G29 Grid Questions

AdamX

Searching through, this seems to have been discussed before, but I'm not tracking on something.

I've got the following definition for my bltouch, mounted to the right of my nozzle:

M307 H3 A-1 C-1 D-1 ;Disable Heater 3. This is needed to free up the PWM channel for the BLTouch
M558 P9 H5 F750 T3500 ;Define a new probe type
G31 X36 Y-2 Z2.2 P25 ;Define the Location of the BLTouch relative to the nozzle
M557 X2:295 Y15:231 S35 ; Define mesh grid

My printable area is just under 300x230 and my BLTouch sits 36mm to the right of my nozzle.
I've defined M557 of X2:295 as X1 still contacts my limit switch. However, when running G29, I see;

Warning: Skipping grid point (2.0, 50.0) because Z probe cannot reach it
Warning: Skipping grid point (2.0, 85.0) because Z probe cannot reach it

Etc, on again for each time it attempts to probe X2. Now, the probe still actuates at those locations.

I think I understand that G31 defines the probe offset, so my question is whether M557's X/Y coordinate limits are defined relative to the NOZZLE or the PROBE?

Or if I've hosed something else up here, feel free to make me awares

Thanks!

dc42

M557 defines the coordinates you want to probe. Your probe is offset by +36mm from the head reference point, which is the nozzle unless you are using a tool offset, so unless your M208 commands allow the nozzle to move to X= -34mm, then x=2mm is not reachable by the probe.

Phaedrux

@adamx said in G29 Grid Questions:

M557 X2:295

Use M557 X36:295

AdamX

So, in short, the dimension constraints passed in M557 are relative to the probe? Not sure where an M208 factors in here?

Phaedrux

I think of it as m208 is where the nozzle can get to and m557 is where the probe can get to.