# Small dent problem

Whenever I print, I tend to have a small dent that appears on several of my prints, that are not in the original design. These are not following the layer orientation.

As far as I notice, nothing blocks the extruder of my prusa-i3. I print with PLA, so not a material where I would expect weird behaviour.

What could cause that problem?

• what is the model? – Trish Apr 6 '19 at 17:43
• @Trish: the model is one of the russian doll maze, available here: thingiverse.com/thing:2410748 – Emile D. Apr 6 '19 at 18:03
• In case the question leads to the size of the wall, I don't think it is the issue, since it is always at least 3 nozzle large. – Emile D. Apr 6 '19 at 18:11
• Looks like some kind of backlash issue with your printer. One way to know for sure is to print a part that has this issue, and then rotate the part in data and reprint. If the 'dent' stays in the same place relative to the bed/printer, then it's definitely a mechanical issue and not a data issue. – BobT Apr 6 '19 at 18:12
• Also, looking at the rest of the print, aren't the side supposed to be smooth? In the thingiverse model, it appears to be so. I'd think you may need to tighten things up a little bit. Also, not sure how the nibs which run the maze are supposed to be supported during print or if there's enough overhang (or angle of the nib while printing) to allow it to print correctly at the top. If you have support turned on, could this be causing the issue where the nib is at? – Pᴀᴜʟsᴛᴇʀ2 Apr 6 '19 at 18:54

This looks very much like it is the seam between the outer perimeters that is placed one over the other. This can be solved by choosing a different Z-seam alignment. In Ultimatker Cura, the setting is called Z-seam alignment and should be set to random for cylindrical items.