DLP resin printing is a different sort of 3d printer from the plastic filament depositing FDM-style printer. Instead of melting a string of plastic, then moving a hot print head around the design, depositing that melted plastic, the DLP resin 3d printer builds a model out of liquid resin, hardening a layer at a time using UV light. It sounds like science fiction, but it’s a reality today.
A DLP resin printer is a very good choice for an adult (or an adult-like mature young person) to start with. It produces superior results, but is limited by a very small print volume, so only smaller items can be printed. The uncured liquid resin, however, is somewhat expensive, poisonous, caustic and smells rather bad, unless you print with the even more expensive ECO-Friendly UV resin (in which case it is not poisonous or caustic, and smells far more pleasant).
The real advantage to DLP resin printers is that they are high quality, relatively fast and not that expensive. Small format DLP resin printers can be purchased for sub-$300.00USD, and come with everything that you’ll need to get started (including, in many cases, a starter bottle of resin).
What is DLP Resin Printing?
DLP, or digital light processing, is a relatively simple technology. A computer display screen is placed over a UV light source. A pattern is placed on the computer display screen blocking the light from shining through, leaving only those pixels that you want to harden unblocked. That light shines through the bottom of a clear-bottomed resin bath. Above the resin bath, a metal plate is lowered down mechanically so that it rests near the bottom of the resin bath (one layer width above it), sandwiching liquid resin between it and the bottom. The UV curable liquid resin gets exposed to the UV light in the pattern allowed through, hardening it.
After a few seconds (enough to harden the resin in that thin layer), the build plate mechanically rises up with the first layer stuck to the build plate. It then lowers to one layer height higher than the position it was in last time. This traps liquid resin between the bottom and the lower surface of layer one. The pattern on the computer display screen changes to the pattern required for layer 2, and the UV light shines through again.
This process is repeated for each layer, all the way up until the model is completed. When it does complete, the build plate rises up, leaving the finished model hanging upside down from the build plate, dripping excess liquid resin. The model is complete, but must be removed carefully from the build plate and cleaned of any remaining liquid resin.
Once the models are cleaned, any support structures that were printed with the model can be removed (usually snipped off with hand side-cutters), and then the model needs to be cured. Although the resin was cured as each layer was made, it remains somewhat soft. Exposure to sunlight or in a UV curing chamber for an hour or so will harden the model to its final form. Once cured, the model is hard enough to be sanded, filed and can be painted, if desired.
What Makes DLP Resin Printers Different?
DLP resin printers only have one axis of movement. The entire layer (in the X Y plane) is printed (hardened) all at the same time. Then, the build plate raises and lowers to a point one layer height above the last layer. So the printer only has to worry about the Z axis for movement. It moves slowly enough that the inertia of the build plate and model can be dissipated easily, so more precise control can place the build plate at the next position. This means that layer heights of 25 microns (0.025mm) are capable with even the cheapest DLP resin printers.
The models you make are made of hardened resin, but they tend to be harder and more brittle than the resin or plastic models that you’d print using an FDM filament printer. The material can have different properties than those from FDM filaments, too. Generally, the resin makes hard models but they aren’t flexible. There are plant-based resins and high temperature resins, so there is a variety of materials, and a variety of colors available.
What Are the Safety Considerations For DLP Resin Printers?
Normal UV hardening liquid resin is both poisonous and caustic. That means don’t get it in your mouth or your eyes, as it will both chemically burn and poison you. If you spill on your clothing, it will soak through and burn your underlying skin. If you leave it for a few hours, it will cause serious burns, enough to require hospitalization or burn unit treatment. So it’s very nasty stuff!
With some very basic safety procedures, though, you can mitigate the risk and print happily with no fear of issue. First, always wear nitrile rubber gloves (not just any rubber gloves, but nitrile rubber gloves). Nitrile rubber gloves resist the chemicals, making it save to handle and even immerse your gloved fingers in the resin with no danger.
Wear eye protection when pouring resin. It’s thick, so it’s unlikely to splash, but it can happen. And don’t touch your eyes with contaminated gloves. That seems obvious but a little eye itch can generate an automatic response to rub your eye. With clear safety goggles on, you’ll not be able to do that.
Have a roll of paper towel near your work area and easily accessed. Any spills should be immediately cleaned up. Even a drop. Don’t let it sit around anywhere. When you remove a model from the build plate, you’re likely to get a few drops of uncured resin dripping off the build plate or model. If you do this over a sheet of paper towel, it will soak it up. Simply throw away that paper towel when you’re finished.
