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.
@@EnjoyCocaColaLight Probably wouldn't do much. Sand/Water would fill the space and prevent volumetric compression, (look up poissan's ratio) but wouldn't help much with linear compression and shear.
I also want to see him try with smaller and larger gears, to see if the failure moves around and/or if the force at a location is the determining factor.
Так он же сравнительный тест делал. Шестерню хреново наслайсил, да. За то у всех пластиков одинаковые условия. Ну и так, чисто придраться - силовые шестерни делают под шпонку, а не под шестигранник - так удобнее упираться.
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.
I've always been skeptical of fancy "pla blends" but seems there may be something to it. I think its only undoing may be heat during operation but at ~800rpm output I'm not too concerned.
@@MakersMuse spot on. I print gears for varying industrial applications and found for sacrificial purposes and low temp operation, pla+ lasts longer than abs and even nylon in some cases.
The only thing I would quibble with is the description of why the hex fails instead of the teeth. The involute tooth profile is such that, if properly shaped, the force is applied tangentially to the circle. With the hex, the force direction is mostly outwards, so matching a particular amount of torque requires far more force, even if you ignore that the hex is also much smaller diameter. As far as the results with the gear, yeah. This testing is primarily looking for yield strength, not toughness. At least from an engineering perspective. I realize that the engineering definitions of terms like "Strength", "Toughness", and "Hardness" are far more exact than a colloquial usage of them, in which case they're often relatively interchangable. Unfortunately, yield strength is often times correlated with being a brittle material, which almost definitionally means a low toughness. In other words, materials like PLA with a high yield strength are likely also going to not take abrupt application of force well at all. Fortunately, that probably is desirable in this application, because a sudden failure is still going to be a lot less likely to bind up and cause the motors to run hot for an extended period of time.
@@MakersMuse In my experience PLA gears stay cooler, because the surface is relatively hard and has less friction than a softer more rubbery material (like PETG or nylon). Lubricating the gears keeps them even cooler, since it further reduces the friction. Then the temp shouldn't be an issue.
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.
This same EXACT technique is used in my rotor for large Amatuer radio antennas. There is a fiber gear that is meant to fail before anything else can be damaged. So, this is a wise choice, and the gear can be made progressively stronger, until you get close to the breaking point for another gear or the actual housing! Some Kitchen-Aid mixers use a plastic gearcase as the ultimate failure component--I replaced mine with an aluminum one because their plastic one is just too weak...
a specifically designed flaw, intentional and easy to perform routine maintenance part, to protect the multi thousand dollar (at the time, adjust for inflation) machine - that would be key to making profits for years to come. Pure Genius. If only we made most things like that now a days, instead of soldered in batteries and "buy a new one" attitudes.
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!
True. Moreover, using this adapter will give more accurate results. During the test the specimen was loaded then unloaded several times in order to adjust the torque wrench. While a proper test should be carried out in a linear manner as possible until failure. The cycled load can harden the material, through minor plastic deformations, thus getting higher false result.
@@landmarker That was the purpose of the second gear, which was tested to failure at the torque found for the first gear. Not perfect, but a good check on the result.
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
Yes, and so any of the filaments cause nozzle wear in your printer? That concern, along with needing to run at higher temperatures and fewer color choices are what keep me away from filaments more exotic than PLA and PETG.
I wouldn't call Nylon self-lubricating, its partly flexible which helps. eSun PLA+ I would call self lubricating as it literally leaves a slight oily film if you rub it with your fingers
@@aidangillett5396 Nylon in and of itself is not self-lubricating, but there are some grades of it that you can buy as bar stock which have been oil-impregnated. These are intended for use as bushings / plain bearings or for sliding contact surfaces. I don't think you could make those into filament, though- the oil content would most likely cause some fairly important problems when heated.
One of the most important things on a gear is that it's designed correctly. If you do it with the correct tooth profile for a gear (and correct distance for meshing), they don't slide at all, they just roll. That reduces a lot the wear on gears. Now it does make sense to lubricate them anyway, specially the shaft and sides as those will be sliding over something.
PLA was used for gears and linear slides on hobby 3d pritners because it powderizes as it wears, effectively becoming a dry lube for itself. I've actually been thinking of using it as a linear slide on aluminum extrusions (8020 sells these made from POM) for a project I have in mind where linear rails would be overkill.
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.
@@Darfail I mean perimeters count. In PrusaSlicer it is "Perimeters" in "Layers and Perimeters." I don't know how it called in Cura. "Wall thickness" I guess.
Same with orientation of the Hex shaped mount, and the orientation of the teeth meshing. Two teeth meshing equally might be stronger than 1 tooth meshing, since the gears are of different materials. Obviously in a real application the weakest orientation will be the mode of failure. Maybe the test could be re-performed with rotating the gears a few times at each torque level? That would also help even-out the wear during testing.
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.
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.
Helical gears are not as efficient as standard spur gears due to the higher contact load and sliding friction for a given torque, although for most applications the difference is not significant considering the other advantages. Helical gears are stronger though due to the tooth effectively being longer. It would be interesting if he repeated the experiment with helical and herringbone and double helix (slight gap between the helixes) gears to test the strength increase. Herringbone gears are a bit stiffer in the centre where the helixes meet.
@@Bordpie I agree with the part you are saying on single helixes but double helix and herringbone don't have this downside. Yes herringbone is stronger due to the lack of a gap, but double helix is ideal for when the gear might get dirt or grease stuck in it, since it doesn't build up in a double helix due to the gap but in a herringbone it does.
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.
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!
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.
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).
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.
It would be hard to get a good shape because gears would ideally want to roll consistently between all the teeth. But with testing, you could get as nice in the middle to keep that precision in the gear profile
consider how low PLA glass transition temperature is, you have to consider the heat from motors and batteries if there are any, and other factor like material fatigue.
