Changing tool change z movement sequence

[dannssy 0]

Hi all.

 

I have a 2 nozzle extruder.  If like the tool change process to be

T1

Print.

Lift nozzle

Switch nozzle to T2

Move to next position

Drop nozzle to new position. 

Print

 

It seems cura wants to :

T1

Print

Lift nozzle

Switch to T2

Drop nozzle

Move to next position

Print.

 

Can anyone offer advice how to fix this?  Should this be a post processing thing?  Any ideas greatly appreciated 

 

 

 

 

[dannssy 0]

Figured it out.  In Machine settings Extruder 1 and 2 End Gcode 

G91
G1 Z10 ; Set to whatever clearance required. 
G90

 

Next, ensure "Z Hop After Extruder Switch Height" is set to 0.   (Very important)

Also Uncheck "Z Hop after extruder switch".

 

Seems to be a bug in Cura 4.6 where regardless of "Z Hop after extruder switch" being unchecked, if a value other than 0 remains in "Z Hop After Extruder Switch Height", the code which drops the nozzle before moving to the new position is inserted into the gcode.   IMO, these 2 settings are very poorly thought out and hence troublesome if not useless.   Further  "Z Hop After Extruder Switch Height" is hidden from view if either "Z Hop when retracted" or "Z Hop after extruder switch" is unchecked.  This is a problem because despite being hidden, if "Z Hop After Extruder Switch Height" contained a positive value before it was hidden, this value will be translated into gcode, causing the problem. 

 

One problem I've found is that the resulting nozzle return move is synchronous, meaning the new z height and XY coordinates are all in the one move.  On small prints, this is unlikely to be an issue, but on large surface, its possible the second nozzle may scrape as it approaches its new position.   It would be better to have the XY coordinates sent in one move, then the Z move to follow.  This would prevent any chance of nozzle scrape.  

 

So, not perfect, but at least usable.