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I've bought a new type of filament (GreenTEC Pro Natural) for my Anycubic Mega i3 to print some food-safe cookie cutters. Now I have changed the print settings to an extruder temperature of 210 °C and a heated bed temperture of 60 °C and everything works well.

But when I look at the print, I see that too little filament is extruded at the beginning of an extrusion and at the end. So every time the nozzle is lifted to move without extruding, it takes too long for the filament to correctly start extruding again (see picture).

enter image description here

What can I do? Is there a setting to print slower at these points (I'm currently using Cura)? Maybe change retraction distance? Different extrusion temp? Before I used PLA from Anycubic and everything worked fine...

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    $\begingroup$ how much retraction are you using? $\endgroup$
    – Trish
    Dec 6, 2019 at 21:46
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    $\begingroup$ Welcome to 3DPrinting.SE! Essential to solving this is to know what the settings for the retraction, and re-retraction (loading) of filament are. $\endgroup$
    – 0scar
    Dec 7, 2019 at 11:34
  • $\begingroup$ My first thought was a retraction issue as well. $\endgroup$ Dec 7, 2019 at 16:21
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    $\begingroup$ I see some heavy excess material deposited on those combing moves. Maybe turn off combing too. $\endgroup$ Dec 8, 2019 at 2:14
  • $\begingroup$ What is your slicers overlap perimeter/infill %? $\endgroup$ Jan 27 at 21:31

2 Answers 2

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I think there's a retraction issue(had the same issue). You need to change retraction and check whether there are any improvements. Some times different filament types need slight filament setting calibration.

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  • $\begingroup$ One critical detail; if extrusion isn't starting smoothly after a retraction move, most slicers allow an "extra restart distance" or similar setting, which basically tells the extruder to advance the filament more than it retracted by this additional amount. @Lieselottelernt should increase this, probably by tenths of a millimeter, and test using some simple print shapes like leveling squares, until the jitters at the beginning of a print move after a travel move are smoothed out. $\endgroup$
    – KeithS
    Jan 7, 2020 at 20:52
  • $\begingroup$ @keiths: That option is a hack that always, necessarily extrudes the wrong total amount of material. To fix the issue you need to stop it from getting extruded in the wrong place, not just extrude more to "compensate". $\endgroup$ May 7, 2020 at 3:09
  • $\begingroup$ @KeithS the extra length on restart is controversial because it assumes a small amount of plastic is disappearing into thin air. It might be the overall extrusion amount is off, or linear advance is off. Could also be oozing out because travel is slow. The hard part about fixing ooze while traveling is the ooze will depend on how long the travel move is, how long the extruder is retracted, temperature (how oozey). One number often won’t cover that, with a variety of objects. $\endgroup$ Jan 27 at 21:48
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Check your retraction settings.. It's either too far or one of your priming/wipe settings is off, some slicers call it priming or extra restart distance.

Your linear advance "k" might be set wrong if you're using linear advance.

I see a bit of under-extrusion on the between walls and center, your overlap % might a little short. Or you're printing too fast for the filament to melt and deposit.

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