Separation of layers or failure with the grain?

Z-Peers ~  I'm in the process of revising my design files because I'm moving from Replicator 2 and PLA to M200s and Z-ABS. PLA was more rigid and stronger but much less temperature resistant (melts in a car on a sunny day) so I'm bolstering my designs with more material where necessary. I've attached a picture of Z-ABS printed pieces that are failing the "spirited fondle test" and I'm trying to understand if it's a layer separation issue or if it's failing naturally along the filament grain as a structural issue. I can't consider Z-UltraT because it's too expensive for these products (I can't use $4 of plastic on a $7 item).

I do have an enclosure (top is open) on my M200 but started having issues with it getting too warm and not feeding filament so I'm working with the enclosure open on the sides for now.

Print settings:  .29, High, Full, 20%

Any idea on the difference time-wise and adhesion between "Normal" & "High" speed?

Should I try with the fan at 0%?

Would love to hear your thoughts. Thank you!

I don’t know the exact dimensions of your piece but by the looks of it that’s a tall print and if you want better adhesion between layers you need the heat inside of the enclosure to prevent warp and delamination. It’s a must not an option with abs. Your zortrax shouldn’t clog with the enclosure on if the top is open. I would check on that first. I printed a 60 hour print with full volume of the bed and had no warp or layer delamination with the print. You may want to contact zortrax support or upgrade the fan from the extruder assembly located on top of the aluminum block.

Ps I wouldn’t use the fast setting on large prints either you want to give the layer time to adhere to the layer below it

Yep, I agree with Techbuilder.  You might also want to try a slightly smaller layer thickness.


Thank you both! I'll slow down the speed, check the fan & reclose the enclosure and try a slightly smaller layer thickness as well. Will let you know what I discover. I appreciate your help!  -David

David, I have had the same problem with .39 layers. My hypothesis on what is happening is the thicker layer contains more heat/volume than the thinner layers, but have around the same surface area to adhere to. Think of a tube. It will always only have a small point where it touches the ground, regardless of the diameter. More heat means more shrinkage when it cools, which exerts greater force on the point the layers bond, creating cracks. Especially in taller objects.

I would certainly try printing without the fan, however it didn't help much for me. Keeping the chamber as warm as possible is also a must, but even at 52C my parts still split.

Perhaps UltraT might work better in this regard, but the higher thickness layers aren't available for this material. Not sure why.

I've had good results since yesterday with increasing outer wall thickness (.8mm), slowing the print speed to "normal" and printing with the enclosure. wilsonj your comment on thicker layers shrinking more and cooling differently makes since and appears to have been fixed with slightly thicker walls all the way around.  Thanks for your help and thought provoking ideas.  -David