Z-layers skipped (Marlin / Wilson TS)

My printer very occasionally seems to skip a bunch of layers while printing.

In the attached image, I printed the same model (from SD card) twice. First time (on the right) it came out okay, but the second time (on the left), it seems to have skipped about 10% of the Z-layers (notice the diagonal groove being shifted, because of missing layers, and the reduced height).



I've been scratching my head over this one, but I can't seem to understand what's going wrong... Anyone ever experienced anything like this? Or has a clue as to what might be going wrong?

I'm using a Mega 2560 clone, with Marlin 1.0.2 firmware. The printer is a Reprap Wilson TS, with an original E3D Lite6 extruder. Both prints were done with exactly the same STL file, and were printed straight from SD card.

Can you post a copy of your configuration.h and configuration_adv.h?

Also are you using a geared 3mm extruder or direct drive 1.75mm extruder?

Edited 1 time(s). Last edit at 09/21/2015 03:44PM by jjazzyj.

I haven't had this problem anymore after this time. So I just consider it a fluke now, thx.

But if it reoccurs, I'll make sure to post my configuration here, thanks.