@@nhozdien5058 Indeed, James Bruton has had a number of failures where the motors in his robots are directly attached to 3D printed PLA brackets through the PLA softening.
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.
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 ;).
(BASF) is short for the name when originally founded back way in the past: 'Badische Anilin & SodaFabrik(en)' > 'Baden' is an area of the Southwest of Germany / State 'Baden-Württemberg' - where BIG Companies like Mercedes-Benz/Daimler, Porsche, NSU (Part of Audi production in Neckarsulm), Lidl, Layher, GetrAG, SAP, ZF, Gardena etc.all come from ...
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)
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.
True but at the same time if he choose for example 100% infill it could be that the first failure point moves from the tooths towards the inner hex mount. 20% will never be ideal for strength but it gives us information about how and where the materials start to fail, which is important aswell to make an informed decision. Nevertheless the testing is not conclusive without testing say grid infill and 40% infill, 55% and 100% infill.
I always print parts that need peak strength at 100%, just to be sure. At 3-4 shells and high percentage of infill you can get higher print times than with 2 shells solid (and therefore linear) infill, for certain shapes at least.
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.
glass of carbon fiber (fill) is not for gears (or anything with mating surfaces) as it's very abrasive, and it's way even stronger not a good idea for gears.
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.
Yup, they can. A good idea for someone doing a video like this would be to test in the way this guy did, which was great, but then test different types of gears, then do it all under a hotter temperature because gears tend to generate a little heat. Nothing too serious, if you grease them or w/e, but they still get a little warm which can change the whole experiment.
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.
@@timehunter9467 good point, I don't know too, but when we think about it, if you stick a torx driver inside, the profile on the printed part actually has the rounded shapes which may be easy enough to handle in 3D printing.
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!
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
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...
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!
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.
For any others interested in 3D Printing beyblade parts. Funnily enough, I'm just watching this cause I wanna make a 3d printed beyblade layer with high durability, since I notice some amount of other 3d printed layers like to break sometimes, and I think I know why now. I've never done 3d printing before, and still don't have a printer nor the filaments for one, but this will be useful. In terms of 3d printed beyblades, the best for a durable beyblade would be the BASF Pro 1 PLA, and if you want an effective spin steal layer, as well as the high durability, PA12 is definitely the way to go. 13:09 pretty much sums up the reasoning for the spin steal, and the chart at 15:50 shows the good durability. The same BASF and PA12 filaments can also be used for the driver tips, the PA12 should be useful in place of rubber tips, and BASF is good for the basic tips. if you want to 3d print discs however investing in a form of metal filament, such as a stainless steel or brass filament would be more ideal, otherwise you can just use existing discs. Put Simply::::: Layer:: Basic:: BASF PRO 1 PLA Spin Steal:: Fiberlogy PA12 Disc:: Stainless Steel / Brass Filament Driver:: Basic:: BASF PRO 1 PLA Metal Tip:: Stainless Steel / Brass Filament Rubber Like Tip:: Fiberlogy PA12 Thinking about it now, I might make some form of article on 3d printing beyblade parts, in it, I will simply go over the process of it, and of course have this video in the credits, when I do end up making it, I'll replace this statement with a link, although it may take a while to do. Hope this helps for others interested in 3d printed beyblade parts.
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?
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.
4:46 You might think 8Nm is pathetic, but if you calculate the force on the teeth, you'd be surprised. The radius must be like 3cm or so, which would mean that they transfer a force of about 266N there! That equivalent to over 25kg hanging on that teeth. Suddenly pretty impressive. I am sure if you calculate the stress on the tooth by using the surface area, it is still quite impressive. On that note, if you want to transfer more torque, as others have mentioned, herringbone gears have a larger surface area per tooth, thus allowing higher forces before reaching yield strength of the tooth/material. Also to be noted, only tested here are fairly static torques. In real life applications you also have many peak torques, which can immediately cause a very stiff gear to fail (even if it has a high yield strength) whilst lower stiffness materials might absorb these impacts much better. I suspect that with this kind of testing PLA will perform far worse, and gears such as nylon and abs will excel. Seeing how the gears fail, I suspect that higher infill ratios would significantly increase strength, as the limited contact between outer walls and infill (which transfers the torque) is where they seem to fail. With low infill ratios this is of course a very limited contact patch. Never mind that these contact patches feature very sharp angles, which induce stress concentrations.
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.
*@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.)
BIG factor for 3d printed gears is heat resistance. local heating at the contact points due to rubbing and flexing can quickly build up and cause rapid wear. In my experience over heating is the cause of the vast majority of 3d printed gear failures. This results in the best gear materials also being optimized for 3 things; high melting point, low friction, and low flexural hysteresis. (so Torlon > PEEK > Delrin > Nylon > PETG etc.)
Late to the party but if you ever plan on doing similar teasing in the future (speaking specifically to gathering torque data) I'd recommend a torque wrench adapter than a regular torque wrench. You can just keep cranking on it till the part fails and the digital adapter will tell you the peak torque. I first learned about using this method from ProjectFarm who does this in his videos when testing torque numbers. You can get an idea of what I'm describing if you check out his video on Anti Seize compounds, around the 4:30 mark! Or, really, most of his videos on small tools and such but that was the first one that came to mind
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.
100% Incrementing up on a standard torque wrench introduces all kinds of nasty variables, especially in plastic. Testing methodology probably eliminated some of that, but just one iteration is a tad low.
I replaced all the gears on my old craftsman 6 inch lathe with 3d printed gears made out of Taulman Alloy 910. Been using it on and off for years now. Works great. Plus it has two added benefits: 1st, they are self lubricating, so no need to oil them, and 2nd, they are much much quieter.
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.
