Step-by-Step Guide on Using 3D Printer Slicer
A 3D printer isn’t complete on its own. Left to its own devices, it cannot tell one 3D model apart from another, let alone print one. Fortunately, you have got the Slicer for that.
The 3D printer slicer is a program that bridges the gap between the digital model on your computer to the physical construction of the printer. But how does it work? Which slicer application should you use? More importantly, what are all those settings and how do you configure them?
Fret not. Here is a complete step-by-step guide to 3D printer slicers.
What is a 3D Printer Slicer?
To put it simply, a slicer converts an STL file into a set of printing instructions called G-code. Without it, you cannot print anything, no matter how great a printer you have.
The temperature of the extruder, the speed of printing, even the exact motions that it needs to make – everything has to be specified down to the smallest detail. Slicer is the software responsible for doing that.
For the most part, the process is automatic, and you don’t need to mess around with it. That being said, slicing is the most important part of the 3D printing process. If the 3D model is the blueprint then the slicer is the engineer directing its construction.
How does a Slicer Work?
A digital 3D model is composed of purely mathematical geometry. Vertices, edges, faces and the angles between them is all the data it has. The problem is, a 3D printer cannot exactly build an object that way.
That is where a slicer comes in. As the name suggests, slicing software slices the model into horizontal layers stacked on top of one another to give the desired product. But its role doesn’t end there.
Printers cannot figure out how to lay down even 2D shapes by themselves. They need to be told exactly how to move the extruder, how much material to push out, how fast to extrude it, and so on. A slicing application decides these and a dozen other details, controlling the printer.
Step 1: Choosing a Slicer
There are plenty of slicers available for free. Some of these are open-source, while others are free offerings from 3D printer manufacturers. Ultimaker’s Cura and the Makerbot Print are leading examples of the latter. Both of these applications are used by millions of 3D printing enthusiasts around the globe and include all features that you might need.
For open-source lovers, there is Slic3r. It is the source of many of the features now found on proprietary applications, and the original free slicer. While it offers much more customization than other options, it can also be somewhat difficult to use.
Chances are, your 3D printer came with a small disk containing a slicing application. If you are unsure, you can always go with this option. No matter which slicing application you use, the core functionality is the same.
Step 2: Connecting the Printer
Once you have chosen which slicing software you are going to use, there are a couple of things left to do. You need three things:
- A computer
- A digital 3D model (STL or OBJ)
- And of course, a 3D printer
Install the software that came with the printer, or download another one. Before connecting it though, you need the right profile for it.
A printer profile tells the slicer the exact technical details of your printer, besides specifying some default settings to be used. Slicing programs like Cura or Slic3r include most profiles by default.
Load up the profile corresponding to your printer model (and the filament being used) and you can finally start printing.
Step 3: Adjusting the Slicer Settings
Mastery of the slicing application is what sets a 3D printing beginner and expert apart. If you never fiddle with the slicer settings, your prints will always be ‘average’. To take your printing skills to the next level, you need to thoroughly understand each aspect of the slicing process.
So here is an overview of every important setting that has a bearing on your prints.
A basic factor to modify is the layer height. Each segment of the print is created in a single pass of the extruder. Obviously, the larger the height of each horizontal slice, the smaller the number of layers required. This also reduces printing time.
But this costs you print quality. The bigger each layer is, the less detail that can be put into the print. like screens with more pixels can show higher resolution images, a print with more layers can craft more detailed objects.
Layer height is thus one of the parameters requiring user intervention. You need to judge the number of layers for every print individually. When the model is relatively simple (like a cube), a larger layer height is doable. But when you are printing something like a miniature, turn it down to get better quality, even if it slows down the print time.
If there is one slicer setting you are going to fiddle with, it should be the temperature.
The temperature of the extruder nozzle is the single most important factor in the quality and cohesiveness of your print. This is because different materials have different working temperatures. Too hot and excess material starts pouring out, too low and the printed layers hardly form.
And that’s the extruder. Most printers will have a heated printed bed too, with its own temperature setting. The print bed’s purpose is not to deform the material but to ensure it sticks and sets easily. For this, the print bed needs to be warm enough to be adhesive.
In the slicer, you will notice multiple sub-categories below the default speed value. For the most part, these specific speed settings can be safely ignored, as they are decided by the program based on the needs of each individual layer. What you should add is the primary speed setting.
