extruder will not feed plastic due to a clogged nozzle. It needs to be cleaned up.

Classification of defects

Almost all defects are one way or another related to two reasons: a malfunction of the mechanical part of the printer or incorrect software settings. Based on these parameters, it is possible to make a classification based on the most common problems in printing:

  1. Deterioration of nodes and the absence of a normal fastener feed. This parameter affects vibrations, nozzle movement trajectories.
  2. Poor extruder maintenance. The print head needs to be cleaned from time to time, to remove the sintered filament.
  3. Inaccurate (wrong) calibration of the platen and nozzle height. Another common mistake that causes a lot of print defects.
  4. Problems with printer settings. Most often solved through manual setting of parameters or adjustment of the G-code.
  5. Lost settings in the slicer. This includes: changed parameters, errors or inaccuracies in the firmware.
  6. Poor quality filament. The problem may lie in the quality of the plastic. It is necessary to monitor its condition, quantity. If necessary, try to replace the manufacturer, or even switch to another type of filament.
  7. Electrical problems. To find such a malfunction, you need to arm yourself with a multimeter and ring all the circuits after the controller.
  8. Factory defect. The problem is solved by replacing a low-quality part.

These are the main printer malfunctions that in one way or another affect its operation, which leads to printing defects. The printer may have several problems at once. They will lead to the appearance of a group of defects. You need to be able to recognize the first signs of breakdown in time and eliminate them.

Important! At least once every two weeks, pay attention to the mechanics of the printer, carry out maintenance on the device. Clean the nodes, lubricate the shafts with oil. Check the platen and extruder calibration.

Defects during printing are annoying. An experienced 3D maker should be able to recognize and classify a malfunction in time. Knowing the causes will help to quickly eliminate the breakdown. The user will not spend a lot of time and effort to eliminate the defect, and will not lose money on a damaged filament.

  • 07 March 2021
  • 13048

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Problems, defects, 3D printing errors and solutions

Often during the operation of a 3D printer, problems may arise due to which defects appear on the finished model. Or instead of a neat product, plastic noodles suddenly appear on the table.

In fact, the causes of defects can be conditionally divided into 2 types - these are physical and software.

Physical ones are those that arise due to problems with the mechanics or any other causes that can be eliminated physically. These include problems with printer mechanisms (belt tension, backlash), clogged or deformed nozzle, incorrect table geometry, etc.

Software - these are defects that occur due to incorrect slicer settings or, less often, errors in the printer firmware. For example, incorrectly selected print speed, retract settings, incorrectly selected temperature for plastic, etc.

Very rarely, the problem may lie in the wrong or “flying” printer firmware (although usually the printer simply will not start then), overheating of some boards during printing, etc. These are rather special cases, so we will not consider them.

Model peels off or does not stick to the build plate

This is the most common 3D printing problem. Every 3D printer has had a case when the first layer treacherously rolls, clinging to the extruder, or the most offensive - when it tears off a partially printed model from the table. The first layer must stick tightly otherwise nothing will be printed.


Gap between table and nozzle too large

This is the most common reason. You just need to set the correct gap between the table and the nozzle.

Modern printers often use an auto-calibration (auto-leveling) table system or an auxiliary table leveling program. To calibrate such printers, use the instructions. If there is no manual, it can be downloaded from the manufacturer's website.

If you have a simple printer without auto-calibration, a self-assembly or KIT kit, use a probe or a piece of paper folded in half to calibrate. The probe should be slightly pressed against the table by the nozzle. Before calibration, the table and extruder must be heated. Align the table surface over each adjustment screw (there may be 3 or 4) in turn, and only then check the center point.

If you're having trouble getting your table surface perfectly level, try raft printing. Raft is a thick substrate in several layers that is printed under the model. It will help smooth out the slight curvature of the table.


A small cheat sheet to determine the correct gap on the first layer

Plastic with poor adhesion

Some types of plastic, due to various reasons, such as large shrinkage, do not adhere well to the surface of the printing platform. In this case, try using stickers or special 3D adhesives to improve adhesion between the table and the first layer of plastic.

