3D printing problem: how to avoid mistakes?- 3dnatives

Posted on October 12, 2020 by Mélanie W.

3D printing can be used in different ways, opening up previously impossible possibilities, especially in terms of design.However, these possibilities can only be fully exploited if 3D printing works as you wish.Unfortunately, this is not always the case, so that even the simplest models sometimes do not want to print correctly.But why this 3D printing problem?Where is he from ?We have therefore looked at the various errors or faults that a user may meet as well as the associated solutions.These errors here only concern FDM technology based on filaments.There are of course others when it comes to other processes and materials.The current list is not exhaustive, we have gathered the main challenges that users are generally faced.

A 3D printing problem linked to the set to the set

The first layers of an impression are crucial: as they constitute the basis of the model, it is essential that they adhere to the print set.If this is not the case, 3D printing may present some faults.First of all, it is important to clean the tray and the 3D printer nozzle because material residues can affect printing and therefore adhesion.Also note that not all platforms have the same type of surface which can affect your printing: thermoplastics will not adhere in the same way.For example, a build-tak surface is particularly suitable for printing.

The warping can cause the room to detach

A first 3D printing problem concerns this warping or left -handing phenomenon, linked to insufficient adhesion on the tray: the corners of the printed part swell up, sometimes causing its entire detachment of the tray.It is particularly frequent when printing large or long parts with materials such as ABS, Nylon, PEEK, etc..This is due to the fact that plastic parts are still contracted often after printing when they cool.For example, if you print ABS at 230 ° C and then let it cool to room temperature, it contracts almost 1.5 %.Using a heating tray is then highly recommended, keeping the filament at the glass transition temperature and reducing the contraction.The optimal temperature of the printing tray is generally found on the filament packaging.

Also note that the printing speed is of great importance, especially for the first layer.A solution could therefore consist in reducing this speed in order to give the material enough time to adhere to the surface of the construction platform.

Conversely, it can happen that the room sticks too well on the tray so that it is difficult to remove it.As it is absolutely necessary that the model be completely cooled, you can put the tray - with the piece on it - in the freezer.If it still does not lose its grip, you can try to remove it with a spatula.However, it must be done with the greatest caution, otherwise the model will be damaged or the striped tray.

You can remove the part with a spatula

Another solution to counter this 3D printing problem is to put the tray and the room in a hot water bath.The glass transition temperature should not be exceeded, otherwise the model can deform.In addition, it is possible to modify your membership settings in the software.If we deselect additional membership parameters, such as edge or raft, this should make it possible to detach the model even more easily.

Boursouflures

The second 3D printing defect is what is called elephant feet or fellows: the lower layers swell outside.This 3D printing problem appears when the lower layers have not cooled enough, but the weight of the rest of the room acts on them, pushing them outwards.

The first solution may consist in adjusting the printing tray.You have to make sure it is level, otherwise there will be different distances between the tray and the nozzle.Another way to eliminate the defect could be to reduce the temperature of the printing bed.It is important to cool the lower layers enough, but not too quickly, otherwise the deformation problem mentioned above will occur.You can opt for a cooling system or put more part on the tray: the printer will take more time to design the different models which will leave more time for cooling.

The first layer is more swollen than the others

The underestimated

The third 3D printing problem is the underestimated.It means that there is not enough material that comes out of the nozzle.It is noticed by the empty spaces between the layers, that is to say that they are not correctly attached.The underestrusion is due to the fact that the quantity of material coming out of the nozzle is lower than what the software provides, because 3D printers do not yet provide this type of information.Several causes explain this phenomenon.

The problem may be linked to the diameter of the filament: it must be well specified in the software.If the diameters of the filaments correspond, but the problem of the underestimation remains, the amount of extruded material must be modified.This is done with the extrusion multiplier: by increasing it, more material is extruded.It may be advisable to proceed in 5% and print a test version after each increase to ensure that the right amount of material is extruded.The underestimation can also be linked to a blocked nozzle or a filament blocked upstream of the extruder.

