Dinamic Daemon.g

bernardomattiucci

I have a 1200-watt heated platen (600x600mm) and having the printing chamber fully enclosed (with two, adjustable, ventilation grills at the top, I do not need to keep the platen constantly on during the entire duration of printing.
With this code I keep the heater on for the first few Bed_layers_initial_number layers, then decrease the temperature by keeping it in the range from Bed_layers_limit_lower_temperature to Bed_layers_limit_highest_temperature up to the printing percentage indicated with Bed_layers_limit_number. When that percentage is reached, the print bed heater is turned off.

With the PLA I heat at the preset temperature of 50°C for the first 5-10 layers, then the temperature is maintained between 40° and 50°C until 30% of the print is done. From then on the heater is turned off.
For prints of about 3 hours, the bed temperature at the end of the print is about 30-35°C depending on the ambient temperature (I am staying in the attic, without a heater). For longer prints I have to change the Bed_layers_limit_number percentage.

For PETG, which is more sensitive, I have to set the Bed_layers_limit_number to at least 70% and the initial temperature to 60°C.

fcwilt

@bernardomattiucci

Does your bed change temperatures fast enough for those changes to take place in the times allotted?

Interesting idea for sure.

Thanks.

Frederick

bernardomattiucci

@fcwilt

Yes, on average it takes less than 2 minutes to go from 20 to 60°C.
Of course, to go from 40 to 50°C takes only a few tens of seconds.

I'll time it tomorrow and let you know.

fcwilt

@bernardomattiucci

Those temperature changes seem fast.

I need to time some of my printers - they seem slower when waiting to print.

Thanks.

Frederick

bernardomattiucci

@fcwilt

Just over 3 minutes to go from 17.5 to 60°C.

https://youtu.be/c9aaBvKcnFk

fcwilt

@bernardomattiucci said in Dinamic Daemon.g:

@fcwilt

Just over 3 minutes to go from 17.5 to 60°C.

https://youtu.be/c9aaBvKcnFk

Thanks for the reply and the video.

What is the wattage rating of the bed heater?

Frederick

bernardomattiucci

@fcwilt 1200W 220v

bernardomattiucci

@oliof I have no idea how to do it

fcwilt

@bernardomattiucci said in Dinamic Daemon.g:

@fcwilt 1200W 220v

Thanks.

I now know why my beds don't heat as fast.

Frederick

bernardomattiucci

@fcwilt

"If you want reasonably fast heating to around 100C for printing ABS, then a good figure to use is 0.4W per square cm of bed area. Here are some example bed sizes and the corresponding suggested heater power..."

https://docs.duet3d.com/User_manual/Connecting_hardware/Heaters_bed#:~:text=If you want reasonably fast,square cm of bed area.

The area of my print bed is 60x60=3600cm^2. The power of the heater is 1200 watts. The ideal would be 1440 watts. But the power consumption would have too high a cost that I absolutely cannot afford. This is the reason for the script above.

Now I have to figure out how to set the variables in the CGode and, most importantly, how to read them.

And I have no idea how to do it!

fcwilt

@bernardomattiucci said in Dinamic Daemon.g:

Now I have to figure out how to set the variables in the CGode and, most importantly, how to read them.

And I have no idea how to do it!

I can help with that - I use the conditional coding, variables and meta-commands quite a bit in my printer configurations.

How would you like it all to work?

Would you considering installing the BtnCmd plug-in?

Frederick

bernardomattiucci

@fcwilt

In SuperSlicer, I have the ability to set up a GCode script for each filament set up.
This script is inserted just before the printing starts.

I would insert a number of variables into it, like this:

; Filament gcode
;Bed_layers_initial_number = 15
;Bed_layers_initial_temperature = {first_layer_bed_temperature}
;Bed_layers_limit_number = 44
;Bed_layers_limit_lower_temperature = 40
;Bed_layers_limit_highest_temperature = {bed_temperature}

At this point, from the duet daemon.g I would like to read those values and replace them in the script at the beginning of this post.

fcwilt

@bernardomattiucci

I believe that global variables will do what you want.

First you need to create the global variables - I do this in a file called create_globals.g that I invoke from config.g - but it could be done directly in config.g.

To create a global variable you do this:

global name_of_variable = some_initial_value_that_you_may_never_use

Once they are created you can set them to the desired values like this:

set global.name_of_variable = desired_value

Then to use them you do this - here I am setting temperatures for the bed:

M140 S{global.print_beg_bed_temp_a} R{global.print_beg_bed_temp_s}

It is the { and } characters that make the variable work in a command like M140

--

Hopefully this is enough to get you started - if not feel free to ask questions.

Frederick

bernardomattiucci

@fcwilt

This should work. I only did one test and it seems to have gone well.

This is the variable declaration at the bottom of the config.g:

global Bed_layers_initial_number = 1
global Bed_layers_initial_temperature = 2
global Bed_layers_limit_number = 3
global Bed_layers_limit_lower_temperature = 4
global Bed_layers_limit_highest_temperature = 5

This is the "variabili.g" macro with which the values passed via gcode are set:

;variabili.g
set global.Bed_layers_initial_number = param.A
set global.Bed_layers_initial_temperature = param.B
set global.Bed_layers_limit_number = param.C
set global.Bed_layers_limit_lower_temperature = param.D
set global.Bed_layers_limit_highest_temperature = param.E

This is the gcode line in the superslicer settings for PETG filament:

; Filament gcode
M98 P"variabili.g" A15 B{first_layer_bed_temperature} C44 D40 E{bed_temperature}

This is the same gcode line in the print file:

; Filament gcode
M98 P"variabili.g" A15 B60 C44 D40 E50

And finally, this is my updated daemon.g file:

if job.build != null
	if job.layer != null && job.layer < {global.Bed_layers_initial_number}
		M140 S{global.Bed_layers_initial_temperature}
		
	if job.layer != null && job.layer >= {global.Bed_layers_initial_number} && job.layer < (job.file.numLayers*{global.Bed_layers_limit_number})/100
		if heat.heaters[0].current < {global.Bed_layers_limit_lower_temperature}
			M140 S{global.Bed_layers_limit_highest_temperature}
		if heat.heaters[0].current > {global.Bed_layers_limit_highest_temperature}
			M140 S{global.Bed_layers_limit_lower_temperature}
	if job.layer != null && job.layer > (job.file.numLayers*{global.Bed_layers_limit_number})/100
		M140 S0

fcwilt

@bernardomattiucci

Glad to hear you got it work.

One thing to remember about M98 parameters: Certain letters cannot be used. It has to do with the fact that there is nothing special to indicate that what follows is actually a parameter as opposed to be a new command.

For example: M98 P"some_code_to_run.g" G1

You might have intended G1 to be a parameter but G1 is a valid command and gets treated as such.

The letters P and M also won't work, if memory serves, and I think there may be a few others.

I have suggested that an alternate syntax be allowed - something like: M98 P"some_code_to_run.g" (A1 B2 C3 D4 E5)

The ( and ) would make it clear that the letters are parameters and not commands.

Frederick