If you’re looking for a resin 3D printer there are a few things you will need to consider. If you are coming from traditional FDM printing not much of the knowledge base is transferable to the world of resin 3D printing. Let’s start with the types of resin 3D printers.
First let’s look at the differences.
SLA vs. MSLA/LCD vs. DLP
Image from https://formlabs.com/blog/3d-printing-technology-comparison-sla-dlp/
SLA 3D printing utilizes two motors known as galvanometers. These motors work as the X and Y axes to rapidly angle two mirrors that direct a laser beam. The laser traces the print much like a traditional FDM printer and hardens the resin where it is traced.
LCD 3D printing is also known as Mask Stereolithography or MSLA. This utilizes a UV light source that shines up into an LCD screen. The LCD screen is used as mask to generate an image of each layer. This hardens the entire layer at a time.
DLP 3D printing uses a digital projector screen to flash a single image of each layer across the entire platform at once. Each layer of the 3D model is displayed as square pixels, meaning that the print is comprised of voxels.
SLA and LCD resin printers are by far the most common of the three for desktop resin printers. For that reason we will be focusing mainly on SLA and LCD printers.
The advantage of SLA printers is that they tend to have better quality due to the finer dimensions of the laser and the laser’s analog movement. For LCD printers, the quality is determined by the resolution of the LCD screen used to mask the UV light. The standard is a 2k resolution LCD screen, but certain printers can be upgraded to a 4k screen which give better detail. Because the LCD screen is made up of pixels, the print will inevitably not be completely smooth but it is not noticeable unless closely examined.
Depending on what you are printing, there are print speed differences between SLA and LCD printers. For small tall objects SLA has an advantage in speed. Because the laser in SLA machines trace the object, the print speed will depend on the size of print in the X, Y and Z. The wider the object, the longer the duration for each layer. The taller the object, the more layers there are to print.
For LCD printers large short objects have an advantage when compared to SLA. Because it prints an entire layer at a time, the length of the print is solely dependent on the height of the print. This means that if you are utilizing the full build volume, it should print faster than SLA 3D printers.
Due to the components used, SLA printers are generally going to be more expensive than their LCD counterpart. Also, there are a lot more LCD printers to choose from which leads to their lower price due to competition. Here are some of the most popular printers for both SLA and DLP types and their prices to give you an idea of the difference in pricing.
As with any 3D printer, certain parts of the printer are consumable. These parts are different for SLA and LCD variants. We’ll go over these differences and the rough cost of replacing these parts.
For SLA and LCD Printers
A printer that uses resin tanks have a non-stick bottom that helps the print release from the tank when curing the layers. This non-stick layer wears out over time and the whole tank needs to be replaced. The recommended lifetime of the tank is about 1000 - 1300 layers or 1 - 2 liters of resin. The tanks vary in cost but are typically anywhere from $50 to $100. SLA and LCD printers can utilize resin tanks but they are mostly used in SLA printers.
FEP Sheet Tanks/Vats
A Printer that uses FEP sheet tanks have a flexible sheet of FEP as the bottom of the tank. This is a non-stick sheet that helps the print release from the tank when curing the layers. Unlike the Resin tanks, the whole tank does not need to be replaced. Only the FEP sheet needs to be replaced. The lifetime of the sheet is similar to the tank version, about 1000 - 1300 layers or 1 - 2 liters of resin. The typical cost is about $10 per sheet. FEP sheets(link this) can be cheaper if purchased in packs.
For LCD Printers
For LCD 3D Printers the LCD itself is a consumable part. It has a lifespan of approximately 1000 hours of printing. Replacement LCDs run somewhere between $40 to $80.
There are many types and brands of resins available. Typically, the machines cure resin at a 405nm wavelength so any resins that cure in that range will work. Technically, any resin in that range will work for both SLA and LCD printers but there are specific resins made for each. SLA uses a much more powerful UV light than LCD printers so if an SLA resin is used in an LCD printer, it will still cure but the cure times would be incredibly long. If LCD resins are used in SLA printers, the resin will cure too fast and loss of detail will occur.
The price range for resins vary quite a bit depending on the type of resin. Below are examples of resins with their properties and cost to give you an idea of what is available in the market.
Formlabs Standard SLA Resin - 1L - $149
Bluecast Castable Wax Resin - 500g - $180
Peopoly Tough Resin - 1L - $110
Peopoly High Temp Resin - 1L - $95
Formlabs Biocompatible Dental Resin - 1L - $399
There are many more types of resin so there should be a resin that would fit any use case needed.
Other Things You Will Need
- UV curing station - Post curing is needed after washing the finished print. Any 405nm UV light source would work for this.
- Latex gloves - Protects your hands from resin.
- Flush cutters - For cutting away supports.
- Funnel - For pouring unused resin back in bottles.
- Strainer - Strain small cured bits when pouring unused resin back in bottles.
- Resinaway or Isopropyl Alcohol - To clean off excess resin on the surface of your finished print.
- Paper towels - For cleaning up.
- Plastic Scraper - To remove prints from build plate and cured resin that may be stuck to bottom of vat.