Page 1 of 1

I start to hate PLA! (PETG vs PLA)

Posted: Mon Feb 12, 2018 5:33 pm
by CarstenWartmann
I am starting to hate PLA.

PETG was in the last month my material of choice, so far I can only see two minor drawbacks for me: You need to construct your parts thicker to achieve the same stiffness and cutted threads are quite weak (so using a integrated nut is mostly better for threads which need to hold bigger forces).

Another thing is the avaibility of colors, especially metallic looking (like copper, gold etc) colors are rare. And that lead me to use a PLA again, for a project ( I wated a nice looking material and used Copper (color, not filled) PLA which really looks fantastic.

However my overhangs looked terrible (of course I use my PLA slic3r settings :-)) and my (maybe poorly) constructed battery door snapper either did not print at all (curling and the snap from my buildplate) or did break while using. The layer adhesion seems to be too weak (compared to PETG where I did not manage to break that part) and I can't construct it any thinner to make it more flexible.

I did try some other PLA I have around but no cigar.

Suggestions welcome, but so far I will stay withe PETG. Or maybe print the case in PLA but the battery door in PETG.


PS Attached the part and where it breaks, Blender Source from the link above
Krack.png (4.15 KiB) Viewed 3302 times

Re: I start to hate PLA! (PETG vs PLA)

Posted: Mon Feb 12, 2018 8:49 pm
by chumm
I assume you printed that in the same orientation as the picture? While that makes the most sense for the shape of the model, the forces that you are introducing in the battery clip are shearing the layer lines, which will make it break easily. Any time you are bending a part you want that bend to happen in the same direction as the layer lines, not perpendicular to them. To achieve that on this print you'd print it on its side, using support material to hold up the clip and tabs. The supports will cause it to look pretty messy, but the mechanical function should be much better.

That said, anything with a snap fit will always work better PETG and even better in ABS, but if you can't get the color you want, you can probably make PLA work.