{"action":"created","issue":{"url":"https://api.github.com/repos/grbl/grbl/issues/629","labels_url":"https://api.github.com/repos/grbl/grbl/issues/629/labels{/name}","comments_url":"https://api.github.com/repos/grbl/grbl/issues/629/comments","events_url":"https://api.github.com/repos/grbl/grbl/issues/629/events","html_url":"https://github.com/grbl/grbl/issues/629","id":63238238,"number":629,"title":"Homing Problem","user":{"login":"wheniwas19","id":547651,"avatar_url":"https://avatars.githubusercontent.com/u/547651?v=3","gravatar_id":"","url":"https://api.github.com/users/wheniwas19","html_url":"https://github.com/wheniwas19","followers_url":"https://api.github.com/users/wheniwas19/followers","following_url":"https://api.github.com/users/wheniwas19/following{/other_user}","gists_url":"https://api.github.com/users/wheniwas19/gists{/gist_id}","starred_url":"https://api.github.com/users/wheniwas19/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/wheniwas19/subscriptions","organizations_url":"https://api.github.com/users/wheniwas19/orgs","repos_url":"https://api.github.com/users/wheniwas19/repos","events_url":"https://api.github.com/users/wheniwas19/events{/privacy}","received_events_url":"https://api.github.com/users/wheniwas19/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":7,"created_at":"2015-03-20T14:24:55Z","updated_at":"2015-03-20T15:43:30Z","closed_at":null,"body":"I've built a homebrew 3-axis plotter out of foam-core and hardware I had laying around. GRBL. Holy shit. SO happy this exists.\r\n\r\nOvercome a lot of stupid \"why did I do that?\" errors and finally have a successful homing sequence. \r\n\r\nI hate to call this an <i>issue</i> because this is not a fault with GRBL, but my understanding of functionality, maybe. My pull-off moves directly into the negative. My understanding of the homing sequence was to use the limit switches to find 0,0,0, then pull-off by the amount in the settings. In my case, that's 1 mm. Once each axis locates 0, it then moves <i>further</i> by the pull-off amount leaving me in the negative. While the homing reports success, I am now over-limit and any attempt to use gcode, is \"thwarted\" by being on my switches.\r\n\r\nI could use some advice. Not sure how to make this NOT happen. \r\nMy settings:\r\n    $0=10 (step pulse, usec)\r\n    $1=25 (step idle delay, msec)\r\n    $2=0 (step port invert mask:00000000)\r\n    $3=6 (dir port invert mask:00000110)\r\n    $4=0 (step enable invert, bool)\r\n    $5=0 (limit pins invert, bool)\r\n    $6=0 (probe pin invert, bool)\r\n    $10=3 (status report mask:00000011)\r\n    $11=0.020 (junction deviation, mm)\r\n    $12=0.002 (arc tolerance, mm)\r\n    $13=0 (report inches, bool)\r\n    $14=1 (auto start, bool)\r\n    $20=0 (soft limits, bool)\r\n    $21=1 (hard limits, bool)\r\n    $22=1 (homing cycle, bool)\r\n    $23=0 (homing dir invert mask:00000000)\r\n    $24=25.000 (homing feed, mm/min)\r\n    $25=500.000 (homing seek, mm/min)\r\n    $26=250 (homing debounce, msec)\r\n    $27=1.000 (homing pull-off, mm)\r\n    $100=80.000 (x, step/mm)\r\n    $101=80.000 (y, step/mm)\r\n    $102=98.522 (z, step/mm)\r\n    $110=500.000 (x max rate, mm/min)\r\n    $111=500.000 (y max rate, mm/min)\r\n    $112=500.000 (z max rate, mm/min)\r\n    $120=100.000 (x accel, mm/sec^2)\r\n    $121=100.000 (y accel, mm/sec^2)\r\n    $122=100.000 (z accel, mm/sec^2)\r\n    $130=300.000 (x max travel, mm)\r\n    $131=360.000 (y max travel, mm)\r\n    $132=140.000 (z max travel, mm)\r\n\r\nOnce homing is run, you can see positioning.\r\n    <Idle,MPos:-1.000,-1.000,-1.005,WPos:-1.000,-1.000,-1.005>\r\n\r\nAny advice?\r\n\r\nJust for sh*ts and gigles, here's my build. I wasn't kidding. Foam core.\r\n\r\n![screen shot 2015-03-20 at 10 23 30 am](https://cloud.githubusercontent.com/assets/547651/6753290/48e159ea-ceeb-11e4-8e6d-b47950dc784b.png)\r\n"},"comment":{"url":"https://api.github.com/repos/grbl/grbl/issues/comments/84052334","html_url":"https://github.com/grbl/grbl/issues/629#issuecomment-84052334","issue_url":"https://api.github.com/repos/grbl/grbl/issues/629","id":84052334,"user":{"login":"chamnit","id":948029,"avatar_url":"https://avatars.githubusercontent.com/u/948029?v=3","gravatar_id":"","url":"https://api.github.com/users/chamnit","html_url":"https://github.com/chamnit","followers_url":"https://api.github.com/users/chamnit/followers","following_url":"https://api.github.com/users/chamnit/following{/other_user}","gists_url":"https://api.github.com/users/chamnit/gists{/gist_id}","starred_url":"https://api.github.com/users/chamnit/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/chamnit/subscriptions","organizations_url":"https://api.github.com/users/chamnit/orgs","repos_url":"https://api.github.com/users/chamnit/repos","events_url":"https://api.github.com/users/chamnit/events{/privacy}","received_events_url":"https://api.github.com/users/chamnit/received_events","type":"User","site_admin":false},"created_at":"2015-03-20T15:43:30Z","updated_at":"2015-03-20T15:43:30Z","body":"@wheniwas19 : First make sure you axes are moving correctly. Type `G91 G0 X1`, such that the X moves 1mm in the positive X direction. On your machine that means the toolhead moves to the right. If it moves left, invert the direction port setting. With `G91 G0 Y1`, your Y gantry should move away from you. \r\n\r\nOnce that is set, the limit switches should be located on the right side of the X-axis and the back side of the Y-axis. If not, invert the homing direction setting for the ones that are setup this way."}}