Overview
The speaker documents the assembly and testing of custom PCBs and hardware for a DIY MSLA 3D printer based on Arduino code. Progress was made with successful PCB tests, but a wiring mistake prevented full printer operation; assembly and further testing are planned for a future update.
Project Background & Components
- The project involves building an MSLA 3D printer using custom PCBs and Arduino-based code.
- Four main PCBs were designed: UV light control, TFT display, main control, and buttons/display interface.
- A larger 4-inch display (90 x 60 mm) replaces a previously used smaller TFT display.
- The 3D-printed enclosure includes parts for the main case, Z-axis tower, stepper motor housing, and controls.
PCB Assembly & Testing
- UV LED board was assembled with 18 UV LEDs and power resistors to ensure uniform light distribution and heat dissipation.
- The TFT display module was detached from its original PCB, then attached and soldered to the custom display PCB.
- The main control board was populated with an ESP32, power regulation components, motor driver, MOSFETs, connectors, and buttons.
- Initial electrical tests confirmed that the display, ESP32, and UV LED control function properly.
- PCB stacking allows the UV LED board to sit above the main board for heat management.
Issues & Limitations Encountered
- Incorrect GPIO pins (39, 34, 35) were assigned for stepper driver control; these are input-only on the ESP32, preventing driver operation.
- Full printer assembly and stepper motor testing were postponed until a revised PCB is designed and ordered.
Workflow & Software Integration
- Cheto box slicing software was set up with customized printer settings for resolution and screen size.
- Test object layers were exported to images, loaded onto an SD card, and displayed on the TFT via the ESP32, confirming SD card and screen operation.
- Firmware was updated to synchronize UV light with image display, simulating printer exposure.
Mechanical Design & Assembly
- Printed enclosure parts were designed to fit the boards, screen, and mechanical components precisely.
- A linear stepper motor with integrated screw and a linear bearing slider were sourced for the Z-axis.
- A future calibration plan includes using an aluminum block and ball connector for the print table.
Known Issues & Planned Improvements
- The SD card slot is difficult to access; a redesign or tool may be needed for easier use.
- A transparent protective cover is planned to shield the resin from external light.
- The resin bath design and enclosure water sealing need further development.
Next Steps
- Redesign and order the main PCB to address the stepper driver pin issue.
- Complete enclosure design and remaining parts.
- Finalize and test the code with all hardware components.
- Implement enclosure improvements and finish the resin bath.
Acknowledgements
- The speaker thanks viewers, patrons, and supporters, encouraging interaction and feedback for future updates.