EDUCATION

Common Problems in 3D Printing & How to Resolve Them – Part II

DIY or Desktop FDM 3D printing is still new to many students and they face a lot of problems while 3D printing and getting their prints right. In the first part of this series, we helped you resolve some of the common problems in 3D printing and also shared some easy 3D printing tips to overcome them. Now we have come up with part two of this series where we will also share settings in slicing software for resolving the problems. 

We bring you a checklist of simple 3D printing tips on how to resolve the most common problems in 3D printing, namely FDM 3D printing.

Read on to understand the problems you are facing and the relevant 3D printing tips to resolve them so you always have a successful 3D printing experience.

 

1. LAYER SHIFTING/SLIPPING

Slicing software
Above: Example of layer shifting in the X-axis/Image Credit: Prusa

A layer shifting problem occurs when due to some internal or external reasons the printhead moves out of position but the printing continues. Due to the unaccounted movement of the printhead, the printer prints at a different geometric location. Due to the open-loop control system, most 3D printers operate upon, there is no way to detect this abnormality.

The result is the misalignment of the layers hen the printhead moved to lead to a failed print. There is no in-built system to detect this problem but still, we can help you avoid this seemingly unavoidable but common problem in 3D printing.

  • High-Speed Printing

If printing is conducted at high speeds than the recommended settings then the printhead suffers consistent jerks at the endpoints and this jerk may cause distortion and shifting of the printhead.

Also, if the print speeds are high then the motors struggle to position the printhead at the right place at the right time and the material may not be deposited at the desired location and the layer shifting will occur thus failing the print.

So, with simple settings in the slicing software, the printing speeds can be maintained within the speed limits specified by the manufacturer. If ignored, it may also eventually lead to misalignment of the overall system and cause multiple problems in the 3D printer itself.

  • Belt & Pulley Tension

3D Printing Tips
Above: Checking belt tension on the Ultimaker 2+/Image Credit: Ultimaker

One of the most common reasons for layer shifting is wrong tension in the belts and pulleys. Over some time the tension in the belts and pulleys will loosen and the same will have to be tightened.

  1. For belts, users can use belt-tensioners to increase tension in the belts. Alternatively, users can also replace the belts with new ones.
  2. For pulleys, since they are in constant motion, the screws holding the pulley in place also sometimes may unscrew a bit. They should also be checked and tightened in case they have loosened up.
  • Overheating of Electronics

3D Printing Tips
Above: Zortrax Motherboard in M Series 3D Printers/Image Credit: Zortrax

It is a possibility that the electronics are overheated and so the current supply to the motors is getting affected. This will affect the spinning of the motor and the printhead will not move the required distance. To avoid it, the electronics systems must be allowed to cool down after every long print.

 

2. UNDER EXTRUSION

problems in 3D Printing
Above: Poor Infill structure/Image Credit: Rigid.ink

Under-extrusion is a common problem in 3D printing. It is frequently encountered by new users and refers to the phenomenon when the extruder extrudes less material than expected.

Under extrusion is spotted when the top surface of the 3D printed part has tiny gaps in it and generally at the end of an extrusion line.

Such a problem in 3D printing can occur due to reasons like:

  • Low Print Temperature

If the print temperature is low the material does not flow as freely as expected and thus the flow will be reduced leading to lesser material being deposited. This results in gaps in the 3D print. To avoid such issues, the simple 3D printing tip is to keep the extruder temperature in the ideal range as communicated by the filament manufacturer. Temperature settings can be found in the slicing software.

  • Filament Diameter

3D Printing Tips
Above: 3D Printing filament diameter/Image Credit: Tinkerine

Incorrect filament diameter can also cause the under extrusion problem in 3D printing. In case you load a filament with a 3 mm diameter and in the slicing software specify a 1.75 mm diameter then the extruder won’t push the required amount of filament thus causing gaps in the print.

The ideal 3D printing tip to overcome this issue is to increase the extrusion multiplier in the slicing software.

  • Extrusion Multiplier

If you find out that the extruder is not pushing enough material, then the simplest 3D printing tip is to increase the extrusion multiplier through the slicing software. But care should be taken to increase the multiplier in small gradual increments.

 

3. OVER EXTRUSION

Problems in 3D Printing
Above: Over extrusion/Image Credit: 3DBenchy

Over extrusion is pretty rare but since it closely relates to the under extrusion problem, we will be explaining it in detail. The over extrusion problem occurs when the extruder extrudes an excess material than expected and thus leading to thick layers which distort the shape of the object being printed.

