Also, if you plan on driving offroad, I would definitely recommend swapping the herringbone gears for some doublehelix gears. Any dirt or substance that gets into the gears gets dragged into the centre and quickly binds up the gears, the double helix solves this because there is a gap for the dirt/grime to be pushed into. :)
Also, yes there is a difference between herringbone and double helix. And that is what I listed in the above comment. A herringbone is simply a specific type of double helix gear :)
Question. If dirt and grime is push up one direction on a helical gear, would going in reverse push the grime in the other direction? And, if so, could you orient a herringbone gear to push grime out of the center when the car drives forward? (Since it will be going forward 90% of the time)
Love your content - no egocentric b.s. Just the interesing stuff. Coming up for reirement I bought a 3D printer and Wow! You don't even have to leave the house to go on a big adventure. Been subbed for a while and come to you first when I want facts. Please keep it up, you're a terrific teacher.
*Engineer here* You're mods for strength and print clarity are next level. If you are not already a CAD drafter, you should consider it. Some companies do not require a FE to draft.
@@snorttroll4379 Designer or Drafter, but more often search for the CAD software name (Solidworks, Creo, Fusion360, etc) for the best results. (I used to be one).
I would recommend going 95% in stead of 100. reason being that if you have a tiny bit of overextrusion in your printer, this will compensate, and avoid outer layer blobbing, as this will make the gear teeth nearly unusable, or at least time consuming to clean up. Another reason is that when force is applied to the structure there is nowhere for the force to distribute if it's all solid, but with tiny gaps the material has a tiny space to deform slightly, mitigating some of the force running through it.
You’re right at the first part, but the part about forces distributing is complete nonsense. A 100% solid part will always take more load than something that is not 100% solid
@@jr764 Well, not always. For example, for parts that have an angle that is less than 90° have ofter an circle cut off where the angle is, because if not forces will rip the material where the acute angle is. When you cut off a circle in place of this angle, you will make a better repartition of forces and hence avoid ripping. So by removing some of material you can actually make it stronger.
One thing I like is how you go from the drawing board to design the part and going to the manufacturing, where you describe how you went through the analysis of on printing the part and provide details around each of the components needed to be reviewed and looked at having the proper parameters to print the parts that would be under a large amount of stress. Typical most people would just print the parts and slap it on the RC vehicle and do not understand why the plastic part broke. I like to see how you would design a part and go through the process of printing that part on a 3D printer and what methods you use to make sense to print the part so that it would print as you would expect it to be.
I really like this focused-collection-of-findings format. Not so much a "tutorial" that focuses on one project (just one point in a design space), but an attempt to report on how to generalize a particular technique. It would be nice if other maker-focused youtubers adopted such a format, so we could have a library of such hard-won info, organized not by integrated project but by technique.
I often ask the question why hardware/mechanical design can't get the same kind of love / support that electronics and software does. I generally thought maybe it's too specific in nature but you're right this video communicated generally
Build an enclosure for your printer, upgrade hot end as needed, put in a direct drive, and print in PC (Polycarbonate). When tuned right the results are genuinely incredible. Extremely strong.
@@pogi1803 upgrades will take time and money however. To print PC you'd need an all metal hot end like the micro swiss, or if you want a direct drive extruder as well get a hemera. You'll need to make some changes to your firmware to accommodate the new hot end. Get an enclosure for the ender 3 on amazon. I'd say that's the minimum requirements
keeping a spare nut or to on the heated bed and filling that when you purge can be fun & produce useful quick generic bits after smoothing too, dip your old stranded wire in dissolved scrap plastic and stick that in your bolts as a core infill etc, etc..
