Brick Layers - Why did no one do this before?

[@lightsnsiren79]

We own a print farm and run hundreds of prints in PETG that are subject to high daily stress loads. We found that larger nozzles with slight over-extrusion increasing the XY plane contact between rows along with optimal temp gave us the highest strength. There is an upper limit though, forcing us to design based on the print direction. Stefan, I’ll have to run some torture test samples at the larger nozzle diameter to see if it’s worth implementing for our prints. Thanks for the info!

[@nick11crafter]

Get back to us with your results please

[@rockstopsthetraffic]

I have a much smaller operation but my use-case is similar in scope, functional prints of PETG. I'm also curious for your results.

[@Firehazard159]

Is there a way we can follow you for updates? Lol

[@ramicaza]

Very interesting. By “slight over extrusion” do you mean flow rate or line width?

[@shodanxx]

Try z axis fuzzy skin, half layer height on all walls

[@connorerb2338]

Coming from concrete strength testing, you want the test cylinder to explode under compression. If just a part snaps off, or it cracks just by one cleavage point than the test cylinder is not homogeneous. Similar to how your parts exploded it likely means more parts of your model were experiencing stress at the same time tell the plastic itself had to give. For ridged materials optimal strength testing often ends with an explosion.

[@brianhunt6943]

Yep That one PETG test gave me flash backs to concrete cylinder test in Material testing 101. The rebar reinforced ones would shake the building when they went off it done right!

[@Arterexius]

Pardon me, but I struggle to see the similarity in material properties concerning Concrete versus Plastics. Plastics usually behave worse in strength tests when particles are introduced to the structure, whereas concrete derives its strength from the aggregates mixed in. Injection molding of PETG should preferably make the part string out when subjected to tension (as in these tests). However, since these parts aren't entirely homogenous due to the process of 3D printing rather than injecting liquid material into a mould, I'd argue there's an increase in strength due to the parts being more homogenous than traditional parts. I base this off of the parts breaking in several directions, rather than just cleanly snapping off. If they were less homogenous, they would have broken sooner

[@brianhunt6943]

@@Arterexius Ideally in both cases neither should end up with a plasticity failure. plasticity failures are nice in that it gives you a safety factor, but fractures in multiple planes means the part took all it could handle in the current composition. Plastics can benefit from aggregates as well. Carbon fiber and glass reinforcement is valuable in plastics. This printing style is getting a lot closer to what you would expect with an injection molded failure. Concrete, steel, plastic, wood. It's all just materials and when engineered *chef's kiss* just right that's key.

[@Arterexius]

@@brianhunt6943 Ah, I must have misinterpreted what you meant. I thought your argument was that it was further from what could be expected with an injection molded part, rather than closer. Apologies for that and thanks for the explanation that aggregates work well in plastics too.

[@jakobhansen1396]

​@@Arterexiusconcrete paste can have strengths upwards of 400MPa and commercial strength products and commercial products around 120MPa but aggregates are suddenly the weak point. Sheared granite aggregate looks cool though

[@mausball]

The crack features on the brick printed parts strongly implies increased vertical and horizontal bonding, leading to increased homogeneity, which is why the failures were 3d and not 2d. The 45 degree oriented bonding in the brick prints is notable in this regard.

[@BOTmaster15]

I wouldn't be suprised if printing sample horizontally wouldn't bring any better sample resistance. I would expect this feature in slicers in near future after this video.

[@Martial-Mat]

Is that a good thing or not?

[@Resyektt]

@@Martial-MatI believe it’s good because it’s sharing the stress on bonds across both planes rather than just horizontal (layer adhesion) I could be wrong though

[@QuippersUnited]

But if that is the case, the failure plane would still be perpendicular to the force vector. The parallel cracks would suggest that there is now a different travel path for stress, along a secondary plane of anisotropy. I bet this would be confirmed by prints made flat on the bed.

[@enotdetcelfer]

Yes but this is different than brick. A brick pattern, as he illustrates in the beginning with the blocks, is when the vertical surfaces are distributed over multiple cells above and below it. This successively doubles the surface area that is carrying any load. Instead, with this hexagonal linking, while it connects each course to more courses and of course makes it stronger, is not a brick pattern. he says there is an issue with stacking vertically, but staggering vertically maintains most of the qualities of the vertical stack and only partly links horizontally to more tracks, but arguably it already connected horizontally, and instead of just linking to the nearby track, is now linking to two nearby tracks on each side, but half as much. he should instead do what he describes in the beginning of the video and actually stagger horizontally.

[@Pizzapleaze]

I'm a bricklayer. Problem here is your stacking your "bricks" again, just on a different plane. Real bricks on running bond sit so each brick sits equally above two other bricks. The point of this is to divide the weight of the wall equally down, so the compressive load is much greater. Shear strength is not it's specialty. Your thumbnail image would be more correct if you rotated it 90⁰. In the thumbnail all I see is four stacked columns. But that would only be for compressive strength, which is all real bricks do.

[@JokerDoom]

This was my thought but I’m not a bricklayer and didn’t know how to explain it.

[@Epsicronics]

Yeah comparing it to bricks doesn't work anyway since here we are testing pulling forces, not compressive, 3d prints already do fine under compression. But the thumbnail is correct if you think about layer adhesion, with normal layers, a line only adheres to it's sides and down, with this pattern I does slightly melt into and adhere to the ones diagonal below it, so the thumbnail is sorta correct in showing the contact points between each line.

[@GeneralMalaize]

I thought the gain in interweaving layers would be in lateral shear, not in the way he tested.

[@lacikeri3102]

Even though the direction is different, you also bind the brick, and here also the fibers. That's the point. If you stacked the bricks on top of each other, the wall would fall.

[@NijiflianBustock]

Regardless of if the layers are stacked like bricks this technique increases the amount of layers each strand is touching; in theory increasing bond strength between layers.

[@ethansdad3d]

A 10% increase in strength with negligible changes in print times sounds pretty good. Seems like prints using this method may be more water tight as well. We need definitely need more testing. Great video!

[@chrisblake4198]

I suspect the boosts would be even more significant if you tested for twisting or bending.

