"Every other layer" modifier - potential patent issues (brick layering)?
Hi all. Not sure if this has ever been brought up or not. I couldn't find anything in a search however that might be because I'm using the wrong wording for this concept.
I was reading up about brick layering and the issue of the patents preventing it being implemented in slicers and got to thinking about alternative methods of increasing layer adhesion. I had the idea of changing the line size every other layer so that new lines were put down in the "middle" of the lines from previous layers. I've been using the "Alternate extra wall" feature to achieve this (using thicker/thinner infill lines compared to the walls) however it doesn't really work too well unless using only 1-2 walls and even it doesn't really work properly and requires a lot of fine tuning depending on part thickness.
So I created a modifier object that's literally a bunch of 0.2mm high cubes with 0.2mm gaps between them and I then set the modifier's walls to be 1.5x the thickness of the global wall size. The result worked quite well in terms of print quality - the lines do indeed set down in between each other and even when the outer wall's thickness varies every other layer, it doesn't appear to affect surface quality in any way.
I haven't really had the chance to really test it this does indeed increase inter-layer adhesion (I don't have the materials to) but will be getting some transparent PETG and using a G10 print bed to print a test transparent cube to see if the layer lines are less pronounced due to being "filled in" by the alternating layers. Though just with testing out parts, it does appear that the alternate-line size increases inter-layer adhesion, it could just be a psychological thing. I thought before I actually put any real effort into testing it out that I'd ask the community if anyone else has tried this.
The issues with doing it this way is that I essentially need to create a new SCAD model with a model's height and dimensions/layer height for every model I do this for, and doing it this way seems to override the top/bottom surface settings so if I have 5 top and bottom layers of 100% infill, only the first layer will have 100%, with subsequent layers defaulting to the universal/modifier infill settings.
Of course, I do wonder why no slicer seems to have an "every x layer" height modifier. I mean technically one could use a whole bunch of height range modifiers but that's pretty inefficient. I thought about making a script where I could output two Gcode files - one with thick walls and the other with thin walls and have the script splice them together in a new file by search/replacing every x layers on one file with the gcode from the second but I'm not even sure with verbose GCode on whether there's a reliable way of finding and replacing the gcode for every 2nd layer.
I wonder if the vaguely-worded patents around brick-layers are part the reason why this feature hasn't been tried before or whether this is just something that no-one has thought about before, or even if its something no-one really feels is necessary. Personally I think there are a lot of uses for having an "every x layer" modifier - for instance being able to have, say, every 10th and 11th layer have 100% solid infill to add strength/rigidity to a tall part. Curious on what others think and if anyone can shed light on the potential issues this kind of feature would have when it comes to the current patents that are still out there for 3D-printing, thanks!
