Z-vobble or PA defects?



  • I have some z-vobble I bin struggling to get rid of. It’s a hypercube evolution with 12mm rods and single bearings. It is speed dependent, so I raise acceleration/speed I get more noticeable horizontal lines. Today I tried printing without PA and it’s not as bad, I can barley even see it. So could PA be my issue?
    Left one k0 right one k0.03 Black one k0.07
    (As always hit or miss to upload pictures so here is a img link instead)
    Pictures


  • Moderator

    I think there may be two issues there. The first photo definitely looks like z banding, but it could also be a case of the slicer placing the z seam at alternating corners and the bulges alternate every few layers making it look like z banding. The others look like you have some ghosting.

    Try forcing the slicer to use a single point for the Z seam. That will give you a better idea of what's going on.

    Also, post your config.g so we can see what your speed settings are and what your slicer settings are.

    Also, try printing something other than a tiny cube.



  • @Phaedrux all printed with aligned seam in one corner. It’s all same slicer settings and speeds. Only thing that do differ is the k value. My set acceleration are 1000 and 450 jerk.
    What I don’t understand is why a higher k value would cause this. It’s impossible to take a picture on the good cube but there still is banding on that but it’s barley noticeable.
    I do have some vertical banding but that’s not what I am trying to fix atm. One thing at a time and I want to get rid of the horizontal lines first. Cause those I can feel with my finger the vertical ones are just noticeable.



  • @Phaedrux I tried all different shapes and they all have it. Here is a circle no infill and 3 walls.
    I doubt it would be a extrusion issue cause I had it when I was using a bondtech with a e3d v6 and now I have it using a new bondtech extruder with a mosquito.

    ![0_1589201775727_73677EB6-D479-4EC3-B654-005F8179E7C9.jpeg](Uploading 100%)

    As of usual uploading pictures can’t be uploaded so here is picture of circle.
    Here is open with higher clylinder and box



  • It sort of looks like it could be an artifact that can be caused by a PCB heated bed that flexes as it turns on and off. What type of heated bed are you using and are you using it in bang bang or PID mode?



  • @JamesM in pid mode. I actually printed directly on my aluminum bed with some tape to rule out the heat bed. As soon as first layer was down it shut it self of.
    It is in PID though and it’s a silicone mat.


  • Moderator

    Z axis issues are tricky as you're at the mercy of the quality of the lead screws, nuts, and motors. It's hard to tell from the photos, but can you determine if there is a repetitive frequency to the ridges? If so, how far is the spacing?

    How is your Z axis setup? Is it aligned? Is it binding anywhere? Check some of the HEVO discussion places for other users insights.



  • @Phaedrux the lead screws are from a decent place, dold-mechatronik.de same with bearings and the rods. The steppers is a high torque e3d .9. As far as I can tell my z is aligned. The spacing is hard to measure but it is consistent although more visible at some spots. Look here
    I am not even going to ask on the hevo forum cause it’s just full of toxic bullshit. I asked about my bed ones. All just said it’s the bed can’t be anything else even though I at one point had a perfect straight bed. Kinda sad 13000 people have not figured out that the design makes it so the rods can bend like bananas.
    What I don’t understand is how PA can make it worse.


  • Moderator

    @Alucardi said in Z-vobble or PA defects?:

    What I don’t understand is how PA can make it worse.

    I suspect that it's more visible because the actual thickness of the extrusion will vary when using PA if it's not tuned perfectly. But if the seam was aligned I would think the extra thickness should also be aligned and not vary layer by layer like it seems to be. So I'm not sure what to think about that.

    Does the defect persist when using vase mode?



  • @Phaedrux i have not tried vasemode so I will give that one a try.



  • What extruder are you using?



  • I had that problem when I used Pursaslicer 2.1 and 2.2. Switching to Slic3r 1.3 reduced the issue.
    Don't know why, all the settings were the same, even exported imported the .ini settings between slicers, no change. PA was .05 on both
    Wish I could figure it out, I really like the Pursaslicer.

    2020-04-15-1.jpg



  • @Nuramori bondtech. I had one with a v6 installed but that one is on my prusa now. So it’s new bondtech with a mosquito now. I had the issue on all. Maybe a bit more showing using the mosquito.



  • @William your left cube is kinda similair to mine but yours is stil la bit more vissable.



  • @Phaedrux
    It does sadly. I did however spot a small bent in on of my z motors. Not sure how that happen. It had some marks cause of bolts from a pulley slipped or something. So I sanded them down and while doing that I felt the shaft being bent like a banana. So I ordered a new motor from e3d and hope that’s it, but they have 1-2 weeks before an order is shipped 😕

    Here is the vase. As always uploading a picture from iOS and safari seems broken.

    ![0_1589352490260_E1A9F47D-FB52-4635-842E-4B3318CA9D30.jpeg](Uploading 100%)


  • Moderator

    At least you found a likely culprit.


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