Simultaneous heating of the bed and extruder.

[tana4]

How do I set up S3D to automatically switch on the extruder and bed heating at startup at the same time? Like, for example, on a screenshot.

[greybeard]

The first question to consider is: Why do printers heat Extruder and Bed separately?

I recommend a bit of homework before burning your power board... Of course, many printers use a $30 board so, for $30, you can have some fun while creating what will end up as a paper-weight...

[airscapes]

If you want the print to start before the bed is hot, uncheck the box on the temperature tab. Some times with ABS I will turn the bed heater on while I am prepping the model as it takes 20 minutes to reach 110C.. this is why they don't go on at the same time.. your filament would be cooked to death as the extruder only takes a minute or so to reach 235C .

[tana4]

Heatbed heat at 100C in about 2 minutes. I have a 12V bed MK3 200x300 connected to 24V. I control it with an external mosfet (STH315N10). The current consumption is 26A

Sometimes the desired temperature reaches the bed faster, sometimes the extruder.

[tana4]

Is there really no way to do this?

[airscapes]

Typically the bed takes much longer to heat than the extruder.. you will be cooking your filament waiting for the bed.. However what I do when printing ABS and have the bed at 110C (takes a long time to get there even with 24v bed heater) I comment out the line in the end script that shuts off the bed heater so it stay on between prints.. have to remember to turn it off if there is no second print but it helps to speed the time between prints.

[tana4]

The bed consumes about 700W, so it is heated very quickly (2minutes/100C). I'm waiting unnecessarily for the extruder to warm up.
Or I have to edit the g-code manually, which is annoying.

[parallyze]

Or I have to edit the g-code manually, which is annoying.

Simply edit your start script to heat in the order you'd like to... depending on the firmware commands might differ.

Marlin for example:

M140 -> Set bed temperature, don't wait
M190 -> Set bed temperature, wait

M104 -> Set hotend temperature, don't wait
M109 -> Set hotend temperature, wait

https://marlinfw.org/docs/gcode/M104.html

[fythios]

You can add to the starting script to heat both up while not waiting using the variable for temperatures e.g.

M140 S[bed0_temperature] ; Set Bed Heater No Wait
M104 S[extruder0_temperature] T0 ; Set Extruder Heater No Wait