syntax for {nozzle_disallowed_areas}?

[Andrew_F 0]

Hi all,

Using different brands of PLA that run at different temperatures on a UM2 with an Olsson block/2+ upgrade.

As there is no way to change temperature in Cura ( the Ultimaker draws on the values in it's config file,) I created a custom printer in Cura.

 

I am looking to block out the corners of the build plate to avoid the nozzle hitting the bed clips.  Ideally adding this to the Start G-code, assuming I can do this without manually editing the fdmprinter.def.json file

 

I did find this, which was promising. https://files.fieldofview.com/cura/Replacement_Patterns.html

 

I can change the nozzle temp using this syntax, but couldn't find a syntax on how to clip out the corners of the build plate

A 1hr google did not show syntax - tried the Reprap forums also as well.  

 

Could anybody point me in the right direction for this syntax?

 

Regards,

 

A

 

ps:

 
FWIW, the below is the custom Start G-code to allow custom temperature setting  in Cura on an Ultimaker and produce a prime blob on a 0.25mm nozzle as well as a nozzle wipe. 
For a 0.4mm nozzle, I'd increase the E values by 16/6.25 ~250%.  Not a perfect blob, but good enough to prime it.

 

M82 ;absolute extrusion mode
G28 ;Home
G0 X0 Y12; reset bed zero to miss clips
G92 X0 Y0; assign new zero position
M190 S{material_bed_temperature_layer_0}
M109 S{material_print_temperature_layer_0}

G1 Z15.0 F6000 ;Move the platform down 15mm
;Prime the extruder
G0 X0 Y10 Z0.5
G92 E0
G1 F300
G1 E13.5 Z2 F4000
G0 F300
G0 Z3.5
G4 S5
G0 Z8 F300
G4 S10
G0 X0 Y30 F2000
G0 Z 0.15
G1 X0 Y200 E15 F500
G0 X0.4 Y200
G1 X0.4 Y30 E20
G0 Z3
G92 E0

 

 

Edited May 6, 2024 by Andrew_F
Updated syntax and improve clarity

[Slashee_the_Cow 619]

Disallowed areas have to be specified in the machine's definition file, in the overrides section - not in gcode.

 

Here's an example (taken from the Ender-3/Ender-3 V2 definition if you want to add that to see what it looks like in action)

"machine_disallowed_areas":
{
    "default_value": [
        [
            [-117.5, 117.5],
            [-117.5, 108],
            [117.5, 108],
            [117.5, 117.5]
        ],
        [
            [-117.5, -108],
            [-117.5, -117.5],
            [117.5, -117.5],
            [117.5, -108]
        ]
    ]
}

 

[Andrew_F 0]

Thank you, 'Slashee,' appreciate it.

[DivingDuck 105]

Maybe as additional explanation to @Slashee_the_Cow,

The definition of disallowed areas starts from the center of the bed as origin and is defined by an polygon with x/y coordinates of 4 point's: [[x,y],[x,y],[x,y],[x,y]].

There are two types of disallowed areas available: nozzle_disallowed_areas and machine_disallowed_areas.

 

 

 

[Andrew_F 0]

Thanks D_D.
I'll dig around in the next few weeks, locate the def file and modify it.

Short term solution was to make the bed 208 x 225mm from memory - ie: the area inside the bed clips.

A

[Slashee_the_Cow 619]

2 hours ago, Andrew_F said:

Short term solution was to make the bed 208 x 225mm from memory - ie: the area inside the bed clips.

That will only work if your bed clips are exclusively on the rear and right sides. It will still treat 0, 0 as the bottom left corner and if there are clips there it's going to hit them.

 

Fortunately, if this is the case, this is where gcode can come in handy. In your startup gcode, after the G28 (home) insert this:

G0 X20 Y20 ; please replace the 20mm example there with how much space the clips do take up
G92 X0 Y0 ; make it treat this position as 0,0

 

[Andrew_F 0]

Makes perfect sense, Slashee.

Thanks.