Problems with Z direction of travel

[Grahamd666]

Yesterday I was profiling a small part when the spindle motor on my Denford Novamill bogged down so I hit the E-stop. The material was only aluminium with a 1mm depth of cut to check the profile. When it came up to a slightly taller depth of the material the spindle started to lose speed so I pressed the E stop.

Upon attempting to rerun I saw that the X datum had shifted so I went to home all axes. I pressed home all and noticed the Z axis started to go down instead of up. I stopped it and homed the X and Y individually and they homed correctly. However the Z is still going down instead of up.

I asked the question on a UCCNC Facebook page and had various suggestions to try and remedy the situation. On one of the last restarts it I then had an issue with the X trying to home in the opposite direction so I unchecked the Dir. positive which rectified the problem. However I’m not understanding why it had been running fine with the original Dir.positive checked. The only way I have managed to home the Z axis is by unchecking the Dir. positive box. When attempting to move it was giving me a limit switch error so I disabled the soft limits. The Z will move down when I press the up button and be an increasing positive value. When I press the down button it goes up and no amount of changing the Dir.positive and also the Active box will make the Z travel down in a negative value when pressing the down jog button.

Is this a software issue? I’ve made other parts the previous days with no issues so I’m not really understanding what has occurred.
I have a AXBB-E with version 1.2113 installed.

[cncdrive]

I don't really know what could have happened to your system.
I mean you talking about so many different problems that it is strange.

One thing to check if you loading the correct profile for your machine?
I would verify that.

Also verify that your home switch is OK and not locking up, because if it locks up then the homing starts to the wrong direction.

[Grahamd666]

I’m not sure what you mean by loading the correct profile? I produced two parts on the machine with no issues. I then loaded my next program which is the one I have described to you. The machine was not switched off or altered in any way from producing the two other parts.

[dezsoe]

There's no problem with your profiles. When the homing suddenly changes direction then it's your home sensor. Jog the machine away from all the home sensors and go to the diagnostics page. You'll see that at least one of the home sensors is active. If you have more (or all) configured to one input then more (or all) of them will light. So, check the home sensors. When the axes are away from the sensors none of the home LEDs should light.

You have to understand how the homing works. The program move the axis until the sensor activates. Then it moves to the opposite direction until the sensor becomes inactive. If the sensor is active when you start to home the axis then the program assumes that the axis is already on the sensor and skips the first movement and tries to get off the sensor: that is why it starts to the wrong direction.

[Grahamd666]

There's no problem with your profiles. When the homing suddenly changes direction then it's your home sensor. Jog the machine away from all the home sensors and go to the diagnostics page. You'll see that at least one of the home sensors is active. If you have more (or all) configured to one input then more (or all) of them will light. So, check the home sensors. When the axes are away from the sensors none of the home LEDs should light.

You have to understand how the homing works. The program move the axis until the sensor activates. Then it moves to the opposite direction until the sensor becomes inactive. If the sensor is active when you start to home the axis then the program assumes that the axis is already on the sensor and skips the first movement and tries to get off the sensor: that is why it starts to the wrong direction.

Thanks for your reply. I’ve took some videos of the screens and I will upload them.

[Grahamd666]

Is there a support email address I can send the videos to as there appears to be a 2mb maximum file size.

[dezsoe]

Yes, support at cncdrive dot com.