Ringing/ Ghosting pattern all over my prints :/  

RE: Ringing/ Ghosting pattern all over my prints :/

How were those parts orientated on the bed? I’ve seen similar from the belts when printing corner to corner. It’s caused by the belts in the idlers imo

RE: Ringing/ Ghosting pattern all over my prints :/

I see the same artifacts on my XL 5T but not quite as apparent as what you show.  If there is a way to fix this I would be keen to know as well!

RE: Ringing/ Ghosting pattern all over my prints :/

I´m having the same issue. For me the ripples often have a pitch of exactly 2mm, so i suspect its the gates belt (teeth side) running over the smooth idler. Currently im playing with different belt tensions. It seems to me that it gets worse with higher belt tension, though that might be a fluke.

Also something else i noticed is that it gets worse if the printed line is 0°/90° to the front of the printer. If its oriented 45° its less noticeable. A reason for this could be that for a 45° line only one motor needs to move while the other one is stationary. So it could also be interference from slightly out of phase steps, although that should not be a thing if its truly 0°/90°.

RE:

Any update on this? I have the same issue, tried with and without phase stepping and input shaper and 5.x and 6.x firmwares, always more or less the same result, most visibly in X axis, no issues in Y axis, which is weird, because for straight X or Y movements, both belts have to work. So it should be something on the gantry where the toolhead carriage is? Not sure how to describe better.

RE: Ringing/ Ghosting pattern all over my prints :/

The Issue

I'm experiencing a consistent, periodic ringing pattern on my prints. Here are the key characteristics:

• Consistent across all parts of the print bed
• Present regardless of print speed or firmware settings
• Not typical ghosting/vibration artifacts, as it appears at all heights and speeds
• Approximately 2mm apart
• Visible only on straight X walls, not noticeable on 45-degree walls, and not visible on Y walls
• Consistent across all toolheads

Troubleshooting Steps Taken

1. Tested multiple firmware versions (5.x and 6.x series)
2. Tried printing with and without Input Shaping (IS) and Phase Stepping (PS)
3. Repeated all calibration procedures multiple times
4. Checked and adjusted belt tension (to about 80Hz)
5. Printed the homing tower test (results were good)
6. Manually moved the gantry to check for tight spots
7. Rotated print objects to confirm the pattern is always in X direction
8. Tried various print speeds (down to 50% and below 60mm/s)
9. Visually inspected belts for damage or rubbing
10. Checked belt movement in pulleys
11. Disassembled the XY gantry
12. Checked all idlers for smooth operation
13. Manually rotated motors to check for differences
14. Tested with all toolheads, different materials, different slicer versions
15. Used Prusa's pre-sliced code (homing tower)
16. Checked linear rails
17. Loosened the tension (helped movement but caused issues with the homing tower)

My Current Suspicions

After all these tests, I'm suspecting a potential issue with:

1. The X-axis motors or their synchronization
2. The motor drivers on the Buddy board

I've noticed that the right side motor is harder to rotate and makes a slight clicking noise compared to the left when rotated manually. This I would only notice in comparison.

Next Steps

I'm currently in communication with Prusa support, and they're escalating this to their dev team for review. I'm hoping they might consider sending replacement motors to test if that resolves the issue. Overall this is really annoying and exhausting. All the hours troubleshooting and new chats with the support without any improvement. While every chat partner was really nice and tried their best, no one was really able to help me or willing to send replacement parts that I could try. I am not sure how the procedure works, once my issue reached the dev or quality control team as they promised.

RE: Ringing/ Ghosting pattern all over my prints :/

Keep us informed 

RE: Ringing/ Ghosting pattern all over my prints :/

Hoi 🙂 I can't answer your private message :/

Well I did not solve the Issue yet and I had many hours of troubleshooting and chatting too without any solution in sight. So I gave up on this and simply live with the quality my XL is providing.

I think the ringing on my prints is a bit less now than it was at start.

Keep us updated if you learn sth. new! I really gave up on this topic xD

RE: Ringing/ Ghosting pattern all over my prints :/

Thanks for your reply here!

I am not really in the mood to give up on that issue, as it is a clear visual defect caused by the printer and not by the user. I want to sell some of my prints and even for functional parts it's just disappointing to see these patterns.

I just had another thought that did not cross my mind before:

I always assumend I have to look for something that is happening in the X travel direction, so maybe speed changes in the travel direction, but still in straight X motion, if you understand what I mean. Also, it happens perfectly predictable for every part on every position on the print bed, and for every speed, never changing the pattern in any way. But what if it actually is a wobbly motion in the Y direction, that only has a visible effect when printing in the X direction, like a snake? This would also explain why (in my case) the prints in Y direction are perfect, because in that case the X gantry is not moving at all, although both motors have to be active in sync.

The spacing of the pattern not only fits the spacing of the ripples in the belts but it also could match the circumference of the ball bearings inside the linear X rail. I moved the gantry after removing both belts but I just checked how easy it moves, not if there was a disruption in the motion or even in the Y direction.

Do you notice the pattern on your prints in all directions?

RE: Ringing/ Ghosting pattern all over my prints :/

To support my "snaky-X-path" idea, i scrubbed with my thumbnail over the pattern and while I am not capable of feeling the pattern, I can clearly hear it. So it is not just an optical deformation on the filament.

