Pattern on prints using Cura 4.3 but not 4.2.1

[LindsayPatten 1]

Since I installed Cura 4.3 my prints have been getting horizontal patterns on them, see the attached photo.  Note that the pattern only becomes noticeable/severe some ways into the print, in the photo it doesn't start getting noticeable until a little above the knees, and then become more severe at the top of the thighs, which makes for a very prolonged testing process.  Essentially the layers are being offset in X and Y by small amounts for some number of layers and then changing again.  Where the strip protrudes on one side of the model it is an indentation on the opposite side.  The stripes seem to be in a regular pattern at some points and then random widths at others.  The offsets are not huge, I've set the model at a small angle to the light so that the shadows make them more noticeable.

At first I thought it was a printer issue, it's an AnyCubic Chiron printer, but after many many attempted adjustments I tried slicing with Cura 4.2.1 and I no longer got these artifacts.

Since it doesn't seem other people are having this issue I am at a loss as to what is going on.  Does anyone have any thoughts on this?  Or suggestions on what further investigation I should try?

[burtoogle 516]

Hello @LindsayPatten, please slice a small model that has this problem using both 4.2.1 and 4.3 and attach the gcode files to this thread so they can be compared. Thanks.

[LindsayPatten 1]

I'll try to find a simple model that exhibits this issue, it will likely take some time because it takes a long time to print and the issue, at least on the couple models I've been working with, doesn't manifest until well into the print.  In this statue, the square base alone takes 5 hours to print.  I'm currently printing a smaller version of this model that takes less than a day to print.

 

Although there are issues with the 4.2.1 print on the left, the difference with the banding in the 4.3 print on the right is clear.  That said, I can't swear that every setting is identical.

 

My first print reverting back to 4.2.1 I only printed the top part, starting with where the bands had become prominent on the 4.3 print, that printed out without any noticeable banding, I only did some light sanding to produce what is shown in the photo below. 

[LindsayPatten 1]

I printed out 20cm versions with 4.3 (on the left) and 4.2.1 (on the right) with exactly the same settings, scaling and position.  The banding is still only there in 4.3.  Unfortunately the model and the gcode are far from small.  I've got a simple cone printing now to see if the banding will occur.

[LindsayPatten 1]

It appears that the problem isn't related to the software version but rather perhaps to tree supports.  I started a print that was generated with 4.2.1 and had the banding show up.

 

I'll post further in a new thread.

[excalibre 0]

I would suggest a couple of things to test here, from my limited Chiron experiences.

 

Firstly ensure your hotend is not loose. just gently hold it (cold) and see if it moves at all.

also check out this video about problems on the assembly of the z axis where problems were seen when getting higher in the z axis prints. https://www.youtube.com/watch?v=9tK32mePaXw

 

Hope it helps, or at least removes the possibility.