In the early days of 3D printing, there were experiments with different homemade 3D adhesive recipes. ABS diluted in acetone, BF glue, sugar syrup and even beer. Some experiments have been successful. Until now, some enthusiasts use some types of hairspray or glue sticks as 3D glue. But still they are inferior in their properties to industrial 3D adhesives.

Some types of high temperature plastics with a high percentage of shrinkage (ABS, Nylon, etc.) may peel off the table during printing. This is due to uneven cooling and “compression” of the model (the lower layers have already cooled down, but the upper ones have not yet). For such plastics, it is imperative to use a 3D printer with a heated table and a closed case.

Plastic temperature too low

The hotter the plastic is when it exits the nozzle, the better it will adhere to the print bed. It is better to print the first 5-10 layers at a higher temperature (+ 5-10 degrees) and turn off the blower fan.

Incorrect first layer settings (speed and thickness)

A thicker layer sticks easier, so the standard first layer is 0.3mm thick. With an increase in print speed, the heating block may simply not have time to heat the plastic to the desired temperature and it will stick to the table worse. Before printing, check the speed and thickness settings of the first layer in the slicer.


A lot depends on how the 3D printer prints the first layer. Try to control the printing of the first layer and only then leave the printer to work alone.

Plastic does not choke from nozzle

The printer has already begun to print, but the print table remains empty. Or part of the model did not print.


Clogged nozzle

In 3D printing, a nozzle is a consumable. The nozzles are clogged or worn out (frequency depends on the type of plastic). The simplest thing is to replace the nozzle. But if there was no spare at hand, you can try to clean the old one. To do this, there is a whole set of thin needles. Or you can heat a clogged nozzle above the melting point of the plastic and “burn out” the blockage. But later it is still better to replace the nozzle.

Low temperature nozzle

You need to increase the temperature of the extruder in the slicer settings or check the thermistor and heating block. Sometimes the thermistor may not read the temperature correctly due to a malfunction or incorrect 3D printer firmware settings.

If the problem occurs after replacing the thermistor - contact the manufacturer or read articles about PID tuning.

Empty extruder

As the extruder heats up, plastic begins to ooze out of the nozzle. Because of this, the extruder may start printing half empty. Because of this, part of the first layer is not printed. You can push the plastic manually by simply pushing the bar into the nozzle. Or solve this problem programmatically - in the slicer, add a contour print around the model (one line).

Some manufacturers and 3D enthusiasts add a line print on the edge of the table at the beginning of each GCode. This is done so that there is plastic in the nozzle by the time the model is printed.

Feeder does not push through plastic

The plastic pushes the feed mechanism to the extruder - a motor with a special pulley put on the shaft. If for some reason the plastic is not pushed through (nozzle clogged, extruder temperature low, etc. ), then the pulley “gnaws” through the bar. You need to push the plastic bar with your hands or cut off the damaged piece.


Elephant foot

The first layers of the model are wider and protrude beyond the boundaries of the model. This is due to the fact that the upper layers put pressure on the first ones that have not yet cooled down and flatten them.


Table high temperature

Due to the too high temperature of the table, the lower layers remain soft for a long time. Try lowering the table temperature. It is better to reduce gradually (in increments of 5 degrees). You can try to turn on the blower when printing the first layers.

Small gap between nozzle and platen

If, when printing the first layer, the nozzle is too close to the table, then excess plastic will be forced out. After a few coats, this will not be as noticeable, but can lead to the effect of an “elephant's foot”.


Plastic re-extrusion

When too much material is squeezed out of the nozzle, the walls of the model are not smooth, but bumpy, with sagging.


The solution is software - in the settings of the slicer, you need to set the material feed rate (fluidity) to a lower value. The average value is 95-98%.

It is worth checking the diameter of the rod. If its size is greater than 1.75, then the plastic will be squeezed out more than necessary.


