Does Layer Height effect print strength?

[QuitNoMore]

This is a question that I can't seem to find anywhere. Does layer height effect the sturdiness of a print? I would imagine it has too, but in which direction does it go? Would a higher or lower layer height make the print stronger? Would a print with layers at 0.15mm be stronger or weaker than one with a layer height of 0.3mm?
Anyone ever test this, or have an answer?

[DrLuigi]

I did once use a stretch test of a piece of about 0.1 and 0.25, It was hardly any diffrence,

I doubt it would make a diffrence when we are talking about 0.5 or 0.25.

[RobH2]

One thing I have noticed is that on some prints with higher layers I sometimes don't get as good adhesion as ones with thinner layers. I think with the thinner layers each one may get pushed into the subsequent one better. For instance, I printed a conical part about the size of a D battery. It was about 4" tall and I used .25 as the layer height. I flexed it just a bit to test it and it split between layers. So I reprinted it a .18 and when I tested it, it was really tight. I even bent it pretty firmly and it did not separate.

I'm not sure if my printer was malfunctioning or it it's just the nature of layer heights in general, but from my experience, I don't trust the integrity of prints with thicker layers as much as I do those with thinner ones.

[MeoWorks]

One thing I have noticed is that on some prints with higher layers I sometimes don't get as good adhesion as ones with thinner layers. I think with the thinner layers each one may get pushed into the subsequent one better. For instance, I printed a conical part about the size of a D battery. It was about 4" tall and I used .25 as the layer height. I flexed it just a bit to test it and it split between layers. So I reprinted it a .18 and when I tested it, it was really tight. I even bent it pretty firmly and it did not separate.

I'm not sure if my printer was malfunctioning or it it's just the nature of layer heights in general, but from my experience, I don't trust the integrity of prints with thicker layers as much as I do those with thinner ones.

Same experience here, my sturdier prints are all 0.1mm or lower. I do think parameter (shell thickness) plays a bigger role though.

[Geoff]

Same experience here, my sturdier prints are all 0.1mm or lower. I do think parameter (shell thickness) plays a bigger role though.

Definitely shells. All my quadcopters require 20%infill minimum and 2-3 shells for rigidity. Layer height makes very little difference, but it depends on your force distribution. For a quadcotper arm, I print them flat - so the layers run horizontally, or the same way it's going to sit on the quad. If I was to print them standing up, as in long and tall... they would print layer by layer in the wrong direction...

hard to explain, but print out a small tube. Print one out standing up and the other lying down flat.

The one standing up straight will be more round and look better, but the one you printed laying down witll be 10x stronger to flex and wont snap.

Look at the two pictures. See the cylinder standing up is built with small cricles - these are ok but not as strong as picture 2, where it's layed down in long strips - this is much much more rigid.
basnap.JPGnosnap.JPG

[intohim]

I haven't done any 'official' tests, but from my experience, the smaller the layers the stronger it is. However, it would also probably depend on the material used. I'm talking about PLA here.

[trimmedup]

Layer height really doesn't effect the strength in any noticeable way. However I'm assuming there are some small differences. I've never used shell infill. I'll have to try this. Do shells work better than honey comb?

[Davo]

We like 3-4 shells with a 25-35% rectilinear infill at a 45 degrees for our printed parts; 2-3 solid layers at top and bottom.

[RobH2]

Layer height really doesn't effect the strength in any noticeable way. However I'm assuming there are some small differences. I've never used shell infill. I'll have to try this. Do shells work better than honey comb?

I haven't done any scientific experiments either but I've definitely experienced weaker parts with higher layer heights. I've reprinted a number of parts with thinner layers and they are much stronger. They don't suffer layer separation like the higher layer versions have. Again, this is just my experience as I've done no scientific stress tests.

[Frans]

Hi 3D Print Board!

I did a master thesis project about 3D printing and durability, including how layer height affects strength. I thought you may find my results interesting! I also researched and tested mechanical properties of FFF 3D-printed PLA, ABS, PET and three Taulman nylon filaments as well as other factors affecting layer bonding performance.

I will attach the major findings and data as pictures in this post, but be sure to check out the full report for further information about the tests, Google Drive PDF: https://drive.google.com/file/d/0Bxo...JWR2lHcFU/view










Feel free to ask any questions about the project. Hopefully this could come in handy for you 3D printing entusiasts!



Edit: Thanks for the kind feedback! I don't seem to be able to make new posts for some reason.