[@Cineenvenordquist]

It sounds conceptually bankrupt since MIT published well on this and of course the issue is running a heat pump and/or thermal IR panels to get the heat bay good and hot for adhesion and mixing (where my ultrasound hot end at?) Though on the other hand you don't want the heated baseplate overperforming or motors and controls overheating. Weird good news; looks like NIST (in Nature Communications ystrdy) found a way to use cellie compasses to do clutch NMR or at least some low key chemical measurement, though maybe outgassing things like PETG losing the glycol to atmosphere are too small.

[@ethansdad3d]

@@Cineenvenordquist Even if true that MIT published this, it's not "conceptually bankrupt" to have the same idea.

[@uncertaintytoworldpeace3650]

What about sandpaper thing that scratches up slightly the top of printed piece for better connection like in pottery?

[@mattiaslundberg5806]

@@uncertaintytoworldpeace3650Maybe a micro jagged edge on the nozzle tip to get a similar effect with greater bonding surface

[@mw4222]

I tested this method last Auguest for my Master's degree. I implemented it in PrusaSlicer with some CAD trickery. In addition to the things tested in the video I also tested a parameter that I call overlap. Overlap is the amount that the adjascent extrusion lines intersect with each other. resulting in a more solid part. My results showed that at higher overlap this new approach had no advantage over traditional printing (where higher overlap can be achieved my simply extruding more). The max interlayer strength I acheived was ~35-36Mpa in PLA for both printing methods, but the interlocking layers were printed slower because of double the amount of layer changes.

[@chipcode5538]

Share your results and explain why Stephan measured an increase of 10 to 14%. If you trade speed for strength this is a good thing to know. If the increase in strength is not worth the effort it is also a useful outcome.

[@mw4222]

@@chipcode5538 In this video neither method (interlock and normal) have been pushed to the limit in terms of (over)extrusion. My objectives were a bit different in that I only wanted to test the case where both have maximum extrusion. The nice thing is that I realised both can achieve essentially solid parts, but these solid parts do not have uniform properties as I hoped probably due to the thermal history. Another difference I forgot to mention was that I used ASTM 638 samples which are a different geometry and are solid instead of hollow. However I doubt this would make a huge difference. Ultimately I moved on to other projects. But I wish someone with the equipment could test this idea with more other parameters including material, geometry and other things. Maybe some other materials that are natually good at layer adhesion can benefit from completely solid parts. Another thing I would like to mention is that if you recall the transparent part video, the strength gains were better than this iirc, which kinda is in line with what I found. Overall extruding like crazy will give you higher strength IMO.

[@GeekDetour]

I hope your thesis didn’t result in a company patenting anything - otherwise we will just see it in our lives in three decades 😂

[@owend7212]

one idea i had was to mount the extruder motor to the side of the printer and have a carbon fiber hexagonal drive shaft with a Teflon gear that can slid along it making the hot end super light but still direct drive

[@orbatos]

​@@GeekDetourdepending where it was published it's probably already been sold

[@laszlom.3581]

let's hope this goes viral and the big slicers start implementing stuff like this

[@ldeadpirate9432]

Yeah! We need to share this, definitely.

[@electronicsandewastescrapp7384]

If the big slicers aren't watching this channel with every new video I question their commitment to the industry. @@ldeadpirate9432

[@MrBaskins2010]

after seeing how arachne caught on, i'd say give it 6 months

[@thezyreick4289]

Why? When I implemented and tested it, it came out with weaker parts. I think a lot of it has to do with what kind of printer you use and quality of filament. On my bamboo p1s this made things worse on strength. But on the Bamboo the layer cohesion is already extremely good. I get the concept, it’s not new or revolutionary by any stretch, it’s rather cute and has been done many times. But on higher grade printers, this reduces layer cohesion, resulting in high stress points forming as layers don’t fully bond together. The reason this method is useful for bricks, is because those bricks are not all one solid object, they are multiple objects that are not actually connected, so you have to rely on mechanical connections like interlocking to make them strong. Good printing is not that way though, it’s not multiple separate parts, it’s one solid part, welded together basically. Interlocking like this does not get done in welding applications because it has no practical benefit or effect, and hurts weld integrity even. 3D printing is inherently a welding process. The material is heated up to a critical point that allows it to melt together with other material to form a single solid.

[@SubjektDelta]

maybe they never implemented it, because it is not worth it?!

[@phillipremondini5617]

This is amazing!!! This is the exact reason I watch this channel. Not only to learn how to 3d print but to better the process of 3d printing. I'm not an engineer but was always fascinated by how things were made and how to make something better. This is exactly what this channel offers. Thanks you Stefan!!!

[@4TheRecord]

3:03 There is a 2020, patent but it's a copy of a 1995, patent which had expired so this process is public domain now despite the 2020 patent which should easily be challenged in court.

[@TheAramil]

I don't know how this video ended up on my dash given that I don't own a 3D printer, but I still want to acknowledge your craft. This was both eloquently and succinctly explained, your theory and tests show a strong grasp of the underlying physics, the graphics are clear and informative, and whenever you presented data you did so in a clear and complete manner. Content entirely aside as I don't care about the topic, I still stuck around to relax in the presence of charts with titles, honest axes, and even error bars. Thank you!

[@The3DPrintingGrandad]

Stephen is an excellent content producer. Explains enough but not too much and refers you to other videos for further information you want to know more.

[@eeuse1]

This is indeed a low-cost but effective improvement plan. Thank you for promoting this idea!

[@CNCKitchen]

Thanks! Appreciate it.

[@wormball]

@@CNCKitchen i think you should try slightly increasing flow and temperature, the print may be even stronger

[@MMOchAForPrez]

​@@wormball Wow!! Great suggestion! If you could just adjust the flow to be higher on every inner layer, it'd make a much more homogeneous piece. Print the outside layers first for a barrier to keep the over-extruded insides from oozing out, and you might have yourself a winner!

[@sippingthe]

can someone translate this to dollars please, i’ll match it

[@halkihaxx5]

Always amazes me how the most basic stuff gets neglected for so long. A child could've identified the problem, given enough information, lol.

[@JLaFs]

"Simplify3D" That's a name I haven't heard in a long, long time

[@chevsev]

yep, a lot of us gave up on them about 5 years ago when they told us to pay AGAIN as our free life time updates didn't give us the new version, that and the advancement of free slicers just killed the hobbyist interest in it.

