G29 and M564
-
Hi,
I am using firmware 2.04RC1.
The M208 min/max values of my X & Y axes are set to limit the position of the nozzle to the build surface.
However I can move outside of those limits by 20mm or so even though I cannot print there.
When doing mesh comp probing with G29 I would like to get the Z-probe as close as I can to the min/max values the nozzle can normally reach.
I thought I could use M564 to allow moving outside the normal X & Y axes limits but it doesn't seem to have any effect.
For now I am using M208 to reset the X&Y axes min/max limits during probing and resetting them back to normal when probing is done.
It works fine.
So my question is should M564 work with G29?
Frederick
-
I think the best way to deal with this situation is to use negative values for the axis minima values. So if the 0,0 origin point is the corner of your printer surface, and you can travel 20mm outside of that point, even though you can't print there, your minima would be -20.
That way the slicer commands print moves within the 0,0 envelope, but the firmware understands that your actual travel range extends beyond. This can let the probe reach further, and it keeps your maxima value still equal to the max print volume size.
-
@phaedrux said in G29 and M564:
I think the best way to deal with this situation is to use negative values for the axis minima values. So if the 0,0 origin point is the corner of your printer surface, and you can travel 20mm outside of that point, even though you can't print there, your minima would be -20.
I don't think that would work for me as my 0,0 point is the center of the build surface.
I know I could tell the slicer what my min/max for printing are and it would respect it but I was hoping to have the firmware have the "final say" so nothing could use normal movement commands and move the nozzle outside of the print area. Perhaps that is not really important.
Thanks, Frederick
-
What @Phaedrux wrote applies to center-zero'd printers as well. Just tell the printer it can move a bit further in M208 than you tell your slicer.
-
@oliof said in G29 and M564:
What @Phaedrux wrote applies to center-zero'd printers as well. Just tell the printer it can move a bit further in M208 than you tell your slicer.
Yes I can see how that could work.
Thanks.
Still I would like to understand why M564 doesn't do what it seems it should do in this case.
Frederick
-
I can see why M564 would be limited to user commanded moves. Having an automatic routine able to exit the defined travel bounds could have damaging effects. If it's the user jogging the head manually out of bounds that's one thing.
-
@phaedrux said in G29 and M564:
I can see why M564 would be limited to user commanded moves. Having an automatic routine able to exit the defined travel bounds could have damaging effects. If it's the user jogging the head manually out of bounds that's one thing.
Perhaps M564 is working just as intended. If so perhaps the documentation should mention the circumstances when it comes into play and when it doesn't.
Thanks, Frederick
-
-
M584 applies to moves commanded directly by GCode. It doesn't apply to moves generated automatically by G29.
M208 should reflect the safe motion limits of the machine, including areas outside the bed if they are useful (e.g. because the probe is still within the limits of the bed).
-
@dc42 said in G29 and M564:
M584 applies to moves commanded directly by GCode. It doesn't apply to moves generated automatically by G29.
M208 should reflect the safe motion limits of the machine, including areas outside the bed if they are useful (e.g. because the probe is still within the limits of the bed).
Thanks very much for that info. It's always nice to have confirmation that something is working as intended and that I haven't simply made a mistake on my part.
Frederick