Solved First Layer Un-level, Tapers to Nothing

I have been using my R1 for a couple years now but something recently changed that is causing my first layer to be un-level. It will print normally on the right side (+x) and tapers to nothing at about mid travel of x-axis. On the left side (-x) the hot end drags and does not print because it is so close to print bed. Once it gets to the second layer it prints fine on all areas of the print bed and completes print.

I don't know what has changed to cause this. I am thinking the left z-axis limit switch is going bad, maybe requiring more travel to close contacts so when it does auto level it thinks that side of the print bed is lower than it actually is (or compared to right axis).

Any ideas?

 

By in position do you mean the threaded rod nuts are recessed within the injected molded end pieces? Yes they are both fully in place. The z-axis starting elevation looks to be off by only about 0.25mm from left to right on the x-axis. I use simplify 3-d, it does the 9 point auto level, and it just started doing this.

I question the left z axis micro switch because it is really quiet compared to the right one. Just wondering if anyone has ran into this before I start replacing parts.

Thanks

 

Yes checked switches with meter both are functioning. Its just hard to tell if both switches are closing contacts at the same amount of travel, I think the left is requiring slightly more travel than the right which could be my ~0.25mm issue. I'll replace the micro switch and report back.

Thanks

 

Level the threaded rods manually listen for the click of the switch. Run authored levelling with a piece of paper and uncheck "has levelling hardware" levelling is funny because this is a two point levelling system across the X axis. If your Y platform is bowed, there's not much you can do. Set extruded on one side and drop it onto a piece of paper. Do this to both rods with nozzle at each end. Next run it across. If you see waviness, make small adjustments to the rods.

 

I finally took some time to look at this again and found a loose wire on the right z axis limit switch. During the 9 step auto bed level sequence, when the hot end was coming down on the right side it wouldn't see limit switch input until the left limit switch closed because the right limit switch wasn't connected properly. This made the printer think the bed had a slant, left to right. The left z axis limit switch has its wires soldered on while the right has connectors. Once I re-crimped the right connectors I was back in business. I did have to change my G29 to -0.85mm from -1mm for some reason but my first layer is spot on now.