Topics created by Nightreaver

@nightreaver said in Bltouch offset resetting:

G31 X2 Y57 Z2.155 ; Set Z probe trigger value, offset and trigger height

Your G31 is missing a trigger value (P). For BLTouch add P25.

You can also send G31 by itself at any time to get a read back of what the firmware has configured so you can check if it's actually getting reset somewhere or not.

https://duet3d.dozuki.com/Wiki/Gcode?revisionid=HEAD#Section_G31_Set_or_Report_Current_Probe_status

M558 T250 is a very slow travel speed between probe points. 2mm/s basically. T6000 would be more bearable.

Can you send M98 P"config.g" to check for any syntax errors?

At the start of your homez you may want to add M561 as well to make sure any compensation is removed before homing Z. This may be the cause of the issue you're seeing and not the offset actually being changed.

@Nightreaver said in Improvement to M558 (Bed Temperature Threshold):

H6

6mm is quite high dive height for the BLtouch. Reducing the dive height to be just above the trigger height would reduce the amount of time spent probing and the heater will be off for less time. Try H3.

@Nightreaver You just need a switch which triggers near the top position of the bed but allows the bed to rise further, keeping the switch triggered. In homez.g, you use the switch for a first (and fast) approximation, then, you move over to the Z-probe. I’ve exactly done that with my cartesian and am very happy with this solution. It’s all in homez.g, so that macro has to be invoked whenever Z is to be homed. Here’s my homez.g - for your CoreXY, you just have to think Z upside down. And, as I don’t use a BLTouch, you will have to adjust the corresponding Gcodes accordingly.

; Home the Z-axis ; Z homing happens in 3 steps: ; 1. Move down until the Z switch triggers (if already at or below this level, this is a NOP). ; 2. Move up until we are well above the trigger level, then go down until the switch triggers. ; This move sets Z to a well defined level above the bed (well, it's not really that precise). ; 3. Slowly step down to the bed surface using the analog probe. ; This approach ensures that we do not exceed the top end of the Z axis, which might happen if the ; print head was moved up before to get it out of the way. In our second step, we reach a well defined ; height. Then, we lower the distance to the bed and deploy the probe to perform the final adjustment. M400 ; wait until all moves are finished G91 ; relative mode M574 Z1 S1 ; Z axis uses switch G1 H1 Z-400 F6000 ; move Z down (if switch is not triggered) until the switch triggers G1 H2 Z20 F6000 ; raise head 20 mm to ensure it is above the trigger level G1 H1 Z-25 F500 ; move Z down slowly until the switch triggers G92 Z10 ; say this height is 10 mm above a provisional 0 G90 ; back to absolute mode M564 S0 ; unlimit axes G1 X0 Y-10 Z0 F10000 ; put head over the center of the bed (Note: compensate for probe Y offset) M400 ; wait until all moves are finished ; set up the Z probe: M574 Z1 S2 ; Z axis uses probe M558 P1 F400 T10000 H4 A9 S0.004 R0.0 ; mode 1 (analog in), F=probing speed, T=travel speed, H=dive height ; A=repetitions, S=tolerance, R=recovery time G31 T1 P500 X0 Y9 Z2.20 ; configure probe physics; P=trigger value, Z=probe offset G30 ; run probe, stop when probe triggers and set Z to trigger height M564 H1 S1 ; limit the axes

@jaurand The was one of my Ideas, as the pattern seem to be repeating. I will check my wheels