[@chain3519]

Haven't used it in 5-6 years

[@frijoli9579]

I use it when I want better support removal. It still works best in that application.

[@reasonablebeing5392]

Still using it for non-complex prints (which are in the majority), best and easiest to use interface. I did pony up the discounted update fee gladly.

[@btraker]

It's an older code, sir, but it checks out.

[@juliejones8785]

I actually submitted this as an idea for Bambu Studio/Orca Slicer almost a year ago. It is nice to see it in action. My use case was to make thin walled parts, such as a simple bin/cup stronger by using the offset layers. Imagine a part with a wall three lines thick. Now offset the middle line in the wall, as you have demonstrated. There is no longer a single layer line cutting through the wall. line

[@leocurious9919]

Indeed, it might not be relevantly stronger in tension, but shearing should be much better.

[@supermerill]

Problem is, with slopes, it doesn't work anymore.

[@leocurious9919]

@@supermerill What do you mean? How does it not work anymore?

[@chrisc1140]

@@leocurious9919 The next "low" layer will be partially on top of the previous "high" layer. The mushyness of the plastic still gives you some room to work but it'll probably limit slopes a bit.

[@R0x0r]

Also, couldn't you make the inner lines in walls have higher extrusion so they fill in the space more? You could print the outer lines first then with higher extrusion the inner ones.

[@injesusname3732]

This exists in Cura.. partially. Set infill layer height higher/lower than regular height. Select extra infill wall count. Also increase the outer/inner wall overlap. You should get at least 3 walls overlapping. That's the limitation as far as I know.. but most people dont print with more than 3 walls.

[@rexsolomon6325]

I print only in high strength filament. I don't bother with ABS or PETG, etc. That your brick laid model exploded (rather than cleanly detach from a layer) is ample proof that you have achieved injection level strength. A 10 to 14 percent increase in strength is very significant in functional parts. Great work Stefan!

[@HippyEngineer]

Increasing extrusion temp and enclosing the printer might create a more bonded structure using this pattern. Really great work!

[@Arterexius]

I agree, it would probably make it sensible to build a heated chamber for low melting temp polymers like PLA and PETG

[@oasntet]

Alternately, since the middle perimeter is supported on two sides, you could try disabling part cooling for that perimeter. That should give it way more time to bond to the other two perimeters, and maybe even the next two put down on top.

[@mariusbendiksen163]

Maybe also a higher print temp so it’s more likely to still be at a “receptive” temp when the adjacent line is laid down.

[@MrGerhardGrobler]

​@@mariusbendiksen163 interesting, I usually print my PLA at 225 for that purpose. People point out that I loose the luster of the PLA at that temperature. But I print functional parts. Not display pieces. I need it strong, not pretty.

[@arthurmoore9488]

@@oasntet That's a neat idea, and I'll bet he could test it in Simpify3D.

[@naasking]

Great idea. If combined with the techniques you described in your video about 3D printing clear "glass" (slower, hotter), I think you'll basically fill the voids between lines and the part would be very strong.

[@TheRealPlato]

I was suprised to see any voids in the corners. If I don't get my first layer a near perfect rectangular cross section I have adhesion problems with PETG

[@MMOchAForPrez]

​@@TheRealPlato What kind of build plate are you using? I've heard so much PETG slander about adhesion. Some people say it adheres so well to bare glass that it can chip the build plate on removal... Other say it never adheres at all. I really don't get it, as I've had only a few adhesion issues printing PETG. And that's only on very long prints. I tend to just used glue stick or Magigoo's PC adhesion promoter on every print these days just so I can forget about the whole problem.

[@adamrosenhamer3762]

This channel consistently produces some of the best 3d printing content on the whole platform. Not just in form but in function as well, advancing the community farther and farther with ever video!

[@srilemobitelsrile8809]

Geek Detour made a video about a patent that you were searching.

[@DarkElf2k]

If it's a 202x era patent, it's nuked from orbit from a patent from one of the pioneers of 3D printing that expired globally in 2016. The only thing keeping us from doing this is, bluntly put, cowardice on our part. ;)

[@kimirikscreations]

I can't believe I haven't seen this tried before. It feels extremely obvious in hindsight, especially after seeing how fdm prints tend to split. Thanks for the great work as always, Stefan!

[@zipforth]

Impressive results! I wonder if increasing the flow rate for the middle, higher, wall layer could fill the triangular gaps between bricks more completely, like filling a trough

[@migueldias1873]

This is something really worth looking at!

[@astrodoug1]

I was wondering the same thing.

[@jacob.jaeggli]

Same

[@splowski]

Like mortar to the bricks. Maybe even a different, low viscosity filament in between.

[@APMtube9000]

Fascinating. This is a common source of strength at the molecular level too! Metal becomes more brittle and less likely to slip when the atoms form a tight lattice like this.

[@bosstowndynamics5488]

One thing I couldn't help but notice was that the contact patches for the brick slicing seemed smaller, even though there was a larger number of them. I can't help but wonder if this might have reduced the potential strength gain and if it's possible to increase the extrusion multiplier slightly to increase the squish of each layer and try and increase the contact patch size

[@joshcarter-com]

You identified the main problem with this test: his layers were too high to start with. With low layers they squish into rectangles (in cross section) and as you get to high layers they look like circles. Layer bonding area drops towards zero and tensile strength falls off a cliff. In my experience, nozzle diameter to layer height ratio needs to be 2 or greater. I very much like this idea but I wish he’d done this test with a more conventional layer height (say 0.2mm).

[@Tyler-wg5xh]

That extrustion multiplier makes sense too since you are imparting more "void" space since printing lines naturally tend to round out. I wonder how much a small amount of extrusion multiplication would add to final strength

[@joshcarter-com]

In PrusaSlicer’s default settings, it uses a 0.45 extrusion width on a 0.4mm nozzle. This plus a layer height of 0.2mm or lower creates perimeters that don’t have the giant gaps.

[@frankroquemore4946]

@@Tyler-wg5xh This plus extruding at the high end of the material’s temperature range so that it really squishes itself into the voids might get even closer to near perfect contact!

[@frankroquemore4946]

@@joshcarter-com right but we could increase that for taller layers to make faster prints that take better advantage of this too right?

