A while ago, my K8200 suddenly started doing something different - it would prime the nozzle twice before starting a print. Now, at the first prime, the extruder stepper motor buzzes like it is losing steps, but does not rotate. The second prime works normally.
What could be the cause? How can it be corrected?
Wally
[quote=“WallyL”]A while ago, my K8200 suddenly started doing something different - it would prime the nozzle twice before starting a print. Now, at the first prime, the extruder stepper motor buzzes like it is losing steps, but does not rotate. The second prime works normally.
What could be the cause? How can it be corrected?
Wally[/quote]
Can you post your start g-code please?
It is:
G28 ; home all axes
G90 ; use absolute coordinates
G21 ; set units to millimeters
G92 E0
M82 ; use absolute distances for extrusion
M109 S210 ; wait for temperature to be reached
G1 E10 F200 ; prime the nozzle
This is in the Slic3r 1.1.7 Printer Settings, Custom G-Code; I have found that if I enter it in Repetier V1.0.6, there seems to be a problem, so that is left blank.
Wally
[quote=“WallyL”]It is:
G28 ; home all axes
G90 ; use absolute coordinates
G21 ; set units to millimeters
G92 E0
M82 ; use absolute distances for extrusion
M109 S210 ; wait for temperature to be reached
G1 E10 F200 ; prime the nozzle
This is in the Slic3r 1.1.7 Printer Settings, Custom G-Code; I have found that if I enter it in Repetier V1.0.6, there seems to be a problem, so that is left blank.
Wally[/quote]
Hmm, nothing suspicious so far.
strange
Does the large gear on the extruder turn freely by hand (after it comes up to temp)?
If not you may want to check the bearings in it to see if they are freezing up.
The bearings are OK - this was not a problem while the printer worked OK, but now I am having difficulty eliminating blobs and strings. First I tried setting “Retraction Length” to 1mm and “Extra length on restart” to 1mm - it did the retract, but not the extra length on restart, it just buzzed, missing steps, then started moving and the extruder, but did not extrude for the first 5 or 10mm of travel. This was confirmed by setting the “Extra length” to 5mm and it was clear. The “Retraction speed” is set to 25mm/sec.
Wally
Edit: On checking the g-code, I find
24 G1 F1500.000 E-0.50000
25 G92 E0
26 G1 X83.573 Y70.404 F10800.000
27 G1 E5.50000 F1500.000
Line 24 is clearly the 0,5mm retraction & line 27 the extrusion with 5mm extra length. But why is the sequence of commands different, ie the speed F and distance E reversed?
Edit 2:
I also tried using the firmware retraction (see "Slic3r Printer settings Advanced - checking the box). This put G10 & G11 commands in the GCode:
G10 ; retract
G92 E0
G1 X83.573 Y70.404 F10800.000
G11 ; unretract
but it did not retract.
I then sent
M207 S1 F25 &
M209 S5 F25
and still no retract!
Wally