Very cool! Another tip is that you want to have the walls as thick as possible so that the slicer will not print unneeded lines that could slow the bearing down. For overkill when printing bearings I set the wall thickness to 3.0 mm so that the ball bearing can roll around the grove of the print and not hit cross lines.
I experimented with this design, I made the design in Fusion 360, these were the changes I made. I minimised the clearance between the diagonal 45 degree contact surface of the inner and outer race to zero. You can adjust the pre-tension on the ball by the screws. For a smoother surface I separated the inner and outer race and printed them in vase mode and sequential printing and set the extrusion width to 1 mm, layer height 0.15 mm. I changed the print orientation 180 degrees, so the wide part was down. This minimised the deformation during cooling, 45 degrees angle prints like to curl up during printing. The inner and outer races press fit in the rest of the design, you use a more wear resistant filament for this. You could also machine them is you have a lathe. The results are very promising, there is no play in the bearing. The bearings are silent, you can still feel the balls skipping to the next layer, which are at a slight angle in vase mode. I did this first test with 3mm balls, I didn’t have any 4mm balls. I will try 5mm next.
@@chipcode5538 wow, interesting. My goal was to make a simple design with as few parts as possible to make assembly easier. But it's very cool that you are exploring ways to increase quality. Cheers!
I see to remember that it's a Good Idea to use an odd number of bearing balls. I think it distributes the load better if there are imperfections in balls or races. Much like a three-legged or five-legged chair is more stable than four or six legs on an uneven floor.
this is a really cool idea to save quite a bit of money on prototypes, large bearing can get expensive fast, now i can print them and test if my ideas work before commiting
Great content, reall nice to see a custom created bearings rather than being tied to standard offerings, would be great to see more testing at speed or different loads applied
I like where this project is going, thanks for sharing the design. As an engineer I was quickly making some calculations and changes in my mind while you were showing the 3D prints: 36 balls with 72 kg of load is 2 kg per ball and with a flat surface, the contact area of ball and surface is a single point of contact which is an infinite small area which results in an infinite high force on the plastic race. As long as you rotate the bearing, this will even out along the full circular contact area but as soon as you stop moving, things change. In time (and temperature) you will see that the balls create small dents at a certain location. Will this be a problem ? Yes, definitely. When will this become a problem ? It all depends and we will only know when we try this. 15 years ago we also stated that using PLA for 3D printing was a bad idea since it is bio degradable but we still do and printed stuff holds a very long time.
Interesting point. Generally I think that these bearings should not be used with high load. Deformation under continuous load will 100% be a problem and AFAIK all regular filaments has this problem, only special stuff like CF-nylon or PC can handle that. But these filaments quite hard to print and bearings should be printed with decent quality.
Deformation is key. Temporary deformation of the ball and the plastic are simply part of how the bearing works. If I were to go about calculating deformation, I would assume that all the deformation happens in the plastic, and go from there. If the balls were also plastic, it would be harder to calculate, but something tells me it ought to work better. Do the vendors of balls provide a recommended force per ball? If so, I might optimize my design by finding a ball material with stiffness close to my filament choice, then go with the ball loading recommendation. Permanent deformation to smooth out the races sounds like a good thing. I wonder if I could get the permanent deformation I want, but avoid the deformation I don't. My first thought is to load the bearing with a weight, then get it spinning fast enough to generate the heat to just oh so slightly slightly soften the races. Then my guess is removing most of the load while keeping the bearing spinning would allow the plastic to cool while keeping the smoothed shape. I don't know if that would work, but if it did, it would take precise control of the recipe. Time and temperature have to be just right, just like cooking. Maybe add some lubricant at the right moment to cool rapidly. Possibly cook with one kind of balls (steel or aluminum maybe), and then switch the balls out for use (plastic). I wish I had the time to do all that experimentation.
Nice work. BTW, I've found that you don't need threaded inserts in situations where you aren't taking the screws out that often. Just thread direct into the plastic.
Besonders bei einem Fahrzeug ist aber mit Verschmutzung der Lager zu rechnen und dann sollte die Reinigung wenig Mühe machen. Meine BB-Pellets tausche ich öfter, weil sie rosten, wenn die Messing-Schicht abgenutzt ist.
