SLB Trinamic Homing Seek Rates

With the SLB and gSender 1.4.7, I was wondering if the newer Trinamic-specific homing rates ($180-$193) were active?

On my MilkCr8 (Linear rails, lead screws and NEMA 17 motors) I occasionally have stalls when homing Z. Problem seems to go away after some movement – almost as if “warming up” helped ease the issue. Today I disconnected the lead-not and once again confirmed that the movement up and down the rails was smooth – but it reminded me that my Z assembly (aluminum plates and RoutER11) is pretty dang heavy.

Reading through the enhanced grblHAL configuration – I was jazzed to see axis-specific homing seek rates. I set my Z-axis rate ($192) particularly low (300mm/min), but when homing Z, it seemed the rate of movement wasn’t any slower than the rate listed in $25 (2000 mm/min)

Curious if I’m missing some other flag to activate those settings or if I’m missing something else.

I’ve also uploaded current settings.
gSender-firmware-settings-5_29_2024-9 00 37 PM.json (2.8 KB)

Thanks for any guidance!


I did more testing and yes, it seems that $25 is being used for homing X, Y, and Z, and the $190-$192 rates are being ignored, even though the output of M122 seems to inply that Trinamic driver are in effect.

Am I missing something?

client M122
                      X       Y       Z      Y2
Driver          TMC2660 TMC2660 TMC2660 TMC2660
Set current         630     630     525     630
RMS current         423     423     353     423
Peak current        598     598     499     598
Run current        5/31    5/31    4/31    5/31
Hold current      15/31   15/31   12/31   15/31
Global scaler     0/256   0/256   0/256
CS actual          5/31    5/31    4/31    5/31
PWM scale             0       0       0       0
vsense          1=0.180 1=0.180 1=0.180 1=0.180
stealthChop        true    true    true    true
msteps               32      32      32      32
tstep                 0       0       0       0
threshold             0       0       0       0
[mm/s]                0       0       0       0
OT prewarn        false   false   false   false
OT prewarn has
been triggered    false   false   false   false
off time              1       1       1       1
blank time            1       1       1       1
-end                  5       5       5       5
-start                3       3       3       3

I believe those per-axis rates do not (currently) apply to the TMC2660, they just appear whenever the Trinamic subsystem is activated.

@JohnOCFII, to my knowledge it’s possible that the values might not be getting factored in which I realize is inherently self-defeating so I’ll have to loop back around to seeing if something’s been missed and we could get to work testing a new firmware version internally

Thanks Chris and thanks Drew. For now, I’ve lowered my $25 homing to a speed my Z axis can handle, and will continue to move forward with commissioning. If the separate per-axis homing rates can be activated at some time in the future, that’d be great!


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