Print a part with two materials to test adherence

[dricog 0]

I am triyng to test the adherence between Tough PLA and TPU95A. I made two blocks in solidworks and in Ultimaker Cura I put the two blocks joined by one face defining coordinates. In the prepare stage the blocks seem be together but in the preview stage, I can see a little gap between the blocks (Image 1). When I obtained the printed part, the result is not good (Image 2, 3, 4 and 5) because the blocks get separate between them (only the first layer get continue joined) but I do not know if the cause is the configuration in ultimaker cura or do not exist good adherence between the materials.

Do you know which can be the reason? Is there another way to configure the geometry and have a half with Tough PLA and the other half with TPU95A?

 

Thank you!

[GregValiant 1,115]

If the models are positioned exactly wall-to-wall, and if your machine is calibrated correctly, then the parts should remain separate.  Both outside surfaces end exactly at a plane and there should be no cross-over from one side of that plane to the other.  Maybe you could try using "Outer Wall Inset" (set to a negative number) or "Horizontal Expansion" (as a positive number).  It is likely that the end size of the model would be effected.

If there is some overlap between the models then there will be "double extrusion" in the overlap volume as both nozzle will want to extrude within the overlap volume.

Looking at the preview it appears that you have some Per Model settings that are different from one block to the other.

If the two blocks were to fit together (small mortise joints or something) then they would have a better chance of adhering.