Nice build - One thing i'd recommend is using nylon instead of PC for the gears. PC is great when it comes to impact resistance, however nylon is a lot more resistant to abrasion which is essential for parts that are constantly rubbing up against each other. Furthermore, nylon has almost a sort of natural "lubricant" property to it, which should help your gears turn more freely reducing wear. In terms of trying to print out the axle, have you tried any carbon fiber infused filaments? They could possibly work, as it adds a substantial amount of strength and rigidity to the part. Personally, i'd recommend either CF-nylon or CF-ASA for your particular application. I believe Polymaker recently just came out with their own carbon fiber reinforced nylon filament, so you should get them to send you some and try it out :)
5:12 you could make an internal structure within the axis, with the shell tool or something similar, such that the axis is now built with walls instead of plain infill and you can increase the amount of walls, it would make the structure stronger
I'm a racepilot in 1/8 gte. What i want to ask you is how sensitive the fishbone gear is to grit particles coming from the track. 1/8 gte is raced on tarmac and is similar to a gocarrack but much shorter. We run open gears to cool down the diffs. all gears are made of highgrade steel and standard straight module 1 teeth. The ony gear we could 3d print would be the main spur gear with is driven by the motor pinion gear which is always a module 1 pinion aand extremely hard steel. PLastic gears are often used for the main pinion gear and i would say the are always made from reinforced nylon. cf or glasfibre and 8mm wide to take att grit particle or 2. The output is 2700w or so from the motor. the weight is 3800g minimum for the car. top speed is 110 kph.the issue is than the track is surrunded by grass lawn so when leaving the track (unintentionally) we get grit on the track that might upset the gears if made in plastic. 1/8gte is of couse 4wd with a cneter diff or a spurgear connected to rear and front diffs. the diffs are oilfilled to get the correct response. and the diffs get hot. Being an egnineer aswell as the goto guy for 3d printing on a school in sweden. i See potential för 3d printed gear both for racing and for students. I have been contemplating 2 or 4 motors instead of on a a projekt. just to get rid of a motor in the center 90 degrees off. This create inertia twisting the car. when 2 motors front and rear would make a better sollution. But i would us inrunners beacuse of reduced inerta and better power to weigt ratio. The escs are 180a to 220 amps a still everything gets hot. I'm guessing high temp material is the only way for a GTe car. For offroading i see an even bigger issue for the typ of car you have built. I race 1/8 buggies too... and there we always ha built in gears. the same motors are used 4068- to 4074 sensored motors. But gte takes alot more power to be competive with turbo. Heat is the worst danger to motors and esc
I agree. Spur gears are just noisy and cause vibrations but they are indeed effective for power transmission. However, for printed plastic parts the vibrations alone may be able to break the part which makes double helical gear better for this application.
spur gears are very noisy unless at ridiculous tight tolerances. (have seen them used in a torpedo which requires both quietness and huge power in a small light space. The advantage is no thrust which makes the structural design much worse.) Load on a spur gear is a short cantilever that is loaded and unloaded not very gradually. Forces transferred between teeth are perpendicular to the face. so a helix gear creates a thrust force, apply trigonometry, and when applied to the bending stress on each gear tooth is about the same as a spur gear sees. The load is not put on as abruptly and thus lower noise. To machine of herringbone gears are only done with a shaper with a cam to rotate the blank as the cutting face moves through the part. High end gears are usually finished by grinding. not possible for the herringbone gears shown. Have to sandwich to opposite angled helix gears to form a herringbone gear. Involute gear by design do not slide against each other. Never actually is 100% achieved but close. The 95% plus transfer of power of a gear set is the result. These gears are all involute and adding an angle to make a helix doesn't change this. Another indication of very low friction is that they can be back driven. However; if the axis of the set are not parallel but at some angle then there can be some sliding. The amount can be low and thus can be back driven.
Having experimented with 3D printed gears playing with the OpenRC F1 car (by D. Norée), I have to say, Herringbones are definitely way to go for 3D printing. They’re substantially quieter too.
Big tip when you do high force and torque gears. Swap out your nozzle to 0.1mm do a 0.03mm setback on your outer wall this gives you an additional strength on a wall count of at least 10. Also get yourself some NYLON CF but you can also use eSUN ePA12-CF or even eSUN ePAHT-CF.
