Which is the Best 3D Printed Corner

[@pipdesignshop]

The 2-second lesson on adding multiple fillets with one feature is mind-blowing! The rest of the video is also full of great info!

[@helixxharpell]

Being an old grognard design engineer w/ 30+ yrs designing locks, let me just offer you a compliment. You're one of the few engineers out there who can take concepts we learned from the machine shop & apply them to making printed parts. I would recommend your channel to any young, up-and-coming design engineer. Thank you for your keen insight, sir. And thank you for your efforts! 🫡

[@SonicKiwi123]

I've designed stuff for work with these sorts of features with the intension that they are 3D printed, and been shut down by coworkers with "more design experience" (designing for CNC milling/turning saying that i was adding unnecessary complexity and I'm just increasing cost to make it look cool. I'll show them this video the next time they try to tell me that.

[@stevesclocks]

The very slight extra print time is insignificant, especially when compared to the increase in strength.

[@Rubz]

CNC milling or turning does not break at the layers mate

[@davismccarty6424]

Yikes! At my company we have a policy where you hit a gong and then are allowed to say anything, so I used it to and told the senior engineer “Randy, your a little bitch who can’t get it up” I don’t think he’s forgiven me since. Never questions my designs anymore tho.

[@NicksStuff]

It's funny how these are close and yet so different. Like removing material (thing generative design) is a huge bonus in 3D printing but crazy expensive in subtractive manufacturing

[@squidcaps4308]

3D prints are weird things to design. Often cutting holes in them makes them stronger.. Instead of a shell filled with weak infill you get walls in the middle, and you can chamfer/fillet the hell out of them to get even more stability in multiple directions. It makes more sense when you look at the final weight, a part with lots of holes is heavier than a part that has none. Hope you can get it sorted, i'm just hobbyists but done design for both CNC and printing.. They are just so different disciplines that a CNC modeler really can't afford to criticize 3D print modeler, and it of course goes both ways. 3D printers are the new kids on the block, it is about expected that old timers will feel it a bit threatening... I know that between my CNC and printer.. the latter gets 95% of the stuff done, faster and with FAR less hassle and danger... So many things have started with milling in mind and ended being printed, to be fair my CNC isn't made for metal so it is usually plastic vs plastic or plastic vs wood...

[@daniel_s1337]

Quick fusion tip: hold ctrl to select more fillets if you already set a radius and cant select additional edges! Great vid as always.

[@jangrewe]

Quick Fusion ProTip: Select a face to filet all edges of that face. PS: SHIFT is the correct key to select more (add), while CTRL is selecting and deselecting multiple (add and remove).

[@scaredyfish]

Thank you! Drives me crazy setting my radius to zero just to add more edges.

[@daniel_s1337]

@@scaredyfish been doing exactly that for years, just found out last week 😂

[@daniel_s1337]

@@jangrewe i must be using a different key map, for me its ctrl

[@neoc03]

This was an amazing video. I've been using fillets and chamfers in my designs, but never learned about the other options they have. This is a huge addition to my designing toolbox. Thank you!

[@ge2719]

Seems like the benefit comes from adjusting how far the leverage is from the weakest point in the print. The weakest point being the smallest across sectional area, so this will be where the fillet ends and the cross sectional area becomes the same through the rest of the length. Since this is exactly where the parts broke and the increase in force seems to match what you'd expect from just moving the leverage point close in so it has less force on the weak point. Would be interesting to see if you can take the breaking force for each and multiply it by the distance from the point the weight was at, to the point the part broke. If you get roughly the same value then it shows the benefit is from reduced leverage. Personally if I ever design anything like this and I need it to be very strong, I put a hole through the part for a screw to reinforce it. Makes it pretty much unbreakable.

[@cosmic_cupcake]

Your theory doesn't hold up because the internally swept parts are still stronger, despite having a smaller cross-section than the base part at nearly the same distance to the load as the base part. Inside corners cause cracking, that's just one of the core truths in all of manufacturing.

[@mikedixonphoto]

@@cosmic_cupcake Exactly. A sharp inside corner becomes what is called a stress concentrator. Fillets not only look nicer and print better, but they also help distribute the force across a wider area.

[@tylersingleton9284]

The gusset one proves this point. It still broke at the smallest point, but that point was practically underneath the hook. Plastic layers just behave differently than say welded steel where all the material is inline and the joints are weaker than the material.

