I am using an Anet A8 printer with the latest Marlin 1.1.5 firmware.
Now I am trying to calibrate the printer and I started with calibration the extruders' E steps.
But I am not managing it to print shells that are multiples of my nozzle width (0.4mm).
What did I do?
1) Calibrated the E steps by extruding some 100mm PLA pieces at a speed of 100mm/min.
The resulting value for E was 97.58 that gave me lengths between 99.90 and 100.02mm.
So I stored this values with "M92 E97.58" and "M500".
2) Than in Simplyfy3D it configured my extruder values to
3) After that I printed this calibration object and the resulting shell size was 0.49mm. After doing some calculation and test prints I got a value of 0.72 for the extrusion multiplicator. That gave me not excactly 0.4mm for the shell width but 0.41.
4) But printing with this value is causing heavy under-extrusion.
The top layers (6x 0.2mm) have gaps and the shells are mostly not connected. The lowest multiplicator value I can use is 0.82. But than the shells are too wide again. But the outer and inner dimension of the calibration object is perfect.
Did I miss something?