{"action":"created","issue":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/1761","labels_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/1761/labels{/name}","comments_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/1761/comments","events_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/1761/events","html_url":"https://github.com/MarlinFirmware/Marlin/issues/1761","id":65550786,"number":1761,"title":"Wrong Z homing position.","user":{"login":"fotis400","id":3100169,"avatar_url":"https://avatars.githubusercontent.com/u/3100169?v=3","gravatar_id":"","url":"https://api.github.com/users/fotis400","html_url":"https://github.com/fotis400","followers_url":"https://api.github.com/users/fotis400/followers","following_url":"https://api.github.com/users/fotis400/following{/other_user}","gists_url":"https://api.github.com/users/fotis400/gists{/gist_id}","starred_url":"https://api.github.com/users/fotis400/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/fotis400/subscriptions","organizations_url":"https://api.github.com/users/fotis400/orgs","repos_url":"https://api.github.com/users/fotis400/repos","events_url":"https://api.github.com/users/fotis400/events{/privacy}","received_events_url":"https://api.github.com/users/fotis400/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/labels/Verified%20bug!","name":"Verified bug!","color":"e11d21"}],"state":"open","locked":false,"assignee":{"login":"thinkyhead","id":698003,"avatar_url":"https://avatars.githubusercontent.com/u/698003?v=3","gravatar_id":"","url":"https://api.github.com/users/thinkyhead","html_url":"https://github.com/thinkyhead","followers_url":"https://api.github.com/users/thinkyhead/followers","following_url":"https://api.github.com/users/thinkyhead/following{/other_user}","gists_url":"https://api.github.com/users/thinkyhead/gists{/gist_id}","starred_url":"https://api.github.com/users/thinkyhead/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/thinkyhead/subscriptions","organizations_url":"https://api.github.com/users/thinkyhead/orgs","repos_url":"https://api.github.com/users/thinkyhead/repos","events_url":"https://api.github.com/users/thinkyhead/events{/privacy}","received_events_url":"https://api.github.com/users/thinkyhead/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/milestones/26","html_url":"https://github.com/MarlinFirmware/Marlin/milestones/Bug%20Fixing%20Round%208","labels_url":"https://api.github.com/repos/MarlinFirmware/Marlin/milestones/26/labels","id":1052603,"number":26,"title":"Bug Fixing Round 8","description":"","creator":{"login":"boelle","id":3832239,"avatar_url":"https://avatars.githubusercontent.com/u/3832239?v=3","gravatar_id":"","url":"https://api.github.com/users/boelle","html_url":"https://github.com/boelle","followers_url":"https://api.github.com/users/boelle/followers","following_url":"https://api.github.com/users/boelle/following{/other_user}","gists_url":"https://api.github.com/users/boelle/gists{/gist_id}","starred_url":"https://api.github.com/users/boelle/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/boelle/subscriptions","organizations_url":"https://api.github.com/users/boelle/orgs","repos_url":"https://api.github.com/users/boelle/repos","events_url":"https://api.github.com/users/boelle/events{/privacy}","received_events_url":"https://api.github.com/users/boelle/received_events","type":"User","site_admin":false},"open_issues":5,"closed_issues":2,"state":"open","created_at":"2015-04-04T09:20:20Z","updated_at":"2015-04-27T05:47:12Z","due_on":"2015-09-14T22:00:00Z","closed_at":null},"comments":14,"created_at":"2015-03-31T21:26:08Z","updated_at":"2015-04-28T10:45:48Z","closed_at":null,"body":"I just finished some modifications to my RepRap, and also pulled latest Marlin. be593b600b8b9b427656dd27be7fc277aec0a8a5\r\n\r\nNo matter what are the settings in the config files, when my Z axis homes the printer reports Z 15mm.