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Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 7:19 am
by s3030150
Hi,

I have experienced problems when printing solid layer on top of infill, especially on larger surfaces. the beginning of solid layer line does not hit the infill and it curls (upwards mostly). Then the nozzle hits the curled ends and makes mess. It is possible to avoid this happening by not blowing on the layer right on top of the infill.

My question is, is there any way to turn off printing fan for solid layers? Even better, for 1st layers after infill layer is done?

I have tried post-processing script, but it does not appear to support any variables like [fan_speed_percentage].

the fan speed via M106 is set only on the points specified in Cooling tab. it is not called before every layer.

can anybody advise please?

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 7:30 am
by wirlybird
Go to the cooling tab and on the left side enter a set point for the fan.
The on there is probably something like:

1 0
2 100

So add one where the first number is the layer height where you want a speed change to take place such as -

57 0


Then you can add another to turn the fan back on like this -


60 100

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 7:31 am
by s3030150
yeah, thanks but I'd like to do it automatically.
S3D is a piece of software sophisticated enough to do that. My question is rather general, I don't want to put cooling points for every of my prints

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 8:46 am
by wirlybird
On the other hand I don't want S3D trying to decide when my fan should run. I'll take care of that.

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 9:57 am
by s3030150
yeah, good to know.

not my case anyway, I would like to automate the process as much as possible. Back to the question: is there anything I can do to turn the cooling fan off during solid layers?

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 10:11 am
by wirlybird
You might look at the gcode to see if the start of a solid layer is identified by something like with a comment or something.
You might then be able to do a substitution in the script box below the start script or wherever it is, I forget, to have it add a line when a condition is met.

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 10:27 am
by s3030150
sorry it must be my english or whatever makes my question unclear. Here is what I want



every start of a solid layer is identified as a comment

Code: Select all

; feature solid layer
now I make substitution using {REPLACE} to:

Code: Select all

{REPLACE "; feature solid layer\nM107\n" "; feature solid layer\nM107\n"}
after this layer I need to turn the fan on again. That's not a problem by finding next layer comment. The problem is the VALUE which I need to set the fan, which is the value valid for actual layer. How to find out that value? Variables cannot be used in post-processing scripts, I cannot do this:

Code: Select all

{REPLACE "; feature solid layer" "M106 [fan_speed_percentage]"}
can you suggest something?

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 10:41 am
by wirlybird
I really can't but I am sure someone can.

I wonder if you can use the layer at the turn fan off and increment it to get a new layer point?

Re: Unable to turn off fan for solid layers

Posted: Wed Dec 19, 2018 10:47 am
by s3030150
no, not an option. I need to leave fan control to S3D (bridging, overhangs, short layers) but I need to override it on solid layers on the infill layers