You might not want it to be too strong, imagine a yard rake where the claws of the rake are thin metal and you are pulling it behind your rider mower, you want that gear to last a long time but you'd rather have the gear self destruct in the gear train before the rake mangles itself if caught on a branch or something big!
@@crzprgrmmr and material strength on anisotropic materials depends on many factors. If you print at 40% infill on everything, why would you test a 100% infill gear? It’s about application. That being said of course you could do any level of infill if you’re doing relative strength testing (same conditions, different material). It’s a relative test, absolute testing would be cool but isn’t what’s happening here anyway.
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.
@ 02:00 - Didn't watch the video until the end but i can already tell which is better and for what application, base on my MSc mechanical engineering degree. Nylon for low torque, high impacts and high cycle count applications, nylon is self lubricating so it can endure many cycles without losing its given geometry and tolerances. Also being able to endure higher temperature than the other 2 is a plus for applications that require long and hot runs. ABS when you need it to endure somewhat high temperatures but have medium amount of cycles and impacts, ABS fails in a ductile way, so you can design the gears in such a way one of them is safe guarded from fail. PLA when you need the parts on that moment and only have to endure low cycles and some high impacts so you can collect some data for the new definitive part.
Results of Polycarbonate (PC) would be interesting too. Teeth and area of contact of the teeth to the radius of the gear should be printed with 100% infill and the center with infill, therefore the teeth have more absolute strength but can bend relative to the center of the gear . That avoids too brittle breakage behavior. Additionally, the infill can be designed to correspond to the inner stress introduced into the radius (But therefore has to be manually constructed in the CAD itself and not to be used with the automatic function of the slicer software) Cubic infill f.e. is not suitable because the stress is mainly "in plain" , and therefore the 3-D part of the infill does not have any beneficial effect to the strength of the structure.
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.
the much easier version would be protecting the motor via limiting its current, which is rather trivial and very reliable. The brushless motors are driven by 3 (usually) mosfets, adding a current measurement, aside the hall effect (rpm) should be a nobrainer.
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.
@@BOTmaster15 as you may know, you have to dry nylon before printing it. Doing this makes the nylon brittle. It will rehydrate on it's own in open air after a week or two, if I'm remembering right. I leave my nylon parts in water for a day or so. They are noticeably different afterward. if you tap on them before the soak they have a higher pitch brittle sound. After soaking it's more of a thund.
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.
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
@@jothain For gears I'd worry more about abrasion. Sure, when a resin part breaks, it really _breaks_ and doesn't rip apart or deform otherwise. But if it's stronger, that might not matter. But due to the brittleness, the gears will probably wear down a lot faster than those made from softer plastics.
@@harmless6813 pla last really well the abrasion. I have at work carton packaging machines and there's couple of places I made bit different prototype parts to test. Biggest problem was that layer lines needed to be actually sanded off as they didn't wear off which I was expecting. Also made one prototype part for pneumatic attached anvil/hammer parts. I was expecting it to demolish within hour, but out curiousity left it on for and it was there for couple months until I got machined parts to me. PLA is way, way better "technical" material than many think. Really the only downside is that it doesn't handle heat well.
I love your channel. As a naval mechanic I feel compelled to tell you that you need to learn about counter-torque to save your parts and tools from a devastating end.
That was great, well done, but as you compared gears I started wondering about wear. many applications are more about wear than strength, a winch lifting a load is strength, but car wheels can slip but need to continue for many revolutions and probably heat up causing increased wear with different results for different plastics. Would be more time consuming to test wear but a rig with a small continuous load over an extended time would be interesting. I feel for you down there with the covid thing, I expect we on the Gold Coast have it coming our way soon, 3D printing would be a good pass time during lockdown. Take care mate, love your work.
Good video, I don’t think there really is a preferred method of fail when it comes to gears as the end result is still the same. I guess if gear is deforming you would have some advanced warning but with anything with any real rpm it’s still going to fail quickly. Would be interesting to make a composite gear, say pla hub with a modified nylon teeth.
I would have said the same thing based on the title, but there is a huge difference between 'is best' and 'can handle the highest load before it fails catastrophically'.
@@nocjef agreed. And some PC maybe, or even throw in some HIPS just to get a more rounded view. But yeah, ABS definitely got shafted here, lol. I reckon Titan X would do reasonably well. I would like to see follow up video though on the solid prints
I feel ABS has an overlooked issue here that it has low surface abrasion resistance, so for this reason it's usually not recommended for gears. Overload events are once a lifetime, but surface friction is constant in a mechanism. Still, some ABS filament might actually not exhibit this issue strongly, or might even not be really ABS but SAN. But it would be important to test.
Materials engineer here. "Tough" and "strong" mean different things. Tough materials are able to withstand damage... which is why they tend to be a bit soft. I bet the ST PLA is really great for impact resistance while other generic PLAs can be rather brittle! Your gear test was evaluating strength!
The Fusion 3 F410 printer I was repairing has a dual material 3d printed extruder gear. I don't know which materials as it's not my printer, but I can tell you that having one material interface with the motor and another interface with the gear for the extruder was a really cool design.
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.
Perhaps a two piece gear would work well. Like a stiffer plastic mounted on the 12mm hex, then splined into an outer ring that forms the teeth of the gear made of one of the softer materials such as nylon.
Great video, exactly what I was searching for ! However, I know this is old stuff but I think you should use some sort of fixed guide the diameter of the torque wrench to ensure that the torque you measure is perfectly axial to the gear. With you setup, as soon as you're not perfectly aligned you also measure torque vector components in other directions, which biases the results.
