First layer - big shifts  

RE: First layer - big shifts

Added note,

I think I can feel some gear backlash in my y axis. (Forward,backward)

Belt seems tight.

RE: First layer - big shifts

Or maybe my bearings aren't tight enough.

I can move two of them back and forth with just medium pressure. The ubolt tilts ever so slightly when I move the bearings.

Is it best to remove the bed to properly get to the ubolt nuts? (I do the zip tie spacer placement method.)

RE: First layer - big shifts

I refitted the three bearings. And tightened the grub screws on y motor pulley.

Still have some issues. Three distinct shifts. What night be causing this? Yes, I know I must get my first layer done properly, but one thing at a time. Unless my shifts are due to improper first layer calibration, but I don't think so.

Does the fact that the shifts are horizontal mean a y axis problem?

The locations of the three shifts are almost in the same location as the similar pic in original post.

RE: First layer - big shifts

Don't bother printing anything until you get Z correct. Yours is way too high. Start here:

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

When you get a calibration square printed that you are happy with, post it here. We will let you know if you are GTG.

RE: First layer - big shifts

Well, after two love chats, which were quick and concise, I think I have it.

Yes, having a good z cal is required. I also took off the bed and reset the three bearings. Then (re)tightened the two grub screws on y motor.

But I think the real solution was loosening the y axis belt. I had to take out a few more teeth from the end block.

Now everything seems gtg. The Prusa nameplate came out near perfect. Just a few zits on the letters where the nozzle lifted to go to the next letter. I'll save that for another post. 

Happy New Year.