End code

I'm looking for an extra line of Gcode to add to my end. code file that will retract the filament as soon as the print is finished before the nozzle lifts away from the print. As at the moment I get a bit of a bump from nozzle ooze at the end which isn't helping my finished top layer.

Just having a look through some existing Gcode and I think it uses G1 F960 as the retraction would that be correct? I have highlighted the line in my end code in Red that I was hoping would solve this issue but it doesn't



G91
G1 F70
G1 E-10 F30000 ;suck the filament back quickly to stop ooze #this line doesn't seem to work
G1 Z7 F70 ;lifts nozzle 7mm from finished print surface
G1 F2300
G1 X-10 Y100 F2300 ;moves bed out for easy job removal
G90
M104 S0 ;turns extruder off

Edited 1 time(s). Last edit at 07/25/2011 01:40AM by NelsonRap.

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Experimenting in 3D in New Zealand

Anyone able to help?

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Experimenting in 3D in New Zealand

If you're using SF with retract option then you don't need to add this retract code at the end of the print. Just move the bed away from the carrage towards you by either homing the y axis (G28 Y0) or sending it in the opposite direction (G1 Y190.0 F2000.0) depending on how your Mendel is configured. I think this works better than lifting the nozzle which leaves more bump on the top layer.

G1 E-10 F30000 ;suck the filament back quickly to stop ooze

This should work except it is faster than your machine will move. 30000mm/m / 60 = 500mm/s so try something like:

G1 E-10 F300 ;suck the filament back quickly to stop ooze

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Sublime Wrote:
-------------------------------------------------------
> G1 E-10 F30000 ;suck the filament back quickly to
> stop ooze
>
> This should work except it is faster than your
> machine will move. 30000mm/m / 60 = 500mm/s so try
> something like:
>
> G1 E-10 F300 ;suck the filament back quickly to
> stop ooze

My thinking was leading me towards the speed being the issue, I'm going to reduce this substantially tomorrow and see what happens

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Experimenting in 3D in New Zealand

Are you using Absolute or Relative Extrusion Distance in the Dimension settings? I use absolute. Your start.gcode will have G90 in it for absolute. Your end.gcode switches to relative to do your final moves; G91 (relative) then back to G90 (absolute) at the end. Without these, the line "G1 Z7 F70 ;lifts nozzle 7mm from finished print surface" would send the Z axis to 7mm, crashing it through the print if the print was higher than 7mm.

I agree with Sublime, your speed is probably too high. I'm using Skeinforge 41 and have a final retraction with feed rate of F3000, though I do it like this using absolute positioning, and don't raise the head:

G92 E0 ;reset extruder home
G1 E-10 F3000 ;retract to avoid ooze
G92 E0 ;reset extruder home
G1 X0 Y0 F4000.0 ;move to X Y home
M104 S0.0 ;Heater off

Just been looking through my Gcodes and have changed my end code to

G91
G1 F70
G1 E-15 F30 ;suck the fillament back quickly to stop ooze
G1 Z7 F70 ;lifts nozzle 7mm from finished print surface
G1 F2300
G1 X-10 Y100 F2300 ;moves bed out for easy job removal
G90
M104 S0 ;turns extruder off

but for some reason SF41 will not put the line of code highlighted in red in. Not one of my sets of Gcode have that line yet it is in my end file

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Experimenting in 3D in New Zealand

Do a search of your computer for the name of your end.gcode . I know on my system (ubuntu 10.10) I have a hidden .skeinforge folder which has a copy of it and its also in the ReplicatorG folder. If you find more than one copy delete the extra ones and try regenerating the code.

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FFF Settings Calculator	Gcode post processors	Geometric Object Deposition Tool Blog
Tantillus.org	Mini Printable Lathe	How NOT to install a Pololu driver

Hmm interesting thought as all the other lines appear ok but will give it a go

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Experimenting in 3D in New Zealand

Skeinforge strips out E only G1 moves from the start and end .gcode files. To work around this you can follow the procedure in [forums.reprap.org]

Seems to work thanks won't know until I make a print though

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Experimenting in 3D in New Zealand