fdm vs. sla: which type of 3d printer is right for you? - stereolithography

At present, two very different 3D printing technologies, namely FDM (
Melt deposition modeling)
And advanced SLA (
Photocuring).
The two methods are very, very different, but they may both stay in the 3D printing world.
Each has its own important advantages and applications.
However, if you are buying or learning how to use a 3D printer, it is essential to understand the difference between FDM and SLA.
So we have to talk about it!
Note: There are other types of 3D printing, such as polyjet and SLS.
We talk more about this in our comprehensive 3D print.
However, FDM and SLA are often more common, especially at the consumer market level, so we want to take a closer look at them. FDM (
Melt deposition modeling)
If you watch a video of a 3D printer at work, you may see a carefully programmed print nozzle
Space, squeeze out a melted plastic line to outline a clear shape.
This is a very popular image, and FDM is the most popular technology used by small 3D printers.
It creates a small layer that combines together and finally creates an object.
Let's talk about how it works.
First, the printer must get the right information-essentially a path so that the deposited material can create the right object.
This is done using a 3D model file (such as STL or OBJ file) that contains information about how objects are "sliced" and can be applied to a layer at a time in FDM.
This is one of the easiest ways to program 3D objects, and you can use it for many different types of objects.
Of course, the more complex or smaller the object, the more it needs to be sliced. Not all FDM printers are equipped with equipment for handling complex objects.
As files on the object layer are sent to the printer, it has all the data needed to start.
However, it still needs raw materials.
The printer uses filaments made of raw materials that can be heated and easily pushed out of ropes or threads.
Usually this material is made of relatively safe plastic that is easy to form.
However, there are great differences in filaments, which can also be a combination of other materials to give the printed object additional attributes.
Following the 3D file, the printer now heats the material and squeezes the nozzle when the nozzle moves, one layer at a time.
After completion, there is usually a short waiting time so that these layers can be fully combined.
Then the object can be used!
FDM printers struggle with particularly fine details or objects that need to move parts, etc.
It can't really create high-end prototypes.
They can also be very picky.
Coding and calibration must be very accurate, otherwise the printer will not work properly.
This may mean you have to do a lot of work to "teach" how the printer starts making new objects. SLA (
Photocuring printing)
Technically, stereo lithography was created decades ago: it uses highly responsive plasticslike resin.
This resin is more or less an easy-to-operate liquid under normal conditions.
However, when exposed to the correct type of radiation (
Usually light from directional laser)
The resin is permanently hardened into a new form.
SLA printers only need to apply this process to 3D printing.
They also printed layer by layer, but instead of squeezing the material, zap added a tank filled with resin liquid.
If you haven't seen this process yet, it's worth watching a video-
The mechanical device is surprisingly beautiful.
This process starts with resin fluid and UV laser and can be carefully aligned with the bottom layer of the resin.
The SLA printer uses a very complex 3D file that contains a description of the laser aiming position.
The printer usually includes the foundation of a 3D object.
When the object is built layer by layer, the base passes through the liquid tank and slowly rises from the depths.
However, these layers are completely different from FDM.
They are less than 100 microns thick and form very fast.
Not combined by random melting-
These layers are combined to make the object a uniform material at a chemical level.
Moving part is still a problem-
No matter how good the slicing and layering techniques are, it is still difficult for ordinary 3D printers to do this.
Due to the price of resin and the complexity of printer, SLA printing is also more expensive and more difficult to mess with than FDM.
Resin is also proprietary, which means you have less flexibility when choosing what you want to print.