[@marcbrasse747]

Just had a mighty row with a friend about this very subject. How to make sure that the circular filament fills out the square “channels” in which a slicer “thinks”. He said I was too lazy to make a better = thicker design. I said there is something fundamentally wrong if slicers can not adopt to this problem. Until then 3D printed parts will be very much weaker the those made with conventional molding technology. You’ve taken an important step in the right direction with this very experiment. Well done!

[@Janovich]

the solution would actually be quite simple. Print outer walls first, then for inner walls increase flow so it fills out the empty space neatly squished between the outer walls.

[@marcbrasse747]

@@Janovich In theory? Yes. In practice?

[@S_Roach]

@@marcbrasse747 In practice, I think it'd tend to warp if that's the only change you made.

[@marcbrasse747]

@@S_Roach Your remark is a bit cryptic. Please explain what you mean in more detail. 🙂

[@S_Roach]

@@marcbrasse747 I suspect if you created a shell, then filled that with hot filament, which, please remember, is a non-Newtonian fluid, in that it readily expands after it leaves the nozzle, to its "natural" diameter, that you'd end up with a shell that was being pushed on, constantly, by the filler. I think this would likely result in a print that tended to change its shape over time. To warp like green wood does. It would probably be more obvious in thinner-walled prints. But, that's only my speculation.

[@frankjs]

I'm very late to this comment section, but hopefully you read this and give some thought. Something similar to this, that I have been thinking about for a long time is printing the even and odd perimeters at different extrusion rates. So, as an example, let's consider a five perimeter print. The outermost perimeter, let's call it perimeter 1, then perimeter 3 and subsequently perimeter 5 would be printed first. After perimeters 1, 3 and 5 are finished, perimeter 2 and 4 are printed at a higher extrusion rate, lets say 115%, calculated to fill in the star shaped gaps between layers 1, 3 and 5. Speed might also be reduced to allow the melted filament to fill said gaps. Maybe this is something that already exists en slicers, but have just never seen it. Hopefully you can give this a try, Cheers!

[@Max_Ivanov_Pro]

I'm not an engineer, but the science behind this is fascinating! The potential for improving 3D printing processes is incredible. Great work, Stefan!

[@injesusname3732]

you're a bot, pushing crypto scams. everyone should report

[@Tenuki2]

Dear Stefan, maybe you could host a competition? You already have equipment for testing and this way people would be encouraged to innovate unique slicing methods and verify them. Just an idea.

[@colbylippincott7173]

This would be super cool. Have a standard model, material, and print temperature. Then test the tensile strength to weight ratio using different gcodes people submit, along with their slicer settings and post processing scripts.

[@Zilli_341]

I'd love to watch something like that. Sometimes people have revolutionary ideas and don't even realize it, or don't share them thinking that someone else probably beat them to it.

[@chipcode5538]

I vote for this idea.

[@varencilator]

He did something like this a couple years back except for designing a hook to submit to a competition held by some plastic manufacturer.

[@AustrianEconomist]

This is brilliant. Commenting to bump it up.

[@C-M-E]

I remember trying something like this in 2017 by taking a page out of my composites experience with alternating patterns and rotating layers. It was a pain in the butt getting the printer to run them concurrently without inducing a concentrated repetition zone where the initiation point wasn't a blob in a corner. Gyroid infill works in about the same way and doesn't require manual code adjustment, but it would be worth trying again with modern advances of the last few years on the entire layer slice.

[@hyper_bullet_5097]

The hexagon truly is the bestagon...

[@carlos-ys1xc]

i think highly of the hexagon too but i think i like them by chance. why do you like hexagons?

[@lockplace]

People like you move things forward. Thank you.

[@pantisflyhand]

10% -14% suggests more adhesion than I initially thought. Neat. Great work as usual.

[@dhivan]

Neat

[@masakikusahara5365]

Hi Stefan, what an amazing idea and execution! One add-on I've come up with... MORE FLOW. Let me explain. AFAIK most printers (extruders) are set up to feed slightly less than 100% material. Like 98 to 99%, and that is BEFORE any manual flow rate adjustment you apply. That's because you need to compensate for the inevitable air gaps between the round edges of the "bricks". But with this staggered layering, there's going to be less gap, so you should be able to feed more and yet maintain the dimensional accuracy. And if you really want to take it to the limit, you could keep the reserved flow for the outermost perimeter and push more into all the other perimeters in between. This can make the print much stronger I believe, and I really hope you have time to try it!

[@wormball]

And also i think it is worth to slightly increase the temperature cos the hot sausage is contacting more cold plastic, and it has to slightly melt all of this.

[@masakikusahara5365]

@@wormball Great idea, totally makes sense!

[@antoniomromo]

This is one of the many reasons I love this channel. Not just how and why to 3d print, but amazing explanation of what 3d printing can become.

[@namankansal6131]

How about implementing a random number generator in the slicer, so that the thickness of a small section of any print line is different from it's neighbouring lines in all directions. Potentially introducing a lot of internal asymmetric patterns creating additional area for adhesion.

[@lillegitimate]

If some of the inner layers' height was intermittently doubled, such that the cross-section of some lines is lenticular in shape, it may produce more strength along the diagonal, reducing the catastrophic failure incidents. An example might be at 7:53, the exact frame where it breaks. It breaks nearly symmetrically along the diagonal in the middle, and the two pieces fly away in opposite directions. However, the fractures occurred at nearly the same spots mirrored vertically along the item, which happened to be diagonally along a fault line. The breaks occurred at nearly the same angle which appears proportional to the slope of a slanted failure. My thinking is that failures like that might be caused by the near homogeneity in the size of the material, just like how concrete with near homogenous aggregates can tend to be weaker due to the lack of anisotropic strength due to the accumulation of variances of the aggregates, similar to the fundamental problem of laying your bricks on top of each other. Could be wrong though, but this is just an idea.

