When I home my machine (Blackbox X32, Control) it works fine, but the machine coordinates are set to X-995, Y-995, Z-5. Can someone explain where these numbers come from? It does the homing sequence, then backs off the switches by 5mm in each direction. Why aren't the machine coordinates at X5, Y5, Z-5. If the switches are zero, that seems like the logical machine coordinates to be at. I'm hoping it's just a setting somewhere that I can't find. =)
BTW, I understand that it doesn't really matter what those numbers are as long as the G54-G59 WCSs are set relative to those numbers and homing is consistent. Just want to understand what's happening - crashes are a bummer and tend to happen when I don't really know what's going on.
Machine coordinate origin is always top/back/right (for a moving gantry machine) All machine coordinates are negative relative to this. I'm guessing your machine is set to home at the front / left and has 1000mm nominal travel, so that point will be X=-1000, Y=-1000 in machine coordinates. Since the machine backs off the switches by 5mm, it sits at X=-995, Y=-995 after the homing operation.
Thanks! So it is doing what it's supposed to. My machine doesn't have that much travel though - do you know where I set that? I've poked around and don't see that.
$130, $131,$132 - X, Y & Z max dimensions. Alex. PS you will find this link useful - https://github.com/gnea/grbl/blob/master/doc/markdown/settings.md
Thank you! That's super helpful! I think some/many of these are exposed in Control's advanced settings (?), but I don't remember seeing $130, $131, $132. Oh, and you guessed right - my home position is front/left/up.