Late to the party, but as an engineer, I feel the need to comment. Gears need 100% infill. Yes, in general, material stresses run higher on the surface, but effectively having a hollow part creates surfaces on the inside as well. The sharp inside corner that the slicer will leave under each tooth combined with the inside corner created by the inside surface of the face will create sharp junction of three surfaces on the inside. This will be a huge stress concentrator. If you watch carefully, this is the first point where the plastic turns white. (Crazing) The second place is the root fillet of the tooth. This stress concentration is inherent in any gear tooth. Try again with 100% infill. Also try setting the top/bottom surface thickness to the full thickness of the gear. I would expect that the diagonalized print lines of the top/bottom layer will act to brace the teeth. Also, I would experiment with the shell thickness. I would expect that would allow the diagonal lines to extend into the tooth somewhat, preventing the delamination/crazing at the root of the tooth. Interesting, but the 20% infill is definitely more of a problem than the material.

I have a story for you... Several years back I went on a tour at a local industry location that creates thread and string. They have a set of all-mechanical machines created about 100 years ago. They are not electronic at all. They all have precision custom parts made of metal except for one essential gear that is made of wood. This was deliberate so that the wooden gear would wear down and break before damaging the other parts. This thin gear is cheap and easy to replace by stamping out a new gear from a thin wooden board. Nobody knows who built the machine but the design is very smart. Take inspiration from it.

I’m not surprised by the PLA results. I’ve seen great durability results with many of them. As you found the hex shape is a weakness as it has less surface area for direct force than the gears. But that may give you the slip you want before failing a motor. Great summary and look forward to the other testing you plan.

A digital torque adapter would be more convenient for tests like this, they are not too expensive either - may be a handy addition! Especially with how useful these tests are!

As BASF is an abbreviation, I've always pronounced the individual letters like you do for IBM.

I would love to see the tests with 100% infill, but in two ways. I saw the perimeters separating from the infill. So i'd love a test with 3 perimeters and 100% infill, but also a test were its lets say 100 perimeters with 100%, so that basically the whole thing is a perimeter that doesn't get to cool down and then have a string from the infill just touching it briefly... or heck. Even a test with 1 or even 0 perimeters and just solid infill.

Buddy of mine sent me a hard-to-find drive gear from his Wurlitzer jukebox. I measured and modeled it in Fusion 360 and printed him 6 sets in Nylon on a nearly stock Ender 3. Two years later, and he's still on the first gear. I love 3D printing.

Infill patterns will probably make a huge difference. Next up, take that BASF filament and try different patterns at a fixed density. Would be very interesting!

20% Cubic infill can change the results according to its orientation

Very interesting results! I've been keeping an eye on any updates for your RC platform. Cool to see you do a deep dive on one aspect of it. - Perry

Love this type and level of real-world application testing. This is far more useful than just some numbers on a spec sheet or anecdotal evidence. Thank you for putting in the time and effort!

I think we can all agree the big surprise is "bass-ffff" as a pronunciation

Angus, the amazing thing about 3d printing gears is being able to make herringbone and double helix gears, they are far more efficient, resistant to torque, and quieter. For your requirements I would definitely look at Polymaker CoPA-CF, quite pricy but definitely worth it, my second favourite is their normal CoPA, but they aren't as rigid.

Great insight! Very surprised that you didn't use 100% infill, since your gears are so small. I would print, at least, the top 3 contenders, solid, and retest.

Just want to say that I'm really enjoying your presentations and demonstrations. Excellent and engaging dialogue and cut-away work.

Taulman makes some amazingly strong Nylon. I have used them for gears in an industrial lathe that was out of production and we couldnt get replacement parts. What was one of the best parts was how quiet it made the machine with nylon gears versus metal. I admit the gears only lasted a few years but considering we could print them for a couple bucks each, we just made an inventory of replacements.

Ive been watching you since the “can wild parrots solve puzzles” video, you may think “Hmmm, you must be watching so you know how to 3D and have better prints ect” No, i do not have a 3D printer, i just watch these because they are entertaining videos.

its b a s f @6:59 stands for "Badische Anilin-und Soda-Fabrik" which means "Baden aniline and soda factory" they make all sorts of chemicals, gasses and nasty stuff. i live less than 5km away from it and they recently let out a big orange cloud of NOx after dumping hundred of liters of Dichlorobenzene into a river (not the first time lol)

100% infill would be interesting with a decent amount of wall overlap.

