A very brief intro to 3D printing
3D printing involves melting plastic filaments in an extruder or printhead, which is squeezed out of a nozzle onto a platform in a pre-designed pattern. A 3D print comes from a model that is programmed into the software, but that design has to come from somewhere.
Designing a 3D model
3D printing starts with a 3D model, designed in software to tell a machine how to make an item. A good example of this is called Computer Assisted Drawing, CAD. You probably saw commercials years ago, and now, with a wireframe model and graphics showing a person making a variety of objects with a 3D model by drawing lines in a 3D space. The 3D model, however, doesn't quite speak the same language as your 3D printer, so additional software is needed to convert a 3D model into something that makes sense to the printer.
What does the slicer do?
3D printers don't work without detailed instructions on how to print. 3D models are the other end of the process that designs a 3D model. The slicer is the in-between.
A 3D print works like a regular ink printer but is much more complex as it adds layers, heights, and speeds to squeeze out melted plastic. The purpose of the slicer is to add detailed instructions for a large variety of items like printhead movement, layer depth, and speed movement to the printer so that the printhead can be guided properly to make the item. The slicer also tells the printer how to get and when so that filament is nozzled out at the right width and density to make the right structures.
Slicers do a few additional things to help the process too. This includes programming like “Infill” which can convert what the person designated as a solid object into a hollow one. A slicer can also help make supports for 3D printed objects. For example, if you wanted to print a person holding something, the printer could print small supports to ensure that the arm and item were stable – and you could remove the additional strings that provide that support label if you want. Finally, the slicer can add some skirts, brims, or rafts that keep the melting plastic from being too rough or out texture within the first layer. These are the kinds of details that make slicers very handy.
How do I get slicer software?
Like many computer programs and equipment, your printer might come with slicer software. You also have the option to upgrade slicer software, which can range from a few dollars to hundreds. Note that not all 3D printers can use all slicer software, so do a bit of research on compatibility to make sure you don't buy software you cannot use.
Is there a difference in quality between slicing programs?
We aren't going to explicitly recommend a particular slicing program, but there can indeed be key quality differences in how much detail slicing programs offer. If you are printing detailed objects, you may want to look up the best slicing software for printing at the level of quality you want to achieve. For example, if you want to print figurines of animals or fish, consider looking at which ones best produce detailed renderings of feathers or scales.
Should I pay for a slicer program?
There are more than a few open source programs available, so you have the option not to. The better question is whether or not you are happy with the quality of print and the ease of use of your current slicer. Note that a more expensive slicer might not necessarily be easier to use, and a free one might be easy or hard. You'll definitely want to factor your own experience and expertise into choosing a slicer.
Why is it called a slicer?
We have a theory here: A 3D model is simple by comparison to the instructions needed to produce it. A slicer cuts off the 3D model into even smaller parts, with instructions for layers, then makes each piece into a much larger series of pieces. The code for many 3D printer pieces would be at least a couple hundred pages long, making it a significantly larger file.
Think of a slicer as a translator that knows a lot more words than your 3D model program.
What can a slicer tell me?
Since the slicer produces the commands for your printer, there are a few things that it can predict. This includes the amount of time it will take to make your 3D print, though admittedly, it is possible for this information to not be completely accurate.