I've been looking into this and cannot understand just how to put GRBL 1.1 into positive space. (xPro board.) Can anyone help me out with what the settings should be, or what gcode to run?
why do you want to do that? there really is no need, the standard is that home is x-right, Y-away, z-up and the operator then uses work coordinates for the job, and the JOB is in positive space for the WORK 0,0,0 (or a mix of pos and neg if the work 0,0 is in the middle of the workpeice) just put your machine at machine 0,0,0 manually and then power on (assuming you have no homing switches) now use your GUI of choice to jog to where the work 0,0,0 is and press your GUI's 'set 0 here' button. (this will default to setting G54 work coordinates or G91 offsets depending on the GUI, I prefer real G54-59 offsets over G91) at no time in the above process did you have to know or understand the negative co-ordinates, they do not matter to you but GRBL understands perfectly. now before you turn the machine off you just need to return to machine 0,0,0 and it will be ready for next time. some GUI's have a button for this, some allow you to program a macro button for it. the macro you want is Code: G53 G0 Z0 G53 G0 X0 Y0 which first raises Z to its highest point and then moves to X0Y0 G53 tells GRBL to use the machine coordinates and has to be on each line because it is not remembered.
But you can put home easily anywhere you want, like front / left and then it's positive workspace.. not that it matters one bit..
apart from software like GRBL making assumptions about where home is the importance of constancy cannot be overstressed. in other words, if you are going to put home in a non standard place, make sure you always have in in the SAME place. why? so that you do not break tools or injure yourself. picture this... the tool is in the middle of the machine at the end of a job and you turn it off. tomorrow you turn it on, this is now the home position, MCS 0,0,0. you set the WCS to front left for a large job. at the end of the job the tool is left 1/3 of the way across the bed. so neither at home (MCS) nor at WCS 0,0,0. and you turn it off. next week you turn it on to run the same job again and forget to set WCS (maybe assuming it is correct because it is the same job). WCS0,0,0 is now off in space , off the bed (by the difference between 1/2 the bed and 1/3 the bed)! so, you fire up the Gcode and it issues a G0 X0 Y0 and the tool runs straight into a clamp and then the gantry hits the end stop and you need a cup of tea to calm down after the chaos. this can all be prevented by being consistent about where home is. my OX has no limit or home switches but I do this everytime.... 1 - I always turn on with the gantry at rear right, with Z up at the top. 2 - in bCNC I have set a macro button to 'go to MCS' that does this: G53 G0 Z0 G53 G0 X0 Y0 this raises the tool and then moves off to the right rear corner, to MCS 0,0,0. then I turn off. 3 - next day/next week before turning on I just push the gantry back and right against the stops (and Z at the top), then turn on. now, the WCS that GRBL remembered is still valid and there are no surprises, tool is at safe height. If I have a power failure in the middle of a job resetting is as simple as winding Z up, push back and right against the stops, and reset the GRBL board. goto WCS and restart the job, no problems. If I had started 'anywhere' then this would not work, I would have to re-find the WCS very carefully. Do I ever have to think about negative numbers? NO. power on, jog to where I need the work to be and set zero for X Y and Z. Have not yet looked at any numbers at all! In short, the standard works well in many ways: it prevents surprise moves/crashes it moves Z to a safe height with a simple command 'G53 G0 Z0' it moves the gantry nicely out of the way for loading material. it gives a consistent way to go to a tool change position, something like set G56 WCS to where I want to change tools then G53 G0 Z0 G56 G0 X0 Y0 G54will always put the machine at a good place for toolchange. I should make a macro for that (-: MCS = Machine Coordinate System, where the machine believes home is. WCS = Work Coordinate System, where the work home is.
XPro v3 not connecting- It is my understanding that the xPro v3 controller comes with the latest stable version of Grbl pre-installed. When I to connect (via COM3) to the board using Grbl Panel, it appears to be connected. However, no numbers appear in the axis boxes (see Screenshot 1). When I select the Settings tab, no Grbl version appears ( see Screenshot 2). Clicking "Get Grbl Settings" produces no information. Do I need to re-install Grbl to the xPro or am I missing a step? Screenshot 1 Screenshot 2
Have you tried changing the Baudrate? It's hard to tell from your screen shot but it looks like 9600. I use Laserweb to connect to my xpro and use 115200 as the Baudrate.
@bubba I thought that was checked right off, but guess not. I appreciate your help. That was an easy fix. LOL
