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[Solved] Disable 30-minute heatbed timeout on MK4?  

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Colonial
(@colonial)
Member
Disable 30-minute heatbed timeout on MK4?

I'm trying to dry some PETG using the "box on heatbed" trick, but the damn thing keeps turning off every half hour. Is there a way to bypass this, preferably without flashing the board? Maybe some "print" G-CODE that amounts to "set heatbed then do nothing for 12 hours?"

 

Thanks!

Best Answer by Colonial:

Update: I just started this (extremely simple) GCode:

M140 S70     ; Set temp to 70C
M190 S70     ; Wait for temp
G4 S 43200 ; Wait 12 hours
M140 S0       ; Set temp to 0C
M190 S0       ; Wait for temp

I have something I need to go do, so I'll report back in a few hours. If the firmware still kicks in, I'll probably just copy-paste a bunch of "bump X axis 0.1mm, wait 25 minutes" code.

Posted : 26/01/2024 10:10 pm
Sean Kane liked
Colonial
(@colonial)
Member
Topic starter answered:
RE: Disable 30-minute heatbed timeout on MK4?

Update: I just started this (extremely simple) GCode:

M140 S70     ; Set temp to 70C
M190 S70     ; Wait for temp
G4 S 43200 ; Wait 12 hours
M140 S0       ; Set temp to 0C
M190 S0       ; Wait for temp

I have something I need to go do, so I'll report back in a few hours. If the firmware still kicks in, I'll probably just copy-paste a bunch of "bump X axis 0.1mm, wait 25 minutes" code.

Posted : 27/01/2024 12:10 am
Colonial
(@colonial)
Member
Topic starter answered:
RE: Disable 30-minute heatbed timeout on MK4?

Looks like that was sufficient! It's been almost two hours and the bed is still going strong.

Posted : 27/01/2024 1:47 am
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: Disable 30-minute heatbed timeout on MK4?

The timeout at standby feature is a safety feature to prevent unattended printers being  left heating for excessively long times. 

I expect most of us, have set the Printer to Preheat to save time, then spent so long getting prepared that the safety timer has turned the heater off....   Oooops!   

When you instruct the printer to run a gcode it is no longer at idle... it is running a carefully honed, fully qualified instruction set, telling it to do very little, for a pre determined time!   and the controller is happy to be busy doing that. 

It spends the next 12 hours turning the heater on and off, to maintain a modestly stable temperature... 🙂

then it turns the heater off, and all is well!

Thought for the day... Pre heating to filament temperatures, may slow things down, 
If you heat a Prusa Mini to filament temperature, then start a standard mini profile Gcode, the Mini Gcode will now insist on cooling the nozzle to a lower temperature before Mesh Bed levelling, and then re heating. 

This factor was regularly reported when the mini was new, and is now being reported reference the Mk4 which also has a stepped heating process...

we are never happy!
🙂

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 27/01/2024 9:36 am
Sean Kane
(@sean-kane)
Eminent Member
RE: Disable 30-minute heatbed timeout on MK4?

It is worth noting that the Prusa G-Code viewer will report that this G-Code is invalid if you try to open it with the viewer (likely because there is really nothing in here), but it will work just fine if you load it onto the printer via Connect or a USB stick, and then "print" it.

I ended up naming my file filament-drying-petg-3hours.gcode and then adjusting it like this:

; see:  https://www.machiningdoctor.com/gcodes/ 
; see:  https://help.prusa3d.com/article/prusa-firmware-specific-g-code-commands_112173 
; see:  https://reprap.org/wiki/G-code#M140:_Set_Bed_Temperature_.28Fast.29 

M140 S65     ; Set temp to 65C
M190 S65     ; Wait for temp
G04 S 10800  ; Wait 3 hours
M140 S0      ; Set temp to 0C
M190 S0      ; Wait for temp

 

Posted : 08/10/2024 4:51 am
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