Dear forum
I have had an Ender-3 Neo for a short time now, and initially achieved very good results, but recently my prints have become warped in the X-axis. In other words, the prints are a few millimeters wider than in the file, while the Y and Z axes remain exactly to size. I have already checked the belt tension in the X axis and tightened the belt a little more, but to no avail. does anyone have any ideas as to why this could be?
many thanks for your help
Sascha
Hi @bastelhase and welcome to the forums.
I would recommend checking the settings on the printer for the X and Y axis. Most of the time the settings for both axis should be set to 80 steps/mm. If the X and Y do not match then this could be part of the issue.
Another thing to check is all pulleys and gears to make sure no grub screws have come loose allowing some parts to slip. Sometimes the pulley gear grub screw can work itself loose and cause these issues you are experiencing.
Another possibility is a stretched belt, if the belt becomes stretched this can also often cause this issue.
I would first start with checking over the mechanical things such as pulleys and gears first and also double check the printer configurations are correct. If everything looks right then I would recommend reaching out to support to see if they can send you a replacement belt if you are within the warranty period.
Thanks for the fast reply. I have reset the settings to factory settings. I have not seen any grub screws on the pulleys! when moving the X axis manually, I noticed that there are some “edgy” spots where the print head snaps or hangs a little, I have fixed this by gently loosening the eccentric screws. i have removed the belt, there are no missing teeth. i have now put the printer back into operation and unfortunately the fault is still there. the picture clearly shows that the first lines are printed correctly and the distortion occurs afterwards. unfortunately i still don’t know what to do, which is a bit frustrating as the printer is new and printed perfectly at the beginning.
In addition to the offset, I also have waves and gaps in the filling, I don’t know whether the cause is due to the same problem, but it seems likely to me.
the mystery that has been driving me crazy for days has actually been solved!!! Inside the print head the whole hotend was loose, I unscrewed the housing with the fan on it and then saw that the 2 screws with which the hotend was fastened inside were actually already 4 millimeters out and had almost fallen off!
Wow. I’m thinking that will make a huge difference… Good catch… 
Glad to hear you were able to find the area causing the issue, that was going to be my next suggestion after the belts/pulleys etc were checked 
Hopefully the printer will behave itself for you now
