Delay in before "Start G-code"?

[VladimirK 1]

I replaced my bed heater to silicone 600W from 220V and it heats up to 100+ in less than a minute, thermistor reports right temperature and "M190 S110" thinks the temperature is fine. However above heater I have sandwich from aluminum and glass, bed surface temperature at that moment near 90+ and 110 reaches only after +/- 5 minutes. So I put delay into "Start G-code" "G4 S300 ;wait 5 minutes". Everything is fine except all those time filament in extruder also at high temperature and some of them like PBT becomes brown, can become hard and block the nozzle.

Is this possible to automatically put delay into Cura produced G-code? I have

;Generated with Cura_SteamEngine 4.4.1
 

M140 S110
M105
M190 S110
M104 S260
M105
M109 S260
M82 ;absolute extrusion mode
; below from "Start G-code"
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z15.0 F60 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G1 F60
G4 S300 ;wait 5 minutes
;M117 Printing...

and I would like to put delay G4 after "M190 S110" but before "M104 S260". I asked on Duet forum but there is no such feature in their firmware.

Edited January 3, 2020 by VladimirK

[ahoeben 1,852]

Cura checks if you add a heatup sequence in your start gcode. If you don't, it adds its own heatup before your start gcode. If you don't want Cura to add these lines, make sure your start gcode contains lines which have {material_print_temperature} and {material_bed_temperature} in them respectively (exactly as typed, Cura will replace the {}-text with the temperatures). eg:

G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
; etc

M140 S{material_bed_temperature}   ;Start heating bed
M190 S{material_bed_temperature}   ;Wait for bed to reach temp before proceeding
M104 S{material_print_temperature} ;Start heating extruder 
M109 S{material_print_temperature} ;Wait for extruder to reach temp before proceeding

;etc

Having this in your start gcode prevents Cura from putting heatup commands in front of your start gcode. This means that you can insert your G4 S300 command anywhere you want to relative to your heatup commands.

[VladimirK 1]

Thanks!

[tinkergnome 926]

10 hours ago, ahoeben said:

make sure your start gcode contains lines which have {material_print_temperature} and {material_bed_temperature} in them

 

Wouldn't it be better to use the temperatures for the initial layer in the start script, or has the Cura behavior changed in this point?

 

{material_bed_temperature_layer_0}

{material_print_temperature_layer_0}

 

[ahoeben 1,852]

Yes, that would be better. But I always forget if it is layer0 or layer_0 or just _0, and sometimes I get lazy and don't want to look things up. So I used the temperatures for the normal layers. 😉