Been having this issue from print 1. Layers start to drift then drifts back to place randomly in the prints usually towards the top end of a print. Between the two pics I changed my extruder feed rate from 93 to 100. That seemed to help with the irregular surface but I still get the drift. What can I calibrate? I've adjusted the Polulu pots. I don't mess with the code at all, I have a nonducted cooling fan. https://reprap.org/forum/read.php?262,591306,591306#msg-591306 Sun, 19 Jul 2026 18:13:03 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?262,591306,595240#msg-595240 https://reprap.org/forum/read.php?262,591306,595240#msg-595240 elwood127 Printing Thu, 10 Dec 2015 18:45:58 -0500 https://reprap.org/forum/read.php?262,591306,594457#msg-594457 https://reprap.org/forum/read.php?262,591306,594457#msg-594457 GuerillaEngineer Printing Tue, 08 Dec 2015 16:20:31 -0500 https://reprap.org/forum/read.php?262,591306,593257#msg-593257 https://reprap.org/forum/read.php?262,591306,593257#msg-593257 To me it still looks like a temp and timing problem, especially the "twist" in the middle.
Also try to print the two or three towers at a reduced speed once you get close to the area with the twist and then again for the thin parts of the top.

I recently replaced the springs holding the bed with much stronger ones and it gives a nice improvement on the prints especially at higher speeds.
Before I could feel the plate virbte back and forth with fast support structures, now it is rock solid and the last wave patterns on the sides of my prints are gone too...
(unrelated though)]]> Downunder35m Printing Sat, 05 Dec 2015 15:46:16 -0500 https://reprap.org/forum/read.php?262,591306,593096#msg-593096 https://reprap.org/forum/read.php?262,591306,593096#msg-593096 RRuser Printing Sat, 05 Dec 2015 06:28:30 -0500 https://reprap.org/forum/read.php?262,591306,591729#msg-591729 https://reprap.org/forum/read.php?262,591306,591729#msg-591729 GuerillaEngineer Printing Tue, 01 Dec 2015 23:14:47 -0500 https://reprap.org/forum/read.php?262,591306,591454#msg-591454 https://reprap.org/forum/read.php?262,591306,591454#msg-591454
Might be a problem with the model itself. Try cutting the top off of the model and printing just it, in larger sizes, so you can focus on if the model is correct. This will also tell you if there is a heat problem, but I can't see how heat would only move the layers to one side and back again, unless maybe the extruder temp was varying.]]> RRuser Printing Tue, 01 Dec 2015 08:31:29 -0500 https://reprap.org/forum/read.php?262,591306,591328#msg-591328 https://reprap.org/forum/read.php?262,591306,591328#msg-591328 Before you go overboard try to duplicate the object so instead of one you print two at a time.
If the shifting is still present start with the basics like belt tension, loose grub screws on motors and pulleys and such.]]> Downunder35m Printing Tue, 01 Dec 2015 02:26:06 -0500 https://reprap.org/forum/read.php?262,591306,591306#msg-591306 https://reprap.org/forum/read.php?262,591306,591306#msg-591306 GuerillaEngineer Printing Tue, 01 Dec 2015 00:34:30 -0500