Waiting for Chamber Temp  

RE:

You can turn it off in the slicer in Expert Mode by going to Printers->Custom GCode then putting a semicolon in front of where it says "G29 G ; absorb heat":

I have this saved as my own custom printer profile + with code to use a nozzle wiper mod. This way you don't have to make this change every time.

RE: Waiting for Chamber Temp

Thanks, that helped. The hot end still goes down to 130 but it goes right back to 170 for the leveling. Before when it went down to 130 it stayed there until the chamber came up to temperature then went back to 170. This saves about 8 minutes. I am going to see if I can edit the start gcode to eliminate the hotend cycling down to 130. I will update my progress.

RE: Waiting for Chamber Temp

You can, via the M104 and M109 commands. Read the according pages on the Marlin G-Code website. There's setting, waiting while heating, waiting while cooling or waiting for both.

I'd recommend drawing a flow chart for the Start G-Code, before changing things. Too easy to make crucial mistakes. (not really for nozzle temperature changes, but in general) 

I'm using draw io for such tasks, since it's "free" and can be used standalone or in a browser. 

RE: Waiting for Chamber Temp

Thanks, I'll check that out.

RE: Waiting for Chamber Temp

I changed the relevant section

     {if chamber_minimal_temperature[initial_tool]!=0}
     ...

so that the heating/waiting occurs only when the chamber is heated to above 36 °C - i.e. it heats for every material except PLA, PETG and FLEX:

{if chamber_minimal_temperature[initial_tool] > 36}
; CHAMBER HEATING AND WAIT FOR MATERIALS THAT NEED >36 °C CHAMBER
M104 S{idle_temperature[initial_tool]} ; set idle temp
G1 Z10 F720 ; set bed position
G1 X242 Y-9 F4800 ; set print head position
M191 S{chamber_minimal_temperature[initial_tool]} ; wait for minimal chamber temp
M141 S{chamber_temperature[initial_tool]} ; set nominal chamber temp
M107
M140 S[first_layer_bed_temperature] ; set bed temp
{else}
; SKIP CHAMBER HEATING FOR MATERIALS WITH MINIMAL CHAMBER TEMP ≤ 36 °C (E.G. PLA, PETG)
M141 S0 ; disable chamber heater
{endif}

Also I changed the section

    G29 G ; absorb heat

so that when the chamber temp is below 36 °C, absorb heat is ignored:

{if chamber_minimal_temperature[initial_tool] > 36}
G29 G ; ABSORB HEAT FOR HIGH-TEMP MATERIALS
{else}
G4 S5 ; SHORT PAUSE INSTEAD OF SOAK FOR LOW-TEMP MATERIALS
{endif}

G4 S5 gives a minimal 5-second pause for low-temp materials to avoid skipping abruptly.

If you use this, make a backup of your default custom g-code, just in case 😉

RE: Waiting for Chamber Temp

Posted by: @claylj

Is there a setting to turn this behavior off?

Waiting for the chamber to come up to 35c takes almost 10 minutes. This is way too long to wait for the print to start.

It's commonly called 'soaking time' and it's a good thing, and with some printers people may wait 30 - 60 minutes.  You want to do the z homing and mesh probing just after the temperature stabilize.

The Core ONE chamber heating is relatively fast compared to other printer, probably because of the small volume of the chamber. That's a good thing.

RE: Waiting for Chamber Temp

Thank you for sharing this gcode.  I'll grab a copy of it in case I need to use it in the future. 👍 

In many cases, the Core One is already so much better at retaining heat than the Mk4S that bed holding will be improved even when the heat soak phase is shortened.  The firmware already gives us a chance to skip this if we're standing next to the printer, but I like the option to avoid that extra step when I don't want to babysit.

Just last week I was running some test prints in real polycarbonate (not a blend), and for that I already knew that this printer would be below recommended chamber temp while at it's absolute max.  I was willing to patiently wait for everything to heat up (bed at 120, nozzle at 290, and chamber at 55), even if it took 30-45 minutes before the print started.   It does get a bit easier to wait for this heat-up/heat soaking time when your material costs $96/kg. 😆 

With regard to printing TPU/FLEX.  I recommend picking up a sheet of garolite, wet sand the top surface, clip it on, and adjust your bed temps to zero in the filament settings.  It is a pure joy to run prints with zero bed heat because they start right away, hold very well, and still release easy enough.  *Don't forget to turn the heat off, because the hold gets too strong if you accidentally keep it on.*

-J

RE: Waiting for Chamber Temp

Thanks to everyone for your input. I have decided to leave it as is since it seems to be a good thing. It would have help if Prusa had provided more info on this feature.