\r\n\r\nI really can't get it what causes the 15mm offset. It should report 200mm (Z_MAX_POS), and because of this the software endpoints do not work. (I can send G01 Z20 which will cause crashing of the Z axis).\r\n\r\nIt seems like a bug to me...\r\n\r\nHere is my Configuration.h\r\nhttp://pastebin.com/E2g5gVn8"},"comment":{"url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/comments/97012655","html_url":"https://github.com/MarlinFirmware/Marlin/issues/1761#issuecomment-97012655","issue_url":"https://api.github.com/repos/MarlinFirmware/Marlin/issues/1761","id":97012655,"user":{"login":"davbardi","id":12151604,"avatar_url":"https://avatars.githubusercontent.com/u/12151604?v=3","gravatar_id":"","url":"https://api.github.com/users/davbardi","html_url":"https://github.com/davbardi","followers_url":"https://api.github.com/users/davbardi/followers","following_url":"https://api.github.com/users/davbardi/following{/other_user}","gists_url":"https://api.github.com/users/davbardi/gists{/gist_id}","starred_url":"https://api.github.com/users/davbardi/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/davbardi/subscriptions","organizations_url":"https://api.github.com/users/davbardi/orgs","repos_url":"https://api.github.com/users/davbardi/repos","events_url":"https://api.github.com/users/davbardi/events{/privacy}","received_events_url":"https://api.github.com/users/davbardi/received_events","type":"User","site_admin":false},"created_at":"2015-04-28T10:45:48Z","updated_at":"2015-04-28T10:45:48Z","body":"I'm attempting to auto bed level with a servo mounted z probe on a home made COREXY printer (which still needs some tuning) and I'm getting the issue where the printer head is starting too high. I've noticed the more out of level the bed the higher the head error above the bed (I have glass plates and can create make the bed very unlevel by putting a pencil under one side).  Auto levelling appears to be fundamentally working (apart from the level error) as I can clearly see the X-axis change as the head moves (very obvious with the pencil!). Another point I noticed is if PROBE_SERVO_DEACTIVATION_DELAY 300  is defined then (quite unexpectedly) the error gets much larger.  The hotend is also lifting a lot more between each bed probe during the G29.  Here the verbose responses from G29 V4 for the \"pencil-lifted\" bed.\r\nMy probe offset is -2.16mm\r\n\r\nThis is with PROBE_SERVO_DEACTIVATION_DELAY  not defined (giving a head height approx. 5.2mm too high):-\r\n\r\n20:15:46.856 : +-----------+\r\n20:15:46.856 : |...Back....|\r\n20:15:46.856 : |Left..Right|\r\n20:15:46.856 : |...Front...|\r\n20:15:46.856 : +-----------+\r\n20:15:46.856 : +2.90938 +3.25938\r\n20:15:46.872 : -3.17812 -2.99062\r\n20:15:46.872 : planeNormal x: -0.002337 y: -0.041125 z: 1.000000\r\n20:15:46.872 : \r\n20:15:46.872 : Bed Level Correction Matrix:\r\n20:15:46.872 : +0.999997 +0.000000 +0.002337\r\n20:15:46.872 : -0.000096 +0.999155 +0.041090\r\n20:15:46.872 : -0.002335 -0.041090 +0.999153\r\n\r\nThis is with PROBE_SERVO_DEACTIVATION_DELAY  defined (giving a head height approx. 11.4mm too high):-\r\n20:10:46.525 : +-----------+\r\n20:10:46.525 : |...Back....|\r\n20:10:46.525 : |Left..Right|\r\n20:10:46.525 : |...Front...|\r\n20:10:46.525 : +-----------+\r\n20:10:46.541 : +2.91250 +3.06250\r\n20:10:46.541 : -3.05000 -2.92500\r\n20:10:46.541 : planeNormal x: -0.001196 y: -0.039833 z: 1.000000\r\n20:10:46.541 : \r\n20:10:46.541 : Bed Level Correction Matrix:\r\n20:10:46.541 : +0.999999 +0.000000 +0.001196\r\n20:10:46.541 : -0.000048 +0.999208 +0.039802\r\n20:10:46.541 : -0.001195 -0.039802 +0.999207\r\n\r\nI'm no coder, but hopefully these observations help towards finding the error."}}