Makerbot Switching Regulator Upgrade

thingiverse

Everyone knows one glaring weakness with the MightyBoard: its standard 5v linear regulator gets excessively hot, often failing or blowing up entirely when one of the limit switch cables short-circuits onto its 5v line! After exhaustive research and careful deliberation, I chose a high-quality 5v switching regulator from Digi-Key for a quick, low-cost fix. The MightyBoard, however, has an unorthodox SMD layout, where most regulators have input/output/ground, so a few adjustments are required. A sound solution involves attaching the new regulator to another location and connecting it with wires directly onto the pads on the MightyBoard. I chose the Digi-Key product #811-2196-5-nd. Its datasheet also strongly advises including an input fuse, specifically 2A fast-blow type. To add convenience and avoid potential panel damage, one might think to panel-mount the new fuse; yet if a fuse fails in reality it signals a bigger issue needing closer examination, so for utmost reliability I employed a simple axial-lead pico fuse soldered to the input wire heading towards the MightyBoard and encased in heat-shrink tubing for complete electrical insulation. My chosen replacement is part #0251002.MXL by Digi-Key. With that all resolved, it was crucial to design some method of mounting the switching regulator itself: this meant fabricating a thin plastic board for its easy insertion and a press-fit secure lock – a snug enough hold; in anticipation of safety i decided on hot glue for the lock. Additionally i built in 2 pre-drilled mounting points onto the plate to fix it into the back frame or cabinet using 1 simple twist-tie tie screw with minimal extra assembly involved - however I ended up just sticking with using some more regular hot-glue to affix this plate right on top of wood base of the actual Makerbot! In short switching regulators bring not just enhanced functionality, such as current-limiting & circuit-shutting when things get heated (5% loss max); instead, their heat-output is negligible compared. Not to forget these switching converters maintain 90%-efficiency, no worries there - just solid results, with less strain upon power source & device; they come at the right cost without all headaches inherent of conventional regulators often experienced.