Thin Wall Single Extrusion - Excessive Extrusion

[douggorgen]

I am trying to print the Collapsing Jian from thingiverse:

https://www.thingiverse.com/thing:3837891

This print contains several nested thin wall structures.

If I print with "External Thin Wall Type" set to "Perimeters Only", I get fairly well formed walls as shown circled in red in photo "Perimeters Only.jpg".

If I print with "External Thin Wall Type" set to "Allow Single Extrusion Walls", I get excessive extrusion as shown circled in red in photo "Allow Single Extrusion Walls.jpg".

I was hoping that "Allow Single Extrusion Walls" would give me better control over the printing of these walls. However, this excessive extrusion causes the nested thin wall structures to be stuck together and therefore unusable.

I have looked at (I think) every profile option and could not find any that would fix this problem with "Allow Single Extrusion Walls".

If there is an option that would help, please point me to it.

If this is a bug and you need more information, please let me know.

I tried to upload the factory file but the system said "file too big".

Also, I've prepared a zip file that contains the original stl file, both factory files, both gcode files, the jpg photos, and a text description of the problem. The zip file is 36 megabytes.

I am printing on an Ender 3 Pro running Marlin 1.1.9 with the Teaching Tech mods for BLTouch and filament runout.

[buckker]

I got nearly the same result. After long hours of testing, I find out the "External Thin Wall Type" set to Perimeters only gives a nice print. With "Allow Single Extrusion walls" I got very ugly prints. It seems that simplify has a bug in this case. It would be very nice if someone of the developer team could make a statement.

Here is my post: viewtopic.php?f=9&t=14044