Unable to implement fast/slow probing on 1.1.9

Hello everyone,

I have an i3 clone with a RAMPS 1.4/2560 combo running Marlin. I've been humming along running 1.1.8 for some time, and decided to reflash to 1.1.9 to test out the new linear advance algorithm. I copied every setting over that I could identify (I had previously gone from the stock firmware to 1.1.8, so I was semi-familiar with what settings needed to be configured.

Here's my issue: when doing a G28, the axes all home, but the first and second home for each axis is done at the same (fast) speed. Here are all my setting that I can find that relate to homing:

HOMING_BUMP_DIVISOR { 2, 2, 4 }
// X and Y axis travel speed (mm/m) between probes
#define XY_PROBE_SPEED 8000

// Feedrate (mm/m) for the first approach when double-probing (MULTIPLE_PROBING == 2)
#define Z_PROBE_SPEED_FAST HOMING_FEEDRATE_Z

// Feedrate (mm/m) for the "accurate" probe of each point
#define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 2)

#define Z_SAFE_HOMING

#if ENABLED(Z_SAFE_HOMING)
#define Z_SAFE_HOMING_X_POINT ((X_BED_SIZE) / 2) // X point for Z homing when homing all axes (G28).
#define Z_SAFE_HOMING_Y_POINT ((Y_BED_SIZE) / 2) // Y point for Z homing when homing all axes (G28).
#endif

// Homing speeds (mm/m)
#define HOMING_FEEDRATE_XY (50*60)
#define HOMING_FEEDRATE_Z (4*60)

#define MULTIPLE_PROBING 2

Enabling "#define MULTIPLE_PROBING 2" with values equal to or greater than two has zero effect. It makes me think that something is overriding these settings, but I can't find anything else in the Configuration or Configuration_adv tabs that look like they would have an affect.

Any suggestions?

#define HOMING_FEEDRATE_Z (4*60)

i think 4*60 is too fast for most I3 clones

try changing the 4 to a 2 so 2*60

Edited 1 time(s). Last edit at 01/16/2019 05:42PM by obewan.

Thanks for the suggestion. The weird thing is that HOMING_FEEDRATE_Z was set to (4*60) when I was running version 1.1.7. When running that version, it would home the z axis twice, with the second one at the slower speed. (BTW< did you mean that 4*60 is too fast for i3 clones?)

I forgot to mention that I'm using a BLTouch for my z probe. Is there some other setting being used instead of the obvious ones that I posted above?

Yesterday I changed #define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 2) to #define Z_PROBE_SPEED_SLOW (Z_PROBE_SPEED_FAST / 20), and did observe a significant reduction in the second probe speed (on par with molasses). Also, when I enabled MULTIPLE_PROBING, with values greater than 2, nothing changed. It still only probed all axes twice at the fast speed. However, multiple probes were done on z when I ran a G29 (albeit all at the fast speed).

Edited 1 time(s). Last edit at 01/16/2019 09:42AM by letthewookiewin7.

Quote
BTW< did you mean that 4*60 is too fast for i3 clones?)

Yes, sorry for the typo.

Anyone else have other suggestions on what might be the issue?