Load cell sensor and oozing filament
When I switched from Creality to Prusa back in the day, one Plus for Prusa (at least in my eyes) was the P.I.N.D.A sensor. The Creality CR6 already used a load cell for bed leveling, but you had to take care that there was no filament oozing out of the nozzle prior to bed leveling.
Sure - with a heated nozzle the filament would simply be squished, but either it could leave an unwanted mark on the print bed or it could affect the measurement, considering the claimed high precision of the load cell.
Recent updates to the Mk3 firmware seems to make the Mk3 ooze out more, whereas it did not ooze at all before.
So I wonder if and how Prusa addresses this issues with the Nextruder in the Mk4.
RE: Load cell sensor and oozing filament
Will be the same way its addressed now and that you could also use the method on the creality. You preheat the nozzle to a no ooze temperature of around 160-170 (for pla) , that makes the filament soft enough to not be a problem but means you dont get bits left all over the bed when sensing. It's easy to modify the start gcode to do this. The mini is already set up that way and some of us with Mk3 printers were doing it before the mini was ever released lol.
RE: Load cell sensor and oozing filament
The MK4 profiles released today. Seems like the starting gcode is already doing that. Here's a snippet related to the temps and mesh leveling:
M140 S[first_layer_bed_temperature] ; set bed temp
{if filament_type[initial_tool]=="PC" or filament_type[initial_tool]=="NYLON"}
M104 S{first_layer_temperature[initial_tool]-25} ; set extruder temp for bed leveling
M109 R{first_layer_temperature[initial_tool]-25} ; wait for temp
{elsif filament_type[initial_tool]=="FLEX"}
M104 S210 ; set extruder temp for bed leveling
M109 R210 ; wait for temp
{else}
M104 S170 ; set extruder temp for bed leveling
M109 R170 ; wait for temp
{endif}
M84 E ; turn off E motor
G28 ; home all without mesh bed level
; probe to clean the nozzle
G1 X{(min(print_bed_max[0], first_layer_print_min[0] + 32) - 32)+32} Y{((first_layer_print_min[1]) - 4)} Z{5} F4800
M302 S160 ; lower cold extrusion limit to 160C
{if filament_type[initial_tool]=="FLEX"}
G1 E-4 F2400 ; retraction
{else}
G1 E-2 F2400 ; retraction
{endif}
M84 E ; turn off E motor
G29 P9 X{(min(print_bed_max[0], first_layer_print_min[0] + 32) - 32)} Y{(max(0, first_layer_print_min[1]) - 4)} W{32} H{4}
{if first_layer_bed_temperature[initial_tool]<=60}M106 S100{endif}
G0 X{(min(print_bed_max[0], first_layer_print_min[0] + 32) - 32)} Y{(max(0, first_layer_print_min[1]) - 4)} Z{40} F10000
M190 S[first_layer_bed_temperature] ; wait for bed temp
M107
;
; MBL
;
M84 E ; turn off E motor
G29 ; mesh bed leveling
M104 S[first_layer_temperature] ; set extruder temp