If you slow it down at 11:19 you and you play it you can see the crack start. Awesome video though! Been wanting to get started with 3d printing gears to further my journey into microcontrollers and rasp pis. I was a bit worried about buying a 3d printer but considering most of my prototypes will be plastic only I say these gears should work great.
perhaps you could follow up with a wear test to see which filament has the best wear resistance, instead of having a fixed gear you could attach it to an axle with a paddle on one end in a bucket of water or some other load, and then attach the driven gear to a drill and spin it either stopping every few minutes until you reach a certain amount of backlash or for a fixed time for every gear and compare how much they wore down. for this test it would probably be a good idea for both gears to be made of the same material instead of one being made of metal. a cordless drill wouldn't be ideal since as the battery looses charge the drill will change speeds.
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
I have a roll of CF reinforced nylon i print with when i need strength - Add North Adura X. Has a beautiful matte finish and is way easier to print than regular nylon since it has almost no shrinkage. It's a Swedish brand but I'm sure you can get similar filament in Sydney.
I think heat deformation would be the first issue. As a Northern Australian I find just outside temperature fatal for anything not printed on a heated bed
I would really love to see some ABS blends like fiberlogys ABS plus, Esuns ABS plus or 3DJakes niceABS. And I would really appreciate if those materials were printed in a heated chamber, even if the manufacturer states they "can" be printed without one, because based on my own testing layer adhesion without one is really terrible, even if the print doesn't outright warp.
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!
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.
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.
Try some of the Taulman nylon variants. I use the 910 for gears because it doesn't require lubricants and is more environmentally resistant/durable, but the print quality is not as good as PETG. I would like to see how the different variants compare though. I'd rather have something that fails catastrophically than deforms with degraded performance and puts more stress on the system until it fails completely or enough to be detectable. Nylon > PETG > PLA. I also use a helical or herringbone gear rather than a straight spur/involute profile and I think that that lends itself better to nylon than your tests measures.
Thanks for the very interesting video. I've impressed with CF PLA and CF PETG stiffness, but I'm not sure how a CF filled gear would wear. The surface of CF parts seems fairly abrasive. Maybe a slippery surface is more important than outright stiffness for gears.
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.
My initial thought when seeing a gear sear.. they weren't solid.
Followup: Would it be possible to fill the hollow parts with sand/water?
@@EnjoyCocaColaLight Probably wouldn't do much. Sand/Water would fill the space and prevent volumetric compression, (look up poissan's ratio) but wouldn't help much with linear compression and shear.
I also want to see him try with smaller and larger gears, to see if the failure moves around and/or if the force at a location is the determining factor.
Так он же сравнительный тест делал. Шестерню хреново наслайсил, да. За то у всех пластиков одинаковые условия.
Ну и так, чисто придраться - силовые шестерни делают под шпонку, а не под шестигранник - так удобнее упираться.
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.
I've always been skeptical of fancy "pla blends" but seems there may be something to it. I think its only undoing may be heat during operation but at ~800rpm output I'm not too concerned.
@@MakersMuse spot on. I print gears for varying industrial applications and found for sacrificial purposes and low temp operation, pla+ lasts longer than abs and even nylon in some cases.
The only thing I would quibble with is the description of why the hex fails instead of the teeth. The involute tooth profile is such that, if properly shaped, the force is applied tangentially to the circle. With the hex, the force direction is mostly outwards, so matching a particular amount of torque requires far more force, even if you ignore that the hex is also much smaller diameter.
As far as the results with the gear, yeah. This testing is primarily looking for yield strength, not toughness. At least from an engineering perspective. I realize that the engineering definitions of terms like "Strength", "Toughness", and "Hardness" are far more exact than a colloquial usage of them, in which case they're often relatively interchangable. Unfortunately, yield strength is often times correlated with being a brittle material, which almost definitionally means a low toughness. In other words, materials like PLA with a high yield strength are likely also going to not take abrupt application of force well at all. Fortunately, that probably is desirable in this application, because a sudden failure is still going to be a lot less likely to bind up and cause the motors to run hot for an extended period of time.
@@MakersMuse How about adding annealing to the mix? Great stuff though!
@@MakersMuse In my experience PLA gears stay cooler, because the surface is relatively hard and has less friction than a softer more rubbery material (like PETG or nylon). Lubricating the gears keeps them even cooler, since it further reduces the friction. Then the temp shouldn't be an issue.
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.
That's very clever! I've seen plastic gears used in metal assemblies to similar effect.
This same EXACT technique is used in my rotor for large Amatuer radio antennas. There is a fiber gear that is meant to fail before anything else can be damaged. So, this is a wise choice, and the gear can be made progressively stronger, until you get close to the breaking point for another gear or the actual housing! Some Kitchen-Aid mixers use a plastic gearcase as the ultimate failure component--I replaced mine with an aluminum one because their plastic one is just too weak...
Same as some blacksmithing power hammer that use micarta (paper and resin) gear as mechanical fuses
a specifically designed flaw, intentional and easy to perform routine maintenance part, to protect the multi thousand dollar (at the time, adjust for inflation) machine - that would be key to making profits for years to come. Pure Genius.
If only we made most things like that now a days, instead of soldered in batteries and "buy a new one" attitudes.
Based off what we saw on the video PETG is the ideal filament for this case then?
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!
True. Moreover, using this adapter will give more accurate results. During the test the specimen was loaded then unloaded several times in order to adjust the torque wrench. While a proper test should be carried out in a linear manner as possible until failure. The cycled load can harden the material, through minor plastic deformations, thus getting higher false result.
@@landmarker That was the purpose of the second gear, which was tested to failure at the torque found for the first gear. Not perfect, but a good check on the result.
As BASF is an abbreviation, I've always pronounced the individual letters like you do for IBM.
Not that it really matters, but yes that's how it is pronounced in Germany where the company originates from.
@@martin_mue - Badische Anilin- und Soda Fabrik halt.
Wait, you pronounce Ibbum as Aibe-emm?
@@nemernemer Lol, now I can't stop saying Oosay in my head.
In other countries (like my own) they advertise using the pronunciation of their name as a single word, not an acronym.
