Searched the forum and saw some similar issues, but was unable to parse the solutions. Feel free to poke fun at me, as you tell me how to fix this.
30 month old Shapeoko 3 XL with some miles on it. I flashed to grbl 1.1 this afternoon. When I start the homing cycle in CM4, the z-axis drives DOWN and it errors out.
I followed the procedure – I think – of sending the default XL configuration files (nothing happen on the screen after selecting “XL” from the drop down and clicking the >send< button).
I recall that this machine had a reversed Z when it was new, and that I had to modify some code through the MDI.
When I failed to find that procedure written out in simple language here, I thought I might ask for help. So “help please?”
While Luke’s analysis and fix are good, I would recommend instead also checking the machine mechanically and electronically.
The Z-axis can be reversed by having the Z-axis spindle carriage plate on upside down (the static pulley should be on the left when viewed from the front of the machine), in addition to being mis/re-wired as noted, or reversed in software.
If an axis is running backwards, due to being miswired it’s easily addressed — all wiring extensions should be straight through, and all wiring connectors should be consistent, stepper motors may be reversed in several ways:
swap the left and right pair of wires
reverse the ordering of the wires in the left or the right pair
Most likely this was previously fixed in software (early on, support used to recommend that, mea culpa), and the fix was undone when the defaults were sent as part of the update, which is why fixing this by altering the defaults is a bad idea.
Thanks – think I’ve got it sorted (so far). I must have more than one thing mechanically/electrically reversed-- which is weird, because I am pretty sure I only had to invert the z-axis when I built it.
Sent the S3 XL defaults from settings again. Z-axiz still reversed.
Entered /$3=2 z-axis still reversed.
Entered /$3=0 z-axis drove up to the limit switch, at which point it appeared that both the y-axis and x axis were reversed
I powered everything off, and powered it all back on. It still homes. I am satisfied that it is fixed, but I am puzzled. I ask again, how do I check the configuration?