Some layers are missing, causing holes in the room

Over-extrusion

The counterpart of the underestrusion is over-extrusion.As you can already imagine, this 3D printing problem concerns a surplus of extruded material.This has a negative effect on external dimensions and print quality.Basically, the same solutions are available here as for the underestrusion, except that in this case, the extrusion multiplier must be reduced in order to extrude less material

Holes in my 3D printed room

Once the 3D printing is completed, holes in the upper layer can form if the filament has cooled badly or if the manufacturing parameters are not correct.This 3D printing problem is often due to the part of the room, when it is hollow or with a honeycomb structure.The solution seems obvious: you have to adjust the temperature;However, we can also find solutions on the printing parameters on the.

The first thing to check is whether you have enough upper layers.If the interior is hollow and you try to print a 100 %solid layer there, it is likely that it falls or sinks into empty spaces.To avoid this, you need several solid layers at the top of the model.We advise you to have a thickness of 0.5 mm on the upper edge.The surface quality improves with each additional layer.Another solution could be to increase the filling inside.The higher the filling density, the lower the distances between the different filling walls are low.

Several solutions avoid these holes in the upper layers

A 3D printing problem linked to the extruded filament: the thong

The phenomenon of "thong", or rope in French, corresponds to fine materials left between the sections of a 3D printed part.Generally, this 3D printing problem is linked to the fact that the material continues to get out of the nozzle when it moves from one point to another when it should not.Normally, the 3D printer is able to prevent the nozzle from extruding the filament thanks to the withdrawal.If this parameter is not adjusted correctly, these wires may appear.

One solution to this problem could consist in modifying the withdrawal parameters.You can change the withdrawal distance but also its speed.The optimal value of the filament retraction speed varies, but as an indication, you can fix a value between 20 to 100 mm per second.Another solution is to reduce the extrusion temperature: if it is too high, plastic is more liquid than it should be.In addition, a fan will no longer be able to correct the filament correctly and it will flow from the nozzle more easily or uncontrolled.The last thing you can do is shorten the displacement distances and/or increase the movement speed.

Wires appear between the different parts

The layers separate

If the different extruded layers are not well united with each other, we will observe a separation between certain.A solution to this 3D printing problem can be reduced to layer height.Generally, it is said that the height must not exceed 80% of the outlet diameter of the nozzle.If the height of the layer is higher than this limit, the layers will only be applied to a loose way and will therefore not be binded with the previous layer.If the height of the layer has already been optimized, another solution may consist in increasing the print temperature.It is logical, because hot plastic adheres better than cold plastic.The treatment temperature is indicated on the packaging of each filament.This is the only way to ensure optimal layers of layers.

Separations can appear between certain layers

End details are not printed

3D printing is currently used to use design possibilities, it is important to obtain fine and precise details.However, FDM technology has its limits and if you are trying to print areas thinner than the diameter of the nozzle, you will have problems.

The most obvious solution is therefore to use a smaller diameter nozzle, if possible.Some software settings will also allow you to print finer areas with specific profiles.In addition, the choice of a high quality filament can make the difference.However, if all this does not help, it only remains to redraw the part with thicker characteristics.Shall software such as Cura, Z-Suite or Simplify3D can help you in this field, because they check that your 3D model does not contain components with too fine walls.

Thinner details can cause 3D printing problems

You will understand, a 3D printing problem has happened quickly and there are many.Finding your cause does not always seem easy which makes its correction even more difficult.However, some manufacturers have embarked on the development of 3D software capable of identifying printing defects and correcting them directly.In any case, we encourage you to test different settings of your machine to see what works or not.Do not be discouraged, the practice is key!Do not hesitate to tell us about your 3D printing problem in the comments of the article or with the members of the 3DNATIVE Forum.Find all our videos on our YouTube channel or follow us on Facebook or Twitter!