z axis calibration failure
I just built a MK4S. I am going through the axis calibrations. The X and Y passed but the Z fails. I looked for what to check and everything that I can see looks fine. One time it passed and all was well until I went to print my first item. The key chain that was recommended. Then the print head went down and dug into my print plate. I got an error about the filament jamming. So I did that a couple of times and it did the same thing. So I did some more checking and decided to recalibrate all three axis. Again the X-Y passed. The load sensor passed. I barely had to touch it for it to register. I mean barely. Then it went through the Z check and it failed after it passed the day before. Have not touched anything. I checked the nozzle and it seems located right. I even checked to see if the tape on the sensor was damaged and even though the instructions says it should be white (mine is black) there appears to be no damage. I loosed the bolts on the X-carriage in hopes those nuts would align. No go. Since it worked once but not now I am really confused and not sure what to check. Here are some pictures.
RE: z axis calibration failure
I might add. When I first turned on the printer and went through the checks I got to the load test. It passed but when it went to the Z axis test it screamed at me saying the load sensor was off. Check the bolts. So when I did I noticed they were fairly tight. So I loosened them. I then just snugged them down instead of tightening them. That got me past that point but still had issues with the z-axis failure. I did see the article on checking the nozzle and oriented it like it was on the picture in the article and checked the depth as you can see in the pictures. I noticed the left z rod seemed stiffer when moving it so I loosened the bolts holding in the nut and moved the X axis bar up and down. Then reset the nut but snugging the bolts. After that the test passed until I tried to print since everything was supposedly checked out. That is when I found out that the z axis is again not passing.