UM3: only fine (0.1mm) profile available with 0.25 AA printcore

[pbackx 9]

I just installed a new 0.25 AA PrintCore on my Ultimaker 3 and loaded it with Ultimaker's silver PLA.

 

I was expecting some very fine and detailed profiles would be available for this core, but in Cura 3.1.0 I only see a "fine (0.1mm)" profile.

 

Initially, I thought that this was due to the other PrintCore (which is right now a 0.4 one). However, after forcing some other settings for that PrintCore, no other profiles appear.

 

Do I have to define those profiles manually or is there something else missing from my config? Or is this not possible with PLA?

 

[ghostkeeper 75]

Nothing is missing from your configuration. There is indeed only the 0.1mm profile.

 

When developing a 0.06mm profile we ran into some oozing problems. The reason is that the flow rate for 0.06mm layer height with a 0.25mm core is so extremely low that the material stays inside the nozzle too long and becomes too fluid. It was all right if printing large swaths of material in between but if you retract a lot, such as for thin pillars, then it was a big mess of strings.

 

The Materials & Processing researchers are still working on their profiles for 0.25mm on 0.06mm layer height. It's not clear whether there will be a profile any time soon.

 

As for higher layer heights, you'll quickly hit the flow limits. I'd think that 0.15mm would still be possible, but I don't think that is the focus for the 0.25mm cores.

[ultiarjan 1,162]

1 hour ago, ghostkeeper said:

The reason is that the flow rate for 0.06mm layer height with a 0.25mm core is so extremely low that the material stays inside the nozzle too long and becomes too fluid.

 

So are you saying the CORE design is less suited for printing tiny things compared to f.e. the UM2 heater design? Even in single extrusion?

 

 

[ghostkeeper 75]

25 minutes ago, ultiarjan said:

 

So are you saying the CORE design is less suited for printing tiny things compared to f.e. the UM2 heater design? Even in single extrusion?

 

 

Maybe the hot chamber of the 0.25mm core is too large? I don't know how they compare, really, because another factor is that our standards for print quality have gone up considerably since the 0.06mm profiles for the UM2+ were made.

[pbackx 9]

1 hour ago, ghostkeeper said:

Nothing is missing from your configuration. There is indeed only the 0.1mm profile

Ok, thanks for the explanation.

 

So if I understand it correctly, the main advantage of the 0.25 printcore is the reduced line width of the extrusion.

 

So you get better resolution in the xy-plane.