Adaptive layers

[alexz 0]

Hello, I'm printing a tensile test specimen with a compartment in the middle to insert a flexible film. I'm trying to use adaptive layers to reduce my printing time. The problem is that when I use adaptive layers I get two outcomes: In the first my compartment disappears and the layers get thicker. In the second one my compartment stays but the layer height is too thick so if the layer height is 0.2mm and my film is 0.085mm it won't stick well to the polymer. The layer height doesn't change anywhere. My question is how do I vary my layer height?

[GregValiant 1,342]

At the top of the settings dialog and to the right of the Settings Search box is a drop down list for Settings Visibility.  The bottom option is "All".  Select that so all settings appear.

One of the Settings in the Mesh Fixes area is "Remove all Holes".  Make sure that is NOT checked (enabled it will make your slot will disappear).  Another one to look at is "Make Overhangs Printable" which also should NOT be checked.

 

Adaptive Layers works well with curved features and not at all with straight vertical features (like your rectangular solid).  When you print a sphere, as the print head rises and the sides of the sphere start rolling inward towards the centerline, Adaptive Layers will note the increasing angle and make adjustment to the layer height so the "steps" are shorter and consequently the finish looks better.  The max thickness of any layer will be "Layer Height" but there will be layers that are thinner.  When there is no angle, there is no "topography change" and the layers stay the same height.

 

The end of this model is essentially spherical.  There are other radii (not shown) that cause some local variation in layer height, but denser areas indicate lower layer height.

 

When approaching the top of the spherical area, you can see that Adaptive Layers decreases the layer height.  This also has the effect of turning a 4 hour print into a 7 3/4 hour print.  It looks nicer though.

 

Within Cura there is no option to vary the layer height according to the Z height.  When I want to vary the layer height I slice multiple times and generate a gcode each time (a slice for each layer height change) and splice the Gcode files together at the Z height where I want the change.  I do enough of that I wrote my own post-processor to automate it.

 

For that model, I would print a lower piece with the slot, add the tensile specimen, and glue on an upper piece to trap the specimen.  Too often we want to print things complete when an assembly is indicated and may be a better choice.  If the "top" piece was printed with a slight raised area over the specimen location it would tend to clamp the specimen in place.  I don't know if you would want that, but it's an option.

For location, I put matching 2.2mm holes in each piece and set "Horizontal Hole Expansion" to 0.1.  That allows me to super-glue pieces of filament into one piece which are my locating pins to align the second piece.

 

 

 

 

[alexz 0]

Thank you so much!