Extrusion as line beginning missing
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Hi *,
I have a strange issue since a while and unable to find the root of the issue. I hope that I can find some help her.
Hardware: Mini5+ (in this case 3.6.0-alpha.4 but it happens on the table version too)
A LGX extruder feeds a revo (with HF or with normal nozzle) connected to a Toolboard 1LC.Here a test print:
You see here that there is a substantial part at the lower right corner missing at the "infill" of the first layer, marked in red. I started to print with the perimeter first. You see that the nozzle moved in the green direction but the distance marked in blue is empty. I do not understand why that is the case.
There os no play in the extruder. I have disabled every retraction for that print. You see that in the string between the skirt and the part. I disabled a lot of tuning to reduce the variables.Here is the relevant g-code:
I marked t he perimeter in red. You can see that there is not retraction at all.Any ideas where this problem can come from? The issue is not slicer related. I tested it with various slicers (SuSi, Prusa, Orca, Cura) and all of them came up with the same result. I tested with 3 or 4 nozzels too, no change in the behaviour. A test without PA did not change anything.
I have this issue since a while now, my "fix" was starting with the "print inner perimeter first" was a workaround only, I want to get rid of this ugly workaround now finally.
Cheers, Chriss
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@Chriss That gcode looks a little odd (and we may need to see more of it to be sure what is going on), you have a retract of -0.02 at line 277 and then some sort of unretract of 0.4 at line 284, what is causing that extruder movement? It looks like you may have some sort of z hop between those two moves, maybe your nozzle is in effect losing pressure at that point? A line width of 0.56 is quite wide, what size of nozzle are you using? My understanding is that maintaining pressure with a wider nozzle can be tricky especially with filaments that flow easily (I think prusa had a lot of problems with this with the XL when it shipped with a larger nozzle), what sort of filament are you printing with?
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Hi,
What you see at 277 etc is the end of the skirt, the rectract comes from the wipe than:
The nozzle is a 0.4 revo (normal, straight and new), the material a ABS. The hop came from z-hop in the slicer, but it makes not difference whether it is on or off.
I agree that the 0.56 are a bit wide, my first layer is at 140%, that came from a profile from somebody else. I changed it to 100% and 120% but is stays the same, the gab is still there.
And it makes no difference how much EM I use. It is always, in the margin of EM, the same result. I miss this ~6.5mm of material.
Cheers, Chriss
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Update:
I sliced the same "part" for a other printer with a similar setup, 5+, toolboard and direct drive and revo nozzle but the nozzle in a hemera. The print was good on the other printer, no gab etc but produced the gab on the printer I have the problem with. So I would not expect a problem with the g-code here. It must be something else. Firmware, config or hardware.
Cheers, Chriss
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@Chriss The problem seems to occur after a fast move. After the move from the skirt to the perimeter and after the move from perimeter to infill. Or am i wrong?
Can it be, that something is pulling back the filament during a fast move?
I don't know how. But just as an idea... -
@cosmowave Possible, but I have no idea what could trigger that. There is no way that a mechanical situation can do that. A setting maybe?
Cheers, Chriss
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I rebuild the toolhead including the extruder and it seems to me like the problem is gone now. I will do some more test prints but I think that we can close the problem now.
Cheers, Chriss
