Can anyone tell me if there is a good reason why in the gcode startup the command “move to home position” (G1) comes before the “Heat nozzle” command (M109) ?
The process of heating is a lot slower than homing so in my mind the heating should be first of all. Maybe there is a good reason for the sequence ?
The only reason I can see is that when heating the print head will begin oozing. If you don’t home the head first you’ll get a heap of plastic randomly placed on the bed.
I think not.
It will take a few minutes for the head to warm up and then it will be at home position or are you saying the head can not heat and move simultaneously ?
M109 have a wait function. I dont think you can do the next command untill temp have been reached. However you can do a M104 then move sins M104 dont have a wait function tied to it. And then after the move do M109.
I think Raby is correct.
Also this also tells the control board that the head is at the home position.
If the control board does not know where the print head is there is no telling where it will start printing.