Strange Extruder Behaviour afer upgrade to DuetWifi
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Hi,
Today i got my DuetWifi..an nice upgrade from my old 8bit board in my Delta printer.
Installed everthing..config was easy and then i startet the first test print. A Calibration cube. leveling looks fine..printer starts with a good line..but then the E0 starts to become faster and faster..on second layer the nozzle is already diggin in a fat plastic line
Took the Steps from my old marlin config.h were 96 so i used it here too..did a extruder calibration and after that i should set the steps per mm higher ??
so why the extruder gets faster??
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problably because you sliced with absolute extrusion (M82) and must use relative extrusion (M83)…
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thats the starting code that Cura uses
;Sliced at: {day} {date} {time}
;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}
;Print time: {print_time}
;Filament used: {filament_amount}m {filament_weight}g
;Filament cost: {filament_cost}
;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line
;M109 S{print_temperature} ;Uncomment to add your own temperature line
G21 ;metric values
G90 ;absolute positioning
M107 ;start with the fan off
G28 ;move to endstops
G92 E0 ;zero the extruded length
G1 F200 E2 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G1 F{travel_speed}
;Put printing message on LCD screen
M117 Printing…anyway..tried it again with the default value Steps/mm for E0 even worser..extruder stepper starts slow and speed up until i had to shutdown the printer
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you must include M82 in your start code to tell the Duet you are using absolute extrusion, by default it is set to relative extrusion (M83)
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thats in my config.g
; General preferences
M111 S0 ; Debugging off
G21 ; Work in millimetres
G90 ; Send absolute coordinates…
M83 ; ...but relative extruder moves
M555 P2 ; Set firmware compatibility to look like Marlin
M665 R105.6 L215 B90 H307 ; Set delta radius, diagonal rod length, printable radius and homed height
M666 X0 Y0 Z0 ; Put your endstop adjustments here, or let auto calibration find them
M208 Z0 S1 ; Set minimum Zso M83 is active
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just put M82 in your cura start code…
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yes..thats was the prob..in config.g it was a M83..exchanged it to a M82 and its ok now..just small tweaks left to do
Thx for your competend and fast help
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really strange…i change the M83 to a m82 in the config..first print was done and the printer retracted all the filament ..so i had to put a g83 in the end.code from cura..
had never such problems on the marlin 8 bit -
The alternative fix would have been to put G92 E0 prior to the G1 E command that is retracting filament at the end if your print. That G1 E command might be in your slicer end gcode, or in your stop.g file if you have one.
We recommend using relative extruder coordinates. Recent versions of Cura support it, and every other slicer I know of has done so for years.
