I set up z axis home position exactly as it should be and after I run job, hot end starts scraping on heated bed glass meaning z axis has moved down or something else happened? I've broken two hot end on this, please help!! https://reprap.org/forum/read.php?151,223729,223729#msg-223729 Sun, 15 Mar 2026 06:57:28 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?151,223729,226193#msg-226193 https://reprap.org/forum/read.php?151,223729,226193#msg-226193 -------------------------------------------------------
> Karmavore, I had PLA extruder body which warped
> during print and I replaced it some time ago with
> ABS, but problem persists.
> I think I'll set up z-axis home position when both
> hotend and heated bed are at their operating
> temperatures and then I'll post my findings here.

Ok, I've done this and now it works perfectly! Seems like calibration needs to be done in working conditions.]]> njadric General Mendel Topics Thu, 11 Jul 2013 12:22:15 -0400 https://reprap.org/forum/read.php?151,223729,224408#msg-224408 https://reprap.org/forum/read.php?151,223729,224408#msg-224408 chris33 General Mendel Topics Fri, 05 Jul 2013 14:42:56 -0400 https://reprap.org/forum/read.php?151,223729,224280#msg-224280 https://reprap.org/forum/read.php?151,223729,224280#msg-224280 I think I'll set up z-axis home position when both hotend and heated bed are at their operating temperatures and then I'll post my findings here.]]> njadric General Mendel Topics Fri, 05 Jul 2013 07:24:00 -0400 https://reprap.org/forum/read.php?151,223729,223789#msg-223789 https://reprap.org/forum/read.php?151,223729,223789#msg-223789
My problem wasn't cold z axis homing, nor lost z steps. What was happening was heat from the hot end was deforming the PLA extruder block. The extruder block was sagging just a bit into the hole in the x-carriage. It hadn't sagged when I started the first print, so it went fine. But by the time the second happened it was sagging pretty good, I guess. After printing up a new extruder in ABS with one of my good prints, the problem is completely gone.

HTH.]]> Karmavore General Mendel Topics Wed, 03 Jul 2013 16:57:02 -0400 https://reprap.org/forum/read.php?151,223729,223782#msg-223782 https://reprap.org/forum/read.php?151,223729,223782#msg-223782
However, if you're breaking hot ends on the print bed, you may be losing Z steps occasionally. You should probably adjust your Z axis mechanics to limit the force that can be applied downward. For example, the Z axis nuts can separate from my X axis ends if something prevents the carriage from coming down.]]> Dale Dunn General Mendel Topics Wed, 03 Jul 2013 16:35:56 -0400 https://reprap.org/forum/read.php?151,223729,223729#msg-223729 https://reprap.org/forum/read.php?151,223729,223729#msg-223729 I've broken two hot end on this, please help!!]]> njadric General Mendel Topics Wed, 03 Jul 2013 13:17:49 -0400