[@hayden9944]

Like this idea. 7:56 - certainly introduces other unwanted results but to learn about this we need more testing. PETg should never explode like this. It’s just so difficult to quantify FDM part strength because there are soooo many variables - and these variables become clear from one part to the next. When I want strength - I print my parts one at a time, rather then layer by layer. Your brittle parts were probably the ones that cooled the most between layers. The heat of your previous layer is really important for strength. Printing one at a time not only allows for reduction in complexity- but also allows you to think more critically about the part you are printing - especially in achieving strength. Printing one at a time also reduces the chance of inconsistency in extrusion. I think we need to start breaking down the variables one by one and addressing them. An ideal job for machine learning. But to start with it we figured out… 1. Optimal previous layer temp vs nozzle temp. 2. Extrusion multiplier vs cooling Obviously the above points interact with one another. But if we start breaking it down we will learn. Then we can decide what technology should be added to make it work together. Just to add - keep going! You can find solutions if u keep going! Ur very good - keep going

[@radioactivesdesigns3554]

They have alot of videos on similar tests. The point here wasn't maximum strength, it was to show the difference with this singular change. That being said, I would love to see what this change does when trying to achieve maximum strength of a specific part. Enclosures, reduced fan speed, hotter temps, slower print speed.

[@hayden9944]

@@radioactivesdesigns3554 - yes I agree. I have followed for a good while. But the over-arching goal is to increase strength of FDM parts - which is a great goal because it’s tricky. I really liked the clear printing results. I learned from that myself - helped me print stronger parts. I feel like the clear printing parameter would be a really good place to start on achieving the holy grail of layer bonding. I would love to see more deep diving into this.

[@SianaGearz]

PETG is actually known for flash crystallisation under stress, which causes it to fracture and explode in all directions, forming sharp edges. I have no clue what causes it, it's a weird material. It's also quite capable of producing almost isotropic prints with no clear weak plane even under normal printing algorithm, with just the outer perimeter bead corners and model geometry causing stress risers.

[@hayden9944]

@@SianaGearz - do you mean 3D printed PETg? - PETg sheet / stock is pretty consistent and ductile. But I have seen all kinds of weird results with PETg printed - sometimes really ductile - sometimes really brittle.

[@Lolwutfordawin]

All of my petg parts I've made that underwent prolonged cyclic loads exploded just like that, multiple mounts and adapters I made to attach stuff to my motorcycle (nothing safety critical!) Eventually failed spontaneously and catastrophically just like that. Different filaments and geometries, never failed along a layer line either since I printed to not have significant loads in those directions. Reprinted with CF nylon and they've lastest more than 2 times as long without a single sign of wear so far.

[@101rotarypower]

The essence of this channel for me! All these incremental improvements and optimizations, one of these days Stephan is going to hit upon a critical advantage that can't be ignored for its improvements.

[@juhotuho10]

Super interesting! definitely needs to be investigated further and hopefully get something like this implemented natively in a slicer

[@mcbrite]

I've only ever resin printed and I'm STUNNED!!! that you are the first guy thinking of that in 2024 no less... That's crazy! Gut gemacht!

[@dubadubsk8]

As a welder : what about FILLING these gaps ? what about pushing the material down between the previous layers instead of gently droping plastic and hoping for a weld ?

[@TheInevitableMan]

You can increase the flow of material in your printer settings, that way it spills out more from between the previous layer and nozzle, potentially filling gaps. But you can't really push down since the filament is liquid when printed. What would create a stronger bond is printing at a higher temperature (or reducing fan speed to like 50%) and printing slower for better temperature control. What I think this method improves is adhesion between two rows on the same layer as well as an increased surface area between consecutive layers.

[@thomasfeix7979]

I'd be very interested in testing this approach towards air/water tight prints. Those interlocking lines should also help with reducing gaps between extrusion lines.

[@brettzolstick989]

5:33 I would love to see an impact test along the layer lines like this as well. I fee like that's where the biggest improvement might be with this method. Also, what if you could over-extrude all the inner layers of the wall to fill in those gaps? Could lead to even stronger layer adhesion and maybe more water resistant parts.

[@Ahmad-ii6ht]

The use of dimensional adjustments in simplify was pretty smart! I think most people don't realize how powerful the process settings in Simplify can be. I would have never thought to use them this way. Nice video 👍🏼

[@aleks-ivanov]

True, I used Simplify 5 years ago to achieve the adaptive layer quality almost without time loss (outer perimeter is 0.05mm, inner and all other model parts - 0.3mm) using the same technique with multiple printing processes. Even 5 years later there are no slicers which can offer me this incredible functionality.

[@Moxe.]

couple opinions of mine: 1. great fricking video! 2. great fucking idea 3. In metal-based material science the idea of a crack path is used to analyze the short and long-term strengths of a material. There, one wants to "force a crack to change direction as often as possible". Instead of extrusion lines, metals are composed of tiny little crystals that can deflect the crack in just the same way. I think in English they are called "grains"...Long story short: The idea of increasing part strength like this is already investigated, so research could be built on what has already been figured out for metal grains. 4. Apart from anisotropy, porosity is also a rather significant mark of quality for not only FDM but all of additive manufacturing (except for SLA i guess). The volume the molten polymer has to fill is "framed to a lesser degree" in your approach. This should impact solidification and therefore porosity. IMO these tests should include density measurements + cross section images of the actual part to give some insight into this. That might explain the PETG vertical crack. 5. one last thing...: to truly give a transparent representation of this approach, you would need to disclose the number of filament lines in your test parts + the number of additional interface areas due to the high offset. I would have loved to see that. One might even set the raw crack area of both versions in relation to the part strength... sorry for my incoherent sentences. i love the idea.

[@gerrychen]

One thing you might be interested in is that, for isotropic materials, the break line in pure tension is actually 45 degrees since if you work through the equations (e.g. see Mohr's circle), the max stress is actually 45deg off from the direction of force applied. This is obviously only valid for isotropic materials (e.g. if you pull a rod of steel, in the break interface you will see a cone; and not just the necking - talking about the actual break interface) and I think applies to a smaller size scale than layer lines, but I think there's still two things that should be considered for features/tests like this: 1. The exact type of test matters. A pure tensile test is only testing very particular part properties and can significantly deviate from practical performance, especially for non-isotropic materials 2. Changing the orientation of layer lines can have non-intuitive effects on strength. I wouldn't dismiss your negative results as just being due to print issues, since as part of the scientific process, I don't think it's unreasonable to say that they may be suggesting our intuitions on interlocking layers may be flawed. If we look very closely for example at the images in the flat layers at 7:13, I would argue that all the little flakes we see /might/ be evidence of 45deg angles in the breaks. Awesome idea and testing!

