in the embedded software, there is no blocking of the filament supply to the rod at a temperature below 200 degrees, and the extruder tries to push the filament onto the cold heating element at startup.
Snapmaker j1s
How can you arrive to such a situation?
for example, I have a starter gcode, and its launch begins after the table is warmed up, a 10 cm long plastic line is printed to clean the nozzle. on all my other printers, if the nozzle temperature is below 180°-200°, the extruder does not squeeze out the plastic, here the extruder tries to push through the plastic when hotend is cold.
protection must be enabled in the firmware, which can be disabled by a special command
Setting minimum extrusion temperature at 170C seems to be a reasonable choice but only on PLA. What if ABS or ASA is used? There even 200C can be too cold for successful extrusion.
I can imagine pushing too cold filament through the extruder is either G-code where temperature settings are not properly addressed or users fault, or, of course, fault in heat block temperature sensor. But in latter situation cold extrude prevention will not function anyway.
then why is everything with protection normal on other printers ?
and this printer presses at 30 ° degrees
Any protection against faulty situations is valuable.
But I am still wondering how you can get J1 squeezing room temperature filament running a regular sliced Gcode? My J1 (like any other printer I have been running) waits few seconds more until heated bed and one or both extruders (depending on print mode chosen) have reached their target temperatures and only then starts to print = run extruder stepper.
I myself am in shock, this has happened several times already, here is my starting g.code
G28 ;
M117 ;
G92 E0 ;
G1 Z1.0 F3000 ;
G1 X2 Y20 Z0.3 F5000.0 ;
G1 X2 Y150.0 Z0.3 F1500.0 E15 ;
G1 X2 Y150.0 Z0.4 F5000.0 ;
G1 X2 Y20 Z0.4 F1500.0 E30 ;
this usually happens when you start the second print.
In particular piece of code there is nothing about setting or controlling extruder or table temperatures.
G28 is homing axis
M117 is about LCD messages
G92 E0 is positioning extruder at zero
All remaining G1 lines are for linear moves
I have not been digging into J1 Gcode files yet but on regular Marlin you should have M104 or M109 command like “M109 S200” when hotend will wait for 200 C to be measured by probe and only then will continue on to execute next code line. With two printheads the relevant head has to be written in M109 parameter line as well.
WeTransfer - Send Large Files & Share Photos Online - Up to 2GB Free here is a video on one there is a normal operation of the printer on the second a snapmaker that squeezes plastic onto a cold one I think j1 in the file Configuration.h/line
//# define PREVENT_COLD_EXTRUSION
no temperature limit.
@Gex Why don’t you just change your start Gcode? If it is not possible to use M302/M500 you can use the released source files and compile your own firmware with the feature enabled…
@Gex Probably you are doing with printer something more advanced I have never been around but here is Starter G code as I have it in all my print files if sliced for SJ1 using Cura 5.3.1:
;— Start G-code Begin —
M104 S215 ;Set Hotend Temperature
M140 S52 ;Set Bed Temperature
G28 ;Home
G1 Z0.8
M109 S215
M190 S52
G1 Z0.8 F6000
M201 X10000 Y10000 Z500 E5000
M593 P1 F50
M205 V5
G92 E0
G1 F200 E2
G92 E0
;— Start G-code End —
If native Luban slicer is used, Starter G code is rather similar:
;— Start G-code Begin —
M605 S0
M104 S210 ;Set Hotend Temperature
M140 S65 ;Set Bed Temperature
G28 ;home
G1 Z0.8
M109 S210
M190 S65
G1 Z0.8 F6000
M201 X10000 Y10000 Z500 E5000
M205 V5
G92 E0
G1 F200 E2
G92 E0
;— Start G-code End —
As you see all commands controlling temperatures on hotend (M104, M109) and bed (M140, M190) are there and this is a reason I really can not kick in how you arrive to starter G code without these parameters?