@dc42
Yes now in the clear light of day I see the issue, the commented text from the slicing programme is wrong (in italics)
it is exactly the same issue as the initial post had , sorry to waste folk's time
; End G-code
G4 ; Wait
M220 S100 ; Reset Speed factor override percentage to default (100%)
M221 S100 ; Reset Extrude factor override percentage to default (100%)
G91 ; Set coordinates to relative,
just realised that this (G91) does not affect/alter the extruder/filament setting!!
This line below is the problem as crucially as the E values are still in absolute
G1 F1800 E-3 ; Retract filament 3 mm to prevent oozing
In reality for this item it means pull the filament back to -3mm and as Extruder is still in 'absolute' it will try and rewind about four feet!!
I dont think I need to set to relative as it has already pulled five mm back, but will not to much harm to add a line of code.
G1 F3000 Z20 ; Move Z Axis up 20 mm to allow filament ooze freely
G90 ; Set coordinates to absolute
Not sure how I go about flagging this as an error within the slicing programme?