Julian2801

I've only printed with White PLA so far. In the beginning there was a bit of grey PLA inside of the nozzle from the factory test print.

I've checked the height of the object as well and it has the height it should have. I believe it wouldn't be Z Wobble if the model has the desired height. Am I right? From the looks of it I would say that the darker layers are under-extruded layers. Printing slower and cooler didn't help. The printer doesn't have play on the X/Y axles as well. I'm pretty desperate right now.

Hey, I dont know why some layers are darker than others on my printed objects. I use white Ultimaker PLA. The object itself is pretty smooth and the corners as well as you can see in the photos. Maybe It is Z Wobble but I am not sure. Do you have any ideas?

As you can see the lowered print speed helped quite a bit. The holes nearly dont have a visual effect on the outer layer anymore. But apart from the hole problem there are still tiny imperfections as you can see. May this be caused due to the fact that my spool is nearly at the end?

So it is a slicer problem? I doubt that?

I still have the exact same issue as you. When I printed slower the hole didn't cause an issue anymore. The layers for me also have disorders but I don't know what the cause of this is yet. Which 3D printer do you have?

I can confirm that this is the section where the z seam occurs. My infill speed is 50mm/sec and outer and inner wall speed is set to 20mm/sec. Im printing at 0.1mm layer height at 205 degrees Celsius. I'm starting another print now and see if that helped.

I think that the problem also occurs when the printer is doing the 100% infill for the 10 layers on top

The pictures now are from a different model but they are showing the exact same problem. As you can see when the hole occurs the outer layer goes into the model. As you can also see the outer layer quality isn‘t really good.

It is making 120Hz on the long belt when the head is in the back left corner. I tried it another time now. Maybe my app wasn't really accurate

I also thought of that. But I checked it and everything is in a square.

1) Yeah, you are right about the changing direction. I think the hole was in the x direction. That also fits with my observation that when I pluck the front x belt the frequency is about 310 Hertz ( I'm assuming that this means it is too tight?) 2) When I gently push the nozzle of the printhead in any direction it isn't moving. When I'm moving the whole printhead it is in sync with the stepper movement. 3) So after I eliminated the play on the axles it got a lot better. But still, there is a small imperfection. The imperfections are only on the layers where the hole starts and ends. I will wait if you can say that the front x belt is too tight and then try again. If the issue still is the same I can send you more pictures if you want.

When I replaced my old UMO+ Sliding Blocks with the ones from the UM2 it also was a bit tricky at the beginning. Sometimes you could only achieve a snug fit if you press the rod in at both sliding blocks at the same time. In your case, it could work if you press the head shaft in the front and back sliding block. Sometimes you have to apply much pressure in order to achieve a snug fit as well.

Thank you very much for your quick reply. I've applied some oil (the unilube oil that was included with the UM3). The weird thing is, that I don't have any loose belts. I've tightened the short belts and checked the long belts. I'm trying another print now and see how it goes.

Hey there, I think I might have a mechanical issue with my UM3. As you can see in the picture the quality of the outer wall decreases at the height of the hole. I already noticed that I had a bit of play on axles but I fixed it. But still, the problem remains. Does anyone have an idea about what is going on?