Layer Misalignment: What Have I Done Wrong? [Pic Heavy!]

I am learning the M90 slowly and prints are getting better but there is room for improvement. At least I hope to get better prints since I am unsatisfied with the status quo. Please see pictures of two angle pieces at end of post.

My problem is (I think) I am having layer misalignment. The layers are not stacking perfectly. Faces show irregularity and so do corners and edges. It's an X/Y issue I think. Z seems to look OK to me.

So ...

Are my belts too loose maybe? When the X stepper motor (Y too) reverses from clockwise to counter-clockwise (and vice versa) the belt close against the geared pulley will rise and fall slightly as it changes direction as it is pulled over the pulley. I can also see the center section of the longer section of the X belt vibrate on direction change. Should this happen?

Something else I noticed - and need to fix - is the belt on the X drive motor pulley runs to the front of the pulley and rubs against the sloping inside face of the pulley. This cannot be helping matters at all and I'm wondering if others ever had this?

Can someone troubleshoot from the pictures? I appreciate any help very much. Thank you!

That is some very fine prints. Don't think you can do much to fix it. The layer misalignment (in that small scale you have) is because of z-wobble and filament varaition in thinkness (3-5%).
You can try to print one of these [www.thingiverse.com] and remove your z-axis nuts and spring and put the printed fork with only one nut under your x-ends.
It should be mounted like this [www.thingiverse.com]
Then print the same test and see if it's better. If not, it's your filament varaition.

Jesper

Belts will rise and fall slightly and vibrate in the middle unless they are infinitely tight. It's all a matter of degree. If it is riding up the pulley flange try moving the pulley forward. The belt should find a point where it wants to be. If it wants to come too far forward it means the motor is not at right angles to the bars but I haven't found that to be an issue with the new X end design. If it is you could try slackening the belt, loosen the motor screws and push the front of the motor hard right before tightening them again. Also check the bar clamps are tight or the belt will twist the X end.

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[www.hydraraptor.blogspot.com]

Thank you Jesper. I am encouraged to hear the prints are acceptable. I tried to have the pictures taken to show the objects in their worst light and indeed the flaws were captured at their worst. Looked at from 18" they are very nice and straight and smooth. It's just I am very fussy and tend to look for flaws rather than being satisfied. I might benefit from some therapy ...

I'm not sure how to make those forks fit the M90 X-ends but I will be working to understand and maybe improve on Z-wobble if that is possible.

Best regards,

Garry

Thank you Chris. We did already move the pulley forward till it is flush with the end of the motor shaft. So that means we need to follow your advice to adjust the motor. (The bar clamps are tight.)

But given Kenzu's comment that the prints are acceptable quality I will worry less about this .

Best regards,

Garry

The forks don't have to fit. The x-ends just sit on top off them :-) So the fork have to go between your z-screw and z-axis, with a nut in it.

Whilst I agree that it would be nice to have better quality prints, those examples look very good to me. Comparing to my best and worse prints, I don't think I have ever achieved better than your examples.

Once I work through a few of my build-induced imperfections I expect maybe a slight improvement but I am getting some deadly prints and am surely loving my Mendel90!