What is here the issue? concentric circle / Ormerod1

Dear community,

when doing the [concentric circle test] the print result does not really look bad, but has these bulges in one part, between the center and the edge. I think thats the area, where the nozzle lifted and set to the next inner circle. These bulges almost double the thickness of the thing.

What could this be and how to sort this?

I have tried a lot but not successful so far. I am using iamburnys extruder gears and his extruder tube tongue, which helped to improve my print results. Slicer set to 3 or 4 (I tried both) mm retraction. 200 and 185 °C with PLA.

Many thanks for all hints that help me to get this sorted.

Kind regards
Wolfgang

Nobody any idea?

What are your retraction settings?

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[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

Hi 3dkarma,

Retraction:
length: 4 mm
Lift Z: 0
Speed: 100
Extra length on start: 0
Min travel after retraction: 0.1
Retract on layer change: on
Wipe while retracting: on

You can often see small bulges on the skin of a print where the perimeters stop and start. It looks like that's what's happening in your print, compounded by having the seam in the same place for each circle. Retraction normally cures it. Your retraction looks long enough and quick enough to eliminate the blob, so it's difficult to see what's happening.

I'd try two things: turn off wipe while retracting, then try reducing the filament multiplier to see if too much material is being extruded (under Filament Settings / Filament).

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[3DKarma.com] - suppliers of quality, affordable 3D printer kits and filament for the UK market.

Have you tried reducing the filament factor?

Still trying. Now with 0.96 Bare with me, I have not much time tomorrow, so might take a while before I can come back to you.

Ok guys, have now tried a couple of things. And some success.

Filament factor of 0.9 seems to be almost perfect. And I have reduced the extruder temp a bit: 1st layer 195 degrees, then 185 degrees. Bed 60/55.

however, now the last - and probably more difficult? - issue comes to light. it seems that my printer can not print perfect circles. I have tried quite some ZGears (those from iamburny), and the printer can't get them right. While the tweaks which I mentioned above, helped a lot to get the gear more clean and accurate, there is still a flaw on some of the teeth. See attached foto. The gear is almost perfect but these 3 teeth on one side of the X axis are too short, about up to 1 mm. And less clean. It is on the the far from the X axis stepper motor. The theeth on the side close to the motor are perfect.

The belt is fine, I think. And I can not feel any resistance when moving the bed by hand (when power switched off) along the X axis. I have also turned the gear in Slicer by 90 degrees, does not matter, the flaw stays at the same position.

So seems to be something to do with my printer.

But what and how to fix it??

Thanks again for useful help!

Wolfang

Nobody an idea?

Two new pictures of this symptom. Have now tried to move the thing towards Y=0 on the bed, but no difference.

Why are 2-3 teeth of the gear flattend, and this mostly in the middle? See attached pictures, one shows the side which points towards the bed center, and the right side is closer to the stepper motor.

Nobody here with any idea?