Hi everyone, hoping for some guidance on finalizing how I am using GRBL to run tool paths (from Fusion 360) using UGS… Here’s a pic my machine - the whiteboard was done using manual Gcode commands with a marker mounted. The whole things is still WIP, but I’m now trying to cut air to confirm all is functioning properly.
I think part of the challenge is simply familiarity with typical/proper operating, process even after many YouTube videos…
This picture was taken after homing. Y is far left, and X is close to camera. Z is homing up high. The home switches are installed and the machine homes to all 3 fine. But… in this position, UGS will indicate that the Machine Position is at the negative soft limits. My travel limits in GRBL are (X=500, Y=900, Z=100). So in the home position, my Machine Position is (-498, -898, -98). So all Axis move in a positive direction from home, but from a negative number… Does not seem correct. Thoughts?
But,… when I begin to run a Gcode file, all 3 Axis move diagonally to the opposite side from Home before as the program begins… So effectively the machine went from Homing to a Machine Position of full negative limits on each axis (-498, -898, -98) to starting the job from a Machine Position of (0,0,0). Am I using the UGS “Reset Zero” correctly? Should I flip the operation of my steppers motors? Should I being setting some other Work Coordinate System as well as adding a line of Gcode to my file to tell it to go to that working coordinate space to begin?
And finally, the Axis of my machine are (partly?) inverted. Definitely my Z Axis is moving down the the bottom of the work surface that then ‘machining upwards’, raising upwards to cut. It seems like my X Axis is a mirror image too, but maybe my Y Axis is not… All are wiring the same. Feels like I should flip the motor coils, but I am not sure what that will do to my Homing. Maybe I need to flip the coils and also flip the GRBL Home direction setting?
And finally what is the most common practice for aligning the origin of the CAD model in Fusion360 for example, relative to the stock as it is placed within the physical machine?
I am sure with a bit of experience with it working the right way, it will all make sense. But for now, the combination of these things all not quite right, make it difficult to pinpoint what needs fixing. Thanks for any guidance!!