Z dive - Different dive speeds?

pro3d

Is it possible to have one fast dive speed (Z homing) and secondary pass slower?

dc42

@pro3d said in Z dive - Different dive speeds?:

Is it possible to have one fast dive speed (Z homing) and secondary pass slower?

Only if you use M558 to change the speed between passes. So it's practical when homing using the Z probe, but not for more general bed probing.

pro3d

@dc42
Is there some examples of how to do this?

resam

I am using this in my homez.g:

...
M558 P4 H3 F400 T7000     ; Use E0_STOP as inductive-NPN probe, fast
G30                       ; find Z
M558 P4 H3 F50 T7000 A3   ; Use E0_STOP as inductive-NPN probe, slow, multi-probe
G30                       ; find Z again
...

Look at the different F and A parameters in the second probing.

pro3d

@resam
Thanks. Does this mean you probe 1 fast and 3 slow with this code?

resam

Yes. I have a CoreXY with the bed moving up and down.
I home Z fast to move the bed up quickly - without caring about accuracy.
Then I home again, slowly, with multi-probing to average the probe points.

pro3d

@resam
Nice this is what I want. It goes so slow from bottom up now.

But does the multi probing A3 take a average and use this as Z0? I thought it used last probe of the 3

Phaedrux

@pro3d it means it will probe up to 3 times and at least twice until each probe is within the repeatability range you can set in m558

resam

https://duet3d.dozuki.com/Wiki/Gcode#Section_M558_Set_Z_probe_type says:

The A and S parameters control multiple probing. Probing is repeated until two consecutive probe attempts produce results that differ by no more than the S parameter; then the average of those two results is used. However, if the number of attempts specified by the A parameter is reached without getting two consecutive results within tolerance of each other, no further probe attempts are made and the average result of all the attempts is used.