Object breaks at color boundary
Printed a multi-material snake for my son; not two minutes after I handed it to him he dropped it on a hard surface and it broke apart, right at the interface points between the yellow and the green. Both are Prusament PLA, though the green is noted as a blend on the Prusa site. Sliced with Prusament PLA profile, though I did bump the extruder temp up 5 degrees during print to troubleshoot some loading issues.
Any thoughts as to what I might do differently to get these segments to adhere to each other better? Also, there doesn’t seem to be a reason they have to be butt-joints like this...is there a way to tell the slicer to do the infill as a single object?
RE: Object breaks at color boundary
I presume the 3D model is made up of separate segments which you configured to print with different filaments?
Since each of those segments are printed in a different material, the connection between the two segments is the weakest physical point.
A possible way to solve this is to model these separate parts so that they interlock within each other. This way, the MMU2 will print them as interlocking objects, and this might improve the physical connection between the segments.
RE: Object breaks at color boundary
Yeah it’s this one: https://www.thingiverse.com/thing:2342104
I figured the interface point was the weak point. I was kinda surprised to see it had sliced it to have perimeters between the segments for that reason; seems like if the only difference in the materials is color it would be stronger to slice the interior of a composite object like this as one continuous thing, with color changes only affecting the outside perimeters. I couldn’t find any options that seemed to have that effect though. I’m afraid remixing it to interlock is beyond my abilities. 🙁 Maybe someone’s written a tool to transform something like this into a multicolored sleeve around a single-material core; that would presumably slice more or less like I was describing earlier.
RE: Object breaks at color boundary
This one case where PLA may not be the best material. It has a tendency to shatter when extended parts are shocked, PETG would be less fragile. Reserve the PLA for inherently stronger shapes.
Cheerio,
RE: Object breaks at color boundary
@diem
This is a good point. I thought that because the shattering happened at what looked like pretty weak joints that a different slicing would make this OK even with PLA. The PETG colors that I have aren’t nearly as fun lol. 🙂
RE: Object breaks at color boundary
Search for an articulated snake model, one that will flex when dropped and be much less likely to break. There are dozens to choose from.
Cheerio,