A big advantage of 3D printing is that you can put one of each material on every wheel and see which one fails or wears out first :) People more knowledgeable than us have already solved this problem IMO, almost every injection molded gear is made from nylon (lubricity and toughness). I've also seen acetal (aka POM aka Derlin), but that's a nightmare to print. I would stick with nylon, and I would avoid the fiber filled varieties, both due to lower lubricity and potential health reasons if it liberates carbon fibers (glass fibers may be safer).

Can you test annealed PLA? I think the results would be pretty interesting

7:24 Nylon, cause it slips. No damage to the motor nor the gear.

This was a really interesting watch, thanks Angus. I've been messing with a gear reduction for my Big Mixer project and have been trying to figure out how to deal with the increased torque. I was surprised to see some of my PETG parts fail before PLA, in particular I noticed a significant difference between eSun and Zyltech PETG rigidity. Most of my failures seem to be at the attachment to the axle, rather than the gear teeth. Your approach with a 12mm hex head might be a better idea than using the axle detent and a 2.5mm screw that I have been using previously. Thanks for the idea!

You might see how each material wears as well. I know nylon is known as being self lubricating and slides against other gears well. I printed a couple large gears in bridge nylon for and R2D2 that weighed 50+ pounds and they held up incredibly well. Printing in nylon was a real pain though due to warping and shrinkage

In my experience, the best gears are made from Polymaker Polymide and hardened for 2 hourse at 80C. Also, finer teeth tend to be stronger. I also would fill the gearbox housing with a mixture of mineraloil (babyoil) and vaseline, that reduces friction and cools the teeth, otherwise PLA gears bind up really fast.

That's a pretty interesting lineup!

Landed at the video by accident and then was so fascinated I just had to watch it to the end. Really well done, as uausl, well thought through tests and presented. Polyalchemy really has some nice PLA, I absolutely love the brand. BASF bought Innofil3D, who made this filament before.

I'd love to see a full video series about the strength of these plastics in rotational strength (like this one), crush resistance (for use in hydraulic presses), shear resistance, and tension strength. I mean, if you don't do it I will, but you're actually skilled at this stuff.

i had a BASF ABS and man this was amazing this filament. no warp on a open 3d printer.

Thanks for this interesting test! By the way: We spell it B-A-S-F in Germany. This brand is known for chemical products and even Audio-Cassettes in the past ;).

I like this video, it's so informative. you even put the details how long your filament is in your workshop. I didn't know removing moisture will help until I watched this

I really like this video, and the practical setup of your test. I'd love to see a remake of this for a few of the fillaments where they've been soaked in water overnight. Apparently PLA is stronger when it is humid.

love this test. I had hope for PC and PC/CF thanks for sharing your experience with all of us 👍😀

The ST play is super tough. Toughness is an engineering term where it will deform before fracture. The tougher it is the more deformation before fracture

Glad you got you hands on BASFs Pro1 filament, I've pumped through dozens of kgs of it for fixtures/tooling for my work. It is also advertised as being able to print at a blazing 150 mm/s, but not something I've had success achieving (maybe with a voron build it would be.) Great video!

Great video, thank you for your work and time spent.

I think your choice in infill was suboptimal for a gear that needs to take a high load.

Small 3dp gear: exists Elephants foot effect: NOW HOLD IT RIGHT THERE BUDDY

Great test labs, great for selecting materials. Thanks

Thanks for that incredible testing, I took a lot of notes to improve my 3D printed RC car

I'd also be interested to see how the gears stand up to wear. I understand that your use is mostly for prototypes. However as a hobbyist a lot of the time I'm looking to make a functional (remakeable) part.

Awesome video! Look forward to seeing how PC holds up and how going solid will help. BASF is pronounces "B" "A" "S" "F". I had a family member work there, they make several chemical components and are starting to get into filament and resin material.

Thank you Angus! I may have to try some of that BASF PLA!

Printed a solid gear for my fishing reel with PLA, secondary for oscillation in a spin reel, and it worked like a charm. That particular gear never get much stress unlike the main gear.

would love to see you try the engineering grade PLAs like the anneallable ones, Formfutura Volcano PLA etc

For PLA lubrication would be nice. That lowers the heat generated due to friction thus allowing for a hotter enviroment before the gears melt.

This analysis is actually testing the gear design and fabrication parameters more than the chosen material. Changing the design or parameters for each material can yield much better results. For example, I would expect the nylon gear should have a multitooth (e.g., 16) splined shaft (rather than your hex shaft), with thicker sidewalls, because it would distribute the tensile stresses much more evenly throughout the circumference of the gear’s shaft, as resulting in less overall deformation. There is so much more to consider in this analysis, other than merely the materials. This whole video is a great example of how much really goes into, the engineering and manufacturing of a machine.

