<p>Is there a specific name for that problem? What causes this, and is there a way how to solve it? </p>

<p>Printed with PLA, 2&nbsp;mm nozzle diameter, 0.2&nbsp;mm layer height, 20-60&nbsp;mm/s, 200&nbsp;°C extruder, 60&nbsp;°C bed.</p>

<p></p>

<p><a href="https://i.stack.imgur.com/aSzrJ.jpg" rel="noreferrer" title="Top"><img src="https://i.stack.imgur.com/aSzrJ.jpg" alt="Top" title="Top"></a></p>

<p><a href="https://i.stack.imgur.com/nCgam.jpg" rel="noreferrer" title="Bottom"><img src="https://i.stack.imgur.com/nCgam.jpg" alt="Bottom" title="Bottom"></a></p>

[{'answer_id': 10544, 'author': 'cmm', 'author_id': 2082, 'author_profile': 'https://3dprinting.stackexchange.com/users/2082', 'pm_score': 3, 'selected': False, 'text': '<p>I have experienced this problem.  This picture is one that I could have taken. </p>\n\n<p>It has always been because I was putting too much plastic into the available space.</p>\n\n<p>This has been caused two things: overextrusion -- squirting out too much plastic for the intended layer height, and the bed being too "high" so that the gap between the nozzle and the bed is too thin.</p>\n\n<p>In both cases, too much plastic is trying to be placed in too small a volume.  The plastic has to go somewhere, and ripples follow.  Because the nozzle rubs against the adjacent lines which have already been deposited, an up-bump pushes up the nozzle on the line beside the bump, and a coherent pattern of ripples can form.</p>\n\n<p>The "bump up" is a real effect from the elasticity of the Z-axis, including all the resulting strains of twisting and lifting the nozzle.</p>\n'}, {'answer_id': 10547, 'author': 'dracotdragon', 'author_id': 17001, 'author_profile': 'https://3dprinting.stackexchange.com/users/17001', 'pm_score': 1, 'selected': False, 'text': '<p>This could be a number of things, I personally think it could be either over extrusion or an issue with one of the belts. Depending on the printer, you may need to manually go in and adjust your steps per millimeter, which you should be able to find a guide on. If that doesn\'t work, then look into belt tension adjustment. Hope this is able to help! I like to use the <a href="https://www.simplify3d.com/support/print-quality-troubleshooting/over-extrusion/" rel="nofollow noreferrer">Simplify3D Print Quality Guide</a> for situations like this, it tends to be very useful.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/10505', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/16960/']