[@802Garage]

I left a nearly identical comment, hahaha. While the physics of course make sense, seeing it applied can often make it all the more intuitive.

[@802Garage]

@@cosmic_cupcake This is true, due to stress risers as Mike also said. However, and as Tyler said, there is a difference with FDM printing as well. While the overall volume of the part is reduced, the amount of material used is only barely diminished. That's because the slicer will keep the same number of perimeters or walls regardless of where surface volume is taken out. So the part loses a little strength from the perimeters being moved inward, the total perimeter length being reduced, and slightly reduced infill. However, much of the overall strength is maintained. Reducing the stress risers can compound with this property for an overall stronger part. That is, compared to a part with the same number of perimeters and same percentage infill, of course. If the part was printed 100% solid, the results would likely be different. As for what ge said, it's not just a theory. Leverage and material area are obviously components of what make certain designs stronger. The closer you can get the weakest area to the point where force is applied, the less leverage the force has to break that weak spot. That's why most parts that hold something at a distance will be thicker at the base and thinner at the tip.

[@kyle8575]

Your channel is great. I'm a hobbyist modeler. All the little tips certainly add up and I feel quite confident in my ability to make whatever I need.

[@TheToonamiRevolution]

I'm pretty new to fusion, but I have been improving over the year. But when showed you could do multiple fillets per fillet action to keep the timeline clean my head exploded. You've earned my subscription.

[@coletrainwastaken]

I've been using Fusion360 professionally for years, but this video just now taught me how to properly use variable fillets on multiple edges. Great video!

[@NeedItMakeIt]

I'm with you too, there are so many features that aren't so straight forward to figure out. That feature also allows you to add your own points for start and end of the variable sizes independent of the selected lines. You can do this by selecting the + symbol in the bottom menu and it will allow you to manually pick those transition points. Thanks for your support!

[@coletrainwastaken]

@@NeedItMakeIt ❤️

[@woodcat7180]

Nice video. Also, I'm glad you're showing the design process of the features you use.

[@the_average_canadian]

I usually fillet corners, but learning about the pipe method is definitely going to impact my designs moving forward! I actually ran into this issue recently, where I wanted to fillet an inner corner but couldn't because it had to fit tightly to a square object. I had never heard of the pipe method I never would have thought that *removing* material to round the corner off would increase strength. Great video!

[@Henry_Swanson]

Fillets and chamfers put the failure out closer to the load thus reducing the leverage. I'd be interested if measuring load to failure distance partially or fully explains the different failure loads.

[@NeedItMakeIt]

Yes, effectively reducing the length of the lever. Though the swept version did the opposite with still an increase in performance.

[@legacyofbob]

I prefer chamfers over fillets generally speaking for 3d printed applications. Mainly just due to the stair-stepping look of fillets, and of course if there is a fillet on an overhang it will print poorly whereas a chamfer is easy for most consumer printers these days. Love the content and thanks for doing all this hard work!

[@ricfrye6644]

Also print orientation matters. You are pulling along the layer lines. I would like to see this test with the parts printed horizontally and not vertically.

[@EliteRocketBear]

Often you don't have the luxury of being able to print it flat, knowing what works to combat layer adhesion is good info.

[@SouthernWolff]

If the goal was "how to print this exact part as strong as possible" you'd be right. But this is an example video demonstrating what happens with each corner type with compound stresses which become unavoidable in many complex designs. The orientation you print is useless when you have complex forces and stresses being applied to the print. So one area may be stronger because of the direction of the layer lines, but another section of the print will be forced to have this orientation. All on the same part. This video was just comparing apples to apples. Not apples to oranges.

[@ricfrye6644]

@@SouthernWolff Im tracking. I was just saying this test would be more interesting (subjective) to me to see the strength of the different types of corners when printed for maximum strength. Sometimes when I design parts and I notice that a particular piece will print on the weakest (to the part) axis, I create two different pieces that can be combined to create the strongest part possible. Thats all. I absolutely love the videos and have learned alot from them. I probably could have said the original comment better.

[@DustinShort]

Along those lines, giving it support and printing at 45deg would be really interesting for this particular part. Then the layer lines are in the exact same direction as the moment arm and can act like the cables in a cable stay bridge. Otherwise though, just for illustrative purposes this is a very good demo of the general principle of material stresses being affected by the geometry of the design.

