The basic mechanism of a SLA 3D printer is that a light flash on a photosensitive liquid resin and it hardens. This effect is called photo polymerization. Let’s understand what happens here. The liquid contains of monomers. In a flash of light, the monomers changers its state to solid by creating bonds each other and creates a polymer (“curing” in the terms of chemistry) in a fraction.
The mechanism of a SLA printer
- The laser
- Liquid photosensitive resin
- The object
- The platform
The laser used is mostly a UV radiator. UV is used because it contains more energy than the visible light. Inside a SLA printer is a combination of mirrors and a stationary laser. So What happens is that when you execute the desired 3D model on a 3D slicing software it breaks the model into layers and tells the printer where the UV laser should point. Accordingly, the points into certain positions on the platform which crystalize. After a layer is crystalized(printed) the platform rises up letting the laser to print the next layer
Both DLP and SLA printers have most of the similar properties and working mechanism. What’s the difference is that the DLP printers print a whole layer by one flash of light besides a SLA printer does it with a single point of laser going all over the layer. On a DLP printer instead of a laser a projector is used to do this. When a 3D model is executed in a slicing software it divides the model into layers and instruct the printer which layer should be printed.
Comparison between a SLA printer and a DLP printer
Both above printers are used in more detailed 3D printing. If we compare the printing resolution both of the above 3D printers have a high resolution than a FDM printer. SLA printers can reach a layer resolution up to 0.025mm. Which gives a smooth finishing at the end. For example, if a model is printed with the same resolution in all kinds of 3D printers SLA will have the highest resolution because the laser reaches every single edge of the 3D print. When it comes to the time duration SLA will also have the highest tine duration too. Since the laser moves to every single edge of the it takes a considerable amount of time to even to finish one layer. SLA also have the highest retail price. Since it is more cutting edge it is more expencive.
What we are researching….
SLA printers are very much expensive, and since it has a complex mechanism inside it is also hard to make at home. We are undergoing on a project to build a SLA 3D printer at home