Double extruder temperature regulation

[dadoblu_2000]

I'm using a dual extruder printer, but I can't get the temperature regulation of the two hotends to work properly, only in the initial phase of printing, I'll explain better, practically when I start printing, the two hotends reach the same temperature of 260 degrees but the materials to be printed are different extruder 1 ABS extruder 2 PVA this excess temperature causes the carbonization of the PVA filament waiting must wait for the first layer to be completed by hotend1, I enclose start gcode I hope you can help me.

working temperatures are 260 degrees first layer ABS 255 degrees normal work, 220 degrees first layer PVA 215 degrees normal work

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Double extruder Prefix

; [mm] mode
G21
; absolute mode
G90
; Begin start procedure
; home all axes
G28
M140 S<BED>             ; Riscalda piano
M104 T<ext+0> S<TEMP>   ; Riscalda EXT 1 sinistro
M104 T<ext+1> S<TEMP>   ; Riscalda EXT 1 destro
; Purge extruder 0 by drawing 2 lines
T0
; Riscalda e attendi il raggiungimento TEMP. EXT sinistro
M109 T<ext+0> S<TEMP>   
; reset extruder
G92 E0
; move z down little to prevent scratching of surface
G0 Z30 F3000
; move to start-line position
G0 X20.0 Y201 Z30 F3000.0
G0 Z0.4 F3000.0
; draw 1st line
G1 X200.0 Y201 Z0.3 F1500.0 E15
; move to side a little
G1 X200.0 Y200.7 Z0.3 F3000.0
; draw 2nd line
G1 X20.0 Y200.7 Z0.3 F1500.0 E30
; retract filament 1.5mm
G1 E28.5 F3000
; temp down
M104 T<ext+0>
; reset extruder
G92 E0
; done purging extruder 0
; Purge extruder 1 by drawing 2 lines
T1
; Riscalda e attendi il raggiungimento TEMP. EXT destro
M109 T<ext+1> S<TEMP>  
; reset extruder
G92 E0
; draw 1st line
G1 X200.0 Y200.4 Z0.3 F1500.0 E15
; move to side a little
G1 X200.0 Y200.1 Z0.3 F3000.0
; draw 2nd line
G1 X20.0 Y200.1 Z0.3 F1500.0 E30
G1 E28.5 F3000
; retract filament 1.5mm
G92 E0
; start fan
M106 S0
; temp down
M104 T<ext+1>

[pjr]

No, that's not the way to do it.

Ensure that you are running at least V23.05.

First, if you are using materials which require different bed temps, you should use a raft (interface only) and set the "default extruder" for "interface" to the extruder with the material using the hottest bed temp.

Ensure that you have the Material/Temperature/Main, Layer 1 and Keep Warm settings correct. You may want to have the material defined several times to reduce print times or running costs (e.g. a profile each for "Stay Hot", "Keep Warm" and "Cool Down", where the keep warm temp is set to high, medium and low respectively).

In the Prefix, only heat up <EXT+0> - unless you always use a specific tool for MBL and homing - if this is the case, please let me know and I will reply accordingly.

Then in the relevant G-code sections:

Preheat:

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; Preheat

M104 T<EXT> S<TEMP>	; Set Extruder Temp

Select new ext and warm

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; Select New Extruder and Warm

M109 T<EXT> R<TEMP>		; Set Extruder Temp (accurate)
G4				; Pause - force wait for ext temp
T<EXT> S1			; Select Extruder
;M900 K<MATL>		;Set material LA if required

Warm Same Ext:

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; Warm Same Extruder (Only at first layer end?)

M104 T<EXT> S<TEMP>	; Set Extruder Temp

Cool Same Ext:

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; Cool Same Extruder (Only at first layer end?)

M104 T<EXT> S<TEMP>	; Set Extruder Temp

Cool and Retire Old Ext:

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; Cool and Retire old extruder

M104 T<EXT> S<TEMP>		; Set Extruder temp to "Keep Warm"
;M900 K0				; Turn Off LA if required

You may also want to include additional code for suck and prime before/after tool changes and you can also use

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G1 X<NEXTX-2> Y<NEXTY-2> F24000	; Move to prime pillar - just a little bit away to knock off any ooze

In select new extruder and Warm section before any additional primes - but don't forget there is also a destring prime at the start of the pillar, so you may want to use something like:

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G1 E<2-DESTRING> F2400		; deretract - destring to follow

Of course, all this uses the default prime pillar (or short wall) - neither of these work for me, so I have a post-processor to print the pillar slightly differently.

Peter

[pjr]

There is another alternative...

Soluble support material is usually a lot more expensive than regular print material, so only use soluble for the interface.

Set object, support and raft to the ABS extruder. Set support Z-gap to zero.

The G-code provided above will automatically heat up the PVA extruder when it is required - there may be a time delay before it starts to print, but better that than keeping the PVA hot all the time.

Peter

[dadoblu_2000]

Thanks for your help, I'll try the code you gave me.

[dadoblu_2000]

i sliced it and there are these red and yellow lines that are not flat but they look thin and tall what does that mean?

[dadoblu_2000]

I'm also attaching the first and last part of the g-code so if you're curious you can check if I configured it, I renamed the file as png just delete the png extension but I think it wasn't necessary to tell you , I don't know the procedure for attaching files that are not images.

[pjr]

The red/yellow curves denote where KISS has found arcs and generated G2/G3 G-codes

Peter

P.S. there was no attachment. Just Zip up the G-code and attach the ZIP.

[dadoblu_2000]

I tried to use your configurations but I encounter a problem in printing the second extruder, in detail: the printing starts the two extruders are at 250 degrees, the first extruder ends its layer, the second extruder starts printing which is still at 250 degrees, meanwhile extruder 1 reaches a rest temperature of 200 degrees, the second extruder finishes its layer and rests at a temperature of 200 degrees, extruder 1 reaches a working temperature of 250 degrees and starts printing, at this point a strange thing happens as soon as extruder 1 finishes printing, extruder 2 sets the printing temperature to 120 degrees and as soon as the temperature drops from 200 degrees to 120 degrees it starts printing! I'm honest I don't know how to put my hands to heal this problem!

[dadoblu_2000]

the work I would like would be this: printing started with extruder 1 (left) temperature 250 degrees extruder 2 (right) 200 degrees rest temperature, as soon as extruder 1 finishes the layer switch to extruder 2, wait for working temperature 220 degrees, set temperature of rest extruder 1, this would be the job type for my dual extruder print, my printer is a modified ultimaker 2 with dual extruder like ultimaker 3, i post it just to give idea of ​​tool change mechanism, hope you can give help on how to write the g-code and on which card to put it.

[pjr]

OK, best thing to do is upload a zipped KSP file (Menu/Project/Save Project As).

I can then slice something using your profiles and can have a look at the outcome.

Sounds like you are still setting both extruder temps in Prefix.

Peter