Multiple Z carriage homing routine.

[stephenc]

Hi

with 2 toolheads I wanted to have a z homing routine before printing that each nozzle will be probed one after another in the same center bed location.

here below is my homez.g

I had some success with this but I question whether there's alternate way of doing this. what about using T0 and T1 rather than X and U. If I call T0 in my homez.g routine will it call Tfree0.g as well..?
–------------------------------------------------------
; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool on Mon Sep 18 2017 23:51:32 GMT-0700 (Pacific Daylight Time)

; Lift Z relatively to current position
;G91
;G1 Z5 F12000

; Back to absolute positioning
M0
G90

M584 Z2 ; Split the 2 Z towers for independent control. this will move left tower only
G1 X59 Y59 F12000 ; T0 Go to center bed probe point
G30 ; this will home and probe the left Z tower

; lift left Z tower after probing
G91
G1 Z5 F200
G90
G1 X127 F12000 ; park first toolhead T0

M584 Z5 ; Split the 2 Z towers for independent control. this will move right tower only
G1 U59 Y99 F12000 ; T1 Go to center bed probe point
M558 P6 X0 Y0 Z1 H132 F120 T12000 ; Allow right tower to go all the way down to FSR on bed
G30 ; this will home and probe the right Z tower

; lift right Z tower after probing
G91
G1 Z5.2 F200
G90
G1 U132.2 F12000 ; park second toolhead T1

M584 Z2:5 ; join both Z together
M558 P6 X0 Y0 Z1 H5 F120 T12000
G92 Z5.15

here's picture of the printer for reference

[dc42]

You can use a P parameter on the T commands to control which tool change files are run.

[stephenc]

Not sure what you meant using P parameter with tool select command. Can you elaborate please. I checked T section in wiki but there are no example of T command using P parameter.

[Dougal1957]

From the wiki regarding T Commands

Under special circumstances, the execution of those macro files may not be desired. RepRapFirmware 1.17b or later supports an optional P parameter to specify which macros shall be run. If it is abscent then all of the macros above will be run, else you can pass a bitmap of all the macros to be executed. The bitmap of this value consists of tfree=1, tpre=2 and tpost=4.

[dc42]

@stephenc:

Not sure what you meant using P parameter with tool select command. Can you elaborate please. I checked T section in wiki but there are no example of T command using P parameter.

https://duet3d.com/wiki/G-code#T:_Select_Tool

[stephenc]

Thank you for adding T0 P0 example in the wiki I think it's clear now for me will try that method for my homez.g

Stephen

[stephenc]

this is my tfree0
–-----
G90
G1 X127 F12000
M400

after homing both tool 0 and tool 1 in X and Y I ran
T1 P1

shouldn't that select T1 to active and ran tfree0 only which would then move my T0 to X127 position?

instead, what happened was T1 is set to active but nothing moves.

any suggestion? thx

[stephenc]

hmm interesting. it didn't work because I haven't home z yet.

is there a way to bypass that? I need it to actually probe Z

[stephenc]

I added G92 Z0 before homing z and seems to solve the issue.