Variable line width/supported skin

[dtylerb 0]

I've recently switched from a 0.4 nozzle to a 0.6, and for the most part it's been a good move - I do mostly functional prints and I've benefited from faster printing with few down sides. The one down side I've noticed recently though is that supported areas look worse than before. I assume this is just because of the fact that the line width that makes up the skin is now 0.6 instead of 0.4, and the bigger lines just look worse, and they probably sag more - since a wider line is going to need a bit more cooling.

 

Unless I'm completely off-base or missing a setting or something, I was thinking it would be a good idea if there was an option that allowed you to select a smaller line width for supported skin as there is no reason why the lines here couldn't be 0.4 or possibly even a bit smaller despite the fact I'm using a 0.6 nozzle. When I google information about minimum extrusion width by nozzle size, the information I find seems to suggest that you can print a line width 60% smaller than the nozzle size.

 

[GregValiant 1,250]

You can do this with support blockers.  You might be able to configure the Bridge Settings to do something like this as well.

I set this up with a Line Width of 0.6 at 0.3 layer height.  The support blocker is configured to Modify Settings for Overlaps and then as a Cutting Mesh (Infill mesh didn't work).  I selected "Top/Bottom Line Width" as the lone setting.

The block is "Layer Height" thick and the bottom of the block is flush with the bottom of the first layer above the support interface.

You can see the difference in the line widths here.  The wall division is caused by the Cutting Mesh which I kept in the middle of the supported area to show the difference.  The layer above this one has 0.6 Line Width and no wall lines dividing the surface.

 

Another option for you to investigate is to enable the Bridge Settings and see if you get something usable.  Setting the Bridge Skin Support Threshold to 100% makes Cura treat the first layer as a bridge.

 

The main problem is that your air gap from the top of the Support Interface to the model has gone from .2 to .3 so there is going to be more sag no matter what you do.

In this model the first layer over the support is cantilevered and so it is going to drop .3mm to the top of the support interface.  As a consequence the second layer will be under-extruded as the real world layer height at the cantilevered end will be 0.6.

 

 

 

 

Edited December 7, 2022 by GregValiant

[dtylerb 0]

Thanks for the reply, I've marked it as a solution. I've done that sort of thing with support blockers before, didn't really think to use it for this scenerio, but I suppose it would probably work. I'll try it. I still think it would be a useful thing to be added in to Cura as an option that you can just tick or untick.