IR Probe auto leveling (bed matrix)

jamesarm97

I have the IR Probe setup and have my homez and homeall configured and that seems to work. I have 5 bed probe points setup (4 corners and the center). I run the auto bed compensation routine and it probes all the points and I get the matrix and offsets. I am seeing error messages when I print and know they are related to the bed compensation but don't know what is wrong. Is my bed data out of tolerances? Do the probe points need to be in a certain order? Here is what I get:

After running the probe script:
< 9:31:04 PM: Z probe offsets: -0.011 -0.134 0.006 0.072 -0.194, mean -0.052, deviation from mean 0.097

Debug before a print:
Bed equation fits points [250.0, 280.0, -0.011] [250.0, 30.0, -0.134] [120.0, 160.0, 0.006] [0.0, 30.0, 0.072] [0.0, 280.0, -0.194]

and error messages streaming while trying to print:
Triangle interpolation: point outside all triangles!

Do I need to disable bed compensation before homing then re-enable during print? I see the triangulation errors during any homing attempt after the first homing.

dc42

You need to define the first 4 probe points in a clockwise direction around the bed starting near the corner X=0 Y=0.

jamesarm97

Ok, can or do I need to do a 5th in the center or just the 4 corners?

dc42

That's up to you. If the bed is flat and the X carriage doesn't sag significantly near the middle, then 4 points is enough.

deckingman

Try this
M561
G30 P0 X15 Y30 H0 Z-99999
G30 P1 X15 Y160 H0 Z-99999
G30 P2 X190 Y160 H0 Z-99999
G30 P3 X190 Y30 H0 Z-99999
G30 P4 X100 Y100 H0 Z-99999 S

Edit - you don't need the G1 commands

Sparks

I am getting the same error "Triangle interpolation: point outside all triangles!".

My probe is 62mm from the right nozzle, my script for bed.g is below… any suggestions?

M561 ; clear any existing bed transform
G30 P0 X152 Y34 Z-99999 ; define 4 points in a clockwise direction around the bed, starting near (0,0)
G30 P1 X152 Y184 Z-99999
G30 P2 X392 Y184 Z-99999
G30 P3 X392 Y34 Z-99999
G30 P4 X272 Y104 Z-99999 S0 ; finally probe bed centre, and calculate compensation
;G1 X40 Y40 F5000 ; move the head to the corner (optional)

dc42

Ignore that message about triangle interpolation, if it only happens during homing then it's harmless. I have it on my list to fix that message..

Sparks

Dave do the values get saved to firmware? Also are they aggregated? I have noticed that after completing ABL if I move the head around I dont see any compensation on the Z azis screws…?

dc42

The values are saved, but will be lost when you reboot or run M561. After bed probing has completed successfully and the firmware has reported the bed equation, you should see the Z axis move a little when you move the head around.

Sparks

Thanks Dave, works fine if I do after powerup.