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
Yes, and so any of the filaments cause nozzle wear in your printer? That concern, along with needing to run at higher temperatures and fewer color choices are what keep me away from filaments more exotic than PLA and PETG.
I wouldn't call Nylon self-lubricating, its partly flexible which helps. eSun PLA+ I would call self lubricating as it literally leaves a slight oily film if you rub it with your fingers
@@aidangillett5396 Nylon in and of itself is not self-lubricating, but there are some grades of it that you can buy as bar stock which have been oil-impregnated. These are intended for use as bushings / plain bearings or for sliding contact surfaces. I don't think you could make those into filament, though- the oil content would most likely cause some fairly important problems when heated.
One of the most important things on a gear is that it's designed correctly. If you do it with the correct tooth profile for a gear (and correct distance for meshing), they don't slide at all, they just roll. That reduces a lot the wear on gears. Now it does make sense to lubricate them anyway, specially the shaft and sides as those will be sliding over something.
PLA was used for gears and linear slides on hobby 3d pritners because it powderizes as it wears, effectively becoming a dry lube for itself. I've actually been thinking of using it as a linear slide on aluminum extrusions (8020 sells these made from POM) for a project I have in mind where linear rails would be overkill.
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.
I saw the same thing, so the teeth could not maintain position/mesh.
Yeah exactly.
On that note it would also be interesting seeing 1 perimeter and 100% infill
100% infill with 1 perimeter. Maybe concentric. Use autospeed in PrusaSlicer to perfectly extrude the gapfill and increase flow slightly.
Or tighter infill, there is alot of air in his gear, also extra layers between the infill would strenghten.
100% infill would be interesting with a decent amount of wall overlap.
If you want strong print - increase perimeters. It work better than infill.
@@myudshlihe Not necessarily. Walls can easily delaminate.
@@myudshlihe hi what do you mean by increase perimeters? what setting is that
@@bldjln3158 if walls delaminate - it is bad print. Check your printer and print settings.
@@Darfail I mean perimeters count. In PrusaSlicer it is "Perimeters" in "Layers and Perimeters." I don't know how it called in Cura. "Wall thickness" I guess.
20% Cubic infill can change the results according to its orientation
Yeah.. it seems like a couple of the gears failed not by the teeth splitting but the teeth being peeled from the infill.
Same with orientation of the Hex shaped mount, and the orientation of the teeth meshing. Two teeth meshing equally might be stronger than 1 tooth meshing, since the gears are of different materials. Obviously in a real application the weakest orientation will be the mode of failure.
Maybe the test could be re-performed with rotating the gears a few times at each torque level? That would also help even-out the wear during testing.
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.
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.
Helical gears are not as efficient as standard spur gears due to the higher contact load and sliding friction for a given torque, although for most applications the difference is not significant considering the other advantages. Helical gears are stronger though due to the tooth effectively being longer. It would be interesting if he repeated the experiment with helical and herringbone and double helix (slight gap between the helixes) gears to test the strength increase. Herringbone gears are a bit stiffer in the centre where the helixes meet.
@@Bordpie I agree with the part you are saying on single helixes but double helix and herringbone don't have this downside. Yes herringbone is stronger due to the lack of a gap, but double helix is ideal for when the gear might get dirt or grease stuck in it, since it doesn't build up in a double helix due to the gap but in a herringbone it does.
RCTestflights made a few different style gearboxes for his autonomous solar rovers, much better durability than standard gears.
@@Christian-cz9bu They were also lubricated with slugs lol
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
What filement do u use to print ur 3D printed parts
always popular channels on top
@@Mizai not just any popular channel, but a 3d printer related channel, which makes sense to be on this channel.
hey ood
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.
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!
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.
Larger teeth are stronger, but not as smooth. Yeah, heat (and UV) kills PLA! Nylon can absorb water. Lube is good!
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).
That's a pretty interesting lineup!
What ur doing here, nah im kiding, yep this Is actually use full
always popular channels on top
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.
Can you test annealed PLA? I think the results would be pretty interesting
I think in that case will be need using 100% infill, so maybe will be fair enough compare also against remelted PETG in salt.
It would be hard to get a good shape because gears would ideally want to roll consistently between all the teeth.
But with testing, you could get as nice in the middle to keep that precision in the gear profile
consider how low PLA glass transition temperature is, you have to consider the heat from motors and batteries if there are any, and other factor like material fatigue.
@@nhozdien5058 Indeed, James Bruton has had a number of failures where the motors in his robots are directly attached to 3D printed PLA brackets through the PLA softening.
@@cambridgemart2075 yeah that is a really good point. Does that mean that PETG is worth it for the long run?
Just want to say that I'm really enjoying your presentations and demonstrations. Excellent and engaging dialogue and cut-away work.
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.
Hehe, thanks for sticking around! Popeye still visits us all the time, I'm overdue for making him a new puzzle.
I'm in the exact same position.
@@cameron9830 and i'm too lol
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 ;).
(BASF) is short for the name when originally founded back way in the past: 'Badische Anilin & SodaFabrik(en)' > 'Baden' is an area of the Southwest of Germany / State 'Baden-Württemberg' - where BIG Companies like Mercedes-Benz/Daimler, Porsche, NSU (Part of Audi production in Neckarsulm), Lidl, Layher, GetrAG, SAP, ZF, Gardena etc.all come from ...
In Netherlands we say Bas-F. 😄 I wonder how PC would hold up in this type of test. And does Ultimaker tough PLA compare to the BASF filament?
Und sogar Disketten 😂 hab noch welche im Keller
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)
Oh... that's somewhat awful!
@@MakersMuse No such thing as a guiltless chemical company. but some of them clean up after themselves. And others get shamed into it. eventually.
... and thats not the worst chapter in their history. Well it is huge company with many products, apects and a long history.