Thanks for making this video! I was looking for a good comparison of 3D printed gears all over youtube. If you intend to do further experiments in this direction you could test different gear designs like herringbone gears :D

Very interesting test, but most importantly these results tell me: "Don't use a hex shaft!" Would be nice to have this re-tested with a different force transfer.

Great testing. One thing instead of a torque wrench, a ratchet adapter with torque readout might have been better

Nice work! I'd say the PA12 (nylon) is a better choice since it doesn't damage the gear at all when it fails. Meaning you can keep resuming the use of it, long as the load goes back down and stay under. It's like a fail-safe damage prevention. Ideal for any sudden force/stop situation in RC cars.

I started printing PCTG and i JUST LOVE IT!! It´s great :D

Interesting test, thanks. Incidentally, the whole idea of a keyed shaft is to provide a known point of failure. So using your results, you could build in a keyed fixing which fails just before the gear lets go...

14:47 the PA12 + GF15 test shows one of the gears being permanently damaged and possibly half ripped off at 12Nm, it's partially springing back yes but it's obviously broken at this point.

Great Video. Very useful information. I usually print in 3dfillies PLA+ as its reliably great. For serious toughness, I print in Prusament PC blend. Its crazy strong. I will be trialling PC Blend Carbon Fibre soon. Looking forward to you next video. They are always good. Cheers

finally some real testing!!! Great work...

I think you should try wear resistance too! :D Like... spinning 2 meshed gears at max rpm for a period of time

It's probably also important to test at the speed they will spin at in production for a reasonable work time. They can work great at first but then start to melt.

Hi Angus . Thank's for this video and you showing us your tests results Two years ago I 3d print with PLA all missing change gears of my mid size lathe and it still working, never broken. I use 100 % infill . The gears diameter was betwen 50-140 mm Also I tried to print some small gears ( max diameter was 40mm) with diferent resin brands and the winner was BLU from Siraya

Really interesting! I did not expect that Elixir would perform so good. Also the BASF (Spoken B-A-S-F, it stands for "Badische Anilin und Sodafabrik") seem like a really good underdog filament for structural parts which doesn't break the bank like oder BASF filaments

You should use double helical gears. You are printing so you can do the double helix in a single gear. (Kinda looks like a tractor wheel.)this gear type is great for high load applications.

I like nylon for gears bc of its memory and its self-lubricating. It's important to rehydrate nylon after printing before applying any stress.

Thank you very much for these videos!

thanks for sharing this with us. I found also that the design of the center of the gear is very important. I have designed a double sized gears, one on top of the other. If I just design it to be printed as a single part (layer on top each time) the break point appears at the jonction of the two gears. If on the contrary I design as one small gear inside the bigger one, the print will be stronger.

I think i may have mentioned this on twitter, but I'd be intrigued to see some sla resin gears here too.

I think a Herringbone gear would be able to withstand wayyy more torque

Très bon test...Merci!!

This video and watching how the gears snap geve me a clue how to improve gears design to withstand higher load, not being much heavier or bigger (perhaps even smaller removing material from areas with less load)

This brought to mind an idea. Could you possibly print with metal (washers) imbedded in the material for added strength, perhaps allowing you to control how the gear fails.

Before watching the video I'm going to go ahead and say that my personal favorite is PETG. I'm very curious to see what your results are!! Update: Okay, how could I have been so wrong haha. However, to note, the quality depends so much on producer that I think it's impossible to say which material is the worst. I have been designing some machines lately and the PETG that I used for the parts worked better than any other material I tried to print with. I've never had a failed part with this PETG I'm printing with, and it's lasting much longer than any other PLA I've printed with. Most PLA's would start to crack after one year of use. They say that PETG has worse UV resistance, but I think that in the end the PETG I have holds up better than the PLA I had. On top of that this PETG prints really nice with an E3D hotend with a titanium filament path, so no PTFE tube inside this hotend. I was expecting problems, but my prints never looked this good. One more thing I miss in the comparison is a comparison of the friction coefficient, which greatly impacts how long a gear survives, and how hard it is to turn. Some plastics just really aren't that frictionless. PLA in my experience performs the best as a common filament, but Nylon should have an even lower friction. And eventually PTFE has the best of all of these, but I sincerely recommend against using PTFE in a 3D printer as it's a super dangerous plastic. If you have pet birds, stay away from printing with PTFE as your birds will definitely pass away from even the tiniest amount of fumes.

