Horizontal lines on perimeters

Hello Guys,

I´ve been struggling with this one for a while and decided to ask the experts.

All my parts come out with these horizontal lines on the perimeter. To me they seem randomly placed.

I am using Marlin FW, 1.75mm PLA, 0.3mm layer height and the speed of the perimeters is 20mm/s. Temperature 185 Celsius.

Have any of you seen that before?

Thanks,

Marcus

Looks like inconsistency in layer height.
Do you feel any binding when moving the z-axis? Are your lead screws clean? Linear bearings running smooth?

Hi Lampe,

Thanks for your reply. I don't see any binding on the Z-axis and the lead screw is lubricated (I use only one. My printer is a bottom-up style with a cantilevered table. The lead screw is connected on the mid section of the upper side of the table, like an Ultimaker).

I've been thinking if vibration could be the cause of it. The table vibrates a little bit specially during the infill but I could not expain why the outer perimeters would have the inconsistency since they are layered using a much lower speed. The bearings seem ok also.

Are there any tests that one could do to check if the problem is related to the Z-Axis? Any parameters we could try to adjust?

Thanks for any suggestions,

Marcus

You could try to sync layer height with z-motors full step.
E.g. your leadscrew has 1mm pitch and the stepper has 200 fullsteps ( 1.8°). Then the layer height should be a multiple of 1mm/200 = 0.05mm.

Hi Lampe,

My lead Screw on the Z-Axis has 8mm pitch but I use 1/16 division. In that case, shall I consider 8/200 = 0.04 or 8/(200*16) = 0.0025?

I've tried 0.3mm and 0.28mm layer height. None gave me any improvement.

I've purchased a different filament brand and I read that it could be the cause for this problem.

I will try this new one in th weekend and let you know.

Thanks for you help once again.

Regards,

Marcus

1/16 microsteps are not considered to be as 'safe' as fullsteps are.

Filament diameter can easily be checked with calipers. Also the spool holder can have an influence. If it doesn't roll off smoothly, it can cause skipped steps for the extruder.

185C is pretty low for any filament I know of. Low temperature means thicker melted plastic which is harder for the extruder to push out. On straight walls, with acceleration, the extruder might actually reach the highest speeds set in the slicer. Trying to push thick plastic out at high speeds may be the issue. Try turning the temperature up to 220C and see if you still have a problem. Is there any filament dust on the drive gear teeth? That would indicate that the extruder is struggling (and could also cause intermittent extrusion).

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]