And compiled again.... XYZ calibration was a success this time!

I have to admit that was a little frustrated after I could not get the XYZ calibration to work. So this weekend I first wanted to rule out any mechanical problem.
I unscrewed the trapezoid nuts on the z lead screws from the CNC aluminium x-ends. Then I turned the Delrin nuts all the way up to the top of the z axis.
This way I could freely move the x-axis on the z-axis. I noticed some drag and the z-xis got stuck at some positions. This was truly a problem of the cheap Chinese bearings I used. I lubricated them with  white lithium grease before, but that seemed to make it even worse.
I should have cleaned the bearing in cleaning solvent before, but I was too lazy.
So the quick fix was to move the x-axis assembly up and down by hand, after some time the drag was nearly gone and it did not get stuck anymore.
Now I screwed the Delrin trapezoid nuts back into the alu parts and tried again.

This time it failed again on the XYZ calibration while it was searching the 2nd calibration point.

Now it was time to revisit my changes to the software. I pretty much took all the changes from Chris post on Thingiverse. I already had a suspicion that the changes on the Y-axis might be wrong, I will get into details once I have confirmed it.

So I started with a fresh copy the Configuration_prusa.h and made only one change to the z-axis limit. I changed the value for the Z_MAX_POS from 210 to 218.  And that was all, no other changes.
I did not even change the stall detection sensitivity for the z-axis.

So after flashing the firmware I was able to successfully complete the XYZ calibration. It worked like a charm.

So that proofed two things.
One, I had a mechanical problem on the z-axis and the motors from bluerolls are doing fine.
Second, there is something else wrong with the other changes I made to the software.

I will continue the testing on the weekend to figure out exactly the right values and what needs to be changed.