Using Both Extruders with AA 0.4 Cores (Dual Extrude 2 different PLA colors)

[CRNudo 0]

I've seen some posts about how Cura doesn't let you change materials/colors (using the material station) in the middle of a print, thus unable to print multiple colors. Yes, it would take more time to switch colors, but I still wish this was an option. My other question though, is how come you are not able to put the other AA 0.4 print core in extruder 2 and print two colors of PLA (for example) on the same print? The Cura software allows me to select both extruders with the AA 0.4 print core and lets me choose both PLA (different colors), and it even loads both the colors into the extruders. Only when the calibration starts it errors saying the nozzles are at different heights.

 

Is there a way to adjust the height of the 2nd extruder with the AA 0.4 core so it won't error? Is there a better way to allow both extruders to dual extrude PLA using both AA 0.4 cores? 

[gr5 1,857]

1 hour ago, CRNudo said:

how come you are not able to put the other AA 0.4 print core in extruder 2 and print two colors of PLA (for example) on the same print?

You can definitely do this.  I've done this.

1 hour ago, CRNudo said:

it errors saying the nozzles are at different heights.

Unrelated.  So I don't know why you are getting this error.  I've seen this error many times and there are many causes.  To diagnose the cause I would try a few things:

1) Try running diagnostics on the level sensor - in the maintenance menu somewhere.

2) Watch active leveling when the print starts.  Watch the first 2 leveling processes which are different from the rest.  I believe it does the right core first?  I forget but it levels extra slow the first 2 times and watch what happens.  If things are working correctly it will move the bed up very slowly until it touches the nozzle tip.  It will keep going but only for about 1/4 second and then it jumps the bed away from the nozzle quickly.  Failure modes:

a) It stops well before the nozzle touches the glass

b) The nozzle touches the glass and it keeps going for another second or two

c) same as (b) but  - the nozzle may move upwards inside the print core (not good) instead of the bed moving down

 

3) Make sure the tips of the nozzles are clear of filament.  The leveling is done with the nozzles hot to minimize this as a contributor.

4) Make sure the first two leveling events are using both cores and not the same core 2 times.  If it uses the same core for the first 2 leveling events that means you have a problem with the switch on the print head that raises and lowers the right core.

5) You can learn a lot about the failure if you look at the log file.  You insert a USB flash drive, save the log file.  Then search through the log file for "peak" and "Preliminary".  I think they are supposed to be different by 1.5mm nominally and if it is not 1.5+/-0.7 then it fails?  I forget at the moment but if you publish your results I'll be motivated to look it up.

 

You may have a bad core, or not enough grease on the "fork" in the head or many other issues as well.  Maybe your springs are too tight on the bed or too loose in one of the cores.