I’ve had a single head up and running for over 6 months and it was great after fine tuning, it was very reliable.
However, I recently purchased the second extruder kit, and when i’m trying to print with two heads I get weird shifting in the prints, weirdly though the Repetier software shows the shift on the ‘manual control’ page…
I think I remember reading somewhere about the software self centering but I can’t find that thread.
This is during the start of the print, you can see the difference in the sliced preview and the actual print:
Your object is misplaced. The second nozzle can’t go past the black dot on the Repetier plate. So Repetier positionned the second nozzle where it can print : a bit to the right.
You must place your object where Repetier shows the 2nd nozzle print.
So as the attached picture shows, I have attempted to print a single link in the bracelet, ensuring its in the center away from the out of bounds areas.
After the first layer, the whole print is still shifting to the right…
It seems that sometimes when I start a print, the wrong print head starts the print (head 2), this is when the shifting occurs. Sometimes, head 1 starts the print, which is as expected. But if I cancel the print and start it again, head 2 starts first…
Any ideas why this is happening? Is it a bug?
I’ve already tried reflashing the firmware a few times and i’ve tried on multiple computers.
I can’t make up if your slicer configured correct.
Have you told slicer that you are 2 print heads?
Normal it says single head, take duel had for use of 2 heads.
The gcode you posted is OK, so the shifting that occurs during printing is caused bu to much mechanical resistance when moving the printcarriage. Are all the rods lubricated and is your printer properly calibrated?
Hi, I just installed few days back the 2nd head and I am experiencing the same exact problem.
The first layer is ALWAYS done by head 2 and then from second layer on everything is back to normal but the print is spoiled.
I can see that there was no real solution to this post. Any help guys?
I don’t see any designation of which extruder to use. It is also never stated which extruder to heat up.
It is there in line 965 when the extruder change should happen.
So my guess is now that you ended the last print on extruder T1 and nowhere in your G-Code is stated that T0 should be used in the beginning. If I add a “T1” to your G-Code I get the same picture in the preview window as you get in Manual Control after the print has started. It is also visible in the side by side picture you posted that the shifting does not occur when the second nozzle is used. The shifting occurs when the first should be used but is not. The Manual Control window shows what the printer is actually doing and apparently it’s thinking to use nozzle 2 (T1) because it was never told otherwise.
It can be fixed by adding “T0” manually to the G-Code commands (although in an ideal world that should have been done by the slicer already), so can you please change the Start G-Code in the G-Code tab in Cura settings to the following:
G28 ; Home extruder
T0
G1 Z5 F{Z_TRAVEL_SPEED}
G1 Z0 F{Z_TRAVEL_SPEED}
M106 S165 ; Turn on fan
G90 ; Absolute positioning
M82 ; Extruder in absolute mode
; Activate all used extruder
M104 S{TEMP}
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature
M109 S{TEMP}
M83
G1 E10 F100
M82
G92 E0 ; Reset extruder position
M117 Vertex is printing
G1 F1000 Z5
(note the new “T0” in the second line)
This is the simplest version, but should actually fix the problem. That Start G-Code settings in Cura are apparently wrong, because although the comment states “Activate all used extruders…” it does not do so, because the command M104 Sxxx only works for the current extruder not for all extruders. Same with M109. So if the last used extruder was T1 it still is, because the machine was never told otherwise. For the machine there are no single “jobs” it is simply controlled by G-Code and does not reset when a new print is started.
This does not fix anything if you actually want to start with T1 so keep that in mind for future projects.
I think it has happened to others as well, but without reproducibility.
The reason is that there are only two ways how this can happen. The first one being manually priming the second extruder (T1) before printing, for example to load filament.
The second one is that a print is aborted while the second nozzle was active. This does tend to happen mostly in the beginning when there is still a lot of trial and error involved.
If a print finishes successfully then it is no problem as the End G-Code closes with a “T0” which activates the first nozzle.
I think it has happened to others as well, but without reproducibility.
The reason is that there are only two ways how this can happen. The first one being manually priming the second extruder (T1) before printing, for example to load filament.
The second one is that a print is aborted while the second nozzle was active. This does tend to happen mostly in the beginning when there is still a lot of trial and error involved.
If a print finishes successfully then it is no problem as the End G-Code closes with a “T0” which activates the first nozzle.[/quote]
Thank you Sverenja, your explanation makes perfectly sense.
Here my modified G-code
;Generated with Cura_SteamEngine 15.01
M420 R0 E0 B1; Set the LEDs to blue
G28 ; Home extruder
T0
T1
M420 R1 B0; Set the LEDs to red
G1 Z5 F250
G1 Z0 F250
M106 S165 ; Turn on fan
G90 ; Absolute positioning
M82 ; Extruder in absolute mode
; Activate all used extruder
M104 T0 S210
M104 T1 S210
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature
M109 T0 S210
M109 T1 S210
T0
M420 R0 E1; Set the LEDs to green
M83
G1 E10 F100
M82
G92 E0 ; Reset extruder position
M117 Vertex is printing
G1 F1000 Z5
;Layer count: 25
;LAYER:0