You can use Mean Green cleanser to clean up any spill areas, too. You’ll have this around as you’ll use this for cleaning your models after they’re printed, so it’ll be easy to hand. Mean Green has the ability to break down resin residue and make it harmless, so it’s very useful after you’ve cleaned up any drops or puddles of uncured liquid resin.
If you drip or spill liquid resin on your clothing, remove that clothing right away. Wash the clothes as normal to remove the material. If you find you’ve got a red spot forming on your skin, immerse in water for at least 10 minutes, and likely more. If you have any concerns that this won’t cover it, get some medical attention.
So the resin can be bad if you don’t treat it with respect. But if you do, wearing the very easy protection and cleaning up any drops or spills, you’ll be fine. Don’t let it sit on your skin or in clothing next to your skin. Don’t let this stop you from getting involved with 3d DLP resin printing.
That being said, if you can’t keep kids or pets away from the printer and the resin, then this type of 3d printing isn’t for you. I have pets but no kids. I keep my printer and resin supplies in a closed off, well ventilated room, where my pets cannot get access.
You can sidestep a lot of these issues by using a more expensive plant-based resin. AnyCubic has brought out their ECO UV Resin line. It’s roughly twice as expensive (and maybe a little more) than normal UV resin, but it’s low odor, non-poisonous, non-caustic and produces good results. You’ll still want to keep your kids and pets away from the printer and resin, but at least if they do interact with it, it won’t mean a dangerous situation a trip to the Emergency Room. Still use gloves and eye protection – it’s not water, and I’m no chemist so remain vigilant.
Here’s a link to that resin: https://amzn.to/3gBiCn0
What Size DLP Resin Printers Are Best For Beginners?
You have two choices for printers at the moment. You can go small print bed or large print bed. The small print bed printers are below $300.00USD where large bed printers are around $2,000.00USD. So from cost alone, purchasing the smaller bed printer is the smart choice when starting out.
See this article on differences in size for DLP resin 3d printers:
The only reason to start with a large format DLP resin printer is if you’ve got a compelling use case. A friend of mine produces costume items for Cosplay, a hobby where you create and wear costumes of your favorite media characters. A large format DLP resin printer can produce larger costume items, like full helmets, sword (or laser sword) hilts or even bracelets, pendants or body armor parts. In her specific case, if she’s willing to pay the much larger expense of the large format printer, then it’s the right choice. The small format printer just won’t produce what she needs, regardless of price or resin usage.
For me, I started with an AnyCubic Photon printer. I want to produce scale model vehicles and figures for tabletop gaming. The small format is perfect for this sort of use. I get excellent detail at a great price.
Please note that even if you do decide to go with the large format DLP resin printer, you can still print small items like I am. You can print more at a time if you like, but it’ll do the same job as the small format printer, at the same resolution. Don’t think that the small format printer is more detailed than the large format printer. It’s the same, regardless of the model size.
Where Can I Find 3d Printing Files To Print On a DLP Resin Printer?
So if you’ve decided to go forward with a DLP resin 3d printer, you’re going to want to get some models to print! These models are electronic files, usually with the file extension .STL. There are a bunch of great places to find models to download, but the biggest in the world is https://Thingiverse.Com. Go there and type in a query in the search area in the upper right. They have millions of designs. I have found most of my .STL files there, and they’re free for download and come with a license to print for personal use.
If you want to print and sell the items that you print, you’ll have to contact the designer and purchase a commercial license from them. Otherwise, you’re violating their copyright rights.
To avoid the rights issue altogether, you can design your own items, using either free or commercially available 3d design software. For a free browser based 3d design tool, check out TinkerCad at https://www.tinkercad.com/. Create your model, and download the .STL file, ready to print. To learn how to use TinkerCad, check out this YouTube video:
Which 3d printer is best for beginners?
The best beginner 3d printer is the Ender 3 for an FDM filament printer, as it’s cheaper than most, and has a large community of supporters on social media. For a DLP resin printer, look to the AnyCubic Photon or Elegoo Mars as both cheaper than most, and has excellent quality, along with large communities of supporters on social media.
Is 3d printing resin toxic?
Most UV curable printing resin is toxic and caustic. AnyCubic, however, has a plant-based resin that’s more expensive, but not toxic or caustic. It is available on Amazon.Com or other retailers, including from AnyCubic directly.