0.1mm Layer Height Woes


Hi all, I have an Anycubic i3 Mega with a bowden setup and a V6 hotend, running Octopi with Marlin 1.9 firmware.
I had been using Cura exclusively for slicing but it has become so slow as to be unusable, so I have switched across to Slic3r PE and am slowly getting it dialled in.
I ran a benchy last night at 0.1mm layer height and as you can see the first 10mm is rough with terrible overhang.
After that it is smooth as smooth can be. I am wondering why this is and any thoughts/suggestions would be greatly appreciated

The material is Esun 1.75mm PLA, a new roll, I am printing at 30mm/s, bed 60 degrees filament 200 degrees
My first thoughts are insufficient cooling but why would that change after 10mm? and cooling hasn’t been an issue in the past




Hi Jd,

As you pointed out, you are having trouble with overhangs (the first 10mm happen to be the most extreme overhang). Also notice the front port hole. Two things to check: cooling (you mentioned this) and over extrusion. Filament can vary from roll to roll, room temperature, humidity, etc, so you have to be prepared to make minor adjustments all the time.




hey Jd,

you could also try to lower your heatbed temp to 55°C or even 50°C. This should help to ceep your printed part a bit cooler.




and rotate the front of the ship in direction to the part cooler :smiley:



Thanks for the helpful comments, they give me something to work with.
One thing that is not immediately obvious from the first photo, is that there is appears to be a difference in wall width between the first 10mm and the rest of the benchy. The first 10mm has a rough surface all the way around, and there is a pronounced step outward where I have drawn an arrow (You’ll have to zoom in)

After a band of diagonal effects (about 2mm) the surface is completely smooth, it’s almost as though the outer surface has been shaved off by a blunt razor.