Choosing between manually changing endmill bits on a CNC machine and investing in an expensive automated solution? Not for [Frank Herrmann], who invented the XATC, an eXtremely simple Automated Tool Changer. [Frank’s] ingenious hack achieves the same functionality as an industrial tool changer using only cheap standard hardware you might have lying around the workshop.
Like many ATCs, this one features a tool carousel. The carousel, which is not motorized, stores each milling bit in the center bore of a Gator Grip wrench tool. To change a tool, a fork wrench, actuated by an RC servo, blocks the spindle shaft, just like you would do it to manually change a tool. The machine then positions the current bit in an empty Gator Grip on the carousel and loosens the collet by performing a circular “magic move” around the carousel. This move utilizes the carousel as a wrench to unscrew the collet. A short reverse spin of the spindle takes care of the rest. It then picks another tool from the carousel and does the whole trick in reverse.