Mesh Outside of Limits

tfjield

Any reason to why G29 doesn't obey M564?

fcwilt

@tfjield said in Mesh Outside of Limits:

Any reason to why G29 doesn't obey M564?

What do you mean?

You can use M564 but then you have no limits at all.

Safer to have two sets of limits.

Frederick

engikeneer

@tfjield if you want to avoid lots of variables, you can create 2 macros, one that sets the limits for normal use and one that sets them for probing. Then just call the normal one from config and again at the end if mesh.g (assuming you're using that). I do something similar to change acceleration, jerk and other things for homing and probing

tfjield

@fcwilt
It doesn't actually work. It tells me the z probe can't reach the coordinates specified.

fcwilt

@tfjield said in Mesh Outside of Limits:

@fcwilt
It doesn't actually work. It tells me the z probe can't reach the coordinates specified.

That is surprising. I never tried because I prefer the safer approach to two sets of limits.

What version of firmware are you using?

Frederick

tfjield

@fcwilt And true regarding the two sets of limits. But G30 doesn't have limits... It surprised me that G29 does. In both cases, it would probably be safer to require limits to be turned off via M564 before each of them if they aren't wanted.

tfjield

@fcwilt I'm on 3.4.1.

fcwilt

@tfjield said in Mesh Outside of Limits:

@fcwilt And true regarding the two sets of limits. But G30 doesn't have limits... It surprised me that G29 does. In both cases, it would probably be safer to require limits to be turned off via M564 before each of them if they aren't wanted.

Why would you think it's safer.

Having two sets of limits prevents you from inadvertently specifying a location (for G29 or G30) that results in hitting the end of an axis.

Frederick

tfjield

@fcwilt Sorry, I wasn't clear. I meant it would be safer for G30 to obey the limits by default and only be allowed to exceed them if the limits were manually turned off, first.

fcwilt

@tfjield said in Mesh Outside of Limits:

@fcwilt Sorry, I wasn't clear. I meant it would be safer for G30 to obey the limits by default and only be allowed to exceed them if the limits were manually turned off, first.

Are you perhaps being confused by G30 sometimes taking the probe offset into account whereas G29 never does?

Frederick

tfjield

@fcwilt Maybe! lol. What I mean is that with G30, I can probe wherever I want. The axes limits are not obeyed. Meaning if I set a location for the probe that will move the printhead beyond the limits, it will just do it. (This behavior is warned about in the documentation.) With G29, if such a move would require the printhead to move out of limits, it gives an error. (And trying to avoid the error by using M564 S0 doesn't work. ) And like I said, it surprises me that exceeding the limits is explicitly allowed by G30, but not by G29.

tfjield

@fcwilt But really, at this point it's just a curiosity and I'm working around it.

fcwilt

@tfjield

Now that you mention it I do remember reading about that.

But I tend to be OC and insure any G30 probing points are valid so perhaps that is why I never noticed that behavior.

Frederick

tfjield

@fcwilt I think that's a good approach. I'm still figuring this out and working through Modix' existing macros, so I haven't gotten to the point yet where I will stop and take a top-down approach to configuring everything. Right now I'm bouncing around a bit as I'm getting a better understanding of what's going on...

fcwilt

@tfjield

Here is a snippet of code showing how to have two sets of limits

if exists(param.E) ; E for expanded
  M208 Xmin:max Ymin:max ; values for expanded limits
else
  M208 Xmin:max Ymin:max ; values for normal limits

Put code that into a .G file in the SYS folder and invoke it with M92 P"some_file_name.g" with or without the E parameter as desired.

Frederick