[@SouthernWolff]

@@ricfrye6644 fair enough, brother. I understand what you mean.

[@PaulDominguez]

This channel is like CNC Kitchen but without the German accent. Both are awesome channels. But it misses the intro- Guten Tag! 😂

[@TS_Mind_Swept]

I'm Shtefan, and welcome to CNC KITchen

[@jjbankert]

Here it's "hey *finger guns* I'm Mike".

[@ericschatz4943]

This channel puts CNCK to shame tbh, its not even a competition

[@TS_Mind_Swept]

@@ericschatz4943 what's that is is an opinion and nothing more, one that I highly disagree with

[@ericschatz4943]

@@TS_Mind_Swept "Thats just like, your opinion man"

[@joell439]

Thanks for all the design tips. This was very helpful. Just last week I needed to produce an undercut to create a tight fitting perpendicular wall to a curved surface. The pieces were in compression so I didn’t need a filleted undercut to maintain strength and I didn’t have much wall thickness to work with. I simply recessed a .5mm thick square edged sliver around the perimeter at the corner interface. Turned out perfect and the resulting surface fit was very tight. 👍😎👍

[@802Garage]

Awesome info! Both the design tips and testing. Can be applied to any part design, but also helps you think about 3D printing specifically. I think this basically demonstrates that the failure point is going to be where material is thinnest. So, adding a fillet, chamfer, or gusset is going to strengthen the part for the entire length it runs. Not only that, but moving the weak point closer to where force is exerted on the part decreases leverage on the weak point, making the part stronger overall. You can ideally reach a pretty uniform strength across the entire part if desired. Move the weak point as close to the force as possible and make sure that point is still sufficiently strong. Another advantage to these techniques is anywhere there is a sharp corner it creates a stress riser. Basically a point at which cracking or failure is prone to propagate. While likely more prominent in homogenous parts with no layer lines, it also applies to 3D printed parts. I think this is why the swept results were better than basic. Cool to see even using the sunken corners has an advantage. Since FDM maintains the same number of perimeters even where there is material removed, you aren't losing much strength material wise either. Overall, utilizing all this knowledge about corners can make the part much stronger while also often looking nice.

[@NeedItMakeIt]

Thanks 802! I wasn't really sure if the techniques we use for metal and in some cases for wood can also apply to printing, and I think more testing is required on different materials, but it seems that they do apply at least from the small batch testing I've done. I really need to get a more automated setup for my testing rig. I can't decide if I should go with hydraulic or not though.

[@dasburninator]

This is practices I already do in designs but videos like this are fantastic to be able to send to someone just getting started to help them understand about design limitations in 3d printing.

[@zdog90210]

The sweep and pipe techniques are great for holes that you insert nuts into because the corners of the nuts will fit freely while the faces grab against the 3D printed parts

[@Redo3D]

Great video! Im curious how filament temp and print speed affects the layer adhesion. Would be great to see the gusseted hook redone at various temps and printer speeds that could potentially show the difference it makes in layer adhesion.

[@NeedItMakeIt]

I can do that, I'd love to see that tested and I have just the printer for the job too (2 videos away from showing it off)

[@Redo3D]

Thank you for taking the time to educate us all!​@@NeedItMakeIt

[@ryanmisek]

Great work on this series of strength testing. Really helps me to think more about those smaller details if I'm looking for a part to perform in a certain way. Thank you!

[@timturner7609]

In this case the added strength is just that chamfers/whatever moves the layer separation closer to the force, reducing the moment.

[@justaguy4788]

Loving these video testing strength and designs

[@NeedItMakeIt]

Awesome, I'm glad you thought so!

[@lamarcdesign]

i generally use the pipe variation in very tiny scale to get perfect square inside corners. oftern a diamter of .6mm is enough clearance to give the material in the corner enough room to "expand" without rounding out the corner itself. due to that extra circular move of the nozzle that inside corner inner walls will be actually slighty oversize and thus strengthening the corner from the inside while looking perfectly normal square on the outside. this is a fantastic method to hide actual engineering relevant feature from the final part

[@802Garage]

Would be awesome if slicers could do this for us. :D

[@p4inmaker]

Great presentation and illustration.

[@x3axDev]

This video put very well together

[@MatrixRay19]

I wish you had also tested a standard fillet, to see where it lands in comparison to the other compounded fillets.

