A4988 Heatsink Locator Template

thingiverse

This is an A4988 Heat Sink Locator Template that lets you position the heat sink consistently. I created this for my A4988 controllers (three in total, used for CNC) to improve the heat sink placement and ensure it clears other components. Check out the photos for usage examples and the final positioning achieved. A4988 PCBs can vary significantly, so it's best to print one out and test the position before proceeding. If you're not satisfied with the results, adjust the template in OpenSCAD and re-print. The template has just two offset settings (x and y) from the center of the PCB for the heat sink window. I went through four revisions to get a version that met my requirements (see photos). Before applying the heat sink, inspect it under magnification to ensure it's free from loose metal debris. Some poorly cut heat sinks may need deburring, filing, or sanding to clean them up. Take your time and do the best job possible before sticking on the heat sink. As an extra precautionary measure, use a multi-meter to check that the voltage rails aren't shorted after fitting the heat sink before powering up. The OpenSCAD file is included, but keep in mind that the design is upside down.