Balancing the heating process

[Serge]

Hi,
I've noticed that the extruder will get to its preset temperature in a minute or two. The bed however will take 5 to 10 minutes to reach its preset temp. Is there a way to delay the extruder heating routine so both temperatures will be obtained at approximately the same time?
Thanks

[JFettig]

Some slicers are set up to heat the bed, THEN heat the extruder.

My code typically starts like this:
M82
M106 S0 ;fan off
M140 S80 ;set bed to 80C
M190 S80 ;wait for bed to hit 80C
M104 S235 T0 ;set extruder to 235C
M109 S235 T0; wait for extruder to hit 235C

I'm guessing yours sets the bed, then sets the extruder, then waits for the bed, then waits for the extruder - you could re-order those lines to be similar to what I show and it'll work more efficiently rather than cooking the filament in the nozzle while the bed heats.

[teoman]

Yes there is.

Which software are you using to generate the GCODE?

In matter control under Settings > Printer > Custom G-Code there is Start G-CODE

you should modify that to be:

M190 S{bed_temperature}
M104 S{temperature}
M109 S{temperature}
G28

Which basically says, set the bed temperature and wait for it to reach temperature, then set the extruder temperature and wait for it to reach temperature then perform homing.

I prefer to have first the theated bed heat up, and then the hotend, I believe this gives time for the heat to reach the surface of the heated bed.

[craftymethod]

In matter control, I just punch the bed temp in manually and when that's done I turn enter the nozzle temp value.

[McSlappy]

Same here, I preheat the bed quite a while before printing.
In part so that I don't have to wait, but mainly because I think there's a 'settling' which occurs as the bed heats up, warps slightly, then flattens back out. Perhaps this completely in my mind, but it feels good

[teoman]

Hnm....

But it is a good question.

How would you start the nozzle heatup procedure say 5 minutes after you start the bed heatup?

[teoman]

Ok, if you really really want to do this, you would first need time your heating times.

Lets say that your times are 2 min for the nozzle and 10 min for the bed.
What you want to do is start your nozzle heater 8 minutes AFTER you start heating your bed.

There is a command in repetier called G4, it looks like a wait command. As a parameter it takes seconds. So your 8 minutes would be 480 seconds.

Code: Select all

- G4  - Dwell S<seconds> or P<milliseconds>

So, if we reshuffle JFettig's example:

Code: Select all

M140 S80 ;set bed to 80C
G4 S480
M104 S235 T0 ;set extruder to 235C
M190 S80 ;wait for bed to hit 80C
M109 S235 T0; wait for extruder to hit 235C

Which would get your extruder heating started 8 minutes after you have started to heat the bed. And then it basically first waits for the bed to finish heating up and then waits for the extruder to finish heating up, but they should finish more or less at the same time.

PS: I have not tested this but i see no reason for it not to work.

[rpress]

I set mine up to go like this:

Code: Select all

M104 S151  ;preheat hot end to 151C
M190 S{print_bed_temperature} ;heat bed
G28        ;move to endstops
M109 S{print_temperature} ;fully heat hot end

So it pre-heats the hot end with M104 (which doesn't wait for it to get there), waits for the bed to heat, and then finishes warming up the hotend. I chose 151C because the nozzle won't ooze at that temperature but it's hot enough to turn on the extruder steppers.

[Serge]

Thanks JFeeting and Teoman,
That was my problem. For some reason the command M104 was first, followed by M140. Both heaters were starting at once. That was an easy fix and also it is giving me the opportunity to get acquainted with G-code. That is a good start for me. Thanks.