Anomaly calibrating Prusa i3 "MK1" - Subsurface exposed layers  

Anomaly calibrating Prusa i3 "MK1" - Subsurface exposed layers

Through an assorted sequence of events over the past few weeks, I've been taking a very hard look at the half-hearted attempt I made at calibrating my printer a year or so ago after I completed building the kit.

At the time, it appeared I had great prints coming right "out of the box" so to speak. Recently, through some detailed help and testing in a conversation I started over in reddit: https://www.reddit.com/r/3Dprinting/comments/69pawp/seeking_guidance_on_improving_details_in_3d_prints/ , I've been improving my profiles and calibration.

At this point I have one anomaly that I'm trying to reconcile. The test print I'm using has a collection of embossed images that are sunk 0.8mm below the surface of the print. Prints come out with some of that subsurface layer fine, and some areas of that same layer showing signs of under extrusion. The areas of under extrusion also appear to be sporadic.

Two examples of the test can be seen here:

The issue in question is highlighted between the green and red outlined areas in this close up:

My thought was this was due to bed leveling, but the sporadic nature points to something else. My other thought was variations in filament diameter that isn't huge enough to cause blockage, but does affect the extrusion width. The only problem with that theory is that the areas are consistent across multiple prints which have differing profiles.

The above prints have been with S3D. Through this adventure I've also been testing out the Prusa edition of Slic3r, and my next test is to use as consistent as possible settings to do this same print with Slic3r to see if that makes a difference.

Any other thoughts or suggestions?