3D printers look like something straight out of a sci-fi movie, but recent advancements have made them really accessible to the average hobbyist. Generally, there are two types of economical 3D printers, fused deposition modeling (FDM) and Stereolithography (SLA).

In this article, we are going to talk about resin printers (SLA / MSLA / DLP) and some of the pros and cons of the technology. Let’s start with a comparison.

Resin or filament 3D printers

FDM 3D printers use a spool of plastic filament that is melted by a heated nozzle to recreate the 3D model layer by layer on a build platform. The nozzle should move in all axes as it applies the molten material layer by layer.

SLA printers use a resin tank where the build platform is initially submerged. During printing, a high-precision laser illuminates specific areas to harden the resin and the object is recreated layer by layer. There are fewer moving parts here because the build platform only needs to go up during printing, which is also why prints are created upside down.

Print quality and size

Resin printers are very precise because they use a laser to draw the layers on the platform. For example, take the entry-level LCD Resin Creality Halot One which has a layer thickness of 0.01-0.2mm, while the similarly priced FDM Creality Ender 3 v2 has a layer thickness range 0.1-0.4 mm.

When it comes to print size, FDM printers have an advantage here with the ability to print larger models. Again, taking the same example, the Creality Halot has a print size of 127 * 80 * 160mm while the Creality Ender 3 v2 has a much larger print size of 220x220x250mm.

Price and ease of use

Over the years, the cost of resin printers has dropped dramatically, and nowadays entry-level MSLA and FDM printers are in the same price bracket. The story doesn’t end there, however, as there is a recurring cost in the form of consumables. SLA 3D printers use liquid resin which can cost you US $ 50 per liter (and more depending on the resin material). FDM printers use spools of filament and cost just US $ 15 / kg on the low end.

FDM printers are also easier to use and there is little to no post-processing after printing. However, these prints will have a rough texture and should be polished to a smooth finish.

Resin 3D printers require some post-processing after printing. The finished print is tacky due to the resin and should be washed in isopropyl alcohol. Depending on the type of resin and material, the finished print may also require post-curing.

Types of resin 3D printers

There are 3 common types of resin 3D printers, and while they share the same main technology, there are a few subtle differences.

• Stereolithography 3D printers (SLA)

This has the distinction of being the oldest 3D printing technology and has been around for some time. These 3D printers use a laser point directed by several mirrors inside the machine. The laser cuts out points in each layer individually, which is also why they are so precise. Although they are slower than the other 2 types of 3D printers.

• Digital Light Processing (DLP) 3D Printers

These are basically similar to SLA 3D printers, in that they both use a light source to sculpt the resin. The main difference here is that in DLP 3D printers a light projector is used which draws the entire layer at once. This method allows for faster print times than SLA 3D printers.

• Masked Stereolithography 3D Printers (MSLA)

These printers use an LCD panel to direct light onto the resin. Unlike the other two printers above, MSLA printers do not have mirrors to direct the light, but the light is controlled by the LCD screen. This type of construction does not require specialized mirrors, which greatly reduces the cost of production, which is why almost all budget resin 3D printers are of this type.

Why your first 3D printer has to be resin (or maybe not?)

Recently, with the arrival of LCD Resin printers in the market, the cost of these machines has dropped dramatically, even reaching the US $ 250 mark. Resin printers can reproduce a very high level of detail in printed models, with even fewer print failures than FDM-based 3D printers. Prints from resin 3D printers also have a smooth finish unlike FDM printers where the outer surface has a rough texture.

One of the biggest drawbacks here has to be the size, the SLA 3D printers cannot match the FDM ones here due to the nature of the technology. FDM 3D printers have a nozzle that can move in all three axes, which also means it’s easier to scale out for larger models. In resin 3D printers, the build plate only moves on the y axis and the size is limited to the resin tank. The cost of production per unit is also higher than that of FDM 3D printers due to the higher prices of consumables (liquid resins). There are also some post-printing jobs to consider, and prints should be washed and dried, although a drying station can be purchased to aid in the process, again an additional cost to consider.

If you are looking to create highly detailed miniature models or production tools or anything that needs precision, resin printers might be a better choice for you. If you need to print larger models or prototypes that don’t require a lot of precision, FDM 3D printers might be a better bet. For someone new to 3D printing and doesn’t want to deal with the added nuances (and costs) of a resin 3D printer, FDM printers might be a better entry point into the world of 3d printing.

If you’re looking to buy a 3D printer, we’ve picked the best budget options (under US $ 500) here.