<p>I recently bought an Anet A8 (<a href="https://pevly.com/anet-a8-3d-printer-review/" rel="noreferrer">https://pevly.com/anet-a8-3d-printer-review/</a>). I've managed to get everything up and running, leveled the board, but am now running into a problem.</p>

<p>At the start of the print, the printer moves to 0,0,0, bumps into the switches a couple times (I assume to calibrate or so?), and then starts "printing". But the nozzle "randomly" moves to either an X of 0 or an Y of 0 before returning to the printing position. This movement seems to pull off any basis the printer managed to lay down, which then forms a nice "ball" on the nozzle, to which the rest gets stuck. (I'm still having some other issues with getting the filament to stick to the bed, but there's plenty I still have to try out for that.)</p>

<p>During one attempt of printing a very simple small cube, I carefully pulled the filament "ball" from the nozzle while it did one of those movements to X 0, and afterwards it managed to lay down the bottom layer perfectly fine. This causes me to believe those movements are the biggest problem I'm facing right now.</p>

<p>After it did the first layer, it moved up a bit, moved to X 0, back to the model, and got stuck on a piece of plastic that was standing upwards.</p>

<p>These movements seem to happen at around the same phase in the print, and happen quite consistently. Is this normal behavior? If so, how do I make sure the filament does not get pulled off during these weird movements? If not, how do I get rid of them?</p>

<p>(No, not a duplicate of <a href="https://3dprinting.stackexchange.com/questions/962/printer-randomly-moves-to-home-during-printing-then-resumes-as-normal">Printer randomly moves to home during printing, then resumes as normal</a> as I print directly from PC.)</p>

<hr>

<p>Edit to add more information:</p>

<p>I use Cura 3.0.4 for printing, the stock Anet A8 firmware, and am attempting to print the cube model that comes with Windows 10. (Yes, I've tried different models, same result.)</p>

<p>I seem to have more issues, in the video it's visible that the feeding does not seem to work too great, but I think the random movements are the most clear and biggest problem right now, so I should tackle that first.</p>

<p>In Cura I've used the Pruisa I3 printer, with the following G-codes:</p>

<pre><code>G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G29
G1 Z15.0 F9000 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G1 F9000
M117 Printing...
</code></pre>

<p>and end</p>

<pre><code>M104 S0 ;extruder heater off
M140 S0 ;heated bed heater off (if you have it)
G91 ;relative positioning
G1 E-1 F300  ;retract the filament a bit before lifting the nozzle, to release some of the pressure
G1 Z+0.5 E-5 X-20 Y-20 F9000 ;move Z up a bit and retract filament even more
G28 X0 Y0 ;move X/Y to min endstops, so the head is out of the way
M84 ;steppers off
G90 ;absolute positioning
</code></pre>

<p>(Yes, I added in the G29 in the start code manually, as I bought the official auto-leveling sensor. I'm not sure if it works though, but I read somewhere that I might need a different version of the firmware to support it properly.)</p>

<p><a href="https://youtu.be/lrk8iG1H4ig" rel="noreferrer">And here's a video showing what my printer does do exactly.</a> It started printing from the center in this case, it seems to randomly either move to the middle or to 0,0,0 when I abort the print.</p>

[{'answer_id': 5074, 'author': 'Hacky', 'author_id': 4708, 'author_profile': 'https://3dprinting.stackexchange.com/users/4708', 'pm_score': 2, 'selected': False, 'text': '<p>I see two problems in your video:</p>\n\n<ol>\n<li>It looks like the first layer is built too much upwards. (The level calibration should be so that a Z-height of 0 can barely fit a sheet of paper under the nozzle. )</li>\n<li>Your printer is not extruding at all. As you said, the extrusion has some problems. Extrusion problems will cause adhesion problems too. </li>\n</ol>\n'}, {'answer_id': 5083, 'author': 'Daniël van den Berg', 'author_id': 9237, 'author_profile': 'https://3dprinting.stackexchange.com/users/9237', 'pm_score': 3, 'selected': True, 'text': '<p>I switched to different firmware (the latest Marlin), now the problem has been resolved. So it seems to me that those random movements are not in fact normal, but a flaw in the firmware.</p>\n'}, {'answer_id': 5085, 'author': 'Fernando Baltazar', 'author_id': 4454, 'author_profile': 'https://3dprinting.stackexchange.com/users/4454', 'pm_score': 1, 'selected': False, 'text': "<p>The main problem shown in the video is because you are printing an oversized part, the random movements to X and Y is due the exceeded lines. Also the nozzle has a wrong Z0 and the part won't get adhesion to the bed.</p>\n"}, {'answer_id': 18500, 'author': 'Останин Вадим', 'author_id': 21932, 'author_profile': 'https://3dprinting.stackexchange.com/users/21932', 'pm_score': 0, 'selected': False, 'text': '<p>Formating SD card fixes issue for me.\nI think that writing many times to the same block of SD card corrupt some block of flash SD card memory.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/5066', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/9237/']