Background story: I bought E3D Hemera and wrongly set vref to 0.5v on the stock Ender 3 board. Skipped step severely. Increased vref to 0.7v, calibrated e-steps, etc. Got a rough surface on all sides. Slowing down didn’t help. I printed a cube in vase mode and got salmon skin on all sides. Try varying the print speed. The salmon skin pattern stays the same, but it’s much stronger when printed slower. What!! I always think that print slower = better result. I tried to print even slower, and noticed that the extruder pulled the filament in not smoothly. It seems like the extruder only moves on full or half steps. To verify this observation, I wrote a script to generate G-code that will align the extruder’s full step on every layer. I created a single wall octagon that each side has n * (mm per full step) long. The result confirms that the pattern aligns with the E-stepper’s full step. I can produce a perfect vertical salmon skin when setting the extruder step per mm equal to the setting in the printer’s firmware. A slanting salmon skin can also be produced when setting the extruder step per mm slightly different from the firmware’s setting. Correcting the vref to 0.96v helps a little. The pattern is still there. I’m waiting for SKR Mini E3 board. I’m still not sure if my Hemera has something wrong, or it is just the result of this particular combination with the Ender 3’s stock board. Here is my script: https://3dprinting.wheretogo.in.th/e-stepper.php This octagon was printed at 20,30,40,60,80 mm/s (bottom to top). The pattern is the same for all sides. Left: incorrect vref at 0.7v, Right: 0.96v Using 394.87 step/mm (as set in firmware) the pattern width is 2.57mm. As calculated in the script. slanting salmon skin. Set e-step per mm in script to 409, the firmware is set to 394.87.