[@WallyMay235]

It would be super interesting to see how the brick method affects shear and bending strength. A lot of as printed lugs and bosses have that failure mode and I think the brick method could provide a big improvement there.

[@danilolattaro]

Came here to say the same. I missed some shear loading testing

[@Jynxx_13]

I've tried to do something this before but never got it to work properly. My attempts never got past the first 10-20 layers when the print was irrecoverable. I'm happy to see you actually did it!!

[@SmithyScotland]

A true innovation. I also appreciate how extensive your testing is.

[@brian-z9e]

As a bricklayer, block layer, stone mason; we also add steel horizontally and vertically. As concrete has great compression strength and not such great pulling strength. By adding steel to our work; ie. rebars and or wire lock; we transfer the pulling strength of steel to our masonry, and the compression strength of concrete to the steel. 🇨🇦🙂👍

[@howeydesign]

Really interesting analysis! I've been 3D printing for several months now and I'm learning new things everyday. I had thought about how layers are stacked on top of each other and have broken a few prints by mistake, usually due to poor layer adhesion. This is a really interesting approach - thank you for sharing!

[@m_IDEX]

Great Idea! You should also try shifting extruder lines horizontally just like bricklayers do. Neat S3D trick!

[@GeekDetour]

PURE GENIUS! Stefan, you just figured out the best Draft settings ever! This could be the best 0.32 layer heigh way of printing fast and strong parts. 3D Printing will be better because of this video. Way to go man!

[@identiticrisis]

This was my conclusion after reading the post about over extruded solid parts being equally strong with and without stagger or overlap. This is faster and stronger, for rapid prototyping only.

[@EricPeelMusic]

It's better, but it's not nearly the best. The best would be to print with the fibers aligning with the flow of tension and compression and leave no hole in the center of the cross section of the model as seen in the demo. Instead of a mere 10% improvement, there could be a 20x improvement.

[@giuseppebonatici7169]

A potentially even better solution could be a system of channel and fill. but require 5 layer at least, so it creates something like this: nomeclature: layer x : sequence of the height of the extruded plastic layer 1: 10111 layer 2: 10101 layer 3: 13001 layer 4: 10031 layer 5: 10301 goto layer 3 this way you can create more planar decoupling, but it is a lot harder to implement. the other thing here is that the channels where the multi line is filled could suffer thermal failure an suffer some bucking (or eventually, re melting and welding better the vertical interlayers). Also, this solution only works in close-to-vertical walls. and would reduce printing time as some of the load (machine limiting factor? idk) would move from the kinematics to the extruding system.

[@avomateselfadhesivecablesy9078]

I have tried a similar approach printing relatively basic, flat designs in vase mode. For example a flat profile piece of say 2mm thickness, I use a 0.6mm nozzle and set my perimeter width to 1mm. The ramp effect essentially criss crosses the layers and provided your perimeter width is half the wall thickness both sides of the "vase" bond well. I've used it to produce som nice strong parts with the added bonus of no seam lines..

[@bcs7686]

I love that you keep pushing fdm printing forward with your enthusiasm and your testing good job

[@BaghaShams]

I think you just invented a whole new and important step in 3d printing's history. Incredible work Stefan!

[@NWRefund]

The secondary cracking looks to me like you are approaching isotropy. This is definitely a positive development. I’m excited to see what can be done with ideas like this. Varying deposition width and thickness to direct forces to more advantageous areas. Would it be possible to print a part with small-diameter z-channels, then, when the print head gets to the top of the part, instruct the nozzle to pause over each channel and inject material down into it? I’m curious if you could increase tensile strength by adding z-oriented structural members in this way.

[@colbylippincott7173]

This! I just left a comment about this haha.

[@scalyshooter3033]

Dang little injection molding channels would be incredible!

[@bogdan1543]

Good idea. Bah, in reality might be difficult to achieve. To inject some molten plastic for some length in such a channel you must create a pressure all along already filled region of this channel. Thus, you need to seal somehow the channel entrance and a nozzle. Nozzle is hot. It will melt the walls and plastic will go all around the nozzle but not in the channel. However, maybe it depends on the channel length, and having such a stitches between 3-10 top layers is achievable.

[@robblincoln2152]

@@bogdan1543 consider the possible use of a second material which has a lower melt temperature. It likely wouldn’t bond as well to the surrounding “jacket” but it might offer additional shear resistance none-the-less.

[@akuusist]

This just popped in my KZbin so I'm a bit late... I've tried this by creating a part with z-axis holes and modifying gcode to do the 'extrusion'. 1) Superheated nozzle (260 degrees for PLA instead of 230) 2) Pressed nozzle tight onto the hole (half a layer into the surface) 3) Quick extrusion with some tuning to get timing right (hot PLA was dripping from the nozzle) Managed to extrude about 10 layers deep, which is promising, but I thought same as @robblincoln2152: One should use a second nozzle with lower melting point & viscosity material. Even something like cyanoacrylate if one could prevent it blocking the nozzle.

[@stardust0901]

i feel like increasing extrusion rate in the central layer(s) may fill in the cracks way more and increase homogeneity while maintaining external layer accuracy

[@mouseman225]

Bro the concept is so brilliant. I'm only 23 seconds into the video but I'm so excited to see how it works out

[@dmitriyteslenko5836]

Вude, it's because of people like you our civilization is moving forward. Thanks especially for showing the visual graphs!

[@Nolano386]

Way to keep come up with interesting questions to examine and test! I had never considered something like this.

[@TheGreenlyCan]

Interesting, thanks for the video. I just don't understand why you test the "pure" layer-adhesion and not a shear load. The benefits should be much better there.

[@rodrigob]

Also posting kzbin.info/www/bejne/b3rHf3SVnbycr6csi=tlcxna8Lnicwjfj3 that replies to the "what about patents?" question in this video.

[@MatterMadeMoot]

Awesome stuff man. Came back to this because my professor for principles of AM mentioned this exact concept. Surprised it doesn't have more support yet.

[@MarkusReinisch]

My work around current is place the parts in 45 degrees so the plane is not parallel to the build plate. It often results in low buildplate holding force, so I design often breakable support in the file. FDM is similar handling to wood. One direction is much stronger than the other. Be aware when you’re designing your part. You can also not change the behavior of wood.

