[Henrik72000]

Hi
I have problems with my cnc not coming back to its 0 point. I have now changed all the guides and repacked my ballscrew spindle. But without result. It is as if the machine loses its location when running a program. Usually when it has run it 3 times ok then the fails begins. DRO shows that the axis is moving but it does not. If I "jog" the spindel and DRO is not moving , but "slow jog" it move the axis it as it should. I have tried to change the cable and switch on the control ports, on the g540, where I have used the port from the a-axis. Also without result. Using Mach 3 - 2.0
I have tried today to change the connectors (DB9) on g540 so that x became the y-axis. The problem moved over to the "new" y-axis. I think that it is the g540 that had an error, but then I made the a-axis to the y-axis the problem was still there !!! Can it be mach 3 that doesn't work properly? Or is the g540 not working?

Henrik

[cncuser1]

Henrik, I have a few comments.
I do not under stand if the problem is with the same stepper motor or the same G540 axis(X to Y to A). Can you explain again.

You should use the latest version of the software, your software is old.

The Mach3 software has some settings for the acceleration and speed of the axis. If the software makes the acceleration or speed too fast, the motors will miss steps. Try to slow down the axis.
Make sure you machine moves easily, when the ball screw is not connected, each axis should be able to move freely by hand if the machine is a small tabletop type.

Please be careful using the word spindle in english. For a milling machine only the spindle has a cutting tool .The rest of the machine has X,Y,Z axis that uses ballscrews or trapezoidal/acme screws( not spindle).