Also, by coincidence, I just found the pre sliced "Original Prusa" tag, that came with the printer's USB stick. I printed it on March 1 2024, just after finishing the assembly. It shows exactly the same pattern, so it has been there from day 0.

RE: Ringing/ Ghosting pattern all over my prints :/

Still no good news here. Prusa support is really disappointing to me. I had at least 3-4 chats in the last 20 days, which was mostly me telling them what I have already done and tested and aksing for a reply of the dev team, as they promised the first day. So this week finally someone actually wrote an e-mail and I really hoped that we could now go forward on the topic. The content of the e-mail? "Please try redoing the full calibration..yada yada". Wow! Of course I answered them immediately; again silence since then.

While all of the chat partners have been friendly, only the last one seemed to suggest I could return the printer for checks. So they have all the chatlogs and many more pictures, they tried nothing, had no ground breaking tips, I even asked for motors and pulleys  / idlers to replace them myself but they want me to somehow ship a 25kg (?) assembled 5 toolhead Prusa XL? At this stage this is overkill, but after that e-mail I somehow wished I had accepted the offer.

I am willing skip the support for now to buy the motors and pulleys / idlers test them and see if it works or if I need to return them, but I can't find the articles in the shop. And I still suspect the X gantry or linear rail, which also is not in the shop or the support manuals.

So by now I think it could be:

• one or more of the pulleys / idlers (one does make a sound, but it also does so in Y direction, which has no pattern)
• one or both motors in sync (they do not feel the same, Y is harder to rotate manually and Y also only receives 85-90% vibration reduction with phase stepping calibration compared to 95-97% on X)
  • maybe the stepper motor drivers on the buddy board, but I don't really think so
• X-gantry / X-linear-rail

I will keep you updated.. ! 🤡 

RE: Ringing/ Ghosting pattern all over my prints :/

Hi 

so I have some good news. For me the update with phase stepping and loosening the belts helped a lot. It’s way better now but still not perfect. I can’t send pictures at the moment since I’m not at home but will post them in the future. For me printing in +-45 degree also reduced the problem. Since it got better with phase stepping it has to do with the motors rather then the pulleys. My hunch would be a problem with the manufacturing of the motors that shows when both have to work simultaneously (everything but 45 degrees). Something similar (magnetically) to a sightly elliptically or eccentric formed driven pulley, that produces the print defects when two are out of phase and overlapping (interference). That’s only an uneducated guess though. 
Hope this helps somewhat. 

Have a nice evening. 

RE: Ringing/ Ghosting pattern all over my prints :/

Thanks four your reply. Since Prusa XL is supported by Orca Slicer now (only one toolhead though), I was able to quickly produce the Orca VFA test. With the VFA test and the pre-sliced Prusa homing tower I will be able to see, how loose or tight I can adjust the belts.

Here is a nice documention of the problem: https://github.com/AndrewEllis93/Print-Tuning-Guide/blob/main/articles/troubleshooting/vfas.md

So by now I am pretty sure this is 2mm VFAs (Vertical Fine Artifacts), that are caused by the belt or the pulleys / idlers. The idlers on the X carriage seem to be the only idlers that are positioned in a way, where the teeth of the belt rub against the smooth idler. This could produce the pattern, especially, when the rubber on the tooth compresses during the passing of the pulley and then quickly releases the energy after passing.

I will continue to report on the issue!

RE: Ringing/ Ghosting pattern all over my prints :/

Greetings,

no real progress here, but I continue looking into this problem. Now, that we have a name (VFAs) and some hints, that more than our two printers are affected, I started a new topic and posted a pre-sliced VFA test here in the forum: https://forum.prusa3d.com/forum/original-prusa-xl-tool-changer-hardware-firmware-and-software-help/discussion-is-the-prusa-xl-prone-to-generating-perfectly-spaced-vfas-or-are-they-isolated-cases/

RE: Ringing/ Ghosting pattern all over my prints :/ Found something what could help....

Greetings,

I had the same problem. Also only on the X-Axis. It gets better after adjusting the belt tension (was too high from Prusa) with the Prusa Belt Tuner ( https://belt.connect.prusa3d.com/ ). But the results are still not very good. The main difference between X and Y is, that the teeth of the belt are going directly over the idler at the X-Axis, but not at the Y-Axis. So I changed the flat idlers with a toothed version. I used one with 20 teeth, inner diameter of the ball bearing 3 mm. I ordered them from DMW Industrietechnik over ebay ( https://www.ebay.de/itm/124891190882?var=426153839548 ) After changing the idlers and readjusting the belt, the results were quite good. With some materials, there are still some VFAs visible, but the results are a lot better than before.

With standard flat idler on X-Axis

With toothed idler on X-Axis

RE: Ringing/ Ghosting pattern all over my prints :/

Ive made remix with more tolerance for it:

https://www.printables.com/model/1047056-prusa-xl-y-carriage-for-toothed-idlers-old-o-rings

More infos on printables 🙂 

RE: Ringing/ Ghosting pattern all over my prints :/

Thank you, but I have the new o-rings. It works for me without reprinting the y-carriage. But with glossy material there are still some patterns visible. As next step I will test new motor pulleys. These are the only other parts in direct contact with the belt teeth. It could be a quality/tolerance problem of the motor pulleys. It seems, that there are only a few printers showing this 2 mm pattern. But for a printer in this price-class, I expect a better result.