[@bmorr]

Yeah exactly I watched till the end cus I wanted to see the difference between these two.

[@gltovar]

thanks for sharing, the pipe / shallow pipe method is one i haven’t thought about!

[@GeekDetour]

Michael, to me this video showed that when we test layer adhesion, it will constantly break clean along the layer that has the smallest cross section. Your “cheating” piece introduces something very different: the dove tail was the only one that broke along multiple layers, much more like an injection molded part would behave.

[@genegreiner7766]

I’ve enjoyed this set of testing videos. They’ve helped to inform my own 3d designs. Thanks!

[@MarkusK_]

This was very helpful, thank your for these kind of videos! While it was not the goal here I would have loved to see one further strength comparison with this part being printed horizontally on one of its sides.

[@Valerie_is_doing_stuff]

keep up the great work. love the engineering aspect of all of what i have seen. also your cameras, sound, and lighting are already better then most.

[@NeedItMakeIt]

Thank you! I'm trying to do better with each video, I hope to be one of the better creators within a few years. It's going to be tough to compete, some of these guys have so much hair! :)

[@tommywagner96]

thanks for showing different units, it makes it easier so i dont have to bring the calculator to switch from lbs to kg, most of channels dont do this

[@anon_y_mousse]

I'm definitely going to copy that filleted gusset design, whether you want to call it a fusset or a gillet.

[@SubwayToSchiff]

Wow, rare thing I get to comment this early :D Thanks for the experiments! Intuitively it seems like the overall surface area is the highest factor for strength, and the point of failure is most likely at the thinnest section. The further up that thinnest section is, the lower the leverage, the higher the required force. In my designs Im currently tending to add really long, low angled chamfer to move the point of failure up as much as possible. Also tends to give a nicer look than totally flat faces.

[@jeremybrouillard]

That is exactly my conclusion seeing his results. I was always doubtful the fillet in 3D printing was acting the same way as in metal parts (milling). With metal part you do so to avoir stress concentration, but with 3D printing, because of the layer lines, the stress will still be concentrated at certain points as it is not an homogenous material. But now, with the conclusion you explained very well, it makes much more sense why fillet/chamfer/etc would increase the part strength. It's "just" a matter of layer surface and lever arm.

[@TinTalon]

Such good info here. Thank you. I feel like i just keep learning new things every time. Still above my skill level with CAD but I come back to your videos time and time again to look at things a different way.

[@TNX255]

Great stuff! This is exactly the type of content I'm interested in since I really want to optimize my prints strengthwise without using too much material. However, it would be nice to see tests done with other than these expensive fiber filled filaments. I think the results would be even more valuable for even more people if tested with standard (cheap) filaments like PLA and PETG.

[@baalzevuv4509]

It was more layer adhesion test, swept performed better because walls bounded together better then regular one as there was less time to cool down for small walls than for bigger surface. Also slicing was way different for each part 6:15. If you wanna stronger parts good design is like 10% of success. Material, slicing, temperature and what the most important printed parts orientation are way to go. On the other hand good design is extremely important for injection and cast molding, not only for strength but also for stress relieving, shrinkage porosity and even cooling.

[@squidcaps4308]

Fillet on top edges, chamfer + half a fillet on the bottom. Last one means first chamfer, then fillet only the top edge of that chamfer. That way bottom side is nice 45 degree angle that prints well and rest of the edges are filleted (i often round the bottom corner with scraper tools, so the end result is still a fillet, it just prints better than a real fillet would). And i use the "gusseted fillet" or rib for parts that need to be strong. I've had very good results with that method. Also, i tend to cut holes to parts, and the edges of those are heavily chamfered, the hole shape is an offset line copied from from the outer wall shape. That way it will print walls in the middle, instead of being just shell + infill. Makes things ever stronger and uses less material, printing times are the same though (more travel moves). 3D prints are fascinating to design, often removing stuff makes them stronger just because you are adding more walls.. Overall, i at try to chamfer each visible edge, everything works better that way. Prints often get really sharp edges and corners, way too sharp for humans. Even a 0.5mm chamfer makes them much more humane objects.

[@nuroo1]

the design elements and testing really appeal to me. I've had 3d printers for years but designing is challenging, this helps alot

[@jbrownson]

great videos, I like your style, very clean and clear

[@RayLenses]

Very useful and scientifically, I always use the filets to make my parts strong

[@MichielvanderMeulen]

My tip: play with the order of the fillets. Large ones first, smaller later is the general idea. But sometimes you benefit from a radius very high in the feature tree.