@@lukasskymuh5910 yea sometimes they blow something up and kill a bunch of people Like in 1921 and 1948 and a few smaller incidents after that
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.
I think your choice in infill was suboptimal for a gear that needs to take a high load.
True but at the same time if he choose for example 100% infill it could be that the first failure point moves from the tooths towards the inner hex mount.
20% will never be ideal for strength but it gives us information about how and where the materials start to fail, which is important aswell to make an informed decision. Nevertheless the testing is not conclusive without testing say grid infill and 40% infill, 55% and 100% infill.
I always print parts that need peak strength at 100%, just to be sure. At 3-4 shells and high percentage of infill you can get higher print times than with 2 shells solid (and therefore linear) infill, for certain shapes at least.
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.
Noted that too but for me, if you look closely can see the gear shearing off at 11nm
glass of carbon fiber (fill) is not for gears (or anything with mating surfaces) as it's very abrasive, and it's way even stronger not a good idea for gears.
i had a BASF ABS and man this was amazing this filament. no warp on a open 3d printer.
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.
Small 3dp gear: exists
Elephants foot effect: NOW HOLD IT RIGHT THERE BUDDY
PrusaSlicer has a great compensator for the elephant foot effect.
@@lio1234234 what's is it called haven't seen it
@@lio1234234 Cura too. Initial layer horizontal expansion or something like that. If you set it to a negative value you can get rid of it :)
@@rentaspoon219 Print Settings -> Advanced -> Elephant foot compensation.
Just reduce flow of initial layer.. Or when designing an object give it a chamfer of the bottom layer. Done
I think a Herringbone gear would be able to withstand wayyy more torque
Yup, they can. A good idea for someone doing a video like this would be to test in the way this guy did, which was great, but then test different types of gears, then do it all under a hotter temperature because gears tend to generate a little heat. Nothing too serious, if you grease them or w/e, but they still get a little warm which can change the whole experiment.
love this test.
I had hope for PC and PC/CF
thanks for sharing your experience with all of us 👍😀
yes please! Test PC-CF with 6+ perimeter walls.
For PLA lubrication would be nice. That lowers the heat generated due to friction thus allowing for a hotter enviroment before the gears melt.
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.
Maybe triangular shafts
one reason why torx was invented....
@@Peter_Schluss-Mit-Lustig A square shaft will offer significant improvements too if one cant get a triangular one
@@uwezimmermann5427 True, but I don’t think a printed gear would be able to cope with the tiny splines.
@@timehunter9467 good point, I don't know too, but when we think about it, if you stick a torx driver inside, the profile on the printed part actually has the rounded shapes which may be easy enough to handle in 3D printing.
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!
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
A gear must be stiff, the opposite of though. So regular PLA, the stiffer of all filaments, is the best in this regard.
I think we can all agree the big surprise is "bass-ffff" as a pronunciation
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...
good point. PLA does not hold up well in outdoor conditions
Try tempering the PLA it gets a lot stronger and handels a much higher temperature then all the others after tempering
@@tullgutten yes but annealing pla causes the object to shrink and warp
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!
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.
For any others interested in 3D Printing beyblade parts.
Funnily enough, I'm just watching this cause I wanna make a 3d printed beyblade layer with high durability, since I notice some amount of other 3d printed layers like to break sometimes, and I think I know why now. I've never done 3d printing before, and still don't have a printer nor the filaments for one, but this will be useful. In terms of 3d printed beyblades, the best for a durable beyblade would be the BASF Pro 1 PLA, and if you want an effective spin steal layer, as well as the high durability, PA12 is definitely the way to go. 13:09 pretty much sums up the reasoning for the spin steal, and the chart at 15:50 shows the good durability. The same BASF and PA12 filaments can also be used for the driver tips, the PA12 should be useful in place of rubber tips, and BASF is good for the basic tips. if you want to 3d print discs however investing in a form of metal filament, such as a stainless steel or brass filament would be more ideal, otherwise you can just use existing discs.
Put Simply:::::
Layer::
Basic:: BASF PRO 1 PLA
Spin Steal:: Fiberlogy PA12
Disc::
Stainless Steel / Brass Filament
Driver::
Basic:: BASF PRO 1 PLA
Metal Tip:: Stainless Steel / Brass Filament
Rubber Like Tip:: Fiberlogy PA12
Thinking about it now, I might make some form of article on 3d printing beyblade parts, in it, I will simply go over the process of it, and of course have this video in the credits, when I do end up making it, I'll replace this statement with a link, although it may take a while to do.
Hope this helps for others interested in 3d printed beyblade parts.
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?
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 think you should try wear resistance too! :D Like... spinning 2 meshed gears at max rpm for a period of time
4:46 You might think 8Nm is pathetic, but if you calculate the force on the teeth, you'd be surprised. The radius must be like 3cm or so, which would mean that they transfer a force of about 266N there! That equivalent to over 25kg hanging on that teeth. Suddenly pretty impressive. I am sure if you calculate the stress on the tooth by using the surface area, it is still quite impressive.
On that note, if you want to transfer more torque, as others have mentioned, herringbone gears have a larger surface area per tooth, thus allowing higher forces before reaching yield strength of the tooth/material.
Also to be noted, only tested here are fairly static torques. In real life applications you also have many peak torques, which can immediately cause a very stiff gear to fail (even if it has a high yield strength) whilst lower stiffness materials might absorb these impacts much better. I suspect that with this kind of testing PLA will perform far worse, and gears such as nylon and abs will excel.
Seeing how the gears fail, I suspect that higher infill ratios would significantly increase strength, as the limited contact between outer walls and infill (which transfers the torque) is where they seem to fail. With low infill ratios this is of course a very limited contact patch. Never mind that these contact patches feature very sharp angles, which induce stress concentrations.
would love to see you try the engineering grade PLAs like the anneallable ones, Formfutura Volcano PLA etc
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.
