3D Slicer Software – Basic and Advanced Tips
Slicing software is an essential element of the 3D printing process. Over the years we have seen a rise in the number of free slicing software for 3D printing.
Some extend basic features in their free versions while some are completely free and provide complete access to their package. We will explore some of the best free slicing software for 3D printing in this article.
A 3D printer cannot convert the 3D model directly into a print. It needs a geometric interpretation of the model and slicing software does just that. A slicing software or simply a Slicer converts a 3D model into a set of geometric codes or a set of paths that the 3D printer understands and can trace to create the print.
Slicing software is a necessary mediator between the CAD file and the printer.
For FDM 3D printer owners, there is a wide range of free and open-source slicing software options to choose from. Companies provide proprietary slicing software with the 3D printer or users can also opt for open-source software developed by an open community.
The first step to get started is to select slicing software for your needs.
Selection of Slicing Software
When you buy a 3D printer, chances are high that the manufacturer will provide proprietary slicing software or at the very least recommend software that is compatible with the 3D printer. Users can simply go with the recommended software.
Companies like Ultimaker, Zortrax, MakerBot, and more offer compatible versions of slicing software.
Other slicing software options include open-source Slic3r or Simplify3D (paid software).
Another selection criteria involve understanding the level of the user. If he is a beginner then he can try out Cura or MakerBot Print, a slightly advanced user can work with MatterControl, or Craftware and professionals can use Slic3r or Simplify3D (paid software).
One other important criterion is the level of control a user expects from the software. A beginner-level software will help a user get started with minimal features while professional-level software will provide ultimate control for every print.
BASIC SLICER PARAMETERS
Layer height simply means the resolution of the print. The layer height signifies the height of each layer or the maximum resolution of the print. The value of this parameter will determine the print quality and the features it can capture. The lower the layer height, the higher will be the resolution and the more detailed will be the print and vice versa. However, the higher the resolution, the longer it takes to print the object.
By controlling this parameter a user can get either a smooth, balanced, or rough surface texture and so this is one of the most important parameters in any slicer.
Depending on the application and necessity, a user can determine the layer height. For an FDM 3D printer, the lowest layer height achieved is 100 microns and this will give the best possible result. And anything above this value will only roughen the surface texture.
A shell refers to the number of times the outer walls of the model are traced by the nozzle before it moves to the inner sections. And the shell thickness specifies the thickness of the side walls.
This parameter is important as it defines the strength of the print. The more the number of shells, the better will be the strength but the longer will be the time required to print the object.
The default settings in slicer software are ideal for all prints but if any specific print requires additional strength then a user can modify the value to impart better strength.
Initial Layer Thickness
First layer adhesion is a very common issue in 3D printing and that can significantly be reduced by keeping a thick initial layer. This is the first layer that sticks to the build platform and so the thicker the initial layer, the better will be the bed adhesion.
Fill density represents the infill percentage of a print. It defines whether a print will be hollow or filled. The higher the infill, the stronger and heavier will be the object. But this will require more material thus the part will be costlier. Ideally, it is recommended to use around 20% infill but it can be modified as per the requirement.
Infill pattern represents the pattern in which the object is filled. Slicer software has multiple infill pattern options and the pattern also has implications on multiple factors like the print speed, the strength of the part, and the top and bottom layers.
The grid pattern is one of the most common infill patterns used for regular prints. For better strength, a honeycomb pattern is recommended.
As the name suggests, the print speed controls the speed of the overall print. A user can control how fast or how slow an object is to be printed. In some slicers, individual layer speeds can also be controlled resulting in better print output.
An ideal starting point for speeds in 50mm/s. The speed, however, has an impact on the print quality as the faster the print, the lower will be the quality and minute details may not be captured. So it is recommended to users that they tweak the speeds for individual print jobs.
Support structures help build sections of a print like overhangs that do not have enough base to print upon.
The ideal way to determine whether a part will require a support structure or not is to check whether any section exceeds a 45-degree angle. A slope greater than a 45-degree angle will require support.
Slicer software can also control multiple parameters like speed, density, pattern, and other advanced parameters.
ADVANCED SLICER PARAMETERS
During printing, a lot of users may experience stringing issues. This generally is a result of overheating thus resulting in oozing of the material.
The best solution for this issue is to use retraction settings. Retraction helps in stopping the extruder from releasing filament during “non-print moves.”
Through retraction settings, the filament is retracted inside the nozzle when it is traversing non-print move. By carefully adjusting this distance, the oozing issues can be solved.
During the retraction process, some leftover melted filament may remain in the nozzle and that can ooze out while printing resulting in uncontrolled defects in the print.
By using the coasting setting, the extruder will know when to stop printing a specified distance before a non-print move. This allows any leftover filament to be cleared before retraction sets in.
It is however recommended only for advanced users as there is also a risk of under extrusion if the setting is too high.
Flow Rate (Extrusion Multiplier)
The flow rate, or called the extrusion multiplier setting in slicer software, allows a user to control the filament feed through the nozzle. It means the rate at which the material will be extruded out of the nozzle.