[@floridafoilers]

Great video! I like the Fusion screen share and scientific method for testing design options. Well done 👏

[@interstellarsurfer]

Subscribed. You'll be at 100k in no time, boss. 👍

[@ericschatz4943]

These are absolutely AWESOME thank you!

[@notsonominal]

Been showing up in my feed a lot lately - time to subscribe!

[@alexbolt1227]

I would highly reccomend the "sheer triangles" (original German "Schubdreiecke") that Claus Mattheck describes in his book "Thinking Tools after Nature". Basicly these are three chamfers stacked on top of each other and then the remaining corners are rounded as well. These are what I use if space allows and it worked out even for leaf springs in compliant mechanisms for me.

[@tophlaw4274]

appreciate all the work you put into your videos... it definitely helps justify some of our choices (I've personally used fillets/rounded corners on my designed corners specially for structural parts & there have been times that I've had a nagging feeling that I'm just using more filament for very little gain... thanks to you, those concerns have been quieted) .... now, to find "variable rounded corners" in OnShape 😅 👉looking forward to your next project! (btw, loved your Joints series!)

[@Gefionius]

Those failures were all super clean breaks along layer lines. In addition to the orientation of the print, you might want to print a bit hotter to increase layer adhesion. Test is still valid but all you were really testing is layer adhesion vs FxD at the smallest cross-section, not the stress of the joint.

[@NicksStuff]

15:14 you should put that thing in a vice and test its resistance to torsion, see which corner lets go first!

[@jacksongardiner7657]

Loving the videos! Happy to see the channel growing so much 🎉

[@TheOneOriginalJackal]

I honestly don't understand why 3D Printing analysers like NeedItMakeIt hasn't come out with tests parts with printed insertable "BONES" into parts for strength. All it takes is printing rounds or square sticks in opposite layer lines and inserting them into the part. Plus you get more internal walls around the hole. Glue in for even more strength. I do it all the time and makes super strong parts that never snaps even in PLA. No need for all this chamfer and fillet foofoo trickery that just moves the weak point down the line. Sure Chamfers and fillets are sexy, and help....but Bones will win the test

[@jakeehrlich8113]

I think testing the corner in tension is just testing layer adhesion. A larger surface area will withstand a higher tension before delaminating which in the case of this test just moves the delaminating layer upwards to a more narrow layer. I think testing in compression is better. Also worth considering “equal volumes” and “equal amount of plastic used”

[@802Garage]

Note that the slightly relieved corners actually performed better than the unmodified sharp corner. There are other factors at play.

[@abitnutz6747]

That really does give me some useful information. I'm desperately trying to learn fusion. It's going to be a long road.

[@NeedItMakeIt]

It took me quite a while as well, I started years ago with AutoCAD 2D, and then 3D, and then Inventor and then a few other junky software options, finally I settled with Fusion, it's not perfect, but it does most everything I need. I have to pay for mine sadly.

[@slarti42uk]

I'd be interested to see how the gusset filet works inverted, where the joint would be under compression. Really good video

[@dontlikesoccer]

interesting, the variable fillet, because of the gradual change in cross section along the layer lines, the force was dispersed through multiple layers in a more linear fashion. Compared to any of the other edge features, there's always one layer with that distinct change in cross section.

[@NeedItMakeIt]

Beautiful analysis! That's something that I've also tested in some of the 3D printed connections I've made and it certainly seems that changing the shape to cross many layers, the performance will improve. The Sine Wave connection is a good example of this from the last few videos.

[@epeemagic]

Interesting video! Seeing this and a few of your other videos will definitely be useful down the road for choosing a feature to include in a model at the start and saving some time in testing. Do you have the files of these available/are you willing to share them? I'm kind of interested in running FEA on the different designs and see how they stack up vs your results. Acknowledging that simulating 3d printed material is hard/impossible, it could still be neat to see how close/different it is vs the sim.

