Hello All,

I have been printing fine for a while now and then suddenly this happened and I cannot seem to figure out what is causing it or how to fix it. There are these weird lines of almost over extrusion that occur evenly up the model. The vertical spacing changes depending on the model, but does not seem to change based on infill.

Any advice or suggestions would be greatly appreciated.

More details ...

Everything was working great, great quality and strength then boom this happened. It was about 1/2 way through the roll of plastic I was using so that didn't change. I have tried a different spool with no improvement. What is really weird is it just started happening, there was no obvious change to any thing or switch. Now even models that I printed before looking great have the same weird line thing happening.

Here is what I have done that hasn't made a difference. I have checked everything is mechanically tight. The bots motion is very smooth, it doesn't appear to be jamming or binding anywhere. Used the same plastic that was working, and a new spool. Double checked my slicer settings. Upgraded slic3r from 9.3 to 9.5, reverted to 9.1.

Printer: Makergear Prusa
Nozzle: 0.35 mm Makergear

Print Height - 0.1mm
Infill - 0.4 - 0.8 rectilinear
Feed rate - all 45mm/s
Perimeters - 3
Solid Layers - 3 top and bottom.


I am at a total loss, any suggestions would be greatly appreciated.

Thank you for your time and help.

Z-wobble. Have you played with the z-axis at all. Loosened/tightened the z-springs? Are the motors screwed down? What couplings are you using?

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- akhlut

Just remember - Iterate, Iterate, Iterate!

[myhomelessmind.blogspot.com]

get some grease or 3-1 oil and lubricate the z axis where the nut is.

Thank you for the suggestions so far, but it is still being weird.

And this is starting to get even weirder.

@akhlut
Thank you for the questions, here are your answers below.
> Z-wobble. Have you played with the z-axis at all.
Prior to this problem, no.

> Loosened/tightened the z-springs?
No I have not changed the z-springs

>Are the motors screwed down?
Yes I double checked they are tight.

> What couplings are you using?
I have metal zero backlash couplings.
Other Z details, I am running 8mm rods, two nuts with springs, and they are supported on the lower end by bearings to help ensure vertical alignment. I checked the couplings were tight and tried to see if I could make them slip by hand, which I could not. I also ran the Z up and down repeatedly listening for lost steps.


I oiled up the Z nuts and rods as jamesdanielv suggested, which seemed to help the problem slightly. To test I printed a 50mm tall cube tower and the hollow cube at the same time to check its height and see if I was loosing Z steps. The 50mm tower comes out at 50.05mm tall, which is well within precision in my mind.

This is were it gets weird. Where it was printing the hollow cube and 50mm cube it has the wave problem, once it passed above the hollow cube print it printed the 50mm cube perfectly.

I would think that I had a binding problem at some height, but the problem was occurring in tall prints before, Photo 3 and Photo 4 from the original post are a part that is 100mm tall.

Other odd things, the top infill on the hollow cube is very sparse and well crappy, the top infill on the 50mm tower looks good and normal. Maybe a little over filled, but the cube is seriously under filled.


Any further suggestions? Thank you for your time and help so far.

Edit: I am sorry, but no matter how I rotate the z setup photo the forum turns it sideways again...

Try a test run thru Slic3r 0.7.2b. Looks slice related.

Just wondering if on the tower and cube print it is too high a travel speed /acceleration causing you to get misalignment which then disappears further up the tower as you stop having any travel moves?

Backing off the travel speed seemed to help. Its still not where it was, I guess its time to break it all apart and see what happened mechanically.

Thanks

Check your extruder, X and Y motor pulleys are all still tight. They can fatigue and crack, or just loosen off with heat from the motor.