Nice to see someone else doing this. I printed a thrust bearing to hold my 5kg spools horizontal for my printer. Basically just a bicycle shaped cage to hold 6 metal balls in a ring. I used some spare Plexiglas as the top and bottom to get a smoother and harder raceway, but it would probably work fine if I printed those too.
Well, I think I spent about two weeks to figure it out and refine the design. It wasn't the first idea I had. So it was not THAT easy, the video just doesn't show that :)
i really like this approach. When making mine a couple years ago the flat sections were printed diagonally which left a slughtly bumpy surface. to fix it I added a very narrow and shallow groove where the balls made contact. it still fused as a flat surface but the print path was concentric with the bearing. it worked much better after that.
This sounds interesting, but I'm not quite able to picture it. Was the modification you're describing take place entirely in the sketch for the race revolution?
I refuse to press like because brass inserts look cool in white plastic (even though they do). I pressed like because this is a cool video that taught me a lot of interesting things.
If you go with 6mm, you can use plastic BBs instead of bearings. Generally good for light loads outdoors like a lazy susan, so the bearings don't rust.
In my 3d printed bearings, I use plastic balls for toy guns. I make them so I can put as many balls as is bossible in the outer race. I then whack the inner race with a hammer to suprise the plastic only 1 time. They fall together and run quite smoothly. I've used them in a few projects and they seem to be working as none of them have failed.. I use no bearing cage.
How is the preload in the end? How much play (or on the other hand, how much stiffness) do your bearings end up with? Can you recommend some interference dimensions?
Very well explained and definitely better suited (and cheaper) for 3D printed applications that do not require the thousands of Newton and tens of thousands of RPM that even the smallest of steel bearings can deliver. A significant advantage is that you can design the bearing as part of your machine. Steel bearings are designed to be fitted in metal seats and on metal axes. I just subscribed. Cya !
Preload! Your "radial load" bearings are similar to angular contact ball bearings and those perform best with and because of preload. Simplest modification would be to slightly reduce the height of inner race so there's a small amount of (axial) preload when the screws are fully tightened. However 1) this will mean that the balls will start to mainly ride on the 45 degree secondary races and that's not ideal if loads are mostly radial and 2) there will still be some play from the balls sliding laterally on the secondary race. One 'ideal' solution would be to have the balls ride on both primary and secondary races. To achieve that, first make the primary race not vertical but slighly 'open' by -5 to -15 degrees (visual context at 5:10) and then preload can ensure the dual contact on both inner and outer races (though admittedly only if the print is to very close to dimension). More load bearing contact more better. The end result will be very similar to angular contact ball bearings with a contact angle of 25 to 30 degrees (if on dimension and preload leads to dual contact or 5 to 15 otherwise) and the play will be reduced to close to zero (plastic not being rigid). The other 'ideal' option is to simply copy the angular contact bearing design so instead of main+auxiliary race you have a round race with a slightly bigger radius than the bearing balls you're using. The best way to achieve that is to just fillet the above design since that ensures no overhangs past 45. Also use some lubricant (reduces noise and cage friction).
Wow, thanks for taking your time to write such a comment! Yeah, I read about 4-points angular contact bearing, but didn't know that it is usually preloaded, I learned something :) It's probably the best option if very little play reqiered. Maybe will experiment with this. I also realized that I can just do a deep groove ball bearing with Conrad-style assembly :) I did not talk about it in the video because I realized this while making the video, but I show it at the very last seconds. I think it's the most simple design. I just was not aware about the Conrad assembly and thought it will be impossible to make :)
Cool work. I wonder if a design that doesn't use a bearing cage but instead closely packed bearings would get rid of the play in the bear you show at ~11 minutes? This is what's used in bicycle hubs and headsets, works very well.
I tried with no cage. Too heavy, rattle a lot. And it doesn't fix the play. That play actually is by design. The ball diameter in the CAD was 4.1mm instead of 4mm, so 0.2mm play is expected. It's not too much I think, I am fine with that in my rover. Actually it is possible to make the gap smaller, but it requires a well-adjusted printer that prints really well. Or there is an other option. Just print with no gap at all and assemble. It will not spin freely first, but if you forcefully spin it with some load for some time it will wear-off all roughness and it will be perfect bearing with no play.