Plastic underextrusion

The plastic is squeezed out too little, because of this, gaps may appear between the layer. The finished model will be fragile and fragile.


Wrong thread diameter

Check the filament diameter in the slicer settings. Sometimes, instead of the popular 1.75, the default is 2.85.

Incorrect feed factor settings

Check the fluidity settings in the slicer. The average should be 95-98%.

Clogged nozzle

Something could get into the nozzle and partially block the exit of the plastic. Visually, the plastic will choke from the nozzle, but in a smaller amount than necessary for printing.



Hairiness or gossamer on finished model

Thin threads of plastic protrude from the outer wall of the model (most often on one side). The defect appears due to the flow of plastic from the nozzle during idle movement.


Insufficient retract

A retract is a slight pull of a plastic filament from an extruder. Due to the retract when the extruder is idle (from layer to layer or from model to model), heated plastic does not drip from the nozzle. For some flowable plastics (eg PETG) the speed and amount of retraction must be increased.

"Hairiness" can be easily removed by grinding or cutting off the threads with a sharp scalpel.

High temperature extruder

The higher the extruder temperature, the more fluid the plastic becomes. It is important to find a balance so that the plastic is not too liquid and sticks well in layers.

In the selection of the optimal extruder temperature, a test model - a tower - helps a lot. It clearly shows how plastic behaves when printed at different temperatures.

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Temperature test

Top "perforated" or uneven

The top of the model is bumpy or with holes. The problem may arise if the top of the model is flat. For example, like a cube.


Insufficient airflow

When printing the top plane (cover), the plastic does not have time to cool down and remains too liquid. Because of this, the threads are torn and holes are formed. Increase the fan speed on the last layers.

Few top layers

The top of the print may be too thin and deform as a result. Check slicer settings. The number of upper layers is not recommended to be set less than 6.

Low percentage of filling

If the infill percentage is too low, then the top layer will simply have nothing to rely on. Increase the fill percentage in the slicer settings.

Model deformation

Some parts of the model seem to have melted in some places or on one side. The problem most often occurs when printing with PLA plastic. The defect appears due to the fact that the plastic does not have time to cool and deforms.


Insufficient air flow model

Turn the fans on to maximum. If their power is not enough (in some printers, the fan is located only on one side), you can put a regular desktop fan and direct it to the 3D printer table.

Small model

Small models are difficult to blow well. Try to print small items alongside larger ones, or place several identical models in different corners of the table. So the plastic will have more time to cool.

Layer offset

Layers shift along the x or y axis during printing.


Printhead Jam

Turn off the printer and try to move the extruder along the x and y axes with your hands. The extruder must move freely. If there are jams, check the mechanics of the printer. Bearing wear or the curvature of the shafts may be to blame.

Electronics overheating

Sometimes electronics problems can be to blame for misaligned layers. The most common cause is overheating of the drivers or too low current exposed to them.

Table top is loose

This is most often seen in 3D printers with glass. During printing, the nozzle may hit the model and move the glass slightly. Before printing, check if the glass or other printing surface is well fixed on the heating table.


Skip layers

Small holes are visible on the print, or the shell of the model is not continuous.


Teflon tube deformed

There are 2 types of thermal barriers - all-metal and with a Teflon tube. If overheated, the Teflon tube may deform. Plastic will pass through it, but in a smaller amount.

Low extruder temperature or high print speed

If the extruder is not heated enough, then the plastic will not be liquid enough and simply will not have time to be forced through the nozzle. The higher the print speed, the higher the extruder temperature should be.

Sometimes the outer walls print well, but the infill is “torn”. In this case, slow down the infill print speed in the slicer.

Model bundle

Cracks form on the surface of the printout during or after printing. Cracks can be large or very small. Most often, this problem occurs with plastics with a high percentage of shrinkage - ABS or Nylon.


Sudden temperature difference (if model delaminates during printing)

With a sharp temperature difference (for example, a draft), part of the model cools down faster. This leads to uneven shrinkage and incorrect distribution of internal stress. For plastics with low shrinkage, this is not critical. But if the shrinkage percentage is more than a few percent, the model may burst in layers.