[@davidg5898]

If this gets implemented into slicers, it's something I would definitely use on occasion. Sometimes part strength is more important than printing speed.

[@dibrockly]

This idea needs to be tested with z “wobble” this would drastically increase the surface area and should result in stronger layers. Ps a series on maximizing layer strength would be awesome.

[@JaredJennings-hp3zt]

My mind immediately goes to sinusoidal z-oscillation, but I can imagine there are at least as many variations to try as exist in infill patterns.

[@dibrockly]

Yeah that would be a good idea too!

[@Lolwutfordawin]

Check out additive manufacturing of non-planar layers with variable layer height (Pelzer, hopmann 2001), they attempted something very close to this with fairly promising results.

[@oyuyuy]

How much time did it add to the print?

[@CNCKitchen]

Practically none.

[@simple1000kg]

Correct me if I'm wrong, but I noticed that the test you conducted was tensile stress test. As an analogy you used bricks wall pattern, I'm no engineer so I might be wrong, but I think brick wall pattern is meant to increase resistance to other type of stress like compression and maybe bending. I believe you would see interesting results by testing for other types of stress. Anyway 10% increase is no joke tho, nice video.

[@GhostFS]

About the fracture: it's expected. Brittle fracture start from a point and than proceed to the direction of lower resistance. One of the methods to increase the energy of the fracture (and so the resilience of the material) is to deviate it's path to make it longer with more turns. And this is exactly what you have made here. It's like the impact resistant glass that is more resistant to impact and when it brakes it seems to explode in many rounder and smaller pieces instead of making splitters. This effect is generally consistent in impact test like the Charpy test. You could try it could be interesting. It do not change much the tensile strength. That is more about the surface of contact but... also about the ability of the material to adapt and distribute the load if you have a brittle material. And with interlocking you ad more rigidity and this probably is a counter effect that reduce the gain for the increase contact surface. This could give you a bit of lower effect and less consistency in you other tests.

[@happybobyou]

I really want a longer and more detailed video on this. I'm eagerly awaiting

[@UncleKennysPlace]

In the US, we typically call the proper way of laying overlapping bricks a _running bond._

[@kennethweiss6544]

Found this video via this one which goes into the patterns and that they expired years ago: kzbin.info/www/bejne/b3rHf3SVnbycr6csi=TufSmKKeFKtUUQcs Would love to see this happen

[@Nachtschicht1]

Great video! I think a lot of people thought about this because it makes so much sense, but you actually did it. I hope in future this becomes a standard setting for slicers. To get the most out of this, I think it would be a good idea to slightly increase the pressure so the gaps get filled better, creating basically a hexagonal pattern in the section.

[@maximisatwat]

7:50 If the parts have many cracks and are exploding it probably suggests that the main weakpoints - the bricks lines - are now removed as the main failing point, so you are getting multiple failures all over, distributed around the whole thing - more like you would expect a solid object. like a cup or plate that broke I would think. In other words its a "good thing" Those failure zones were being eclipsed by the brick weakness before

[@zZBucketsZz]

i'm no expert by any means, but pulling those test pieces up and down is like pulling a brick wall up and down. a wall isn't meant to do that.

[@buzzbbird]

When I first got into 3D printing, I had that very thought, alternating layers for better interlocking of layers. Seeing your microscopic view show what is lacking, that being the filling of the empty areas. I see that simplify 3D does not permit individual wall flow changes. That being the case, the voids can be calculated as a percentage of theoretical solidly printed parts, then the flow can be increased as well as printing temp, to get the plastic to flow into those areas.

[@keithwins]

I was just thinking about this approach a few weeks ago, thanks so much for doing this! I'd love to see a comparison across a range of temperatures, maybe with & without being annealed.

[@disabeast3667]

I'm actively doing my CS senior research about this. I finish my preliminary bibliography of existing research last week, and then just saw this.

[@The88Nomad]

"Jack of all trades, Master of none is always better than a Master of one."

[@MikkoRantalainen]

Great work! Having 10% stronger parts with different slicing setup (without increasing fill) seems like a great result and I hope open source slicers implement this trick.

[@lyonscultivars]

also to add smaller layer heights does add more strength. the hotend is more directly connected to the part allowing more heat to be put into the part allowing a better more fuller bond on layers. you also get a better shape with finer layers as the squish is better larger bonding surface and smaller air gaps

[@jamiethomas4079]

Haven't fully watched the video yet but wanted to mention this while I'm thinking it. I started copying certain aspects I see on plastic that manufacturers do to increase strength. There are two things to note. They add these features so they can make plastic thinner and make the part cost less to produce. And they also do the minimal amount of strength adding to also save money. For my personal projects, I copy some of these aspects but go ahead and make the part bigger since I'm not concerned with saving money. And also make the strength adding section bigger. An easy example, is now when making clips I add circles or half circle bumps in straight sections or at corners. I've made some simple clips like for hanging a basket on a metal panel fence that are only between 2-3mm thick and I can't even break them with my hands. So my best advice for making parts stronger is to start paying attention to the fine details on production plastic parts, copy those features, but you may want to exaggerate them for greater effect.

[@raemclellan7693]

At 1:18 you explain that the strength difference between horizontal "sticking" and vertical "sticking" is because there is less melting between these vertical layers. Not mentioned in the video, yet the source of this reduced melting, is the greater time difference between printing of and hence cooling of the adjoining components. Horizontal neighbors are printed more recently, and are therefore warmer and more readily melting into a neighboring bead printed material. Whereas vertical bonding to material on the previous layer only occurs after that entire lower layer has been printed and had time to cool, the cooler material melting less readily with the bead of material applied above it. You can test this theory by using a heated enclosure. You would think that seperating even and odd perimeter wall beads on different layers would eliminate any heat/melting advantage of horizontal bonding, as the horizontal adjacent bonding only comes when the next layer is printed and the previous layer has had time to cool. But your brick pattern gains back some (and as you show, 10% more overall) bonding advantage by each bead of material touching not only it's 4 neighboring beads, but 6. It would truly be interesting if a heated environment would improve the tensile strength of both the normal pattern as well as your brick printing patterns.

[@thomaswiley666]

I've been doing this the hard way with slicing in Orca Slicer then modifying the GCODE in Notepad++. I'm working on a script that should do that automatically. In my case, however, the alternating first layer bands are not 100/150 percent. I experienced some bed adhesion problems so I have mine alternate 50/100. With PLA, this is no problem. However PETG has to have the flow rate reduced for the 50% lines. Nice to see you taking an interest in it.

