Z crash directly after starting program

What would cause my z axis to crash and stall the motor to the up most extent directly after starting a program? This happened twice to me on two different occasions and I am not sure what I did wrong. Following what I assumed to be the same exact setups a second time solved the problem so it must have been something I did inadvertently. Just looking for suggestions on things I could check. The last time this happened I had the Bitsetter turned off because I was attempting to run a toolpath without a tool just to make sure the Bitzero was actually working.

If you turn off the BitSetter, be sure to reinitialize the machine after doing so.

Otherwise, see:


If that doesn’t address things, post the .c2d file, step-by-step notes on how you are securing your stock and setting zero relative to it and managing all tool changes.

The other thing to check is the Z-axis motor wiring and connectors — are they all secure and in good condition? If you power up the machine and leave it for a bit are the connectors warm to the touch? Let us know what you find out at support@carbide3d.com

The proximity sensor for the Z axis may not be operating properly. You didn’t say which machine you have but check for a red light on the sensor when a metal object is placed at the sensor and also check for a blue light on the circuit board for the Z sensor where it plugs into the circuit board. You can also wiggle the connectors to see if any of the lights flicker when the switch is activated.


Double check your retract height in setup.

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I’m pretty sure I didn’t reinitialize after disableing the Bitsetter. This is probably what happened! Yes wiring looks great an not warm. I don’t think anything is wrong with the machine. I was just concerned because I thought the limit switchs were supposed to totally prevent axis crashing but that must not be the case.

The proximity sensor is working I can see the light when I hold metal near it. When I initialize the machine the z axis works good.

I was using a nc file generated by the fusion 360 post processer. I had actually use the same file successfully previously. I think it was because I disabled the Bitsetter without reinitializing the machine based on what William said.

You are correct about the switches. They are not limit switches just homing switches. You can write gcode that trys to send the machine a half a mile but you will crash into the mechanical stops. The newer versions of cm try to warn you if your gcode is out of limits.

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