Cool idea for a video. However I feel it was poorly executed, I feel a tensile test would of been better suited, as Tensile forces lead to the most failures in 3D parts, Not compressive forces. I also have to disagree with the statement that Force values wouldn’t be relevant. As a part may fail uniformly but may fail under a low force. Therefore, the load applied values would be just as if not more important when designing a part to withstand failure.
Agreed. The comment about the actual strength being irrelevant is perhaps the most stupid comment I've ever heard in this field. On the contrary, that's extremely relevant, and something I'm much more interested in than *how* it breaks. I understand that they only do a compression test if that's all they're equipped to do, but other forces would also be very relevant, as you point out.
If you want to improve tensile strength m, you would probably best increase perimeters. I think they did compression because you would improve compression resistance by increasing infill.
I believe the tests were adequately executed given the test criteria clearly stated at the beginning of the video. He said they want to learn how parts break given infill geometry. While you are correct in saying designers need to perform stress calculations to ensure the applied load won’t exceed the yield strength of the part (for critical applications [where critical is loosely defined]). But having force/stress values without any reliable strain measurements from this set of tests would not provide much help in future design processes. If his part failed at XX force, that doesn’t mean your part (of similar infill geometry) but different form and/or sometimes unknown loading conditions (additional forces/moments) will fail at that same compressive force value. BUT it probably will fail at the same stress/strain. The main problem is how can we measure the stress strain? For steel tensile stress tests, the samples are controlled to a certain diameter and length where the strain is measured laterally and longitudinally. This is then plotted and analyzed for applying to future designs with many decades of validation. That would be difficult if not impossible for a gridded 3D printed structure. Thus, I believe this was a properly executed test [video idea] because he stated he wants to identify how parts will break under compressive force. Throughout the video, he characterized each failure mode which in turn gave insight into how the geometry of the infills will affect the performance. This information will be helpful for design intent going forward. The only thing he could have done better is make a chart to summarize his findings. However I see no fault of his. Also, I’m sorry. I really don’t mean to attack you. I’m trying to engage with his videos while also trying to provide a different way to think about this video.
The mass is also an important consideration. 25% infill doesn't use the same amount of filament across types. A more thorough test would include strength vs mass and strength vs print time. Of course, as you said in most cases it's better to move the mass out of the infill and into another perimeter, so I wonder how some Cura features like alternating extra wall compares for equal-mass parts.
@@melody3741 actually you don't even have to weigh them. you can try it out yourself without even printing by looking at filament use estimates with different infill types.
This video would have been 10x better if you could have shown the displacement vs force. It would have been especially interesting to see the behavior BEFORE failure, since that's how I use most of my parts! And, how did you end up with standard grid or standard triangular being best? Gyroid pretty clearly outperformed both.
Agree, without force gauge it doesnt really give much info. And some infills are good only in one direction, so applying force in different direction would be interesting also.
So i think that would be called stress vs strain. I am more familiar with the tensile test, not very useful with 3d printing as a whole, but with tensile testing the ultimate tensile strength (UTS), yeild strength, youngs modulus, and so on. Im sure some of these can translate into compressive force testing though.
@@charliemaybe If you put the part in tension, you are measuring stress vs strain. In compression, you can measure stress vs negative strain, but what I think we're seeing here is buckling failure. That's a lot more complicated. By looking at pressure vs displacement, we should see an initial linear part of the curve, followed by something more complex as it buckles plastically. I don't care about the complicated part, since I operate my parts in the linear region. I think most parts are used like that. In the linear region, it is, in fact, stress vs strain.
Great concept here. Can you do this again with the load oriented in the Z direction relative to the part? Most infills have similar X and Y properties (e.g. "lines" loaded in X should fail similarly to "lines" loaded in Y) but behave differently in Z. Gyroid is supposed to be quasi-isotropic so it would be interesting if you can compare the numbers for these.
