A question about Layer Cooling Fans

[GregValiant 1,248]

Hello to all.

I don't have a multi-extruder printer to play with so I'll ask.

Consider a Dual Extruder printer with separate layer cooling fans for each hot end.  Here is a code snippet:

T0

M106 S255 P0

(...)

T1

M106 S255 P1

What is the T0 fan speed at this point?  Did the tool change automatically turn it off?  Cura does not seem to turn fans off at tool changes.

 

Slightly different:

T1

(...)

T0

M106 S255

What is the T0 fan speed here?  Does the M106 act on the Active Extruder or would it require the P parameter to explicitly call out the fan number?

 

Some clarification would be appreciated.  Google and MarlinFW has not been much help.

[Dustin 129]

This really depends on the firmware configuration settings.. and the hardware configuration..
Lots of "cheap" idex or dual extruder machines have the part cooling fans linked to the same header.. so they are both on or both off. 

[GregValiant 1,248]

Thanks Dustin.  That's what I was thinking.  Pulling a running fan around an area (or for layers), that don't need/want cooling probably isn't a good idea but adding a second fan port might have cost .10 Euro.

[GregValiant 1,248]

I have another couple of questions regarding Cura...

I want to get the "initial_extruder_nr" from Cura in a post-processor.  Getting the "extruders_enabled_count" would be a bonus. 

What do I need to import?

What would be the syntax?

Edited February 16, 2023 by GregValiant

[Cuq 198]

from UM.Application import Application

extruder_count=Application.getInstance().getGlobalContainerStack().getProperty("machine_extruder_count", "value")

 

[GregValiant 1,248]

I have another question.  I've been playing with a post for altering Z-hops.  I want it to exit when Z-hops are not enabled in Cura (or adaptive layers are enabled, or extruder count >1, but those are OK).

 

("extrud" is the extruderlist)

When Z-hops are enabled in Cura

retraction_hop_enabled = (extrud[0].getProperty("retraction_hop_enabled", "value"))

results in 

retraction_hop_enabled = True

but when Z-hops are disabled in Cura it results in:

"TypeError: 'NoneType' object is not subscriptable"

and exits.

I have tried several things but I've been unable to get around this so any help would be appreciated.

 

(My normal system of blindly pushing buttons until I find one that works has let me down.)

 

 

[Cuq 198]

Certainly something wrong in your code but without relation with your analyse.  It works event if Z hop are not Enable.

 

from UM.Message import Message

from cura.CuraApplication import CuraApplication

 

global_container_stack = CuraApplication.getInstance().getGlobalContainerStack()

extruder = global_container_stack.extruderList[0]

retraction_hop_enabled = extruder.getProperty("retraction_hop_enabled", "value")

Message(text = "retraction_hop_enabled : {}".format(retraction_hop_enabled)).show()

 

 

Edited February 21, 2023 by Cuq

[GregValiant 1,248]

"Certainly something wrong in your code."

Cuq, putting it up here where everybody can see that I'm banging rocks together isn't helping my self-esteem.

 

I had "UM.Application" instead of "Cura.CuraApplication".  Curious that it worked with "True" but not with "False".

[Cuq 198]

from UM.Application import Application

global_container_stack = Application.getInstance().getGlobalContainerStack()

 

or 

 

from cura.CuraApplication import CuraApplication

global_container_stack = CuraApplication.getInstance().getGlobalContainerStack()

 

Should give the same Result , But I think it is better to use CuraApplication

[GregValiant 1,248]

It's still broken.  Adaptive Layers has also caught the bug.  

 

retraction_hop_enabled = extruder.getProperty("retraction_hop_enabled", "value") 

and

adaptive_layers = global_container_stack.getProperty("adaptive_layer_height_enabled", "value")

Everything else seems fine and works as expected.  

 

[GregValiant 1,248]

It ended up being my "return" line.

I used a simple "return" figuring it would exit gracefully.  Wrong.  A simple "return" implies "return None" and it wasn't the post-processor that was complaining, it was Cura when the None came back instead of the data.

Using "return data" makes it all good again even though nothing was done to the data.

 

Once again, much thanks.