@dc42 we only use one motor for Z-axis.
@fcwilt yes, the ones with the arm attached to the micro switch.
I hope the beam brake will work... it should be compatible.

We are using mechanic switches with a push bar.
I've ordered a bem break now to try if its working better.
@fcwilt

@dc42 yes we had already ...second hit is really slowmo but it doesn't help.

Now we can home the Z Axis twice thats good!

But everytime we home Z Axis (doesn´t matter if at Z max oder Z min) we have a difference of 0,2 to 0,5 mm between nozzle and bed. Maybe the difference is caused by hitting the endstop a little bit different every time we home the Z-Axis. Do you have any idea how we can fix this problem?

@fcwilt
Because we thought that it is not possible to print the first layer while the endstop is triggered.
Now we try to home Z at Z max. If this makes to much problems we want to change the endstop position to Z min.

@dc42 exactly, that´s right!

@dc42 we will change M574 command!

Our bed is moving and the gantry is fixed in z (only moving x/y).

@dc42
you have an idea?

; Configuration file for Duet WiFi (firmware version 1.21)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Jan 15 2019 15:02:01 GMT+0100 (Mitteleuropäische Zeit)

; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves

M667 S1 ; Select CoreXY mode

; Network
M550 P"My Printer" ; Set machine name
M552 S1 ; Enable network
M587 S"Faurecia" P"1234abcd" ; Configure access point. You can delete this line once connected
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Drives
M569 P0 S0 ; Drive 0 goes backwards
M569 P1 S0 ; Drive 1 goes backwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes Forwards
M569 P6 S0 T5:5:10:0
M584 X0 Y1 Z6 E3 ; Apply custom drive mapping
M350 X64 Y64 Z1 E32 I0 ; Configure microstepping without Interpolation
M92 X320.00 Y320.00 Z2133.333 E820.00 ; Set steps per mm
M566 X900.00 Y900.00 Z300 E300.00 ; Set maximum instantaneous speed changes (mm/min)
M203 X24000.00 Y24000.00 Z800 E3600.00 ; Set maximum speeds (mm/min)
M201 X5000.00 Y5000.00 Z50 E250.00 ; Set accelerations (mm/s^2)
M906 X2200.00 Y2200.00 Z800.00 E2000.00 I30 ; Set motor currents (mA) and motor idle factor in per cent
;M84 S30 ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X390 Y490 Z516.10 S0 ; Set axis maxima

; Endstops
M574 Y2 S0 ; Set active low and disabled endstops
M574 X2 Z1 S1 ; Set active high endstops

; Z-Probe
M558 P0 H0 F2000 T12000 ; Disable Z probe but set dive height, probe speed and travel speed
M557 X15:0 Y15:195 S20 ; Define mesh grid

; Heaters3
M307 H0 B0 S1.00 ; Disable bang-bang mode for the bed heater and set PWM Limit
M307 H1 A927.1 C134.5 D5.9 S0.3 B0
M305 P0 T100000 B4138 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4138 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C

; Fans
M106 P0 S0 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off

; Tools
M563 P0 D0 H1 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

; Automatic saving after power loss is not enabled

; Custom settings are not configured

; Miscellaneous
T0 ; Select first tool

Hello guys,

The X & Y Axis can be homed in two steps. First it hits the endstop fast then it goes a few mm back and hits the endstop again while driving slower. This works perfectly with my Printer.

But how can I programm the Z-Axis to do the same? At the moment it just hits the endstop and stops without turning back etc.

Thanks for your help!

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Jan 15 2019 15:02:03 GMT+0100 (Mitteleuropäische Zeit)
G91 ; relative positioning
G1 Z0 F12000 S2 ; lift Z relative to current position
G1 S1 Z805 F3000 ; move Z up stopping at the endstop
G1 Z-2 F1000 ; go back a few mm
G1 S1 Z550 F100 ; move slowly to Z axis endstop once more (second pass)
G92 Z531.7 ; set Z position to axis minimum (you may want to adjust this)
G90

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2 on Tue Jan 15 2019 15:02:01 GMT+0100 (Mitteleuropäische Zeit)
G91 ; relative positioning
G1 Z0 F12000 S2 ; lift Z relative to current position
G1 S1 X355 Y355 F3000 ; move quickly to X or Y endstop and stop there (first pass)
G1 S1 X355 ; home X axis
G1 S1 Y355 ; home Y axis
G1 X-5 Y-5 F12000 ; go back a few mm
G1 S1 X355 F360 ; move slowly to X axis endstop once more (second pass)
G1 S1 Y355 ; then move slowly to Y axis endstop
G1 S1 Z805 F3000 ; move Z up stopping at the endstop
G1 S1 Z536
G1 Z-2 F1000 ; go back a few mm
G1 S1 Z536.1 F100 ; move slowly to Z axis endstop once more (second pass)
G90 ; absolute positioning
G92 Z536.1 ; set Z to axis minimum (you may want to adjust this)