Start/end g-code

Tried searching for this but cannot find the answer so noob question...
I want to add some startup g-code to lift the hotend up and squirt a bit of filament out before starting the perimeter line. It is always the first few lines that come out thin or inconsistent and I reckon a quick blast will get it working better. Is there a list of g-code commands somewhere or does anyone have an example of the code they use to do a pre-print purge?

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Richmond, New Zealand
Thingiverse ~ YouTube

[reprap.org] for the gcode reference.

I usually just feed some mm of filament at the home position, just after the temperature is reached, before moving to do the skirt :

M140 S60 ;set bed temp, no wait.
M104 S190 ;set hotend temp, no wait.
M116 ;waiting for both temperatures
G90 ;absolute Positioning
G21 ;set units to millimeters
T0 ;select extruder 0
;G28 ;homing (done manually before print)
G92 X0 Y0 Z0 ;set home here
G92 E0 ;reset extruder length
G1 F1800.0
G1 E4.0 ;prime extruder
G92 E0 ;reset extruder length

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Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.

Thanks Deux, just what I was looking for. I'll give it a whirl

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Richmond, New Zealand
Thingiverse ~ YouTube

So I tried this and if I start from cold it tries to prime the hot end before waiting to start printing. I guess I will need to manually start the hotend then click print (I'm using pronterface) when it is up to temperature.
I don't suppose there is g-code to start the hot end and wait for it to heat up before continuing is there?
Pronterface is so slow to start anyway, it seems to sit for 3 or 4 minutes after reaching temperature before it gets going.

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Richmond, New Zealand
Thingiverse ~ YouTube

See [reprap.org]

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[blog.brixandersen.dk] - [twitter.com]

Enter:

M109 S[first_layer_temperature]

at the very beginning of the start gcode and it will automatically insert the temperature before the start gcode. Do not change anything in that line. It will use what's in the bracket to find the temperature set in the slic3r temperature box.

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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

In the link you will find the guide written by me and Lorenzo Cantini of Kent’s strapper for Slic3r.

[www.ivanbortolin.it]

Edited 1 time(s). Last edit at 09/05/2012 04:36PM by Ivan Bortolin.

Can't get that link to work. Will try again later and see if it is fixed.

One weird problem I have is if I prime the hotend manually with Pronterface - ie click on the "extrude" button repeatably until PLA comes out the end - then start a print, the printer starts by rewinding the number of advances I did to prime it. It is a pain in the butt. The only solution is to turn the printer off and rrestart it. I'm sure there must be a way of resetting this without having to resort to such extreme measures.

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Richmond, New Zealand
Thingiverse ~ YouTube

Hi, try now

Yes good thanks. Does this mean there is a newer version of Slic3r out? the pictures in the guide look different to what I see when it is running.

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Richmond, New Zealand
Thingiverse ~ YouTube

> Yes good thanks. Does this mean there is a newer
> version of Slic3r out? the pictures in the guide
> look different to what I see when it is running.

Yes, the guide is for Slic3r 0.9.0. The current version is 0.9.2. I think you use 0.8.4 or older.

In Slic3r, go to the Printer & Filament tab and make sure 'Use relative E distances' is unticked.

If it is unticked, also make sure your machine type is correctly set (remember, machine type refers to your electronics, NOT to the physical machine you have)

Cefiar Wrote:
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> In Slic3r, go to the Printer & Filament tab and
> make sure 'Use relative E distances' is unticked.
>
> If it is unticked, also make sure your machine
> type is correctly set (remember, machine type
> refers to your electronics, NOT to the physical
> machine you have)

Not sure if this is in reply to my rewinding problem but I am currently on version 0.9.1 and there are separate tabs for printer and filament and neither has this option.

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Richmond, New Zealand
Thingiverse ~ YouTube

Oh, with all due respect, I beg to differ. See attached snapshot

Ok thanks for that - I was looking at the print and filament tabs
No it is not ticked, and it still rewinds after manual priming when you start a print. The only way I have found to stop it is to prime it then turn the printer off and close Pronterface then reopen Pronterface and turn the printer back on. Even the reset printer button isn't enough. Another solution is to print two or three perimeters which gives it enough time to prime itself.

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Richmond, New Zealand
Thingiverse ~ YouTube

What electronics and firmware are you using?

Have you tried ticking that box and seeing if it fixes your issue? If not, remember to untick it.

You need to zero the E axis in your start.gcode with

G92 E0 ; zero extruder length

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[www.hydraraptor.blogspot.com]

@wired1...meh...It was referenced in a way that *might confuse (printer and filament settings), since v9x places it in a different tab than in v8.4 (v8.4 drops the setting into the Printer and Filament tab, but that tab doesn't exist in 9.x). I just recalled seeing where the setting was, while glancing over the most recent deploy and familiarizing myself with the menu options (9.x has a modicum of online help so the newbie can learn) and had happened to have literally * just reviewed the English version of the new Slic3r guide that Ivan Bertolin & Kent Strapper posted.

nophead Wrote:
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> You need to zero the E axis in your start.gcode
> with
>
> G92 E0 ; zero extruder length

Exactly. Slic3r should insert that into the gcode automatically (it does for me), but adding it into the start code will work as well.

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Thaks for that, just what I was missing. This is my setup now:

Before print
M140 S60 ;set bed temp, no wait.
M104 S190 ;set hotend temp, no wait.
M116 ;waiting for both temperatures
G28 ; home all axes
G1 E4.0 ; prime extruder
G92 E0 ; zero extruder length

After print
28 X0 ; home X axis
G1 Y10 F4000 ; move the print to the back to unload
M104 S0 ; make sure the extuder is turned off.
M140 S0 ; make sure the bed is turned off.
M84 ; shut down motors
M107 ; fan off

Edited 2 time(s). Last edit at 09/07/2012 12:47AM by Wired1.

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Richmond, New Zealand
Thingiverse ~ YouTube

anyone still admin this forum?