forum.cncdrive.com

Hi to all!
I have self built CNC router using AXBB-E controller and UCCNC software. Dual motors for Y axis, single for X and single for Z with brake due to heavy spindle and drifting issues when machine is powered off.
Everything was working ok - homing, moving, etc, until I've decided to flip the Z axis to move upwards positive and downwards negative as it should be.
I have single sensor on Z axis used as Z+ and for homing. Active low is checked to make the axis moving the right way. Homing is set to be in positive direction.
The problem is that after homing the axis is not moving anywhere when using UCR201 wireless jog pendant. On the DRO numbers are changing but axis is not moving.
Previous setup was active low not checked so positive direction is downwards, homing is towards negative (upwards direction), sensor is set to be used as Z- limit and for homing. After homing everything is moving and working but in the wrong direction for Z.
Any ideas? Thanks in advance!

Lesson learned!
The problem was that reversing direction of travel means that you have to make backoff negative too. I was set 5 units backoff distance which works fine if positive direction is downwards, but reversing that means that backoff needs to be -5 to make the axis move 5 units away from the sensor.
In my case the axis was not moving due to stepper driver going to alarm state after hitting phonically the limit of travel when backing off 5 units but in the wrong direction.