Electrical engineer and self-professed tinkerer, John McNelly, has ingeniously upgraded a drill press to facilitate accurate hole drilling in homemade PCBs and other materials. Tired of squinting at tiny drill bits while attempting to align them with small pads for vias and through holes during PCB fabrication, McNelly developed a digital periscope with cross-hair targeting. This innovative solution features a digital display that projects a cross-hair precisely where the drill bit will make contact, ensuring perfectly centered holes each time.
McNelly’s motivation for designing his own solution, rather than adopting existing methods, was rooted in his specific needs. He sought a standalone microscope-based system that wouldn’t require a PC, allowed for multiple microscope camera types, and was adaptable to different setups. His final design employed a mirrored periscope arrangement, with the microscope camera positioned horizontally atop the drill table and a 45-degree mirror offering a view of the material’s underside. This setup accommodated his existing microscope camera and allowed for easy viewing while operating the drill press.
Driven by a custom PCB hosting components like a buck converter, color and brightness controls, and a Raspberry Pi Pico running MicroPython, the assembly features 3D-printed parts for structure and utilizes magnets to attach to the drill press. The cross-hairs are manually drawn on the display using a removable marker, adding a simple yet effective touch to the setup. McNelly’s comprehensive write-up and project files are available on his blog and GitHub repository, respectively, offering insights and resources for those interested in improving their hole drilling accuracy.