It would be handy to have some sort of indicator to show how hard a CNC router is working. On my old machine I just play it by ear but sometimes that does not work and all sounds fine an the next moment the bit is broken. I once saw a video of some fancy VMC that had a little electronic dial meter showing cutting force. It did not show an actual force reading but more like a green, yellow and red band, if that makes sense. Do you perhaps have any idea how something like works? Strain gauges or maybe load cells come to mind but I can't see a feasible way of fitting those to a DIY router?


On my build the spindle power is likely to be the weak spot so I'm thinking if I can see how hard that is working under certain conditions it would give me a more scientific reference point. On my VFD I have an analog output that I can set to output current (virtual) and then hook that to an old school analog type 0-12V volt meter. Not sure what current "virtual" means as the in this context but I'm assuming the current the motor is pulling will give me a good indication of how hard its working. Does this sound like a workable plan or I'm just wasting my time?