3D Printing Deep Dive: What's the big difference between SLA, DLP and 3SP?
When students at the University of Michigan Dearborn needed to quickly produce large car parts for their SAE electric car competition, they turned to 3SP technology from EnvisionTEC, a global leader in developing 3D printers and materials.
Watch the video about UM-Dearborn's car project here!
Launched in 2013, 3SP is a step ahead of older vat photopolymerization techniques such as SLA and DLP, which that have been in the market for more than a decade and have limitations for printing in larger build envelopes.
SLA stands for stereolithography — lithography means “to write” — and it requires the laser beam draw out a full cross section of a part repeatedly, layer by layer, until a final part is built. In larger build envelopes, however, this process becomes challenging.
Consider this simple analogy: a human standing in the center of a room holding a flashlight aimed directly at a wall. The beam is highly focused in the center, but when directing the flashlight to the farthest edge of the wall, the beam focus elongates or diffuses, losing some of its accuracy at the edges. The bigger the room, the worse the distortion of focus will become.
This same dynamic holds true inside a large SLA machine. The use of a single laser beam across a wide build envelope can cause the beam to lose focus at the widest points of the build envelope, impeding accuracy and surface quality of the cured material.
Over the years, manufacturers have figured out ways to try to minimize this focus distortion by using mirrors controlled by galvanometers, also known as galvo mirrors, often in concert with optical lenses, to reflect the laser beam to further points in the build envelope and simultaneously reduce distortion or flatten the field at point of impact with the resin. Some of these large build-envelope systems also use multiple laser beams and a variety of galvo mirror and optical lens systems. While these systems are effective, the complexity of these systems also increases their price, sometimes dramatically.
Just like EnvisionTEC solved the time problem associated with SLA's drawing out parts with a fine-point laser beam, by pioneering DLP that uses a high-definition projector system, 3SP affordably solves the problem of 3D printing large parts quickly and accurate in an affordable machine design.
Learn more about 3D printing in large build envelopes, whether building large parts or a full envelope of smaller parts, in this white paper from EnvisionTEC.