Additive FFF g-code optimization suggestions

[willerz]

I'm using the generic FFF post processor.

It generates this sequence which I have added comments to:

M140 S70 ; Set bed target heat to 70
M190 S70 ; Wait for bed to reach 70
M104 S205 T0 ; Set tool 0 target heat to 205
M109 S205 T0 ; Wait for tool 0 to reach 205
; move to start position
; begin printing

On my machine, a Snapmaker A350 this means it heats the bed from room temperature to 70, and then it heats the nozzle from room temperature to 205, and then moves to the start position, and then prints. This is a noticeable amount of waiting because I usually want to watch layers 1&2 print to verify everything is looking like working.

It's noticeably faster if I rewrite the gcode to:

M140 S70 ; Set bed target heat to 70
M104 S205 T0 ; Set tool 0 target heat to 205
; move to start position
M190 S70 ; Wait for bed to reach 70
M109 S205 T0 ; Wait for tool 0 to reach 205
; begin printing

This means the heating process begins, and then while that is happening the tool gets to the initial position, and as soon as the temperatures are correct the print begins.

[thomas.stock]

HI @willerz 

This is a really good point and something I have noticed myself when doing testing for Fusion FFF when I also want to watch the first few layers.

Thanks for bringing this up, I'll notify my team and we'll look to implement this in the future as I agree, substantial time would be saved - especially and very small prints where initial nozzle/bed heating is a larger proportion of the overall time

[thomas.stock]

Also apologies for the delay in response.