I was really hoping for a strength comparison… How it breaks is less important, since the whole point is “not to break”. Would have been interesting to see which infill pattern makes a stronger part (probably this would also depend on the geometry/shape of the part)… But at least for this cube, would have been very useful if you’d have mentioned the force or weight that was necessary to break the part
Characterizing failure is super important in designing. Many times we don’t know the loading conditions nor even have a model for predicting failure of our design. When bolts break, it actually is helpful to study pictures of broken bolts and to identify defining features and sort into common categories. Then if we have the back story we can provide links to certain loads/bolt characteristics that could lead to failure. The same goes for welds. Failure analysis is super interesting and vast. It’s not all about numbers. Characteristics and definitions are super helpful tools when loads are unknown. It leads to “intuition” and “experience”which sometimes is far more valuable than a college degree.
Interesting video. Would be cool to see a more in depth series on this topic. For example, how much less infill can you use to get the same strength (with numbers). Also how these patterns work with different materials.
Pretty sure CNC Kitchen did videos comparing different infills crushed at different angles, using different filament materials, instrumented so there are numerical comparisons. This was a great quick side-by-side comparison of HOW the different infills fail as opposed to a full engineering load test to failure analysis.
@@slant3dThat’s great to hear! This was super-interesting, but I did wonder what the force was when each part started to deform and how it changed after initial deformation. The comments about total mass made by some other commenters seemed important too. The strongest pattern might also use the most filament, going against the original purpose of saving filament. I personally make a lot of brackets to hold things at right angles, so would like to know how different infills behave when a beam is being bent. Of course, the answer is usually to crank up the perimeters; after a point, the infill becomes secondary. It was very interesting to see the failure modes though, and whether they were abrupt or gradual. I do agree though, that controlled force rather than controlled displacement would be most relevant to real-world applications. (I really love your whole series on designing for 3D printing BTW; I think you’re a true visionary in dismantling the myths about 3D printing and production.)
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The angle/rotation of the infill pattern can also make a huge differance. Most patterns here were printed at an 45 degree angle but just changing the angle of the infill to 0 degrees and nothing else would have a significant impact on how/when the parts breaks.
Another cool video. I don't know if it's because I haven't had lunch yet or what, but I kept thinking about cookies and ice cream cones and what fill pattern would give the most pleasurable biting experience. I'm thinking zig zag or gyroid would be best and cross 3D or Triangle would be the most painful. Ok, never mind. Carry on...😁
Great content! I’ve got 6 printers so far and I love the approach you’ve taken with your business. Here’s a topic idea: to go over 3D printing tolerances. x/y is different from z, z tolerance with and without support, elephants foot, and how some slicers (like prusa) don’t have an additional expansion setting for inner circles/shapes. I’ve found that I had to set that to .05 to get the inner accuracy to match the outer accuracy. Regardless, you could make it more of a “how to design tolerance into parts” video since you’re using these videos to show people how to design for mass production. That then fuels your business lol. Great business model. I’ve been loving part interfacing, how to attach 3d printed parts to each-other or like how to tolerance a hole to screw a hook into as an example. You could even go into how to use threaded inserts, ect. Again, great video. Thanks for the content!
Very cool video! I would love to see another zoomed in more with the parts on top of a scale to see the force as they crush. And weighing each one before would be cool too. Us Nerds want ALL the Data! 🤣
Super power (I think you mean weekness)! Also, this highlights why 3D printed part should be only used for prototyping and not "silly incoherent strength analysis"... lol
This is interesting, but the same infill percentages can use different amounts of filament which I believe would bias the results. I'd be interested to see how it would work given all the parts weigh the same?
I am missing directions. Like, you could print it at an angle of 45 degrees Z-rotation on the bed, thus rotating the infill by 45 degrees (maybe rotating the hexagonal by 30 degrees)... Should be interesting to compare which infills become more rigid that way. I am sure there are quite some differences to be seen. Apart from that, thanks for the crushings! Very nice work, indeed!
I was really hoping you'd test the compressive strength through the Z-axis as well. I can't decide which infill is stacked in the most robust pattern to hold up a very heavy, static load reliably (but with some transient shock absorption, ideally).