Over extrusion can also cause serious issues like nozzle jams or stringing, and even blobs on the print thereby making a print useless.

The cure for the over extrusion problem in 3D printing is simply the opposite of under extrusion.

  • High Print Temperature

If the print temperature is high the material flows uncontrollably and cannot be controlled even by retraction settings. The solution to avoid this is to decrease the print temperature and keep it around the ideal temperature as specified by the filament manufacturer. A simple adjustment in the slicing software can help in overcoming this problem.

  • Filament Diameter

3D Printing Tips
Above: 3D Printing filament diameter/Image Credit: Tinkerine

Incorrect filament diameter can also cause the under extrusion problem in 3D printing. In case you load a filament with a 1.75 mm diameter and in the slicing software specify a 3 mm diameter then the extruder will push excess material than the required amount of filament thus forming thick layers of even jamming the nozzle. A simple check can be done in the slicing software to avoid this problem.

  • Extrusion Multiplier

In case the extruder is extruding excess material, then check the extrusion multiplier and start reducing it gradually and checking the effect simultaneously. Once you reach an ideal flow level you can keep the setting locked in the slicing software.

 

4. BRIDGING ISSUES

Slicing software
Above: Failed bridging/Image Credit: Prusa

Bridge refers to a length of horizontal part extruded between two raised points. It can be equated with regular construction bridge that we see in our daily life. This is a common problem in 3D printing and occurs when the bridging is too long and the material drops down while printing.

While designing the designer should ensure the span of the bridge is small otherwise the bridge will fail.

For ensuring a perfect and strong bridge we recommend the following 3D printing tips:

  • Bridge Calibration Test

3D Printing Tips
Above: Bridging Test by Walters/Image Credit: Walters/Thingiverse

This is a great way to know the capability of your 3D printer and a simple bridging test can be performed to know how your 3D printer handles bridges to determine the length, size, and angle of the ideal bridge. This will go a long way while designing parts for printing on your 3D printer.

  • Small Length or Supports

As already mentioned, the span of the bridge should be small. Smaller bridges can be 3D printed without any supports. In case there is no way around a long bridge, the best option is to add supports to the bridge to avoid failure.

  • Fan Settings

An interesting way to experiment with the fan settings. Users can print the bridge with increased fan speed. Fan speeds can be easily controlled through any slicing software. This increase will ensure faster cooling of the extruded material and the deposited material will not sag while printing and the bridge will be formed in a perfectly straight line.

But this will need a lot of trial and error but can surely reap better results. Make sure the fan speeds are incrementally increased and are kept within the speed limits to avoid damage to the machine.

  • Print Speed

Another way is to print the bridge at slow speeds. The effect is more or less the same as you get with increased fan speeds. The slow speed ensures the deposited material gets enough time to cool and also the earlier deposited material holds onto the newly released hot material. Thus avoiding material sag.

 

5. POOR SURFACE ABOVE SUPPORTS

Slicing software
Above: Poor surface above supports/Image Credit: Ultimaker

This problem in 3D printing refers to the underside of a print where the part interacts with the support structures. A lot of 3D prints require support structures but if these support structures leave a poor surface finish then they are surely undesirable.

This is a common problem faced by many users and we help you with some 3D printing tips to overcome them.

  • Infill Percentage

Slicing Software
Above: Ultimaker Cura settings for Support structures/Image Credit: Ultimaker Cura

Just as the infill of parts can be controlled, the infill density of support structures can also be controlled through all slicing software. By increasing the infill percentage of the supports, the interface can be printed with a better surface finish

  • Support Interface

This is a very specific feature available in almost all slicing software. This feature adds a layer of material between the interface between the support and the part. The purpose of the interface is to allow easy removal of the supports but also to impart better surface finish to the part

  • Dual Extrusion

dissolvable support material
Above: DPA-100 dissolvable support material/Image Credit: ColorFabb

If the 3D printer supports dual extrusion then users can use the compatible support material to be printed through the second extruder. As both, the part and the support structures are printed with different materials, the bond will be weak. The supports can be easily removed by dissolving in an appropriate solvent and the main part remains unaffected.


About Manufactur3D Magazine: Manufactur3D is an online magazine on 3D printing. which publishes the latest 3D printing news, insights and analysis from all around the world. Visit our 3D Printing Education page to read more such informative articles. To stay up-to-date about the latest happenings in the 3D printing world, like us on Facebook or follow us on LinkedIn.