Cura/resources/extruders/deltacomb_base_extruder_3.def.json

{
    "version":              2,
    "name":                 "Extruder 4",
    "inherits":             "fdmextruder",
    "metadata": {
        "machine":          "deltacomb_base",
        "position":         "3"
    },

    "overrides": {
        "extruder_nr":                   { "default_value": 3, "maximum_value": "3" },
        "machine_nozzle_size":           { "default_value": 0.4 },
        "material_diameter":             { "default_value": 1.75 },
        "machine_nozzle_offset_x":       { "default_value": 0.0 },
        "machine_nozzle_offset_y":       { "default_value": 0.0 },
        "machine_extruder_start_code":   { "default_value": ";Deltacomb Extruder 4\n;Put your custom code here"},
        "machine_extruder_end_code":     { "default_value": ";Deltacomb Extruder 4\n;Put your custom code here"}
    }
}