The 'mechanical fuse' concept is an interesting one. As seen in the comments, there are many instances of them. But one that comes to mind, are called shear pins and often used in lawn and garden equipment, they connect something like an auger to a shaft and will shear if you hit a rock, etc.

Nice set of tests. I am looking at a number of printed gear applications in robotics. Three things worth mentioning. (1) Infill - as many said, a sold gear would be interesting to try. (2) But I think the clearance on the hex is also important for those where the hex rotated. The clearance might seem an insignificant figure when compared with the A/F dimension but, in reality, the clearance should be compared with the difference between the A/F and A/C. This is a much bigger percentage. We drive a lot of 3D printed mechanisms with 1/2" hex rod and always ensure the fit on the hex is as close as possible. (3) It's probably also worth extending the length of the hex socket on the printed gear and perhaps making it thicker to ensure it is not the first point of failure. Then we can see what the teeth will really do with the Nylons. Great work and I always enjoy your clear and concise delivery - one of the best!

the Nylon is good as something like a damper or clutch for too high torque.

you can get digital torque wrench adaptors that have a "max" setting.

Nice video 🙏. BASF ultrafuse used to be innofill until they where aquired by BASF. We print solely ultrafuse PLA and ABS and the properties are indeed very good.

I really like these "real world" tests. When it comes to PLA, there are so many varieties and blends, that I really like the vendors that let you know the base filaments. If you can find some PLA based on NatureWorks 3D870 Ingeo PLA, you'll have a modified PLA that can be anneals very well for extra strength and temperature resistance. I'd also like to see CF-PETG and CF-PC (or an easier to print PC+ Blend).

Knowing torque at which material fails one could design weak point into gear so it will fail predictably and protect other components from both teeth flying around and motor stalling and burning.

hey bro, you really need to test the temperature resistance of PLA. I've had my PLA gears strip out on me on a hot day, Can't say the same for any of the petg or ABS gears that I've used. the BASF filament looks good, but if its like every other PLA and starts to turn into silly putty at only 60c... yeah...

Interesting! Something else to consider is that nylon is lower friction than most of the others, which could impact actual use. Also, I would love to see some Taulman filaments tested. They have some very helpful charts on their website that show strength and stiffness for their filaments, which could be helpful when selecting some for gears.

I have not heard the brand BASF since the 80s days of magnetic tape. Glad to see they are still in business!

FINALLY, SOMETHING I CAN UNDERSTAND, GEARS AND SIMPLE MECHANICS!

I still don't get why you didn't use 100% infill for a strength test of a gear

omdss thankyou thankyou thankyou!!! i really needed to know what filament was strong/strongest .

Great test has been done .

Good vid! Now run them at 2000rpm and see which survive. Static strenghth is a small factor in gear material selection. ;-)

Can’t wait to see the PC tests! I would love to see how Prusa’s new PC Carbon Fiber Blend compares.

I love Ivan Miranda's channel. That's really cool that you gave him a shout out. 🙂

Very interesting results. It looks like it reflects a measure of accumulated material stress, as every torque step increases the material damage level also.

The only thing I wonder is, does age influence the strength? I mean, it printed nice, but that is not necessarily the same thing. Did you test anything that is not +5 years old?

What about wear? Assuming you are operating below the breaking point, material wear would be the next criteria I would look at.

Really nice and interesting video! Thanks :)

*@Maker's Muse* 15:30 it would be nice with some icons of the gears too, those cryptic item codes don't tell me much (it is very good that they exist too). (Maybe also add actual numbers on the bars too, in a up/down configuration inside each pillar, so you don't need to guesstimate or go back in the video to know) (That's the only improvements of the video I would make, I'm really glad the overview exists.)

Try resins, some of them should be like PETG, but prints faster for solid parts and handles high temp better.

I really wish you could test PEEK gears.

Well I was very surprised, I was expecting nylon to be the best! Great to see many other materials tested.

I've used grey PC Blend from Prusa to print a 3:1 reduction spur gear for a large brushed DC servo. I'm not sure of the exact torque, but it's in the region of 35Nm. Printed with 5 perimeters, 7 top/bottom layers at 0.2 layer height and 35% gyroid infill. It has been in service (in a car engine bay, no less!) for months now with no issues whatsoever. The original gear was injection moulded POM.

Before I watch the rest of this I’m going to guess nylon.

are you gonna build a voron now btw, everyone's making one now xD

Huh! Super cool results - keep it up buddy!

I'm using Ultrafuse PRO1 PLA a longer time and like it very much. There is also an option to annealing it, temp resistance go up to 90 degree Celsius. It was before BASF bought it known as Innofil.