Anycubic Photon: SLA Printing At Home
AnyCubic SLA
Stereolithography 3D printing, also known as SLA printing is a newer addition to the home-maker toolkit and I was very excited to get my hands on Anycubic’s Photon Mono X 6K. A newer printer, the Mono 6K offers a higher resolution and a decent printer vat size in comparison to other SLA printers on the market. It is pictured above, on the right, sitting next to the Wash & Cure station that it requires for post-processing.
SLA vs FDM Printing
Unlike traditional FDM 3D printers, which paint melted thermoplastics in layers to build a 3D printed object, SLA printers use a liquid photopolymer to print an entire layer at a time. A photopolymer is a type of liquid resin that when exposed to certain wavelengths of light will undergo a phase transition, from liquid to solid. Using wavelengths of light to cure the resin layer-by-layer allows for much greater detail and accuracy with what you can print, in comparison to FDM printing.
SLA printers accomplish this printing technique by using a vat for the liquid photopolymer with a transparent bottom, sitting on a powerful UV laser array, which can cure the bottom layer of the polymer. A metal plate lowers into the vat, so the polymer can harden onto its surface. In between each layer, the arm must raise up, to detach the dried resin from the bottom of the vat.
While not necessarily faster than a good FDM printer, when it comes to printing speed since the print cures a layer at a time, the speed of the print is only determined by its height, and not its total volume, which gives it an edge over FDM.
SLA Printing Procedure
The procedure for printing with an SLA printer is a bit more involved and comes with more safety risks than with an FDM printer. The steps below are what I followed for my print:
- Download or create a 3D model of your choice
- Put the model into an appropriate slicer which will turn it into instructions the printer can interpret
- Upload the sliced model to the printer
- Prepare the bed and vat
- Give time to let the printer print
- Once finished remove the plate from the printer and place it in the wash tub
- Wash the print in water
- After washing remove the print from the plate
- Carefully cut away any supports
- Place Print in Cure Station and allow to cure
- Remove print and sand away any remaining support material
The Test Model
I chose this model of EVA-01 from Neon Genesis Evangelion to properly test the printer’s ability to do fine details well. This model was taken from Thingiverse.
After downloading the STL file I put it into the slicer I was using, AnyCubic’s Photon Workshop. This program took the 3D model and sliced it into layers matching the layer height setting, and turned each slice into an image the printer’s laser array can use to cure the polymer.
Once the model had been sliced and uploaded it was time to prepare the printer. It is very important when working with photopolymer to wear gloves. Photopolymer is toxic and will absorb into your skin, where it will remain until exposed to UV radiation, which will cause it to heat up, leaving you with nasty burns. I added enough polymer to ensure the model could be printed, placed the protective UV cover over the printer, and let it print.
It is also important to note that an SLA printer can give off fumes. Mine is covered so the fumes won’t release until the hood is lifted. I keep a couple of carbon air filters inside while it prints, as well as a fume extractor next to it, and keep my apartment windows open to ensure proper ventilation.
Post-Processing and Cleaning
Once the print was finished I could remove the cover and take the plate off the printer (with gloves on). At this stage, the print is still slightly soft and is soaked in undeveloped polymer. To ensure the model looks right and will last it needed to be washed. The photopolymer I used was water soluble, meaning I could wash it in a tub of just water, not all photopolymers will work in a water bath, and some need more industrial solvents, like IPA. My printer also came with a wash station, which contains a wash bin that will auto-stir. I made sure to wash it for a few minutes to get most of the liquid off.
After washing it, I used a large palette knife to pry the print off of the plate. This isn’t the easiest step in the process and requires some real elbow grease! Once it was off the plate I could go in with my cutters and remove all of the supports needed for printing. This step also takes some time and is critical to the final look of the piece. Once properly cleaned up the model still needed some final curing to harden. The wash station I have doubles as a curing station, so I placed my print inside and let it get bombarded by UV light until it was properly finished.
Results
In the end, I had some mixed results. I scaled down the print size initially and I think that crushed up some of the small details, leading to a lower-quality print. In addition, the right arm of the print failed, leaving my model disarmed. While it’s not all right, it is certainly all left, and a new arm can be printed and glued on. I think a larger model and longer print would have yielded a better print.
Next Steps
This model was a great start to my SLA printing journey! While I may want to reprint this larger and in better quality in the future, for now, I am fairly happy with the results. A bit more sanding and it will be ready for a coat of primer and then some painting. A new arm will also have to be printed, though I may take the opportunity to make that arm a bit more unique, as I think it will make for a much more dramatic project, in the end.
While printing models is fun, and I have something nice to show for it afterward, I am also excited to start designing parts for project using this printer. The tolerances will allow for much more precision in manufacturing, opening up areas of design I have yet to explore. I am thrilled to be moving forward with such a unique tool.