For printing with such plastics, it is recommended to use a printer with a closed housing. If this is not possible, try to avoid drafts and sudden temperature changes in the room where the 3D printer prints as much as possible.

Print temperature

Due to too low printing temperatures, the layers may not “stick” well to each other. Raise the print temperature in the slicer settings.

Hardening (if the model cracks after printing)

Sometimes cracks appear on the model a few days after printing. This is due to uneven distribution of internal stress after cooling. You can try to “harden” the finished product.

For hardening, the model is placed, for example, in an oven, and heated to the softening temperature of the plastic. After that, the heating is turned off and the oven is left to cool slowly with the model inside. Due to this, the stress inside the print is distributed more evenly. But accuracy is very important in this method - if you make a little mistake with the temperature, the finished product can “float”.

Ringing

In places where the extruder changed direction, ripples are visible. Most often it looks like a shadow around the “sharp” protruding elements of the model.


Mechanical problems

Sometimes the problem occurs due to extruder play. Check if the extruder mount to the rails is loose. Be sure to check the tension of all belts.

High print speed or high accelerations

Moving the extruder too fast can cause vibrations that cause ripples on the wall of the model. The lighter the weight of the extruder, the less noticeable the ripples will be. To get rid of ringing, simply reduce the print speed in the slicer settings.

Slots for thin-walled models (not solid shell)

The thin wall of the model is not solid, but consists of two thin walls with a narrow gap between them. This problem is often faced by fans of printing "cutting" for baking.

Left model with wall defect, right without

Wall thickness and nozzle diameter mismatch

If the wall thickness is 1 mm, and the nozzle diameter is 0.4, it turns out that for a solid wall, 2 nozzle passes are few, and 3 are already many. The result will depend on the slicer algorithm, but most often you will get 2 walls with a thin slot in the middle (the slicer cannot change the wall thickness). The solution to the problem may be a slight refinement of the 3D model or the use of a different slicer.

Algorithms for calculating 3D models are constantly being improved and refined, and now this problem is less common.


When modeling, take into account not only the thickness of the nozzle, but also the percentage of “overlapping” of lines on each other. If you have a nozzle with a diameter of 0.4 - make the wall in your model not 0.8, but 0.7 - 0.75.

Wrong model geometry

When instead of a circle you get an oval, and instead of a square you get a semblance of a rhombus.


The main reason is malfunctions in the mechanics of the printer. Be sure to check:

Belts

Check belt tension in x and y. Belts stretch over time and may need to be tightened or replaced. Each 3D printer has its own way of tightening the belt. If the belts are slightly stretched, you can tighten them with the help of a "spring".

Loose pulleys, etc.

Check if all bolts and nuts are tight. Are there backlashes. Pay special attention to tightening the pulleys located on the motors along the x and y axes.


Sagging of some parts of the model

Some parts are not printed, broken, or instead of a neat surface, a swollen plastic snot is obtained.


No support for overhangs

A 3D printer cannot print in the air, so if there are overhanging elements in the model, you need to set supports - supports. The slicer can set the necessary support itself, you need to check the appropriate box in the settings.


When printing with soluble support, you can set the gap between the model and support - 0. This will make the surface smoother. If the support material and the model are the same, you need to add a small gap. Otherwise, it will be difficult to separate the support from the model.

Split model

Sometimes the supports can take more plastic than the model. In this case, to save material and time, it will be more convenient to cut the model. If you have more than one 3D printer, then the model will print several times faster.

When cutting the model, you can leave grooves or mortgages so that the pieces of the model are connected without displacement.


Totals

In this article, we talked about the most popular 3D printing defects and how to solve them. Don't be intimidated by such a long list. Some problems are rare and you are unlikely to encounter them.

There is a list of problems that arise due to the design features of a 3D printer, so try to choose a printer that suits your needs. To do this, you need to understand what products and what material you need.

Learn more