Project Description: This six-person research project under Professor Liang Pan was my Senior Design experience in Spring 2023. We worked to implement stereolithography (SLA) and direct light projection (DLP) technology into one printer system to gain the benefits of each while reducing their weaknesses, at the cost of complexity.
Software Used: Fusion 360, MATLAB, LabVIEW
My Role: Our professor had a specific target resolution in mind for his research, so we had to use a small projection area and plan to translate our build area with respect to the projection area. I incorporated a microscope XY motion stage to achieve this translation, and then focused on a slicing workflow to go from 3D models to SLA perimeters and DLP layer sections to accommodate tiling.
Other Roles: This project had many aspects tackled by my teammates. These include: deciphering the prior LabVIEW code and figuring out how to control our XY stage and Z actuators, designing and manufacturing metal frame components to hold stages together, designing an optics train to allow for an overlapping area for SLA and DLP exposure, adding a camera to monitor the exposure area for calibration of the two SLA and DLP image components.
Big Wins: I enjoyed the challenge of focusing on secondary skills, it allowed me to develop my programming ability and help round out my skills some. This project deepened my knowledge of resin 3D printing significantly. Our professor was happy with our delivered results.
Challenges: The largest challenge for this project was having to inherit work from a graduated master’s student with limited documentation. Additionally, since this project was a part of an established professor’s lab, we were restricted to using components that they already had for our optic and motion systems. We had minimal additional provided budget and limited design freedom.
Key Takeaways: Documentation “for the next guy” is so important for efficient project handoffs. Building a team with balanced skills is important, four of our six members were design and manufacturing-specialized, so we had to spread out to tackle areas with slightly weaker skills. Knowing where to go to answer questions is important, our professor had to answer a lot to get us moving with the old lab view and with optics systems.
Here is the final CAD and assembly for our printer prototype. The large box was enclosing our DLP projector to prevent incident UV light from spilling to the surrounding area. Next to that is a galvo for the SLA, pointing into an optic train for overlaying the two areas, then focusing the projections onto the bottom of the build plate.
Here’s a close up of the moving gantry area of our printer. The majority of the XY stage could move with respect to a plate on the underside that mounted to our optic table, above a mirror that redirected the UV light from the DLP and SLA systems. The Z motion consisted of two stages since the actuators available to us didn’t have a long enough single range of motion.
For our printer, we divided the layer into 6 segments. The red lines in this sliced image represents interfaces that would be split across to create each DLP frame. SLA toolpaths would be generated from the same model with a method similar to FDM slicing, while only being concerned about the perimeters since DLP covers the bulk nicely, but has pixelated edges.
Here is our team’s final poster summarizing our project