Why so many heat cycles in g-code

Bambu Lab A1 Series General Discussions
1

I’ve noticed this since I purchased my A1, I don’t know if the other machines do the same thing during their calibration cycles etc. But why cycle the heat bed and hot end.

Seems like if you were to bed level at actual print temps you’d get a even better level. Also I’ve seen hot end temps way above normal PLA temps resulting in smoking filament being purged. What is the reason behind so many heat cycles and shouldn’t the software be able to have a enter high and low temps that would update all the g-code to those settings?
Thanks
M1

2

I don’t have an A1, so I don’t know the exact sequence, but what’s the same for all printers is:

  • The high temp for purge is because the software doesn’t know what you printed before: You can’t purge Nylon with PLA temps.
  • The bed leveling can’t be done with full printing temp, because filament might ooze out of the nozzle and ruin your first layer later.
3

“The high temp for purge is because the software doesn’t know what you printed before: You can’t purge Nylon with PLA temps.”

OK but that should be a separate button on the touch display. For example I mostly print PLA. There is no reason to have a 250 degree purge since I’m not switching material type. With that as part of the G-Code on my current prints since it makes for a longer print time. I would be great if there was an option for it that you could turn off.

“The bed leveling can’t be done with full printing temp, because filament might ooze out of the nozzle and ruin your first layer later.”
Well since the AMS Lite typically has all the filament retracted that should be a non issue.

Thanks for the insight
M1

4

There will always be some filament left in the nozzle after the filament is cut and retracted.

BTW, you can modify all the GCODE for startup and end sequences within Bambu Studio so if you think you know better than Bambu Lab then edit it yourself and see how you get on.

5

Not claiming to know more at all, I was a little concerned when I was seeing 250c on a purge cycle that was ejecting smoking PLA rocks into my container, (that randomly will miss sometime and end up on the floor) and the smell of overheated PLA starting to fill the room.
Never claimed to know more than Bambu, just never needed to do that on any of my 5 other printers.
Thanks
M1