This is cool but I imagine there's very few applications where it makes sense. Sure quality industrial bearing can get expensive but common grade bearing are pretty cheap, even with diameters around 60 or 70mm, we're talking like $10 - and even cheaper Chinese bearings will have better tolerances and radial play than your 3D printed bearings. This is useful if you need something within in a few hours, or maybe for very specific weird geometry, but I don't see much other value.
The smallest I made has inner/outer races diameter = 20mm/28mm . Works absolutely fine, I would say maybe 10mm/18mm is the smallest you can reasonably have with 4mm balls.
Cool idea, but how long do they last? and what loads can you apply? and what material is best? but it can always hold for small stuff.. okay i have to do some testing :-) and can you create a pressure greased bushing for longer lifespans and load??
I show a simple load test in the video. I think 4kg per ball for thrust bearing and maybe around 1kg per ball for radial bearing (because most balls are not loaded in this type of bearing) I will do the proper load and wear test in the future. Materials... I personally don't like PLA for mechanical parts. And everything else except PETG could be challenging to print with enough quality and precision. Ofc nylon will be better than PETG, but it's much harder to print. So personally I am planning to work only with PETG right now. Don't know anything about "pressure greased bushing" so can't tell. However, I want to try to make a flexible TPU seal to protect the bearing from water and dust. I have high hopes that this will work.
@@Positive_Altitude Pressure greased bushing is a channel through which you can inject grease into the bearing every so often to lubricate it. Not sure how you would want to lubricate a plastic bearing, though, or which benefits to expect from adding grease.
@@Positive_AltitudeYeah, the low softening temperature of PLA probably means they would deform under lighter load conditions than PETG would... I think. Really more of a hypothesis. As for Nylon, I wonder if its flexibility would cause problems with bearing performance. Might be worth a test. I might hypothesize that PC might be a higher performing material... I suppose I would have to have a good definition of "performance" before I make statements like that 😅
Have you considered embedding the bearings, by pausing the printhead at the correct layer and then placing the carriage inside, before continuing the print?
What is the goal? To reduce the need for the screws? You can split the part and superglue them together instead. Or you can make them snap/lock together. Serviceability has lot so benefits too, especially when making prototypes like the rover.
I was thinking about it but I don't think it's possible. The extruder will collide with balls and I can't think of the design or method to avoid it. Also in real applications I use these bearings as an attachment point. It's like outer races printed as a part of component A and inner races are printed as a part of component B. So you assemble A and B and the bearing at the same time.
Видел у какого то ютубера, он делал вставки из металлической проволоки под шарики. Вставлял металлические кольца изготовленные из ровного прутка, делал что то на подобии рельс для шариков сверху и снизу. Это позволяло выдерживать бОльшие нагрузки без деформации пластика стальными шариками.
have you considered using plastic bbs to have similar hardness materials contacting instead of metal and plastic which will probably wear down the plastic very fast?
Is there any way to completely remove backlash on a 3d printed bearings? Also your bearings looks bigger then typical manufactured bearings, anyway your way to design a bearing is awesome, I'll try to make my own based on your design, thanks!
To get the lowest backlash you can try to print it without any added gaps. It will be quite tight when assembled, but you can "work it out". Just apply some load in altering directions and forcefully rotate. It will become much nicer in a few minutes. I tried it once, and it worked for me. But make sure that your printer is well aligned. XY-skew should be very very low. Also the smallest bearing of similar design that I made was 20mm/28mm inner/outer races diameter it was fine, maybe it could be even smaller
Never heard about it. Anyway, the hotend replacement is not such a big deal and it will be required anyway eventually. I just need the rover to be white. I am going to place it outside in sunny days and white will heat up less.
You can make the play in the angluar contact bearing adjustable by adding a gap in between the two inner races. Use a rubber O-ring or a piece of TPU as a kind of spring allows for easy adjustability
I did not try, but I doubt that it will make a big difference. Grooves appears when the material can not physically handle such force and starts to deform. I think the bearing just should not be used with such load. Maybe nylon will increase the maximum load a bit, but at the same time when both balls and races deforms that will increase friction. Ideally all parts of bearing should be as hard as possible (hardened steel / ceramic) because it reduces deformation and friction. Our races are quite soft, but at least we can have proper balls ... that's what I think.
This timing is violating my privacy lmaooo I was about to dive in myself into topic since I need cusom bearing for diy steering wheel with arduino, need rather uncommon diameter
