Hey guys, images and gcode file attached I'm having some weird issues as of recently with my custom build cnc. it has been working great for a few months now. however, today I went to run a job and I was getting some weird z axis movements at the start of the job that resulted in the tool plunging into the part and breaking the bit. I made a new gcode file with a 50mm offset from the part and got it to work without plunging into the part first. Then I ran the same exact job again and it now plunges 80mm instead of the 50mm into the part at the start and breaks the bit. I'm confused on why this is happening. I'm guessing it could be an EMI issue when the spindle starts up? The rest of the job runs fine after its weird initial movements. I attached a picture of the setup. I know that the VFD controller shouldn't be next to the blackbox and other components due to the EMI it produces, so I do have plans to relocate it outside of that enclosure somewhere. I also know I'm getting interference because the buttons on the touch interface don't work very well unless I cover it with my hands. Do the random Z movements at the start of the job seem like an EMI issue? and what is the best practice for the VDF in terms of blocking the EMI it produces? It needs to stay mounted to the table somewhere but I can put it towards the bottom inside the base towards the right of the entire machine. I've done some research and seen things like the spindle and the VFD need to be earthed, the VFD should be in a shielded enclosure and ferrite cores on the cables. I read though this however I'm not exactly sure how to implement these as I'm not super electrically knowledgeable. Any help and insight with this would be greatly appreciated! docs:blackbox-x32:faq-emi [OpenBuilds Documentation]
Edit: was able to figure out the random movements at the beginning of the job. Dumb error of not homing the machine first... Would still love help with the EMI situation though.
See docs:blackbox-x32:faq-emi [OpenBuilds Documentation] Correct installed VFD itself. Earthed, shielded 3 phase cable. VFD itself earthed. Spindle body Earthed. Some distance seperation between the nasty VFD and your other electronics usually a good idea. Run High voltage cabling separated from signalling. Don't share cable chain with VFD cable, use a swing arm Swing Arm etc Not really - EMI tends to cause connection loss, serial corruption (see link above and review your logs), False limits trips etc. Only random Z moves could rather be - mechanical: stalls or slips - check shaft coupler grub screws, z axis moving freely, no binding, no slipping. - over-enthusiastic settings - heavy spindle, make sure acceleration/max rate tuned for reliability or it will stall during fast moves, fail to raise spindle as commanded etc - wiring docs:blackbox-x32:faq-identify-motor-coils [OpenBuilds Documentation] loose terminal or wire break causing intermittent loss of one of the 4 motor wires for example - motors or mechanicals too weak for heavy spindle, causing stalls while raising it up.
