Precision, smooth surfaces, and fine details are all mainstays of Stereolithography (SLA) 3D printing. Now with the introduction of Digital Light Processing (DLP) technologies, SLA printing has come into its own. A case in point is the MoonRay S - Wireless High-Resolution UV DLP Desktop 3D Printer. The MoonRay S has leaped past traditional laser-based SLA processes, excelling in performance, speed, functionality and flexibility over legacy SLA technologies.

The SprintRay MoonRay S SLA 3D Printer


Overview of the MoonRay S 3D Printer

SLA 3D printing is based upon liquid resin photopolymers that react by solidifying when exposed to a high powered light source. Traditional processes facilitate photopolymerization by using lasers to trace the coordinates of the model footprint in successive layers while printing. With DLP projectors, photopolymerization occurs by projecting visible or Ultraviolet (UV) light over the entire footprint or slice of the model during printing. This allows the photoreaction to occur simultaneously over the layer without having to trace specific coordinates.


The MoonRay S's resin tank allows for a build volume of 127mm x 81mm x 200mm and demonstrates a consistent print speed resulting in a Z-height of 25mm per hour. The layer height may be adjusted to accommodate 20, 50 or 100 micron layers and sports a minimum feature size of 100 microns. The system is wifi enabled which allows for seamless migration and integration of source part files from design to final print.


The foundation of a well constructed SLA ecosystem is a quality light source, quality resins, and the software that knits these elements together. This is what separates the great SLA printers from the just good or average printer, and this is where the MoonRay S team at SprintRay has focused their efforts. At the forefront is the RayOne UV DLP projector. This UV light projector was specifically developed for SLA 3D printing and eliminates the distortion issues of conventional DLP and laser SLA 3D printing systems.

The RayOne - the MoonRay S's DLP Projector


However, a properly tuned light source is only part of the equation. The other part is high-quality resin that reacts and cures with consistency under exposure to UV light. SprintRay offers standard resins in orange, white, and clear along with functional resins that deliver expanded capabilities. First is a castable resin that allows the user to print and cast jewelry in fine detail. Another is modeling gray resin which is an excellent choice for engineers and artists due to its opaque finish and neutral tone.


Castable ResinSprintRay_gray.png


Gray Resin

Tying everything together, the RayWare software client allows users to set up, prepare and slice models and .STL files for printing. However, the most important part of the process is how the software sends each layer slice to the projector and determines how long to make the active exposure. This synergy between the UV light and resin reaction is what makes SLA printing tick.

The advantages of a MoonRay S are evident in print speed, print resolution, lower production cost, and increased efficiency.  With print speed, only the height (Z) of the model matters. The model’s complexity, volume, or footprint do not factor into the speed. This also allows for the integration of multiple models in one print. In comparison to laser based SLA printers, the MoonRay S 3D printer is up to 10 times faster.

The print resolution of the MoonRay S is a game changer. The resolution in the XY direction is 100 microns. Compare this with the diameter of a standard laser which comes in at about 140 microns. This does not even factor the distortion or blooming of light edges caused by the reflection of the laser in the printer’s mirrors. This laser refraction often compromises the level of detail and accuracy on the outer sections of the build platform which results in image distortion. Even with commercial DLP projectors with native lenses, the assembly and quality of the lenses limit the resolution of the image. This is where the full effect of the RayOne UV DLP projector is realized and leaves the competition lacking.

Detailed prints that are unbeatable


The RayOne UV DLP projector utilizes advanced resin curing technology. It is the sole UV light projector developed natively for 3D printing. It is optimized to ensure high details and accuracy within prints, is well-calibrated, and has a long component life. The projector hits the correct light wavelength consistently across the build platform for improved resin curing control and dimensional stability. This consistency is what sets the RayOne apart from other DLP projectors.

One of the largest detractors of SLA printing is the cost of consumables. At the forefront of this cost is the resin tank. Traditional tanks or vats contain Polydimethylsiloxane (PDMS) along the bottom layer of the light interface. After moderate use, PDMS vats start to “cloud” and distort the laser or DLP light as it passes through to the resin. Refurbishment and replacement of the PDMS finish are time-consuming and expensive. In contrast, the resin tank of the MoonRay S has an average lifetime of 50 liters consumed. This durable resin tank lasts up to 25 times longer than the resin tanks or vats of similar 3D printers. Many users have reported printing more than one year without changing the tank. This, in turn, produces cost savings that the competition cannot rival.

Resin tank for the MoonRay S SLA 3D Printer


Finally, incorporating RayWare software makes the process of printing with the MoonRay S relatively straightforward. RayWare’s support generator is an automatic function and is up to 30% more efficient than comparable SLA software clients. Probably more important is the internal smoothing algorithm that significantly improves the surface finish of the printed part. This antialiasing feature will prevent the surface of the part from appearing pixelated.


Final Takeaway on the MoonRay S SLA 3D Printer

The MoonRay S resin 3D printer is one of the best SLA printers that we have had the privilege to work with, thanks to the complete ecosystem that Sprintray has created in order to get you up and printing quickly.  The MoonRay S is competitively priced and stands tall in the desktop DLP 3D printer domain. Take the plunge and understand why SLA 3D printer has a place in your 3D printing arsenal.