Sometimes, a user is required to modify this multiplier to get successful print results. However, an improperly managed multiplier can lead to under or over extrusion and that can also lead to print failures.
Users should take note that generally, the flow rate for ABS is 100% (1) and for PLA it is 90% (0.9). By starting with these standard flow rates, a user can increase or decrease the flow rate and check the corresponding changes in the print to finally fix a rate that suits his requirements.
Temperature settings are quite complicated to beginners as they tend to strictly follow the recommended temperature guideline but such adherence can sometimes result in poor output.
Temperature settings can dramatically affect print quality. Temperature settings control the extruder temperature(s) and users have to adjust the temperature of the extruder according to the material they use.
But oftentimes even the recommended temperature does not yield successful results and so the temperature has to be tweaked to perfection.
At such times, a user should tweak the temperature in an incremental value of 5 degrees and check the print results, and fine-tune the best possible output.
New users generally are not aware of how to use fan settings to their advantage. Fan settings can carefully salvage possible failed prints. Fan control becomes all the more important when printing with ABS material as sometimes it is also important to switch off the fan for some part of the print.
Fan settings, if diligently handled can avoid bed adhesion issues, eliminate cracking and warping, can eliminate overheating, and improve print quality.
Heated Build Plate
Not all 3D printers come with a heated build plate but a heated plate can significantly reduce failed prints and improve build quality.
Depending on the filament used for printing, the temperature of the build plate has to be adjusted. The temperature has to be ideal for printing and the part has to be kept warm, not hot.
Manual support placement is a handy tool to control the quality of the print, to reduce the time to print and the required post-processing, and also the material wastage. By carefully placing the supports, the print quality can also be enhanced.
However, using this tool is not as easy as it sounds. Even advanced users will have to carefully select the places to add support and also remove excess support if needed. This will require practice and a lot of failed parts.
TROUBLESHOOTING THROUGH SLICER PROBLEMS
A lot of print failures can be easily resolved by controlling settings in slicer software. We see some of the common problems and how to troubleshoot them through slicer software.
First Layer Adhesion Problems
First layer adhesion is one of the most common problems faced by all users. This problem refers to a condition where the first layer of the print does not stick to the bed.
For eliminating first layer adhesion issues, using a heated bed is one of the easiest solutions. By heating the bed the first layer of the print remains warm and thus sticks to the bed easily.
The bed temperature can be easily controlled through the slicing software. It is recommended to have a heated bed for materials like ABS.
For avoiding first layer adhesion problems the print speed should be optimum and for identifying the same, slicer settings can be tweaked in small increments. Faster the speed, poor the bed adhesion.
For improving bed adhesion, the first layer should remain warm. For this users can also switch off the fan for the first few layers. This way the print will remain warm and stick to the bed. The fan speed can be controlled through the slicer.
Bed Adhesion Tools
Another way to eliminate the first layer adhesion issue is to use bed adhesion tools in the slicing software. Tools like ‘Brim’ and ‘Raft’ can significantly improve the adhesion properties of the part. These tools are found in all slicing software and using them can solve the adhesion issues to a far extent.
Stringing or Oozing
Stringing or oozing is also a common problem in 3D printing. This problem, again, can be easily eliminated through extensive trial and error techniques. To resolve this issue, users must understand the term ‘Retraction’.
When faced with stringing or oozing issues, the first primary troubleshooting step is to check retraction speeds. This parameter controls the speed at which the filament is pulled back.
If the speed is too fast then the melted filament may form strings while being pulled. So, it is advised to keep the retraction speed slow.
If retraction speed is not resolving the problem then users can test the retraction distance. This is the distance by which the filament is pulled back.
This setting is found in all slicer software and users will have to find out the ideal distance according to the type of material, the printer being used, and the type of extrusion system, (direct-drive or Bowden-drive).
All slicing software have retraction settings to control the retraction distance.
Oozing or stringing may also be caused by overheating of the filament. The viscosity of the material may reduce and it may flow out of the nozzle even when it is not supposed to print. Users can control the extruder temperature from the slicer settings and eliminate this issue.
By reducing travel, stringing can be reduced. At the same time, by increasing the travel speed, the oozing can be minimized. But care should be taken to increase the speed only up to a level that the printing may continue smoothly.
Warping means the curling of the part from the edges of the print. This generally occurs when the part cools down faster than ideal.
The solution to warping is to use a heated bed. This can eliminate the warping issues in almost all cases. It is recommended that materials like ABS should always be printed on a heated bed as ABS is highly prone to warping.
The heated bed will keep the initial layers to remain warm and they will stick to the build plate thus avoid warping.
As explained earlier, the initial layers must be kept warm and as the fan can cool it down, it is recommended that the fan is completely switched off or at least kept at a minimum speed for the first few layers.
Bed Adhesion Tools
Bed adhesion tools also help significantly in avoiding warping issues. Both brim and raft are useful in this case.