Can someone explain to me why my CNC machine always taking a dive when carving or drilling? I have a Stepcraft D840 ATC. Every time I carve or drill somewhere in the process the bit just take a dive and mess up my whole work piece. The machine is leveled runs smooth ATC works ok. The preview of the toolpath look good, but I just can't stop it from going scuba diving without water.Attachment 439227

Here is a video on my YouTube channel.