DLP vs. LETTUCE
Are you considering a resin 3D printer? Then of course you want to know which of the techniques is the best. Whether DLP or SLA is better depends on your requirements.
If your priority is accuracy and resolution, you've probably heard that SLA should be your first choice, but things change. For a long time it was mainly the SLA printers that were able to achieve a Z resolution of 25 microns, while DLP did not fall below 50 microns. Thanks to technological developments, there are more and more DLP printers that achieve a high level of resolution on both the X, Y and Z axis that is difficult to match for good SLA 3D printers.
On the other hand, due to the pixelated lighting of the layers in DLP, the technique consistently shows subtle artifacts at the layer edges that look like “stair steps”. While this is especially true for some DLP printers in the market, there are several companies working to remedy this.
One of the biggest differences between SLA and DLP is the print speed. SLA is generally very slow, due to the highly localized nature of the polymerization approach. To speed up the process a bit, the “fill” areas are exposed faster/shorter than the outer edges. This can save time during 3D printing, but if you want parts that are mechanically more stable, a UV curing post-processing stage is often recommended.
The intrinsic advantage of DLP is that it allows the entire surface of a layer to be cured in one go. With no difference between the outer edges and the inner. As a result, less often is required after processing.
A 30 minute DLP print can take up to 4 hours with an SLA printer for the same 3D file.
Reliability and consistency.
Printer reliability and consistent quality of printed parts are an important factor for anyone looking to run production using these technologies. DLP printers have fewer moving parts compared to SLA machines. Because of this, it is generally said that DLP printers are less likely to malfunction. This sounds very plausible, yet there is no conclusive evidence to confirm this.
Nevertheless, these resin 3D printers are advanced devices that contain a significant amount of electronics and optical elements necessary for proper operation. If they are poorly designed or assembled, they can lead to a lot of headaches, regardless of the technique used.
Maintenance and associated costs are also pertinent points to consider. Due to their complex architecture, SLA machines require professional intervention if the laser needs to be replaced or if one of the optics fails. Calibration of the system is necessary, and often can only be done properly by a professional, which may mean returning the printer to the manufacturer. The advantage of DLP is that it has much simpler components. If one of the parts fails, for example the light source, a replacement part is easy to find.