G28 w/ABL diagonal movement too fast

I've been struggling trying to find the bit of code inside Marlin that effects the speed of the X/Y movement from X0 Y0 to bed center when running G28. I have an ABL sensor installed and working fairly well, but the diagonal movement to the center of the bed is occurring way too fast and causes my Y-steppers to skip every time (maybe X too, but tough to tell). I have tried changing just about every part of the code that I could find that seemed like it might make a difference, but no dice! While it may not be the best illustration, I have a video of the issue here: [goo.gl]

This is more or less the copy of Marlin I am using: [bitbucket.org]

Does anybody have any definitive answers to how I might go about slowing that one movement down?

Thanks in advance!!

Edited 3 time(s). Last edit at 11/25/2016 03:04PM by nonaym.

In RCBugFix:

// X and Y axis travel speed (mm/m) between probes
#define XY_PROBE_SPEED 8000

or it could be these lines:

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

Thanks stephenrc,

I did already try adjusting the "HOMING_FEEDRATES," but these only seem to effect the initial X homing action and the Y homing action (moving X/Y both to 0). And changing the Z "HOMING_FEEDRATE" only seems to effect the Z movement after the problematic diagonal movement. The actual diagonal movement speed remains unaffected (still too fast!)... this is why I am so lost, because all the speed settings I can find are ignored by this one travel movement.

I'll have to research the RCBugFix section you mentioned, as the version of Marlin I am using does not have the "XY_PROBE_SPEED" variable. From the way it looks, this is the same as the "XY_TRAVEL_SPEED" from previous versions which only effects the movements that occur after running a G29 (i.e. ABL procedure).

Edited 3 time(s). Last edit at 11/25/2016 03:46PM by nonaym.

nonaym,

did you actually find a solution to that problem?
I'm stuck exactly at the same point.

Cheers

mosci.to

Quote
mosci.to
nonaym,

did you actually find a solution to that problem?
I'm stuck exactly at the same point.

Cheers

mosci.to

I am now using an updated Marlin firmware from the printer manufacturer (Type A Machines) that seems to have eliminated the issue... BUT, before trying their latest firmware I do believe that I resolved this issue by changing the following line in Configuration.h in Marlin from:

#define DEFAULT_MAX_FEEDRATE {500, 500, 12.5, 500}

to:

#define DEFAULT_MAX_FEEDRATE {500, 250, 12.5, 500}

This seemed to slow the movement down enough to prevent the skipping I was experiencing, without causing any negative side-effects.

I hope this helps!

Edited 3 time(s). Last edit at 06/05/2017 08:41PM by nonaym.