Walls being duplicated on 3D printed objects

[DennisL 0]

I am trying to print enclosures ("dams") and enclosures with closed tops ("caps") fur use in potting electronic printed circuit boards.  These objects have to be extremely accurate to fit amongst other components on the PC boards.  The objects I have tried to print have printed with extra walls in some places in the "vertical" or Y direction (objects are on XY plane).  The extra walls do not appear on the #D Freecad Drawings, exported STL or OBJ files or sliced gcode files yet they print every time.  I have attached all of these files for two different 3D models plus .3mf files for each as well as pictures of the printed models with duplicated walls.  I am using a Creality Ender 3 V2 and have tried printing with the original firmware supplied with the machine and a newer firmware  -  same result.  I have been unable to find a similar problem in this forum and do not know what to try next.  Please assist.

3D printed samples comments.pdf 3D printed samples.pdf C11 Potting cap 1e.3mf C11 Potting cap 1e.gcode C11 Potting cap 1e.obj C11 Potting cap 1e.stl Potting dam 2.3mf Potting dam 2.gcode Potting dam 2.obj Potting dam 2.stl C11 Potting cap 1e.zip Potting dam 2.zip

[DennisL 0]

I forgot to add that the objects are rather small  -  see dimensions on attached PDF.  The walls of the objects are supposed to be 4mm thick.

3D printed samples comments 2.pdf

[GregValiant 1,245]

I printed both of the gcode files.  As you've noticed - the extra walls aren't in  the gcode and they didn't show up in my prints (Ender 3 Pro).  ( I threw out the brim as it made photographing difficult.)

 

Here is the 1e

 

That leaves us at the printer.  One thing about the gcode is that the toolpath alternates between clockwise and counter-clockwise.  I wonder if there is some slop in your X system (like a loose belt) that is causing a different path when going one way than when going the other.

Also - the skins of your 1e print are very sloppy and look over-extruded and they look curved.  Have you calibrated the E-steps?  As you see in my print of the 1e the skin lines are straight.

[DennisL 0]

Thanks GregValiant

You hit the nail on the head  -  my x-travel belt was loose  -  since tightening it is printing perfectly.

[GregValiant 1,245]

Further proof that "Even a blind squirrel finds a nut every once in a while."