Yeees, like all the comments, how much plastic was used, what forces were applied and comparison of the the print times? In the future, it might be very interesting to compare different outer shapes too.
Interesting! Also, do you think the result would be different if the test object had a top and bottom (or in this case, front and back) like ordinary bodies?
You should do more of these. This is a great video. I really would like to understand the strength to speed to material ratio Is one faster for prototypes? Is one cheaper?
I use primarily 3 of them Gyroid for anything that needs some flex, Cubic for anything that needs strength, or Zig zag when speed is most critical. I also like to use modify infill blocks because most of my applications have a specific line where most of the force runs through, so those get 100% i. That area
While it is good to see what is going on inside with the infill, the missing sides add so much to the rigidity to the print. It would also be good to know others parameters of the print, like number of perimeters.
Good video, though a test along the lines of ASTM D638 would also be interesting to see. Test pieces for ASTM D638 need to have a very specific and rather thin shape, so testing infills won't be a straight process using this test. I would advice slightly oversized jaws so that the test piece can be bigger so that infill patterns can be tested by using thicker test pieces, were the only variant would be the infill pattern. Printing so that the tensile forces are along the layer lines and not across would also be needed, so that the infill is the parameter that adds strength to each test piece instead of the adhesion between layer lines.
That was super cool to watch! FWIW, lately I've been to use lightning infill and then adding however much strength is needed by putting more material into the outer walls instead of using more material as infill. Not sure how well this generalizes, but it's been great for my applications.
CNC Kitchen did some testing on this back in the day and came up with similar data supporting your method (more perimeter thickness vs infill). Worth checking out if you haven't seen it already: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-AmEaNAwFSfI.html Just a couple more shell lines tend to print faster than a higher (50%+) infill percentage as well, so there's an inherent advantage in that as well.
There are a couple videos showing the strength and reliability of gyroid is preferable over that of triangle. Do you guys opt for triangle due to time savings and minimal difference in strength?
Would you guys consider doing a video on the Quantitative strengths of More Skins Vs. Greater Infill as it applies to both the structural integrity as well as the planned failure aspects thereof? I would KILL to see that (I just don't have the workspace where this is feasible or else I would do it myself.)
I understand why you wouldn't think the force values would be relevant for this video, BUT literally everyone watching this wants to know what is stronger and by how much. Even percentages would be nice. The weakest is the baseline and then x infill is y% stronger than the baseline would be a better way to do this video.
I dont really want my parts to break. If a part breaks its broken and it doesn't really matter if the failure is uniform and nice, when the part still failed.
Really neat. Wonder how they would perform if crushed on all sides at once. I always use gyroid for most of my stuff unless it is just some trinket then I can go with lightning as I don't need hardly any infill and why not save the filament :)
Here I thought I was the only one weird enough to destroy my print mistakes just to see how and where they fail. But, just so we're clear... I'm not wearing that wig.
Could you do another one of these with PrusaSlicer infills? They have some overlap, but I'd imagine that even the grid infill isn't exactly the same between Cura and PrusaSlicer, and with those two being the most common slicers it'd add some value to have that comparison too
Why do you say that grid or triangle is the best and most reliable? It seems to me that gyroid is best because of the uniform distribution of stress and therefore lack of stress concentrations. Also, gyroid is agnostic to orientation in terms of strength.
Sorry, not knowing the force applied, using the word strength is somewhat useless. For example, lets say the triangle infill broke at 120% of the gyroid infill, how can you mention strong in that situation?
You only tested compressive stress. Would like to see the difference in tensile strength. Also, these infils are designed to take force on the Z, not the X or Y.
"How it breaks is the interesting part" wait, what? If your goal is to get more click is a RU-vid video showing a press destroying stuff, then yes. For everyone else, knowing force vs deflection would be the interesting part.
Ist es nicht eher sinnvoll die Festigkeit zu testen wenn das Bauteil liegt ? Das infill wird ja auch nicht entlang der z Achse gedruckt . Dementsprechend wäre das eher interessant anstatt das Bauteil seitlich auf zu stellen und somit den seitlichen Druck zu prüfen....
