[Shift on dual extrusion print always at layer 220]

 

For me it is a mechanical problem

 

I second this.

For dual extrusion prints the possible build volume is reduced by the amount of the nozzle offsets.

Looking at the first picture - it is pretty obvious that the shift always starts at the height where the "blue" nozzle starts to print the crossbeam of the letter "T".

Probably the printhead is hitting a limiting wall (or something similar) at that height:

 

I understand. Thanks for explaining. I hadn't thought of that.

[Shift on dual extrusion print always at layer 220]

 

The gcode has no errors.

I suspect a mechanical problem.

e.g. Pulley loose

 

The drive gear on the stepper? If thats the case how would 3 of the same thing shift in exactly the same place by exactly the same amount? Im going to check now.

 

Pully/Drive gear is tight. I can't make it slip.Belt tension is like a guitar string.

[Shift on dual extrusion print always at layer 220]

The gcode has no errors.

I suspect a mechanical problem.

e.g. Pulley loose

 

The drive gear on the stepper? If thats the case how would 3 of the same thing shift in exactly the same place by exactly the same amount? Im going to check now.

[Shift on dual extrusion print always at layer 220]

I don't know your printer. But as it only occurs during dual printing did you set the offset between the 2 nozzles correctly?

 

Yes, I have done several prints that use both nozzles and they came out fine. I believe this is an issue in the slicing with cura. I included a link to the picture of the failed print. You can clearly see that the offset is fine. The failure occurs 2/3 of the way through the print.

[Shift on dual extrusion print always at layer 220]

Printer: Geeetech i3 Pro C Dual Extruder

Mods/additions: Heat sink on Y motor, air funnel across ramps drivers, filament guide.

Firmware: Marlin ( I don't know what version)

Software for slicing: Cura 15.04

Method of printing: Octoprint

Problem: When printing a dual extrusion name plate the print shifts on the Y axis 6.87 mm.

Attempts to repair issue:

1. I read that the stepper might be getting to hot and added a heat sink and monitored the temperature by touch. I stayed room temperature.

2. I thought the filament might be getting caught on the lcd and added a guide.

3. I also read that the stepper driver on the RAMPS might be getting too hot and added a shroud that funnels the air from the RAMPS cooling fan across the drivers.

Each time the shift has occurred, it was at the same layer and shifted by the same amount. I have looked at the layer view in Cura, but I don't see the shift there. I haven't had any problems printing anything else.

GCode, STL, and AMF Files Used

Any assistance with this would be awesome.