Cura print settings  

Re: Cura print settings

Looking over the Start gcode in the PLA Cura profile provided by JP, I have a question:

Is there a reason why he did not include the G28 W and the G80 codes? Edit: Do I need to include them in there or no?

Thank you.

Re: Cura print settings

SBS

I use my own profiles, so I can't properly answer your question, but I would guess there is a simple G28 (home all axes). This is the same as a G28 W (home all without 9-point cal) followed by G80 (9-point cal).

Peter

Re: Cura print settings

SBS

I use my own profiles, so I can't properly answer your question, but I would guess there is a simple G28 (home all axes). This is the same as a G28 W (home all without 9-point cal) followed by G80 (9-point cal).

Peter
Thanks Peter;

My only concern is that I don't want to run the nozzle/probe into the bed by neglecting to add some missing code, on my part. For reference, here is what is in the MK2 PLA profile Start gcode, provided by JP:
;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
G90
M82
M107
G28
G92 E0.0
G1 X60.0 E9.0 F1000.0
G1 X100.0 E12.5 F1000.0
G92 E0.0
Well, since nobody has complained about the Start gcode on the MK2, I'll take it as it is good to use.

Re: Cura print settings

Hello, this is my first post, but I want to share something about Cura 2.3-beta settings I'm currently working with.
HW: Prusa i3 MK2 assembled KIT, newest FW to date (3.0.8),
SW: Cura2.3-beta @ MacOSX 10.11.6

Why Cura? because slic3r is making terrible mistakes with slicing my projects, Cura is slicing far better, with all due to respect Slic3r...

Problematic differences between Cura2.3 and slic3r gcode generation:
- cura is using absolute extrusion distance mode (M82 command)
- slic3r is generating gcode with relative extrusion distance (M83 command)
- cura cannot be forced to generate relative extrusion distance mode (AFAIK)
- [email protected] works great with absolute extrusion distance mode (M82)

Cura2.3-beta allows to customize gcode prolog and epilog.
There is currently unsolved problem with initial nozzle-cleaning-sniff at the beginning of printing (generated by slic3r), so I think one should make proper Skirt or Brim to allow filament excess to settle on the outside of object.

My gcode prologue: (Cura/Prefs/Printers/(add Prusa i3 MK2)/Machine Settings/Start gcode:

G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G21 ; set units to millimeters
G90 ; use absolute coordinates
G82 ; absolute extrusion mode

And epilogue:

M104 S0 ; turn off temperature
M140 S0 ; turn off heatbed
M107 ; turn off fan
G1 X0 Y200; home X axis
M84 ; disable motors

Printer settings: X:250mm, Y:210mm, Z:200mm, heated bed:ON
GCode flavour: RepRap (Marlin)

Cura2.3-beta works fine with Print To USB also 😉 Although there is a lack of direct command line or more sophisticated control like pronterface...

Here are my profile settings for 0.2mm prints...

PS. There is problem with initial extrusion chamber fill-up (done at start with Slic3r with commands making rough line outside of printing area) - you should ensure that there was no excessive filament loss during warmup, and set wide Skirt area (about 5 lines) to ensure that extruder will be filled up before starting initial layer.

Re: Cura print settings

Sorry, I've made a mistake in previous post - please edit it or mark as non-valid.
My current prologue :

G82
M82
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G21 ; set units to millimeters
G90 ; use absolute coordinates
G82
M83 ; relative extrusion mode
G1 Y-3.0 F1000.0 ; go outside pritn area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line
M82 ; absolute extrusion mode
G92 E0.0 ; reset extruder distance position

Under heavy testing right now... It should do the intro line.

Re: Cura print settings

My gcode prologue: (Cura/Prefs/Printers/(add Prusa i3 MK2)/Machine Settings/Start gcode:

I went down this same path, and came to most of the same gcode conclusions you did. Two questions, however:

Other than that, good work! Going to try this after work for sure. The new beta seems pretty badass if I can get it running on my Mk2, especially the new dynamic infill options.

Re: Cura print settings

Now that I've had a chance to look at your gcode more carefully, I believe you have both extraneous lines and some incorrect lines.

G82 does not seem to be a standard Marlin-type code. From the comment in one of your earlier posts, it seems you thought this was for absolute/relative extrusion mode, but that's done with M82/M83 respectively. You also had more than one G82 tucked in there.

I believe the starting code should look more like this:


G21 ; set units to millimeters
G90 ; use absolute coordinates
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
M83 ; relative extrusion mode
G1 Y-3.0 F1000.0 ; go outside print area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E12.5 F1000.0 ; intro line
M82 ; absolute extrusion mode
G92 E0.0 ; reset extruder distance position


Alternatively, we should be able to avoid switching extrusion modes by simply converting the intro line/wiping code to absolute extrusions, like this:


G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; absolute extrusion mode
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G92 E0.0 ; reset extruder distance position
G1 Y-3.0 F1000.0 ; go outside print area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E21.5 F1000.0 ; intro line
G92 E0.0 ; reset extruder distance position


In case this isn't super clear...

* Move the extrusion mode-set to the top with the other mode settings
* Zero the extruder position after ABL
* Add 9 to the second line's extrusion distance to make it 12.5 greater than 9, thus absolute terms

I haven't had a chance to try it out yet, but it makes sense to me. Thoughts?

Re: Cura print settings

Ok, screw it. The gcode is fine now, but the machine settings are wrong because the machines to pick from have the wrong feedrates and so forth, which is causing it to move incorrectly and under-extrude, among other issues.

