homing position

Hello guys..

The original board that came with the tevo burned, and I replaced it with this board (mks gen 1.4)
and I don't know this proplem is reltiv with the homing that I'm facing!!!
If I do home all
the X well home good
the Y home good..
But the Z will not home at the centre of the bed !!!
Also when I do bed leveling, it seems that the printer don't know the dimension of the bed, the X and Y maximum will keep on going until it hets the boundary of the printer frame!!!

youtube video
[www.youtube.com]

Thanks

What firmware are you Using.

"But the Z will not home at the centre of the bed !!!"
and it never will it aint meant too. in firmware "marlin" you can set the center and how far to travel after homing if you using marlin look for these lines in config.h line 721 "they're abouts"

// Travel limits after homing (units are in mm)
#define X_MIN_POS 0
#define Y_MIN_POS 0
#define Z_MIN_POS 0
#define X_MAX_POS 180
#define Y_MAX_POS 180
#define Z_MAX_POS 150

setting the bed center can be done in either F/W or slicer, again in marlin @ line 865
// @section homing

// The center of the bed is at (X=0, Y=0)
//#define BED_CENTER_AT_0_0

Quote
jinx
"But the Z will not home at the centre of the bed !!!"
and it never will it aint meant too. in firmware "marlin" you can set the center and how far to travel after homing if you using marlin look for these lines in config.h line 721 "they're abouts"

"Yea!!!
Technically speaking you have to travel to center of bed after homing like this"
//Home to the center of the bed - P.P.
#define Z_SAFE_HOMING

//PJP - allows for homing in the middle of the build plate
#if ENABLED(Z_SAFE_HOMING)
#define Z_SAFE_HOMING_X_POINT (((X_MIN_POS + X_MAX_POS) / 2) + X_PROBE_OFFSET_FROM_EXTRUDER) // X point for Z homing when homing all axis (G28).
#define Z_SAFE_HOMING_Y_POINT (((Y_MIN_POS + Y_MAX_POS) / 2) + Y_PROBE_OFFSET_FROM_EXTRUDER) // Y point for Z homing when homing all axis (G28).
#endif

Edited 1 time(s). Last edit at 07/12/2017 07:33AM by Roberts_Clif.

OOO I stand corrected you can lower the Z in the center but first XY needs homing. good old Tomas [www.youtube.com]
now jinx lowers head walks of to the corner!! orders his probe

Then you can set the Z Height.

// @section homing

#define Z_HOMING_HEIGHT 4 // (in mm) Minimal z height before homing (G28) for Z clearance above the bed, clamps, ...
// Be sure you have this distance over your Z_MAX_POS in case.