<p>Testing my new Wanhao i3+. PLA plastic(Wanhao), basic normal quality settings in Cura (I guess 0.1 mm layer, 40 mm/s speed, 60c bed temp, 200c extruder temp). After 1.5 hours of printing quality degraded, it makes some loose structure. </p>

<p>Edit:
After finish I noticed that problem exists only in layers where it cycles printing/no printing. There is no problem on layers where it print continuously.</p>

<p>What is the reason can be and how can I fix that?</p>

<p><a href="https://i.stack.imgur.com/W90dj.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/W90dj.jpg" alt="enter image description here"></a></p>

[{'answer_id': 4378, 'author': 'markshancock', 'author_id': 6417, 'author_profile': 'https://3dprinting.stackexchange.com/users/6417', 'pm_score': 2, 'selected': False, 'text': "<p><strong>It definitely looks like under extrusion.</strong>  </p>\n\n<ol>\n<li>First thing I would check is the filament feeder to make sure it has\na good grip in the filament.</li>\n<li>After that I would do another print to see if the problem is repeatable.</li>\n</ol>\n\n<p>If it doesn't repeat, it may have been </p>\n\n<ul>\n<li>A temporarily clogged nozzle</li>\n<li>The filament was undersized in that segment and the filament feeder lost its grip.</li>\n<li>The extruder got to cold for some reason in that segment and the feeder couldn't push the material through the extruder fast enough.</li>\n</ul>\n\n<p>If it does repeat:</p>\n\n<ul>\n<li>Re-inspect the filament feeder</li>\n<li>Try increasing the the extruder temp to say, 225.</li>\n<li>Try turning off retraction to see if it is related to those settings.</li>\n</ul>\n"}, {'answer_id': 4392, 'author': 'bardiir', 'author_id': 6982, 'author_profile': 'https://3dprinting.stackexchange.com/users/6982', 'pm_score': 2, 'selected': False, 'text': "<p>This is very likely under extrusion caused by your feeder pressing down too hard onto the filament. If the feeder presses the filament very hard it then gets squished a bit, this is not causing much issues when you're only feeding in one direction as the drive gear is still pulling on fresh filament and shoving the squished part down at a steady rate. BUT once you got retractions things get awful as the squished filament then gets retracted and fed again at the same pace but due to the elongation at a smaller rate of material causing underextrusion.</p>\n\n<p>You can either trade it in to some overextrusion by adjusting the extra length on restart setting, retract a shorter piece of filament (like only retract half a mm or something) or loosen the feeder so it doesn't squish down on the filament as hard.</p>\n"}, {'answer_id': 4406, 'author': 'Davo', 'author_id': 4922, 'author_profile': 'https://3dprinting.stackexchange.com/users/4922', 'pm_score': 2, 'selected': False, 'text': '<p>If the problem occurs most when you are doing the most advance/retract cycles, the problem is likely with your advance/retract settings.</p>\n\n<p>Have you tried cutting each of them in half and executing the same gcode?</p>\n'}]
['https://3dprinting.stackexchange.com/questions/4367', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/7747/']