[@beegee2028]

Will be interesting to see how does “inverted hook” would perform when it works on compression. Obviously does not apply to every situation, but where it does should be much stronger

[@davidbrennan7422]

Enjoying the videos on your channel a lot, so first up thinks for your work. For this test in particular I was interested in how your test rig works. I couldn't find a video with showing the overall setup, so I was wondering how you add load to your samples during testing. The presumed lever arm seems to be off screen right, but are you just pulling on it with your own hand or do you have a motor, weight, etc to provide the loading force? Polymers and materials with cracks in them - and 3D prints are effectively both - are sensitive to loading rate as well as load magnitude. I notice a pause in the force reading on the scale when you were testing and I was curious why. Almost all of the tests show that behaviour and it could be significant to the repeatability of your test and therefore the validity of your results. I'm know it's unreasonable of me to hold you to such a high standard given you're doing this for fun, but I figured you went to the trouble of setting up the whole rig and doing the testing, with multiple samples and all, so you might be open to suggestions. I would also be curious to see if an unfilleted chamfer would be different from the filleted one you made in this test. Keep up the good work, I'm looking forward to your future videos while I trawl through the great back catalog of content you've already made. Subbed!

[@NeedItMakeIt]

Oh sure, this is the same test setup as I've been using for the last couple of videos, it's by no means perfect, but I use a lever arm so that I can fairly evenly apply load from a good distance. That keeps me away for safety and also so that I have far more control. Ideally I'd have something more automated with some measurement systems added. At the moment, I have very limited resources so I have to make do , hopefully as the channel grows I can buy parts and maybe even some dedicated equipment.

[@ObservationofLimits]

Also, I have a solution to printing strong inside corners but afaik no slicer supports it. You'd actually need a way to go back and edit the program after slicing because it would require some slight cross layer motion and afaik slicers don't print across Z layers

[@VeryDramatic]

Incredible Tutorial

[@ObservationofLimits]

Sharp corners wouldn't "slow down the print" due to changes on direction. They'd be slower than a chamfer because the hypotenuse is shorter than the legs. The print head will still run at its regular speed and accel decel. So unless you have a ridiculous A/D problem with your steppers or servos, the change in direction is not the issue. On a diagonal, you still have to change directions on each axis anyways.

[@weisnowhere]

This is such useful content! Thank you!

[@beauslim]

I didn't know Fusion had variable fillets. Thanks! Been using pipe or similar a lot lately to help eliminate bulges in critical areas. You can't always count on users of a model to tune pressure advance.

[@NeedItMakeIt]

I just learned a bit more about the variable fillet, you don't need to base it on segments, you can add your own start and stops for the change in size, that would be done at the bottom with the little + symbol. it could help here and there as well. It's pretty handy, it is getting a lot more use now in my models, that's for sure and that struggle to find fillet size that works for all of those unusual shapes is so much easier now if we can have it vary instead.

[@Roobotics]

I'm not sure I heard you use the term when talking about these stress concentration points, but from my understanding they are denoted as 'stress raisers' in structural engineering. As for the tests, I do have a notion to ponder, the area these blocks are affixed to, bellow them is infil. That means they are on a surface that is more prone to deformation and partially hollow! Merge a cube into the base of the protrusion of same-size, so they are structurally solid their whole length. *Edited: because it's stress raisers, not stress risers.*

[@Splarkszter]

The fillet ones seem to be the ones that don't have solid infill. The first one does have solid where it is predicted to break.

[@jamesfowley4114]

Stress riser was the term my welding instructor used for sharp corners and undercut weld edges.

[@Roobotics]

@@jamesfowley4114 I needed to look it up because I wasn't entirely confident myself, apparently I've been spelling it wrong! "Stress-raisers are sharp corners, grooves, notches or acute changes of section that cause stress concentrations under normal loadings." I believe when they say 'corner' it can refer to either inner or outer corners, in this case his pieces are making inner corners, what's important is it's 'raising' the stress at that specific region.

[@newmonengineering]

Seeing as to how most of them broke on the shaft and not near the mating surface except the control and pipe versions, I don't think solid buys us anything. It might help a bit for the entire protrusion to be solid but that is to be expected. Since he did 6 shells it's pretty decently strong. Just my 2c.

[@802Garage]

@@Roobotics Seems that stress concentration, stress raiser, and stress riser are all acceptable. :)

[@wyattwolf8150]

It would be really interesting to shift the moment arm for each of these parameters as well. One factor that will increase the ultimate strength of each of these is the location of the minimum cross section relative to the applied load. For example, if the load is applied 50 mm away from the base and you add a 6 mm fillet, then the moment arm is only 44 mm to the minimum cross section. Fillets and chamfers definitely do help on their own to reduce stress concentrations, but I wonder how much of these results are due to the change in moment arm from the minimum cross section!