Not showing force is kinda dumb. what is the point then of showing how it breaks? Yea sure maybe i want my part in case of failure to not break catastrophically, but if i don't know how much the trade off against strength is how would i know which infill to use? also why not show stress from the top? most infills are anisotropic so its important to know the direction of force against infill.
This method of testing is not good, a tensile test is more standard. What what kid of test is this without any values? How are you gonna say one is stronger then other without measuring the forces??
This was completely pointless. Infill strength dynamics completely changes with walls. Also youre pressing only in the center and not on the walls which is also an unreasonable expectation.
Very interesting! I understood the idea is to watch the different behaviour of the infill patterns but it will also be interesting to compare if the force applied is the same or not.
Designing for failure is such a fun and fascinating topic! With most infill patterns the pattern is a fixed scale in geometry so is easily handled by slicers. From a design aspect it would be fascinating if could vary infill scale as part of the design so as to create some more robust internal structures to help direct anticipated forces through a design. Infill being part of how a design performs I a deep topic to explore from design aspect. There is much that can evolve between CAD programs and Slider programs that could lead to even more advanced designs better optimized for 3d printing.
I have never seen gyroid infill that look anything like your sample. There is no visible twist and you can see straight through it via the huge holes. I tried to replicate something like in my copy of Cura and I can'e even get close. You must be using some very unusual parameters.
How about showing one solid block with 100% infill. Would be very curious to see as I want to use 3d printed sheet metal bending molds and I’d like to know which filament to use and how strong it is with 100% infill
You can add a void inside an STL and the slicer iwill put walls around it. I heard this somewhere in youtube, maybe this channel. I’ve used this trick to add internal ribs and still keep the infill within parts. The video was pretty enlightening, thanks.
I like Cubic the most. Good video! However, the title should be how infills behave under strain, since you are not measuring force, and thus the stress cannot be deduced.
Interesting video but if you're going to go through all this trouble again, I do think having a force value would be beneficial. Obviously that is going to greatly depend on the shape of the object, but it would make for interesting comparison. Force vs total mass of the part is something to compare as well. If you're looking for ideas for a whole series of videos, you definitely could do it by making more tests with more data.
Everyone keeps posting videos on compression strength for different infill, would be great to see videos regarding other forces. For example, I print various tools to help me with assembly, some of them turn sockets or tabs, would love to see videos comparing those kind of twisting forces.
This is fun to watch and all, but I am not sure I actually gain any real insight as to when to choose what pattern to achieve what effect. Some of these seem to depend more on the top, bottom, and perimeters, and often times, this is all a balancing act. I guess I am more asking for your act of balance, than your final recommendation, but that is just me. Since I don't really crush my parts in real life like you do here, and my parts fail in totally different manners, I pick technique based on that. So when I choose a particular infill, it sort of has a history, and prejudice built into that choice. Since I have been targeting super high quality on my infill, their behavior simply is quite different. But seeing the behavior of Gyroid is a wake up call for me. I need to look closer at it again. So thanks. But all of these patterns have their strength and weaknesses, but I am not really getting any wiser, yet, from watching these.
Things missing from this test: 1. The exact force in Newtons the sample withstands. Or even better a deformation vs. force chart. With an extra: measuring elastic deformation in percentage. 2. Mass of the specimen. How much filament is used. Or as an alternative the infill ratio could have been normalized resulting the same amount of filament used in all infill patterns. 3. Testing in at least two directions of applied force. / or different infill angles 4. Comparison of printing time for each infill pattern.
It would be cool if you did a video where you design a part to be injection molded, sonce from what I know youre a part designer. It could also turn out to be a series where you doesign a part to be CNC machined, woodworked or other manufacturing processes
great video. but one thing is missing. a realtime scale while pressing the parts. the strengthness of all infills would be a nice parameter to know. thank you for your work.
there is a feature on Cura that grants you the ability to adjust the orientation of the infill pattern as well. You can turn it 90 or 45 degrees or depending on whatever you like, and it would be interesting to see the effects of that.
