<p>We have a Prusa i3 MK2 and we've changed for a print with another colour material but when I pressed "load filament", it didn't make anything. </p>

<p>Often after five times doing that the printer works. I don't have any pictures but the filament is in the hole and the printer holds it. However, it doesn't push it into the extruder and the remains of the old filament do not come out, so I wonder why the motors just stop and don't work. </p>

<p>Sometimes there are no problems - sometimes more and sometimes less. I hope someone has the reason for this problem.</p>

[{'answer_id': 5702, 'author': 'Coder_fox', 'author_id': 9771, 'author_profile': 'https://3dprinting.stackexchange.com/users/9771', 'pm_score': 0, 'selected': False, 'text': '<p>First make sure that the hotend is hot enough.\nSecond you need to check your extruder if it is clean.\nThird try to push the filament by hand and look if it comes out. If yes than the problem should be in the motor.\nThe motor connection wire could be loose.</p>\n'}, {'answer_id': 5734, 'author': 'PR90', 'author_id': 10340, 'author_profile': 'https://3dprinting.stackexchange.com/users/10340', 'pm_score': 3, 'selected': True, 'text': '<p>My 0.02c:</p>\n\n<ol>\n<li>Cut the tip of the new filament at an angle so that it is pointed enough. This will ensure that it easily enters the hole leading into the hot end beneath the extruder drive gear. A lot of times the curl in the filament (from being wound on a spool) will cause misalignment and lead to it not entering this hole properly.</li>\n<li>Check filament debris lodged in the extruder gear teeth. Sometimes this will prevent good grip on the filament.</li>\n<li>Finally you can try increasing the nozzle temperature. Often times any residue inside the nozzle will be cleared by elevating temperature and pushing in new filament.</li>\n</ol>\n'}, {'answer_id': 5739, 'author': 'Nathan Bache', 'author_id': 10381, 'author_profile': 'https://3dprinting.stackexchange.com/users/10381', 'pm_score': 0, 'selected': False, 'text': '<p>I would agree with PR90, cutting the filament tip at a 45% angle before inserting might help. If the new material has required a different temperature to the previous, then you could have burnt the old material clogging the nozzle (take nozzle off by unscrewing, if it a brass hex nozzle) - if the new material requires a lower temperature, then it will not melt the materiel old pushing it out. </p>\n\n<p>See if you can go into Move Axis (manually) and then go to 0.01&nbsp;mm then Extrude and see if that works. </p>\n\n<p>If you hear a slipping or backlash sound coming from the extruder stepper motor, look at motor gear and check for clogging. </p>\n\n<p><em>Please check the heat requirements of the new and old materials</em></p>\n'}]
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