As you might expect, this value controls how fast the print is realized. Now, why shouldn’t you turn it up to eleven and forget about it?
Quality. As a rule of the thumb, the faster the print speed, the lower the print quality. Of course, you need to play around with the speed settings to arrive at a balanced value that gives a decent print without taking forever.
This setting controls the extruder’s internal motor. Basically, a higher flow value pushes out more material. Setting this multiplier lower than 100% throttles the flow, forcing less filament to be extruded.
You need to manually ad the flow parameter if over-extrusion ever becomes an issue. You can spot it by the blobs of material hanging over the edges of your print. Reduce the multiplier to ensure that the extrusion does not extend past the actual print.
Normally though, you should not need to look at this setting. Smaller printing artifacts can always be filed off with a sharp tool. And, if the printer calibration was done right, there wouldn’t be any over-extrusion in the first place.
This is a bit of a tricky setting to master. Retraction includes both the speed and the distance at which the extruder nozzle pulls back material when not in use. Normally, the default values are fine.
The problem is when you notice stringing on your print. Hair-like threads of material all over the printed object are a sign of slow retraction. It can also be due to a too high temperature, so make sure to adjust that first.
When the temperature is not the issue, you can try tampering with retraction settings a bit. Make small changes and try out some test prints to find the sweet spot. Putting it too high can clog the extruder, so try to go slow.
If you are looking to print things that last, you need infill for your prints. Simply put, infill is a pattern that is used to fill up all the empty volume inside a print. This pattern will never be seen from the outside but will help strengthen the object.
You must be wondering, why not print the whole thing solid? Because it is waste of time and resources. You can get similar levels of strength from a good infill pattern that uses half the material.
There are many infill patterns you can select, like the honeycomb. You can also specify the infill density, giving you fine control over how the inside of the print is filled up. Try out different patterns to see which works the best for you.
Along with the infill, this setting is what determines the toughness of a print. It specifies the thickness of the walls of the print. It can be measured either in layers or in millimeters.
You should set the shell thickness based on the size of the object being printed. Larger objects need a thicker shell to withstand impacts without breaking. Smaller prints, on the other hand, can make do with a much thinner sell without a hitch.
Setting a thinner shell thickness along with a good infill pattern is a good way to save material on the printing without sacrificing the strength. don’t make it so thin that it snaps on pressure.
The more surface area that is in contact with the print bed, the better it sticks to it. The problem is, not all models have flat bases. When an object you are printing has a complicated geometry, it can come off during the process.
That is where adhesion assistants come in. With simple structures like rafts, brims, or skirts, the model is made to adhere to the print bed properly.
Rafts are complete printed bases for anchoring the print without direct contact to the print bed. It becomes necessary when you have a rounded base that is hard to support otherwise.
Brims attach surfaces spreading out from the base of the model, like the brim of a hat. These can help when the base area is too small for rafts.
Skirts consume the least material of all adhesion assistants. A skirt is an outline of a print’s surface, laid down to help get the material flowing smoothly. While it doesn’t support a print directly, it is useful in determining if the bed is properly leveled or not. Usually, a slicer will include skirts by default.
Occasionally, your model has overhanging features that extend beyond the layer below it. Such features can be very difficult to print, as the layers have nothing to rest upon. They often break apart before the print can even be completed.
Support columns are the only way to print overhangs. These structures are printed alongside the model using the same material. They prop up extended parts of the model, giving the extruder a base to lay down the layers on.
This is thus a crucial slicer setting for anyone who wants to print miniatures or other complex designs. You can modify the support area of each column and the infill used to customize these support structures.
Lastly, there is cooling. This parameter ads the speed and power of the parts cooling fans present on your printer.
While it isn’t something that you need to bother with for most prints, sometimes it can be necessary to do so. For example, if you are printing with ABS, you do not want cooling. ABS is a rigid plastic, and cooling it too quickly develops cracks in the print.
For some other materials (or printing overhangs) rapid cooling is needed. For that, you can increase the power diverted to the cooling fans.
For someone getting into 3D printing, a 3D printer slicer can seem like rocket science. Most beginners get by with the default settings, accepting that their prints would never be as good.
But it doesn’t have to be that way. You don’t have to master each and every setting to be able to get the best out of your printer. Slight adjustments to common parameters like retraction or layer height are often all you need.
There is no academic course to learn which settings lead to what results. get a good printer and start experimenting.