Cura pre and post Script help for Ender 3 v2 with BLtouch

[lokester 0]

New user, Ender 3 v2 with BL Touch bed leveling, Marlin FW.  Have had printer for a few months now and using Cura 5.5 (and now 5.6) for my slicer.  Reading on the web, I get all sorts of opinions as to what the pre and post machine g-code scripts should be.  I will past my pre script below but will also attach a text file with both pre and post scripts as well as an actual gcode file from a recent project.  Currently, every time I print a job, the printer does the Bed Leveling - which I don't really mind that much, however; on another post I see where there is a way to start the bed leveling as soon as the bed is up to temperature.  My current setup does not start leveling until after the bed is at temp, and then waits more time until the nozzle is at temp.  Looking at the actual gcode from a project, I see where there are several lines of gcode "before" the pre print script.  Some are redundant.

 

Not to take up too much of your time, but request someone with more knowledge take a peek at my pre start script and the first few lines of my project gcode and offer opinion as to how to streamline my bed leveling so it starts as soon as the bed is at temp allowing the nozzle to heat up while the leveling process is taking place.

 

; Script based on an original created by tjjfvi (https://github.com/tjjfvi)
; An up-to-date version of the tjjfvi's original script can be found
; here: https://csi.t6.fyi/
; Note - This script will only work in Cura V4.2 and above!
; --- Global Settings
; layer_height = {layer_height}
; smooth_spiralized_contours = {smooth_spiralized_contours}
; magic_mesh_surface_mode = {magic_mesh_surface_mode}
; machine_extruder_count = {machine_extruder_count}
; --- Single Extruder Settings
; speed_z_hop = {speed_z_hop}
; retraction_amount = {retraction_amount}
; retraction_hop = {retraction_hop}
; retraction_hop_enabled = {retraction_hop_enabled}
; retraction_enable = {retraction_enable}
; retraction_speed = {retraction_speed}
; retraction_retract_speed = {retraction_retract_speed}
; retraction_prime_speed = {retraction_prime_speed}
; speed_travel = {speed_travel}

; Ender 3 Custom Start G-code
G92 E0 ; Reset Extruder
G28    ; Home all axes
G29 P1 ; run auto bed leveling routine
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X0.1 Y20 Z0.3 F5000.0 ; Move to start position
G1 X0.1 Y200.0 Z0.3 F1500.0 E15 ; Draw the first line
G1 X0.4 Y200.0 Z0.3 F5000.0 ; Move to side a little
G1 X0.4 Y20 Z0.3 F1500.0 E30 ; Draw the second line
G92 E0 ; Reset Extruder
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X5 Y20 Z0.3 F5000.0 ; Move over to prevent blob squish

 

pre and post scripts.pdf CE3E3V2_Massey Ferguson Steering Wheel Center Cover.gcode

[Slashee_the_Cow 409]

There isn't actually any code in the startup sequence to heat up anything. But it's easy:

G92 E0 ; Reset Extruder
M104 S{material_print_temperature_layer_0} ; start heating up the hot end
M190 S{material_bed_temperature_layer_0} ; wait for bed to heat up
G28    ; Home all axes
G29 P1 ; run auto bed leveling routine
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X0.1 Y20 Z0.3 F5000.0 ; Move to start position
M109 S{material_print_temperature_layer_0} ; wait for hot end to be hot before we start
G1 X0.1 Y200.0 Z0.3 F1500.0 E15 ; Draw the first line
G1 X0.4 Y200.0 Z0.3 F5000.0 ; Move to side a little
G1 X0.4 Y20 Z0.3 F1500.0 E30 ; Draw the second line
G92 E0 ; Reset Extruder
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X5 Y20 Z0.3 F5000.0 ; Move over to prevent blob squish

 

[lokester 0]

When I look at my gcode files after slicing, it looks like Cura is adding a few lines "before" the startup script as follows:

 

;FLAVOR:Marlin
;TIME:7272
;Filament used: 4.89266m
;Layer height: 0.2
;MINX:85.576
;MINY:81.578
;MINZ:0.2
;MAXX:145.167
;MAXY:141.168
;MAXZ:16.2
;TARGET_MACHINE.NAME:Creality Ender-3
;POSTPROCESSED
;Generated with Cura_SteamEngine 5.5.0
M140 S60
M105
M190 S60
M104 S210
M105
M109 S210
M82 ;absolute extrusion mode
; Script based on an original created by tjjfvi (https://github.com/tjjfvi)       (first line of startup script)

 

The heating sequence that I am dealing with is in these lines of code.  I will change my startup script as you suggest and see how it affects how Cura slices.

 

Thanks!

 

[lokester 0]

@Slashee_the_Cow, 

Your instructions worked great.  With the temperature preheat instructions placed in my startup scripts as you suggest, Cura no longer places any such instructions in my gcode prior to the startup script.

 

Many Thanks !!