Auto-Toolsetter

My favorite part about engineering is solving problems. While working at the USC Undergraduate Fabrication Lab, I saw a problem that was causing us to have long program run times resulting in less accurate parts on our CNC Mill. Typically, when machining a part, multiple different cutters are used to optimize material removal rate, surface finish, and accuracy. However, since changing a tool on our machine required the operator to manually unscrew it with a wrench and then manually set the tool length, most people designed programs that used as few tools as possible. I solved this problem by turning the multi-step tool change process into an automatic process that takes just two button presses.  

First, I repaired and installed a “power-drawbar” that we already had to remove the necessity of a wrench. I originally had plans to create my own but using the old one helped me save time and money without compromising usability. I then researched, designed, and then machined a “auto-tool-setter”. This device took advantage of the fact that the machine’s 24V power supply used the machine body as a ground. When a tool touched the “auto-tool-setter”, the controller would detect that the circuit had been broken and record the position. Finally, I wrote a macro using cypress basic to automate the process of determining an offset and setting the zeroes for each tool.