docs: Note PROBE_CALIBRATE results invalidated on motion system update

Any hardware change to the hotend or probe, change to the kinematics,
or change to the bed tilt is likely to invalidate the results of
PROBE_CALIBRATE.  Try to warn the user of that.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
This commit is contained in:
Kevin O'Connor 2020-10-17 19:36:45 -04:00
parent f8cb1e30eb
commit 1b471b482d
3 changed files with 40 additions and 0 deletions

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@ -30,6 +30,13 @@ automatic probe has a bias of more than 25 microns (.025mm) then use
manual probing instead. Manual probing only takes a few minutes and it manual probing instead. Manual probing only takes a few minutes and it
eliminates error introduced by the probe. eliminates error introduced by the probe.
If using a probe that is mounted on the side of the hotend (that is,
it has an X or Y offset) then note that performing delta calibration
will invalidate the results of probe calibration. These types of
probes are rarely suitable for use on a delta (because minor effector
tilt will result in a probe location bias). If using the probe anyway,
then be sure to rerun probe calibration after any delta calibration.
Basic delta calibration Basic delta calibration
======================= =======================
@ -228,3 +235,15 @@ Additional notes
errors elsewhere in the hardware. For example, small differences in errors elsewhere in the hardware. For example, small differences in
arm length may result in a tilt to the effector and some of that arm length may result in a tilt to the effector and some of that
tilt may be accounted for by adjusting the arm length parameters. tilt may be accounted for by adjusting the arm length parameters.
Using Bed Mesh on a Delta
=========================
It is possible to use [bed mesh](Bed_Mesh.md) on a delta. However, it
is important to obtain good delta calibration prior to enabling a bed
mesh. Running bed mesh with poor delta calibration will result in
confusing and poor results.
Note that performing delta calibration will invalidate any previously
obtained bed mesh. After performing a new delta calibration be sure to
rerun BED_MESH_CALIBRATE.

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@ -185,3 +185,9 @@ This means that:
Repeat the process several times until you get a good level bed - Repeat the process several times until you get a good level bed -
normally when all adjustments are below 6 minutes. normally when all adjustments are below 6 minutes.
If using a probe that is mounted on the side of the hotend (that is,
it has an X or Y offset) then note that adjusting the bed tilt will
invalidate any previous probe calibration that was performed with a
tilted bed. Be sure to run [probe calibration](Probe_Calibrate.md)
after the bed screws have been adjusted.

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@ -70,6 +70,21 @@ results to the config file with:
SAVE_CONFIG SAVE_CONFIG
``` ```
Note that if a change is made to the printer's motion system, hotend
position, or probe location then it will invalidate the results of
PROBE_CALIBRATE.
If the probe has an X or Y offset and the bed tilt is changed (eg, by
adjusting bed screws, running DELTA_CALIBRATE, running Z_TILT_ADJUST,
running QUAD_GANTRY_LEVEL, or similar) then it will invalidate the
results of PROBE_CALIBRATE. After making any of the above adjustments
it will be necessary to run PROBE_CALIBRATE again.
If the results of PROBE_CALIBRATE are invalidated, then any previous
[bed mesh](Bed_Mesh.md) results that were obtained using the probe are
also invalidated - it will be necessary to rerun BED_MESH_CALIBRATE
after recalibrating the probe.
# Repeatability check # Repeatability check
After calibrating the probe X, Y, and Z offsets it is a good idea to After calibrating the probe X, Y, and Z offsets it is a good idea to