Great testing. One thing instead of a torque wrench, a ratchet adapter with torque readout might have been better
*@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.)
BIG factor for 3d printed gears is heat resistance. local heating at the contact points due to rubbing and flexing can quickly build up and cause rapid wear. In my experience over heating is the cause of the vast majority of 3d printed gear failures. This results in the best gear materials also being optimized for 3 things; high melting point, low friction, and low flexural hysteresis. (so Torlon > PEEK > Delrin > Nylon > PETG etc.)
Late to the party but if you ever plan on doing similar teasing in the future (speaking specifically to gathering torque data) I'd recommend a torque wrench adapter than a regular torque wrench. You can just keep cranking on it till the part fails and the digital adapter will tell you the peak torque. I first learned about using this method from ProjectFarm who does this in his videos when testing torque numbers. You can get an idea of what I'm describing if you check out his video on Anti Seize compounds, around the 4:30 mark! Or, really, most of his videos on small tools and such but that was the first one that came to mind
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 love Ivan Miranda's channel. That's really cool that you gave him a shout out. 🙂
you can get digital torque wrench adaptors that have a "max" setting.
100%
Incrementing up on a standard torque wrench introduces all kinds of nasty variables, especially in plastic. Testing methodology probably eliminated some of that, but just one iteration is a tad low.
I replaced all the gears on my old craftsman 6 inch lathe with 3d printed gears made out of Taulman Alloy 910. Been using it on and off for years now. Works great. Plus it has two added benefits: 1st, they are self lubricating, so no need to oil them, and 2nd, they are much much quieter.
No wonder I read comments! Thanks for the recommendation.
the Nylon is good as something like a damper or clutch for too high torque.
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.
I still don't get why you didn't use 100% infill for a strength test of a gear
Yeah I stopped watching cause if I was printing a gear, I would want it strong, I'd then test material strength for final prints.
You might not want it to be too strong, imagine a yard rake where the claws of the rake are thin metal and you are pulling it behind your rider mower, you want that gear to last a long time but you'd rather have the gear self destruct in the gear train before the rake mangles itself if caught on a branch or something big!
@@wolfrig2000 this video is about material strength comparison, not a specific application where you want to limit the strength.
@@crzprgrmmr and material strength on anisotropic materials depends on many factors. If you print at 40% infill on everything, why would you test a 100% infill gear? It’s about application. That being said of course you could do any level of infill if you’re doing relative strength testing (same conditions, different material). It’s a relative test, absolute testing would be cool but isn’t what’s happening here anyway.
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.
@ 02:00 - Didn't watch the video until the end but i can already tell which is better and for what application, base on my MSc mechanical engineering degree.
Nylon for low torque, high impacts and high cycle count applications, nylon is self lubricating so it can endure many cycles without losing its given geometry and tolerances. Also being able to endure higher temperature than the other 2 is a plus for applications that require long and hot runs.
ABS when you need it to endure somewhat high temperatures but have medium amount of cycles and impacts, ABS fails in a ductile way, so you can design the gears in such a way one of them is safe guarded from fail.
PLA when you need the parts on that moment and only have to endure low cycles and some high impacts so you can collect some data for the new definitive part.
I think i may have mentioned this on twitter, but I'd be intrigued to see some sla resin gears here too.
Definitely on the list!
Results of Polycarbonate (PC) would be interesting too. Teeth and area of contact of the teeth to the radius of the gear should be printed with 100% infill and the center with infill, therefore the teeth have more absolute strength but can bend relative to the center of the gear . That avoids too brittle breakage behavior. Additionally, the infill can be designed to correspond to the inner stress introduced into the radius (But therefore has to be manually constructed in the CAD itself and not to be used with the automatic function of the slicer software) Cubic infill f.e. is not suitable because the stress is mainly "in plain" , and therefore the 3-D part of the infill does not have any beneficial effect to the strength of the structure.
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.
the much easier version would be protecting the motor via limiting its current, which is rather trivial and very reliable. The brushless motors are driven by 3 (usually) mosfets, adding a current measurement, aside the hall effect (rpm) should be a nobrainer.
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.
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.
Rehydrate? Could you tell more about this?
@@BOTmaster15 as you may know, you have to dry nylon before printing it. Doing this makes the nylon brittle. It will rehydrate on it's own in open air after a week or two, if I'm remembering right. I leave my nylon parts in water for a day or so. They are noticeably different afterward. if you tap on them before the soak they have a higher pitch brittle sound. After soaking it's more of a thund.
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.
FINALLY, SOMETHING I CAN UNDERSTAND, GEARS AND SIMPLE MECHANICS!
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
Try resins, some of them should be like PETG, but prints faster for solid parts and handles high temp better.
Resins generally speaking are really fragile compared to any fdm machine.
@@jothain For gears I'd worry more about abrasion. Sure, when a resin part breaks, it really _breaks_ and doesn't rip apart or deform otherwise. But if it's stronger, that might not matter. But due to the brittleness, the gears will probably wear down a lot faster than those made from softer plastics.
@@harmless6813 pla last really well the abrasion. I have at work carton packaging machines and there's couple of places I made bit different prototype parts to test. Biggest problem was that layer lines needed to be actually sanded off as they didn't wear off which I was expecting. Also made one prototype part for pneumatic attached anvil/hammer parts. I was expecting it to demolish within hour, but out curiousity left it on for and it was there for couple months until I got machined parts to me. PLA is way, way better "technical" material than many think. Really the only downside is that it doesn't handle heat well.
I love your channel. As a naval mechanic I feel compelled to tell you that you need to learn about counter-torque to save your parts and tools from a devastating end.
