Printing with IS is worse than without (Ringing)
I am getting really bad results with Input shaping enabled (see pictures below). There is ringing everywhere. My MK4 is standing on the floor (not on a wobbly desk).
With Input Shaping disabled the results are much better even if I increas the speed to almost match the speed of the IS profiles. In picture 3 the upper part is printed without IS and the lower part with IS and ringing.
Has anyone an idea what is going on here?
Simon 🙂
RE: Printing with IS is worse than without (Ringing)
Is the rippling happening in one axis only? I had a loose belt which made the y-axis ripple like this while the x-axis was fine.
RE: Printing with IS is worse than without (Ringing)
No it is happening on both axis but the spacing of the ripples are different
RE:
Hey Simon.
I printed a mount for the Apple Watch yesterday and had exactly the same problem. Massive ringing.I suspect that it was due to an outdated IS profile in Prusaslicer where old values were still stored. I'm using the latest alpha of Prusaslicer and since then my old MK3s+ profiles that I had actually deleted were back.If you have already found a solution to your problem, please let me know.
lg Cloud
RE: Printing with IS is worse than without (Ringing)
Hi Cloud,
I chatted with prusa support and they are currently discussing this Problem in the background. I sent them the z axis motor IDs so they can check if my motors may be faulty. Because I think the motors have a problem.
LG Simon
RE: Printing with IS is worse than without (Ringing)
Interesting. Thanks for the answer.
RE: Printing with IS is worse than without (Ringing)
Does the problem exist in structural and speed profile?
RE: Printing with IS is worse than without (Ringing)
yes in both profiles
RE: Printing with IS is worse than without (Ringing)
The support Team now came up with a solution which may work (I had no time yet to actually test it):
Prusa support:
As of right now we almost completely ruled out the possibility of the motors themselves being faulty and are inclined to think that this is likely to be caused by some issue with the assembly. With that said, please check following things in your printer:
1. Please redo steps 12-13 in this assembly guide. Remove the trapezoid nuts and Z top covers and make sure that the lead screws are perfectly centered. Should they be off-center, please make sure to adjust their position accordingly. While the trapezoid nuts are off, please also rotate the lead screws by hand to check if the screws themselves are not bent.
2. After step 1 is done, please make sure to apply even pressure with the screws that hold the trapezoid nuts in place. Make sure none of them are overtightened, there is no need to apply a lot of force and fully tightening these screws.
RE: Printing with IS is worse than without (Ringing)
Do you ever hear the nozzle hitting rubbing the print? Here is what mine is doing:
RE: Printing with IS is worse than without (Ringing)
No I did not had this issue you have in this video.
RE: Printing with IS is worse than without (Ringing)
I'm doing the same print without IS and it's printing perfectly but it's SO SLOW after having IS.
RE: Printing with IS is worse than without (Ringing)
Ok, that is really strange. Did you already contacted Prusa support?
RE: Printing with IS is worse than without (Ringing)
I did, they thought it was very strange and couldn't figure it out. We think the mesh might be off in the back left but I've also had plenty of issues printing in just the middle.
RE:
I suspect that these problems ( and those of many other MK4 users ) are the logical consequence of Prusa’s absurd I.S. implementation. Instead of installing accelerometers on the machine, allowing the user to perform a custom calibration for their specific setup, they decided to ship the printers with a generic profile “one-size-fits-them-all”.
That IS. solution is what we’d expect from a cheapo no-name Chinese printer, but Prusa should be ashamed for doing that. To put it simply, they’re taking the customers for a ride. In the best of cases, a generic profile is a wild shot. Depending on how much the resonances of a specific MK4 unit matches the generic profile, the quality of the print will range from quite good to bad, even worse than without IS (as in this case).
Don’t listen to what Prusa or Prusa fanboys say, the resonances of the printer change noticeably, considering the vastly different kind of benches where we may install the machine, the type of floor under the bench, the dampening material, the use or not of an enclosure, the spool management, tension of the belts, torque of the screws, etc. etc.. No way a generic profile will work well for all printers.
Take for instance a computer’s monitor. Even models using the same panel require the use of a colorimeter to generate a custom profile, if we want accurate color. Ditto for PID calibration on 3D printers. It’s essential for a good control of the hotend and bed temperatures.
RE: Printing with IS is worse than without (Ringing)
I absolutely agree with you. A accelerometer costs only a few dollars and would make a big difference in print quality. I do not understand Prusa.
RE:
I agree that the generic IS won’t work for all users but you don’t have to have an accelerometer to calibrate the IS. You can print a model that will identify the correct parameters for the IS for your set up. This link has all the details.
https://marlinfw.org/docs/gcode/M593.html
RE:
Yes, I tried to do this. But unfortunately the result still had vertical artefacts and ringing every layer and every frequency. So something really strange is happening on my printer
RE: Printing with IS is worse than without (Ringing)
You can only use InputShaper to remove artifacts caused by resonances. Your vertical structures look like a mechanical cause. Belt tension, pully, alignment. Maybe you should look for that first.
The ringing test is not about removing it completely but about finding the best setting. It is a test to increase the ringing. With a normal print it is usually no longer visible. And no, an accellrometer won't help you. At least not in such a way that you simply connect it and everything will be fine.
RE: Printing with IS is worse than without (Ringing)
We had the case of a defective puller in the forum.
You might try printing a box with 150mm edge length in vase mode and increasing the speed from 20 to 200mm. To see if the speed has an effect. I just saw that you are already in contact with support. Any progress?