Preheating in Cura. First Heatbed, second Nozzle?

[thomass 0]

Hi Daid,

is it possible to change the preheating from first nozzle to first heatbed in cura?

While the time for heating the nozzle is about 2 minutes and the time for the heatbed is about 10 minutes and in that time the filament is melting away.

Regards

Thomas

 

[gr5 2,167]

Not good! Sometimes if you overheat pla and don't print for too long it causes a jam in the print head.

Maybe you should turn on your heatbed. Walk away and then after 10 minutes start your print.

Personally I always set the temperatures in Cura all to 0. This makes it so that Cura doesn't wait and just starts printing when you tell it to. Instead you have to set the temps manually (either with ulticontroller or with Cura printing window).

 

[Daid 306]

Cura currently heats up both at the same time. However, you can change this behavior.

Put the following code at the top of the start.gcode:

 

M190 S{print_bed_temperature}
M109 S{print_temperature}

Cura will see the {} tags in the start code and will not emit the default heatup commands.

 

[gr5 2,167]

That's good to know!

Note that gcodes are explained here:

https://github.com/ErikZalm/Marlin

And note that while M190 and M109 don't move onto the next command until the temperature stabilizes, M140 and M104 move immediately onto the next command and don't wait for the temp to reach the requested value.

 

[thomass 0]

@Daid

Thank you very much for setting it in the start.gcode.

It works with one nozzle, but not with the second nozzle.

Until now, I always changed the sequence of the Mxxx in gcode, but it would be better to set it in cure before.

e.g. from:

M140 S50.000000

M104 T1 S210.000000

M109 T0 S215.000000

M109 T1 S210.000000

T0

M190 S50.000000

to:

M140 S90.000000

M190 S90.000000

T0

T1

M104 T1 S200.000000

M104 T0 S235.000000

M109 T1 S200.000000

M109 T0 S235.000000

 

Works very fine, because the two nozzles are heating at the same time, after bedheating.

 

@gr5

Thank you for the link.

 

[thomass 0]

@Daid

I set this at the top of the start.gcode.

M140 S{print_bed_temperature}

M190 S{print_bed_temperature}

M104 T0 S{print_temperature}

M104 T1 S{print_temperature}

M109 T0 S{print_temperature}

M109 T1 S{print_temperature}

In cura are two different temp´s of the nozzles.

But cura set all temp´s at T0. :(

What´s wrong with the start.gcode?

 

[Daid 306]

I think you need to do:

M140 S{print_bed_temperature}

M190 S{print_bed_temperature}

M104 T0 S{print_temperature}

M104 T1 S{print_temperature2}

M109 T0 S{print_temperature}

M109 T1 S{print_temperature2}

 

[thomass 0]

That's it.

It works fine now .

Thank very much.

 

[prusatorrex 0]

Hi, I have tried putting the above code at the end of my start code. Unfortunately it won't work for me. I am using one extruder and heat bed, and my bed takes ages to get hot, so I need for the nozzle to start heating after the bed has reached it's final temp.

With the code above, it does start heating the bed first, but after it reaches the final temp, nothing happens. The extruder does not warm up so it gets stuck there, just mantaining the bed temp.

Any suggestions, please?

Thx in advance

 

[Daid 306]

Latest versions of Cura do bed-first by default now. So you don't have to change a thing then.

 

[prusatorrex 0]

Great to see that! I had a recent version but now that I downloaded the latest one I can see it's in the changelog. It makes so much more sense now.

Thank you

 

[prusatorrex 0]

Well, I have a different problem now, when I print via USB it works as expected, heating bed first, great!

However if I print with SD card, the same gcode heats bed and just stays like that forever keeping bed temp. It does not start heating the nozzle.

Anyone else having this problem or know possible cause and solution?

[Goral 0]

On 1/11/2015 at 1:08 PM, Daid said:

Latest versions of Cura do bed-first by default now. So you don't have to change a thing then.

 

 

 

And what can you do to make the bed back heated only after the head?
Cura inserts the code into the gcode:

; Generated with Cura_SteamEngine 3.6.0
M140 S60
M105
M190 S60
M104 S200
M105
M109 S200

It adds its own code to Start G-code:

M104 S {print_temperature}
M105
M109 S {print_temperature}
M140 S {print_bed_temperature}
M105
M190 S {print_bed_temperature}

And Cura to gcode now saves:

; Generated with Cura_SteamEngine 3.6.0
M140 S60
M105
M190 S60
M104 S200
M105
M109 S200
M82; absolute extrusion mode
M104 S200
M105
M109 S200
M140 S60
M105
M190 S60

Which, of course, makes no sense.

Is it possible to somehow disable Cura inserting the code for heating the head and table so that only my code from the Start G-code will be left?

 

Edited February 13, 2019 by Goral

[ahoeben 1,948]

21 hours ago, Goral said:

Is it possible to somehow disable Cura inserting the code

Yes, by using the correct replacement patterns in your start gcode. If Cura sees the actual use of the replacement pattern {material_print_temperature} in your start gcode, it will not add its own extruder preheating. Same with {material_bed_temperature} for the bed. And I mean that actual text, including the curly braces.

[Goral 0]

Thank you very much. It works!!!

[nils91 0]

; Ender 3 Custom Start G-code

M140 S{material_bed_temperature_layer_0} ; start heating bed

M104 S170 ; start heating extruder but avoid oouzing

G28 ; home axis while heating

M420 S1 ; enable BL mesh

G1 Z10 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed

G1 X0.1 Y20 Z0.3 F5000.0 ; Move to start position

M190 S{material_bed_temperature_layer_0} ; wait for bed

M104 S{material_print_temperature_layer_0} ; start heating extruder

M109 S{material_print_temperature_layer_0} ; wait for extruder

G92 E0 ; Reset Extruder

G1 X0.1 Y200.0 Z0.3 F1500.0 E15 ; Draw the first line

G1 X0.4 Y200.0 Z0.3 F5000.0 ; Move to side a little

G1 X0.4 Y40 Z0.3 F1500.0 E25 ; Draw the second line

G1 X0.4 Y20 Z0.3 F1500.0 ; Draw the second line without filament

G92 E0 ; Reset Extruder

G1 Z3.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed

 

try this