[@Trepanazzia]

Have you considered the option of perpendicular pouring of layers? If the first layer is filled with a spiral, and the next one with a snake. The threads between the layers will be perpendicular to each other. This can help to increase the strength of the adhesion between the layers.

[@juhanaleiwo]

How about printing the lines of each next layer onto the seams of each previous layer? Some tweaks would have to be made to get rid of the missing half line at the outer perimeter, but the overlap/interlock would be wider than with the method you presented here.

[@TalonCain]

You could cast samples to see if you're approaching homogeneous strength. I'd guess you're not, given the microscope pictures provided. I'd suggest increasing extrusion on inner walls to close the gaps and decreasing the fan to allow the material stay hot while it presses in. Just my quick assessment.

[@honeybadgeractual5734]

One issue you may also be running into is the gaps,bricks have mortar to fill gaps. Let's also consider that bricks are meant to be used against a COMPRESSIVE force, not tension, or shear forces. Perhaps test each method for other types of failure as well, checking resistance to shearing, and to being malformed by crushing (basically both are accomplished with a press and set of jigs to apply forces compressive and laterally into a media across it's layer boundaries both perpendicular and parallel to the layers.) I know that tensile, and tension are important, but by using a mixture of layering methods for parts in different areas, you could accomplish some amazing results I'm sure. Also consider crossing layers perpendicular to one another for better resistance to layer shearing In a compressive plane of force, something like a stopper bushing for a sliding rod or spring assembly.

[@lyonscultivars]

im at 8 mins. to add to the shattering its due to the layers being partial wedged. so for them to pull apart they must push away there neighbouring paths to pass. it will add more rigidity as there are more bonded angles of restricted motion but as metals go it also makes things more shatter prone where before you get yielding or plastic deformation. really good test so far.

[@CoreMaster111]

If it breaks along the layer line then you have not extruded enough material. I make sure infill gets higher extrusion amount so it fills gaps. My parts rarely break along the layer line. PETG can be weird and explode. It comes down to how rapidly it's cooled and probably other factors. For example one of my PETG models had one side very brittle and the other side malleable. Only difference was that cooling was blowing onto one side only.

[@jbay088]

I'm always heartened to see that the spirit of independent innovation is still alive and well in 3D printing. Great job!

[@DerekPetersonLives]

This was literally on my mind out of the blue on Friday, I was thinking of alternating layer width and line counts so they would print into the valleys instead of peaks of the previous layer ie: layer 1 @ 100% width 4 outlines layer 2 @ 133-145% width 3 outlines etc

[@Zipo214]

I think the answer might be a combo of this, and something I call interlayer interlock. Like pleating. For visualization draw three pencil lines on a sheet of paper, equally spaced (you are going to look at the length-wise cross section/ one layer ontop of another). Draw each line 2.5 inches long or 10 cm (not a direct conversion). Then mark the middle at 1.25(5cm), and the quarter at 0.625"(2.5cm). now make a second set of 3 lines exactly like this, as a second image. On the first image of 3 lines, take line 1 and 3 and trace them with a dark blue marker. Then trace the middle with a red marker. Here you can see that you have 3 equal length lines, one red in between to blue. Image 2: on the first layer take the blue maker and draw a line from the end to the 0.625" (2.5cm) mark. Then red on line 2 to its 0.625 mark, now go a little past and draw a line 90 degrees to connect to the 1st layer just a bit after the blue line's end at 0.625" then continue to the red line until you reach the 1.25 mark on the first layer. (the red line should look like a little stair step from the beginning of the 2nd line, ending at the 1.25" (5cm) point on the 1st line. Go to the third line, and with a blue marker, and go from 0" to after the drop point after the red line on 2nd line and drop down to the second line and continue on the second line a little past the 1.25" distance and drop down to the 1st line. You've now take the top most layer and dropped down to the 1st layer. Resulting in a pleated design if you continue the patter over the whole 2.5 inches(10cm). I know 2.5"= 6.35 cm. But 10 cm and 2.5" both make nice ruler segments. This pleated design is tough to implement because it makes it so the 1st layer isnt finished until your 3/4 of the way through the 2nd layer. alternatively, this drawing instead of being a slice from the side, could be a slice looking down (top down view). interlocking internal and external layers. Either method (length-wise or top-down cross section) can be integrated into you design of offsetting the layer heights. This would interlock independent layers, both horizontally and vertically.

[@InTheWrongTimeline]

I love it - your statistical variance showed on the first results showed that the weakest of your brick layer samples was stronger than the strongest of the "normal" layer samples.

[@JohnSmith-op7ls]

The issue is these 3D printers don’t heat the material enough for the layers to fully bond. You’d never use this for anything that needed real strength. When they 3D print metal components for vehicles, they’re using lasers to actually melt the layers together, not just warm them up so their edges stick together a bit. These cheap 3D printers are never going to be on par with cast or molded results unless they heat the layers so they become one.

[@cassgraham7058]

One of the things I thought of during this is a different fundamental problem with FDM, which you're going to deal with more using this technique: the adhesion between layers is temperature dependent. If the filament is laid across a more fluid surface, the layers will bond better - and your images show that bonding is minimal. Not dealing with a reservoir or enclosed area is one of the advantages to FDM, but if you're working toward stronger bonds a warmer environment (not enough to cause sag, but enough to maintain a fluid interface between layers during the printing process) seems like something to explore.

[@zeitseele7109]

There are two techniques I told a friend of mine to implement in his 3D printing mechines they manufacturing. One is nozzel rail turning hexagonal printing, the other is poly powder trailing.

[@hortshack]

Congrats on the Heise article. 🎉

[@CNCKitchen]

Thanks. I was quite surprised myself.

[@melissa3920]

In trying to see if I could do this in Orca Slicer, I found that they do something similar by default. The outer wall is printed 0.42mm while the inner wall is printed with a 0.45mm thickness. This is the 0.2mm standard layer height. It also allows the setting to use percentages. There is also an extra wall every other layer option that is supposed to enhance the fusion between the wall and the infill. I know it's not the same as the brick method, but it is a step in that direction.