Beam Interlocking with PETG and TPU  

Beam Interlocking with PETG and TPU

In Orcaslicer (hopefully in Prusaslicer in the future) there is the ability to interlock different materials at their interface.  It's called "Beam Interlocking" and it's in the multimaterial section.  This creates a mechanical interface between different materials.  I have not found any useful information on how to be use this feature.

I am making an Ipad stand and I don't want it to slide on my countertop when typing on it.  I decided to put a 1mm layer of TPU on the bottom and print the rest in PETG.  This was my first time trying this new feature.  My first print was a failure.  It failed because the PETG was not hot enough to stick well to the TPU and becasue my PETG speed setting was too fast for the interface with TPU.

My second print went much better.  I slowed the overall speed down to about 50mm/sec and changed the PETG temperature to 265C.  This did the trick.  To speed things up after the printing the interface layers I used a height range modifier and returned the speeds to my normal PETG speeds.  I had tried the height range modifier in the interface area but found that the interface program did not create an interface when a height range modifier is present in the same area.  I assume this is a problem for any type of modifier.  That is why I slowed the global speeds and then sped up above the interface using the modifiers.

The inface strength is good but is not as strong as the layer interfaces of any one material.  When trying to break the print the interface failed between the top interface layer and the first PETG layer which was an infill layer.  Perhaps a solid PETG layer would be better.

So the bottom line is this is a great tool for the Prusa XL but it does take some adjustment of other parameters to make it work.  I have not tried the adjusting the interface settings yet, such as changing the number of layers of interface from 2 layers.  Since the weakest part is not in the interface layers I don't think this will help.

I recommend trying this to fully get the best out of your XL with multimaterials.  Enjoy!