Z Height at Start or Tool Change

andyvirus

After years away from using my machines, I lost my S3D profiles after changing laptop. I have decided to stop using scripts in S3D (Start, Tool Change, End) and do it in Macros as much as possible and let my DuetWifi(s) decide what to do.

For the most part I have it all working perfectly (ish) except for 1 thing which I can't figure out how to achieve.

When I was using scripts in S3D I had it so the bed would lower by 20mm, move the active extruder to the next start point raise the bed to the correct high for that layer and begin.

How do I achieve this in just macros? Can this be achieved.

What happens currently is the tool heats up, when ready the bed lowers 20mm then instantly raises back up then moves to position and begins the layer. This while not causing me an issue at the moment, scares the living sh** out of me every time as the nozel is 0.24mm from the build plate as it zips from dock to first position.

Is there anyway to achieve lower Z axis a bit, move to start position in gcode and resume absolute positioning? And the same for reverse, so on tool change or end of print, lover the bed a bit and then move extruder to dock?

Apologies if this has been covered before, after hours searching I gave up.

andyvirus

~~And the same for reverse, so on tool change or end of print, lover the bed a bit and then move extruder to dock?~~ End is fine as I can say :

M83               ; relative extruder movement
G1 E-2 F3600      ; retract 2mm
G91               ; relative axis movement
G1 Z3 F500        ; up 3mm
G90               ; absolute axis movement
G1 X30 Y-30 F6000 ; move the X carriage in front of dock
G1 X0 F6000       ; Move the X carriage into dock

Just need to figure out how to do this on start or in tpostx.g so that I assume I would

; lift the head
G91 ; relative positioning
G1 Z5
G90 ; absolute positioning

But have that G90 occur AFTER the move to first G1 in the gcode file (or something, obviously this needs to be absolute too in order to start).

Apologies if this has been covered before, after hours searching I gave up.

copperbricks

@andyvirus I stumbled across this thread with a similar issue to yours. I figured I'd reply in case anyone else finds this thread looking for a solution. I fixed my issue by removing any "T" commands from my Tpost/Tfree/TPre macros. I had a T-1 in the beginning of a few of them and I believe this was causing my G-code for lowering the bed to be run twice.