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Start/end g-code

Posted by Wired1 
Start/end g-code
August 06, 2012 11:19PM
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
Re: Start/end g-code
August 07, 2012 01:51AM
[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


Most of my technical comments should be correct, but is THIS one ?
Anyway, as a rule of thumb, always double check what people write.
Re: Start/end g-code
August 07, 2012 01:56AM
Thanks Deux, just what I was looking for. I'll give it a whirl smiling smiley


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Richmond, New Zealand
Thingiverse ~ YouTube
Re: Start/end g-code
August 07, 2012 01:36PM
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
Re: Start/end g-code
August 07, 2012 02:05PM
Re: Start/end g-code
August 07, 2012 04:34PM
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.


FFF Settings Calculator Gcode post processors Geometric Object Deposition Tool Blog
Tantillus.org Mini Printable Lathe How NOT to install a Pololu driver
Re: Start/end g-code
September 05, 2012 10:35AM
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 01:36PM by Ivan Bortolin.
Re: Start/end g-code
September 05, 2012 01:27PM
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
Re: Start/end g-code
September 05, 2012 01:36PM
Hi, try now smiling smiley
Re: Start/end g-code
September 05, 2012 01:40PM
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
Re: Start/end g-code
September 05, 2012 02:27PM
> 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.
Re: Start/end g-code
September 05, 2012 04:59PM
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)
Re: Start/end g-code
September 05, 2012 08:10PM
Cefiar Wrote:
-------------------------------------------------------
> 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
Re: Start/end g-code
September 05, 2012 08:16PM
Oh, with all due respect, I beg to differ. See attached snapshot
Attachments:
open | download - slic3r_proof.png (67.5 KB)
Re: Start/end g-code
September 06, 2012 03:38AM
Ok thanks for that - I was looking at the print and filament tabs smiling smiley
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
Re: Start/end g-code
September 06, 2012 05:58AM
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.
Re: Start/end g-code
September 06, 2012 06:00AM
You need to zero the E axis in your start.gcode with

G92 E0 ; zero extruder length


[www.hydraraptor.blogspot.com]
Re: Start/end g-code
September 06, 2012 08:40AM
@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. smiling smiley
Re: Start/end g-code
September 06, 2012 11:55AM
nophead Wrote:
-------------------------------------------------------
> 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.


Cameron

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Re: Start/end g-code
September 06, 2012 09:43PM
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 09/06/2012 09:47PM by Wired1.

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Richmond, New Zealand
Thingiverse ~ YouTube
Re: Start/end g-code
October 26, 2017 12:57PM
anyone still admin this forum?
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