[@astorMorisson]

Really nice tests. It would be interesting to do a basic sample test with a strong print direction were the layers are horizontal just for comparisson. I think the fillet size on the chamfer are almost at the layer height so they are probably not really effective.

[@Phenom5]

I agree, most of the tests were basically the same and didn’t make sense to me. As said above, print orientation matters and most of them broke at the same spot, where it basically went down to the force needed to separate basic layers

[@kronisknatur]

Nice video. I use chamfer for strong parts. But now I can see that i Shud se if fillet is a better option in the part that I'm making. I think if it's possible I will make a little filled in the bottom of the part to make i even stronger.🤔

[@chipcode5538]

Thank you for another great video. For this part changing the print orientation probably makes it a lot stronger. Why do you use sunken holes and use normal bolts during the test.

[@NeedItMakeIt]

You're welcome. The reason for the difference in holes comes down to me being a dum-dum. I originally was going to use a different approach to test the parts, but instead settled on putting them into the test rig. Ideally there would be no counterbore at all. I really need to order some more screws, I'm getting very low. That's very perceptive of you to pickup on that!

[@joshdovi5141]

Really cool video! Unfortunately most of the design principles you demonstrated were established for parts made of isotropic material (like CNC'd aluminium), which 3d printed parts are not. In isotropic materials, sharp inside corners are bad because more stress travels through that small area, introducing highly concentrated stress points which is the key ingredient to forming cracks in parts. In 3D printed parts, layer adhesion will cause the part to fail long before the material limits of the plastic which could be verified by plotting the force to failure against the cross section of the failed layer. It won't make a perfect linear graph as you have varying smallest layer geometry as well as varying distances between the load and the layer with the smallest area, but it should show a consistant increase. Your last design though introduces a new and interesting question: What design principles should be implemented specifically into 3d printed part features to give them better mechanical properties? These will definitely be different to conventional design principles. Would love to see this explored further though! Awesome work :)

[@polishTinkerer]

Great test, I must say. You've tested the worst case of worst cases - those elements won't get any weaker. What is already said - it was printed vertically, this way you actually test the strength of layer adhesion. What you did was printing all elements at the same time, which also influences layer adhesion negatively. How about printing those elements one by one or using sequential printing ("complete individual objects" in Prusa slicer)? I wonder if the results will significantly change.

[@christopherstephens2699]

I'd like to see this done printed horizontally so the layer lines aren't contributing so much to your shear point. It would also be interesting to see these same parts from a resin printer just to get an idea of how they stand up without the layers as a factor, although that wouldn't be a small thing to add on.

[@leonjiang2882]

I think it would be nice to also calculate the strangth:mass ratio to take into account the extra/reduced material.

[@adamkrtek9004]

Would be very interested to see how much stronger some of these shapes perform if printed horizontally vs their vertical orientation variations

[@14768]

I can not stand the look of the increasing island sizes that doing a radius on a horizontally printed edge makes. Secondly on a vertical edge a radius prints faster and smoother. A chamfer has a less aggressive change in direction but it's still pretty abrupt so it can cause ringing. So in printing orientation I always chamfer horizontal edges and radius vertical edges.

[@terryclair2914]

Well done a great review!

[@saw2k720]

Variable swept would be interesting to see. You would disipate the forces in the center, but taper out to the edges to remove less material. Perhaps a marginal difference, but it would be interesting to see.

[@hydroponikstuttgart4515]

Hey, your first dust separatpr could use some threads on the inside to direct airflow downwards. Would make it the superior design. Cheers

[@KylejvT]

Printing this out in PLA, then using the super heated acetone to smooth it should also give interesting results as that would make the layer lines flow into each other nicely. (Before anyone starts yes you can smooth PLA with Acetone, you're using the acetone as a heat conveyor to melt the out layer and not using it as a chemical smoother. If people are interested ill post a followup of the setup needed to achieve this.)

[@jakeMTSU]

if you just rotate the print on a 30 degree it will make a difference as well, not sure much... but supports are needed when printing

[@karlosss1868]

Love the testing!!... Couldnt help but notice the scales stop reading any weight gain approx 1.5 seconds into each test. About 0.5 seconds later they start reading again so some of the readings may be off. They don't seem to have this issue when breaking the weaker models as they break in less time.