Good vid! Now run them at 2000rpm and see which survive. Static strenghth is a small factor in gear material selection. ;-)
At 2000 RPM, heat will play a role. What about a long duration at 500 rpm?
Huh! Super cool results - keep it up buddy!
Can’t wait to see the PC tests! I would love to see how Prusa’s new PC Carbon Fiber Blend compares.
The only problem is that carbon fiber and glass are really abrasive. Think the gears would each other too fast.
That was great, well done, but as you compared gears I started wondering about wear. many applications are more about wear than strength, a winch lifting a load is strength, but car wheels can slip but need to continue for many revolutions and probably heat up causing increased wear with different results for different plastics. Would be more time consuming to test wear but a rig with a small continuous load over an extended time would be interesting. I feel for you down there with the covid thing, I expect we on the Gold Coast have it coming our way soon, 3D printing would be a good pass time during lockdown. Take care mate, love your work.
Before I watch the rest of this I’m going to guess nylon.
Nylons are definitely very good. My favourite nylons are from Polymaker's polymide series. They are definitely the best I've tested!
Good video, I don’t think there really is a preferred method of fail when it comes to gears as the end result is still the same. I guess if gear is deforming you would have some advanced warning but with anything with any real rpm it’s still going to fail quickly. Would be interesting to make a composite gear, say pla hub with a modified nylon teeth.
@@karlnowakowski7866 nylons are better anyway because of their naturally lubricating properties.
I would have said the same thing based on the title, but there is a huge difference between 'is best' and 'can handle the highest load before it fails catastrophically'.
I have not heard the brand BASF since the 80s days of magnetic tape. Glad to see they are still in business!
Didnt give ABS a fair chance. There are plenty of them that would crush this test, excuse the pun. I still prefer printing ABS over PLA
Felt the same. Used ancient/outdated materials. Would also like to see ASA tested.
@@nocjef agreed. And some PC maybe, or even throw in some HIPS just to get a more rounded view. But yeah, ABS definitely got shafted here, lol. I reckon Titan X would do reasonably well. I would like to see follow up video though on the solid prints
I feel ABS has an overlooked issue here that it has low surface abrasion resistance, so for this reason it's usually not recommended for gears. Overload events are once a lifetime, but surface friction is constant in a mechanism.
Still, some ABS filament might actually not exhibit this issue strongly, or might even not be really ABS but SAN. But it would be important to test.
Materials engineer here. "Tough" and "strong" mean different things. Tough materials are able to withstand damage... which is why they tend to be a bit soft. I bet the ST PLA is really great for impact resistance while other generic PLAs can be rather brittle! Your gear test was evaluating strength!
I know the company pronounced as bas-eff. Know them from cassette tapes and VCR tapes.
The Fusion 3 F410 printer I was repairing has a dual material 3d printed extruder gear. I don't know which materials as it's not my printer, but I can tell you that having one material interface with the motor and another interface with the gear for the extruder was a really cool design.
Missed polycarbonate
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.
Why, it's "Fiberlogy" not "Fibrology"
Perhaps a two piece gear would work well. Like a stiffer plastic mounted on the 12mm hex, then splined into an outer ring that forms the teeth of the gear made of one of the softer materials such as nylon.
Great video, exactly what I was searching for ! However, I know this is old stuff but I think you should use some sort of fixed guide the diameter of the torque wrench to ensure that the torque you measure is perfectly axial to the gear. With you setup, as soon as you're not perfectly aligned you also measure torque vector components in other directions, which biases the results.
If you slow it down at 11:19 you and you play it you can see the crack start. Awesome video though! Been wanting to get started with 3d printing gears to further my journey into microcontrollers and rasp pis. I was a bit worried about buying a 3d printer but considering most of my prototypes will be plastic only I say these gears should work great.
perhaps you could follow up with a wear test to see which filament has the best wear resistance, instead of having a fixed gear you could attach it to an axle with a paddle on one end in a bucket of water or some other load, and then attach the driven gear to a drill and spin it either stopping every few minutes until you reach a certain amount of backlash or for a fixed time for every gear and compare how much they wore down. for this test it would probably be a good idea for both gears to be made of the same material instead of one being made of metal. a cordless drill wouldn't be ideal since as the battery looses charge the drill will change speeds.
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
I've been using Cubic Tech for years. The owner is the nicest guy!
I have a roll of CF reinforced nylon i print with when i need strength - Add North Adura X. Has a beautiful matte finish and is way easier to print than regular nylon since it has almost no shrinkage.
It's a Swedish brand but I'm sure you can get similar filament in Sydney.
I think heat deformation would be the first issue. As a Northern Australian I find just outside temperature fatal for anything not printed on a heated bed
Great video, thank you for your work and time spent.
I would really love to see some ABS blends like fiberlogys ABS plus, Esuns ABS plus or 3DJakes niceABS. And I would really appreciate if those materials were printed in a heated chamber, even if the manufacturer states they "can" be printed without one, because based on my own testing layer adhesion without one is really terrible, even if the print doesn't outright warp.
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!
finally some real testing!!! Great work...
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.
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.
surprised you did not do 100% fill, would be interested to see those results, great vids! cheers
Try some of the Taulman nylon variants. I use the 910 for gears because it doesn't require lubricants and is more environmentally resistant/durable, but the print quality is not as good as PETG. I would like to see how the different variants compare though. I'd rather have something that fails catastrophically than deforms with degraded performance and puts more stress on the system until it fails completely or enough to be detectable. Nylon > PETG > PLA. I also use a helical or herringbone gear rather than a straight spur/involute profile and I think that that lends itself better to nylon than your tests measures.
Thanks for the very interesting video. I've impressed with CF PLA and CF PETG stiffness, but I'm not sure how a CF filled gear would wear. The surface of CF parts seems fairly abrasive. Maybe a slippery surface is more important than outright stiffness for gears.