[Shifting Along Y Axis Due To Slicing, I Think]

I tightened the set screws and marked the shaft and the pulley as you mentioned.  The pulley us not slipping on the shaft.  It doesn't shift the layers with other files. I have tested this with a test cube file that I use, a test file that I use for calibrating the height of the build plate, other small cylinder shapes, and a popular sculpture of Captain Picard from Star Trek. These all print out perfectly, but the cylinder-shaped objects that I'm trying to make fail miserably.

 

I forgot to mention before that I have another printer that is the same make and model which is exhibiting the same behavior.  I thought it was probably the slicing program but I am not sure that is the case.  I have written to the people who sold me the printer to see what they think.  I have a third printer that seems to print the parts just fine using Cura.  Can you offer any other suggestions?

[Shifting Along Y Axis Due To Slicing, I Think]

I am using Ultimaker Cura 4.8.0.  Lately, I have been having Layer shifting along the Y axis.  My first thought was to check for loose belts or other mechanical problems.  I noticed that it didn't do this all of the time.  It seemed to do it while printing large cylinder shapes (about 3" Dia.).  I was starting to suspect that the Cura program was the problem, so I uninstalled and re-installed it, but that didn't help.  Finally, I sliced the file I was working on with Slic3r and it worked great.  I'm pretty sure that the Cura program on my machine is the problem.  Does anyone know how to fix this?