[@abc121xyz]

variable fillet and chamfer did not seem to end at the same high which is like putting the fulcrum of the chamfer one near the base which makes it easier to break

[@eslmatt811]

I don't feel like doing the math. But it looks like adding the chamfers and the gusset moves the thin section further out. Thus reducing the leaver length, therefore reducing the meters part of newton meters. Picture the breaking point as the fulcrum.

[@Lexxus17]

It would be interesting to see how a series of smaller fillet gusset would compare to these

[@Hotwire_RCTrix]

Slant 3D has an excellent short on this topic. Design for 3D printing and the resulting product could look a lot different for the same application.

[@erikrustad5200]

Interesting video! One thing, it seems like the test shows what type of corner is stronger than the pin itself, as the breaking point is just outside where the corner fillet ends. Also, to properly test corners, you should change the design so you can print them laying down instead of standing up. It would make the part way way stronger, putting the load more on the corner. I am unsure of the choice of filament. CF PETG is not the strongest, but it is rigid. It might be the filament of choice. Keep up the good work :)

[@phizc]

Standing up is good for this test. Of course it would be stronger when printed laying flat, but some parts has to have pieces sticking up like the ones in the test. It's the worst case scenario, and the test shows how the problem can be mitigated.

[@erikrustad5200]

@@phizc I partially agree. My point was, when the part breaks outside of the corner, we dont know how strong the corner really is, which was the point of the video. Printing in a different orientation would make the part so much stronger, that we might get to see corner strength instead.

[@kendunstan3270]

@@erikrustad5200 Agree that a break outside of the corner, leaves us with no good info on just how strong the filleted corner had become. These tests would have been better with the horizontal "beam" set with a flat top, rather than the inverted "V". I.e. have the horizontal beam spun by 45Deg. Then the highest stress point would/should be back at the corner.

[@Guardian_Arias]

I am not contesting the techniques but there is more at play than simple fillets and chamfers utilized in traditional subtractive manufacturing, especially on the swept versions. By default, most slicers will add material on any angled wall relative to the bed, usually considerably more than one would intuitively think. Additionally, the tool path, speed, direction and number of passes per layer change dramatically depending on geometry and type of line. It would have been nice if you had shared the step files, also if you didn't know orca slicer can use step files directly and can often result in more accurate parts.

[@Smokinjoewhite]

I would be interested to see the amount of material used for each part and the print time for each version.

[@zekesnack]

Instead of the filleted a gusset, a loft would be much more effective and would use a similar amount of material. Might be worth giving a shot.

[@riba2233]

another very useful vide0, thanks!

[@PaymaanJafari]

I wish you could also print and test this test object sideways to test the strengths. it will be much higher for sure

[@anoukk_]

So the breaking point is a function of the arm of the applied force and the area of the breaking slice. I think the role of the sharp corner as a weak point because of the shape of the corner is a lot less significant than the relationship between the arm of the force as a result of this setup and the area of the slice. I wonder how you could optimise the shape to maximise the strength for the material used.

[@JohnDoe-fk6id]

I love the work you're doing, but you really need to have error bars on your graphs, when you have multiple samples, so we can see how much scatter there is in the average

[@NeedItMakeIt]

I can always do more, I really need more of the identical printer and material. A better more accurate way of applying load and measuring deflection and failure load. We'll get there, I have to do this incrementally, I'm not quite at the point with the channel to be able to spend a lot. I hope to be in a more sustainable position by 2025.

[@JohnDoe-fk6id]

@@NeedItMakeIt Totally understand. I'm coming from an R&D engineering background, and I've honestly been spoiled by CNCkitchen's test data and rigor. I look forward to seeing you grow this channel!

[@olafmarzocchi6194]

Besides the as usual good content of the video, cyclone separators can be bought for little money, less than the cost of the filament... I gave up spending time in designing, optimising, printing such common parts

[@TheBaseUK]

Very interesting, do you think you'll continue with the ender 3 v3 ke vids?

[@wktodd]

They seem to break at the minimum cross section so is the addition strength actually caused by the reduced lever lenghth , from the tension source?

[@DavZell]

It would be interesting to see the gusset on the bottom.

These test pieces seem to just be moving leverage point closer to the load which of course will increase the strength.