I've figured out how the machine definition files work and I'm currently writing the JSON for a proper i3 Mk2 machine definition, based on the various EEPROM defaults from my machine. Once I verify it's working correctly I'll provide the file and instructions on where to put it.

Re: Cura print settings

Alright, success!

I created an extensive printer definition file and printed a calibration cube using the stock "Normal Quality" settings, but at 0.2mm layer height in Prusa PLA. The results are fantastic for zero tuning!

More pictures here: http://imgur.com/a/vh2oC

The dimensions were within 0.03mm of 20mm on all sides, and the imperfections are very minor.

I created a github project to host the definition file and track any changes I or others might need to make, and wrote a brief README for how to use it, and my rationale behind some decisions.

The repository is here: https://github.com/Apsu/cura-i3-mk2
And a direct link to the definition file is here: https://raw.githubusercontent.com/Apsu/cura-i3-mk2/master/prusa_i3_mk2.def.json

Please read the instructions in the repository for more details on how to use the definition.

Happy printing!

Re: Cura print settings

Evan, great job!

But I've noticed one nasty thing that IMHO shouldn't be - the bed and extruder heats up when Z pos is 0.0 after mesh bed levelling - (nozzle is heated up sticking to bed surface) - maybe heating whole thing before MBL is not a bad idea?

Re: Cura print settings

Evan, great job!

But I've noticed one nasty thing that IMHO shouldn't be - the bed and extruder heats up when Z pos is 0.0 after mesh bed levelling - (nozzle is heated up sticking to bed surface) - maybe heating whole thing before MBL is not a bad idea?

Thanks!

As for the heating/MBL order, I actually did this on purpose, to avoid the MBL dragging oozed filament around the bed and depositing it randomly prior to the initial wiping strip printed outside the bed area. The heatbed mounting system and the probe leveling system should have the probe at least a mm or two above the bed surface post-MBL and during the heating process, so the separation just leaves a tiny blob of filament before wiping, for me.

I did consider modifying the gcode slightly to raise the head to Z 3-5mm for heating, then dropping again to start the wipe. I'm very open to input and ideas for how to further improve the process, but I personally feel like there's no mechanical advantages (like making sure the bed is hot before leveling to take into account possible bed warpage) to heating before leveling, and minor to zero concern with the brief idling time of the nozzle at 0,0,0 while getting hot. In contrast, I see clear advantages to not dragging oozed filament around the bed that will possibly break off and interfere with initial layer printing.

Opinions?

Re: Cura print settings

Yep, but I didn't noticed any ooze of filament during MBL (I've built Prusa i3 mk2 kit myself) - that's why I was concerned about that heatup stage at [0,0,0]. Instead I noticed that nozzle landed into the bed somehow using your prologue gcode and that was strange. I've got live Z axis set at -0.675mm with my current PINDA alignment.

Re: Cura print settings

Might be worth checking to see if your slicer has a Z offset specified, or just looking at the generated gcode directly. The wiping code is identical to all Prusa supplied code minus the conversion to absolute extrusion distances in the second, wider line. It doesn't otherwise change or effect the Z-height at 0,0,0 with all axes homed. So if Z0 is crashing into your bed, it's either your construction, calibration, live Z adjust or slicer Z offset 😀

Re: Cura print settings

Slight clarification -- the bed leveling leaves the nozzle at Z0.15, and the wiping occurs at that height. That said, for higher temp materials and higher bed temps, it does take a while to heat up with the probe in that position, so I'm planning to test parking the head at Z5 instead.

I'm also considering starting the nozzle and bed heating, probing, then waiting for them to finish heating, to cut down pre-print time even further. If it works out how I expect, obviously the gcode can be used in any slicer, so I think it's worth tweaking.

Re: Cura print settings

Hi I sent you an email 🙂

Re: Cura print settings

Hi I sent you an email 🙂

Hey Josef, I sent you a few in response, but not sure if you end up getting them at the address yours came from, info@. Figured I'd ping you here as well just in case ;P

Re: Cura print settings

Hi Evan... So Cura have fixed the problem of the retraction settings being lost have they?

Re: Cura print settings

3Delight

From what I read it was a matter of those settings being stored in 2 places whilst being read from one place and written to the other.

It was possible to manually edit one of the settings files to get retraction correct.

Peter

Re: Cura print settings

Indeed, if you have the config files from the older series of Cura still on disk, it will mess with certain settings in the 2.x UI, including retraction. If you clean all that out and start fresh, it all seems to work quite reasonably so far.

Re: Cura print settings

I've tried to print with such prolog code:

M104 S{material_print_temperature} ; set extruder temp
M140 S{material_bed_temperature} ; set bed temp
G21 ; set units to millimeters
G90 ; use absolute positioning
M82 ; absolute extrusion mode
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G1 Y-3.0 Z5.0 F1000.0 ; ramp up while heating
M190 S{material_bed_temperature} ; wait for bed temp
M109 S{material_print_temperature} ; wait for extruder temp
G28 W ; home all without mesh bed level
G92 E0.0 ; reset extruder distance position
G1 Y-3.0 F1000.0 ; go outside print area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E21.5 F1000.0 ; intro line
G92 E0.0 ; reset extruder distance position

Sequence :
- start heating of bed and nozzle
- go home & do mesh bed leveling
- go up to Z5.0 and wait till heating done
- go back home and print intro line

but that code would leave nozzle higher than Z0.15 and first layer just floats over the bed.
even addition of :
G1 Y-3.0 Z0.15 F1000.0 ; first layer level
after second *G28 W* don't help much.

Any thoughts?