Wanhao d12/230

[Apostoliszev 0]

Hello,
I want to make a stucture with my d12/230.
I am going to use 2 materials:PLA,PVA.
PVA is my support. During my printing when its changes ... for example from PVA to PLA ...my extruder moves to the corner.. it is changing the material and then it continues printing.
But as I have one single extruder i have noticed that a little amount of PVA printing with my PLA so my structrure collapses when i put it into water.
Is a solution to keep my extruder more time at the corner so it can put away ALL of the previous material??
If yes... does anyone knows how to change the gcode?
Thanks a lot

[GregValiant 1,250]

We would need to see a project file that uses both extruders.  After loading a couple of calibration cubes (one set to each extruder) use the "File| Save Project" command and post the 3mf file here.

I think your "Extruder Start" and "Extruder End" gcodes are keeping Cura from using it's own "Nozzle Switch Extra Prime Amount" (which might be helpful).  You might also get by changing the line in both "Extruder Start" from G1 F2100 E70 to G1 F2100 E85.  That will push an additional 15mm of filament on changeover.

 

There are errors in both your machine StartUp and Ending Gcodes.

You have the temperature lines commented out.  If you wanted to use them the Keywords would need to be changed.

{material_bed_temperature_layer_0}

{material_print_temperature_layer_0}

 

The keyword {travel_speed} is in mm/sec and gcode uses mm/minute. 

The first instance should be something like G1 Z10 F1500 and the second should be G1 F7200.  What you have now would translate to G1 F120 which is 2mm/sec.

In the Ending Gcodes remove the M84v line.  M84 is "Disable Stepper Motors" which you wouldn't want to do.  M84v is an illegal command as it contains a lowercase letter that is not a Parameter of M84 and so the command is ignored by the printer.

[Apostoliszev 0]

ok i am sending you my 3mf file.

CFFFP_turbinecrown.3mf

[GregValiant 1,250]

I made changes to the project file and saved it under a different name.  I don't know how this would work with a purge tower but it looks good using the park position to purge at.

In the "Extruder Start" gcodes you will see a line "G1 F600 E30 ;Purge".  That 30mm is the amount of purge.  You may want to increase or decrease that after you see how it goes with a print.

 

When you open this project file and are asked if you want to "Update" your printer - select "Create New" instead.  That will allow you to keep your current printer with your current Start/End gcodes.

GV_Wanhao Start and End.3mf

[Apostoliszev 0]

ok i will try it..thanks a lot

[Apostoliszev 0]

Also i would like to ask you something else.. when i try to print this... it prints the bottom axis and the bottom part of the hub with pva... how can I control it and print it with PLA?
Thanks a lot
 

test_turbine.gcode

[GregValiant 1,250]

NOTE:  I found an error in the Ending Gcode of the 3mf file I posted.  It's missing a G91 "Relative" command and a G90 "Absolute" command.  It should be like this:

; Ending Gcode

M104 S0

M140 S0

M106 S0

M83

;Retract the filament

G1 E-5 F1500

M82

G91

G1 X5 Y5 F6000 ;wipeout

G1 Z5 F1500 ;move up

G90

G1 X0 Y{machine_depth} F6000 ;present print

M84 X Y E ;turn off steppers except Z

; End of End

Did you open that project file I created?  Among the things I changed were the settings "Extruders Share Heater" and "Extruders Share Nozzle".  They are not available in the regular Cura settings.  You have to load the "Printer Settings" plugin from the MarketPlace to get to them.  You need them because right now the way the hot end is configured Cura is dropping the temperature to "Standby Temperature" for the inactive extruder.  That won't work because your "extruders share heater" and there is never an Inactive Extruder.

Within the Dual Extrusion settings is "Nozzle Switch Retraction Distance" and you have it at 16mm for each extruder.  That is playing some havoc as well.

 

There are a couple of problems within your gcode file.  #1 is that your tool switch codes "Extruder Start" and "Extruder End" move the filament 70mm, but within "Extruder Start" there is no purge and if T0 ended it's previous extrusions with a retraction, that is not accounted for either.  Moving 70mm might leave the filament 6.5mm behind the nozzle.

The gcode properly calls for T0 to print the model, but 6.5mm of material is 195mm of extrusion.  Add that to the fact there is still PVA within the nozzle (no purge), coupled with the small size of the model spindle, yes, the model appears to be printed with PVA on those lower layers but T0 is doing the extruding.  The gcode is correct, but the print is wrong because what is supposed to be 100% PLA is contaminated with PVA until it clears out.  When it switches to T1 you have the same problem.  The PVA is contaminated with PLA until it clears out.  You may not have looked close enough at the support to see that.

 

I would suggest you open that 3mf file I posted, allow it to "Create" a new printer, and slice the file.  Go into the Machine Settings and look at what I did in there.  You can use a different color PLA instead of the expensive PVA since it's only a test.  You can also abort the print after about 5mm in the Z so you can check to see if that tiny spindle is being printed in the correct color..  If the nozzle purges correctly there shouldn't be a problem.  It isn't that I think what I did is perfect, but it might be a better starting point than where you are now.

 

Right now, the nozzle isn't purging at all and I think the Dual Extruder settings for both extruders are conflicting with your Extruder Start and Extruder End codes. Couple that with not being able too extrude at all because of the temperature change to Standby and you have trouble.

 

Once the model starts to get larger then the nozzle starts putting down the correct plastic and the problem gets harder to see but it is still there in those first couple of dozen mm of extrusion.

 

 

Edited July 20, 2022 by GregValiant

[Apostoliszev 0]

Hey,
First of all thanks for the help. I noticed a problem.
It doesn't load temperature in nozzle at first.
Also when it moves away to change the material.. at the begging beacause there isn't such a distance between extruder and the build plate.. a lot of material is collected in the nozzle.. so it is created small balls of PVA.. and the nozzle carries them back to the main design and it destroyes my print.

...So should I try to do it with to "enable Prime Tower" with my start/end gcode that i had posted in the beggining?
 

CFFFP_3mf_forum.3mf

[GregValiant 1,250]

Your startup gcode from that 3mf file looks good.  The bed starts to heat, the hot end starts to heat, then the bed waits until it's up to temp, followed by the hot end waiting to get up to temp.  After they are heated the print starts.

If the printer isn't doing that then you might have to change to heating them separately as the firmware might not allow for them to heat together.  It could be designed in because the power supply can't handle the load of both heaters starting together.

You could try switching the order in the startup to:

M140 S{material_bed_temperature_layer_0} ;start heating bed

M190 S{material_bed_temperature_layer_0} ;wait for bed temperature

M104 S{material_print_temperature_layer_0} ;start heating hot end

M109 S{material_print_temperature_layer_0} ;wait for hot end

 

Although I play around with virtual multi-extruders in Cura I don't actually have one.  My practical knowledge of them is limited (read that as "zero") and I'm not comfortable to give advice on exactly how they should be configured.  You need to do some experimenting.

If you want to "Enable Prime Tower" then it would need to be done in Cura (Dual Extruder section, not the StartUp gcode) because there are moves over to the prime tower and then extrusions at the prime tower that have to be calculated and added to the gcode file as part of the toolpath.

Rather than a full Prime Tower you might be able to get by with the Ooze Shield or a Draft Shield.  They are away from the model and maybe the mess would take place over them instead of over the model.

I suppose you could add some relative movement to your Extruder Start Gcodes.  Moving in the Z is easy but moving in the X Y is tough because there is no way to know where to return to.  When you have the Prime Tower enabled then Cura knows where it's going and where to return to for the start of the next extrusion.

Edited September 10, 2022 by GregValiant