PS 2.3.0-rc2 start g-code position
Hello,
I am quite new to Prusa Slicer. I used simplify for the last two years an wanted to check out Prusa Slicer and what to say...I love it 😉
I don't have a prusa printer yet (waiting for mk4 ;))...so using my Anycubic I3 Mega with the Silcer.
I set up everything and I am quite happy with the results. One thing I found out is the following "issue":
I added my personal Start g-code that works fine with simplify but I had little weired behavior in the start sequence (different than with simplify). So I found the reason in the start g-code:
M190 S60 ; set bed temperature and wait for it to be reached
M104 S200 ; set temperature
;TYPE:Custom
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28
M501
M420 S1
G0 Z0.30
G92 E0 ;zero the extruded length
G1 X40 E15 F500 ; Extrude 15mm of filament in a 4cm line.
G92 E0 ;zero the extruded length again
G1 E-0.5 F500 ; Retract a little
G1 X80 F4000 ; Quickly wipe away from the filament line
M109 S200 ; set temperature and wait for it to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M83 ; use relative distances for extrusion
; Filament gcode
The blue lines are the prusa lines the red lines are my personal ones. Problem is the M109 comming after my "priming and wiping line" which stops the printer for few seconds until it starts printing and...as it is not in front of the start code it can also happen that the priming and wiping would run with a nearly cold hotend.
So is this a bug or is it by reason?
Of course I could add M109 in my Start code myself to prevent cold priming but I think M109 should be right before the custom start code not behind.
Thanks for any advice
Manuel
RE: PS 2.3.0-rc2 start g-code position
No it isn't a bug its designed to do that. If you don't add the temperature lines to your custom start gcode prusa slicer will add them automatically, at least for marlin firmware. Not sure about the other firmware flavours. So its better to add them yourself at the points you want them.
For a prusa printer using the defaults it normally has a section like this in the start gcode-
M140 S[first_layer_bed_temperature] ; set bed final temp
M104 S[first_layer_temperature] ; set extruder final temp
M109 S[first_layer_temperature] ; wait for extruder final temp
M190 S[first_layer_bed_temperature] ; wait for bed final temp
Notice the placeholders in the above block. These will pick up the first layer temps from the filament profile for the bed and filament so the temperatures don't have to be hard coded into the start.
I use a similar start sequence to the one listed by Bob at his web page here http://projects.ttlexceeded.com/3dprinting_prusaslicer_gcode.html
A lot of it is applicable to other machines though and its nicely annotated so its worth a read through
RE: PS 2.3.0-rc2 start g-code position
@neophyl
Hi,
ok...that was easy...I added it to the custom part and it works. I didn`t know that the slicer checks the custom code for the content and adapts the g-code respectively. Means if the slicer recognizes the M109 in the custom code it doesn't put it behind it anymore. I found Bobs page yesterday while trying to solve this...but couldn't find the importend information I mentioned above.
I should definitively take a closer look to g-code behavior 😉 Did't need it really before.
Thanks!
RE: PS 2.3.0-rc2 start g-code position
Note the way Neophyl set both temps then waits for both. If you just wait for one the other wont start to heat untill the first is up to temp. A tiny improvement on the posted code is
M104 S{first_layer_temperature[0]*0.9} ; set extruder temp to 90%\n
M140 S[first_layer_bed_temperature] ; set bed temp\n
M190 S[first_layer_bed_temperature] ; wait for bed temp\n
M104 S[first_layer_temperature] ; set real extruder temp\n
M109 S[first_layer_temperature] ; wait for extruder temp\n
Particularly useful for high bed temps as the nozzle would sit at high temp, waiting for the bed and doing nothing for a while.
RE: PS 2.3.0-rc2 start g-code position
@towlerg
@towlerg
nice idea!
Thank you