No you want thicker lines, wider nozzle not a smaller one. And no you don't want CF anything for gears. Fibers make your prints weaker in exchange for stiffness. Stiffness is not an issue, but strength definitely is. What's with everyone hearing engineering words and assuming they just work for all situations. Stop it.
I highly highly recommend using Taulmans Nylon 230. It is a nylon that you can print on any stock printer at only 230°C. It is also cheap on Amazon. It has amazing durability. And the gear teeth will not wear away. It prints awesome. You need gluestick on your bed for it to stock as it is a naturally lubricating material. It is so perfect for gears. You NEED to try it.
See also this video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-UtRJ4lnNAXY.html The best material depends on if you need high torque or high wear resistance. I agree that Nylon should be the best for high wear resistance as long as torque is not too high. Surprisingly high quality PLA seems to be pretty good, too.
I like the fact that you are using roller bearings for your gears that are in direct contact with the motor. There is no need to use ball bearings because the forces acting on the gears in radial not axial. Plus like you said you will get less wear.
Excellent video-, i found my Wood working background helped a lot in working out the best origination for printing parts that are under a heavy load, Simply because the the Grain of the wood is like the layer lines in printing-. Thanks for the Recommendation on Polymaker Filaments-.
Hey man, wsp, i have a more or less 1/6 1/8 "car" (only the exterior) and i want to learn more about this things cause im gonna make my own RC car for high performance, Awd and 100-120Kmh but i need to learn more u can recommend me things? like, suspenssion, engines (electric), etc or some channels that have content about that
I found myself in your position around a year ago. When I started the Raptor project I knew very little about mechanical design. Personally, I find that the best way to learn is to just try and build something. If you look back at my older videos you'll see that Raptor 2 evolved from many mistakes. I failed over and over again until I ended up with something that actually worked! I'm definitely no chassis expert, but I learned by doing and produced what I think is a pretty good result. I'm a big advocate of this mentality. Hope this helps man!
Hi, great video! Really liked the design and the comment about splitting the shafts! From your experience - what module of the gears worked best for your printer - how small can you get? Any suggestions for the glues used on the splitted shafts?
Why not cap off the top of the smaller gear with a bearing? I guess the M3 through the center must be good enough then if they stopped breaking after that though, but I wonder how much flex they endure due to trying to track up or down on the larger gear when torque is induced. Also I'm curious about the roller bearings.. why not normal bearings with a metal inner? So that the plastic isn't even a factor in wearing those parts out? Was there a significant price savings, or anything to do with larger radius for torque transfer?
Wonderful video! Might I suggest a solution your axel strength issue? Add fillet between your axel and the gear face if you have enough room, even a small 2-3mm fillet can exponentially reduce the stress riser created by that shoulder. Excellent work!
I was a little surprised to see you are running the roller bearings without some kind of inner race. Did I miss it, or is the material holding up OK without one?
Engineering wise I highly agree with your advice on stronger gears. The only other thing that could possibly help is breaking down the gear reduction over multiple gears, similar to a counter shaft in a gearbox or planetary gear set. Or though given that it’s rc applications it would be a rather tight fit in a chassis.
Cool project! Regarding improvements, look into "beaking PETG". Basically printing 100% infill and baking it in an oven (inside of salt powder), to get solid plastic part.
En la teoría usar dos motores interconectados funciona bien y aumenta la fuerza del vehículo, pero en la práctica es complicado ya que los motores son mecánicos y como toda pieza mecánica, tiene fallas, en el caso de los motores puede ser impurezas en los imanes o la bobina de cobre que haga que uno gire unos pocos RPM menos que el otro y sea arrastrado, lo que lo lastima. Si ya los calibraste para que vayan a los mismos RMP reales con un velocímetro o algo entonces perfecto, pero si no te recomiendo hacerlo.
Great Video! I`ve also landed on Polymaker PC Max after experimenting with Taulman Alloy 910 before, but i never put as much care into it as you. But i can vouch for their durability - i made a inner gear ring design that transferred the power of 3,5kW motors on an electric mountainboard and the gears never failed!
Nylon to me actually it’s a little bit too soft... 😂, it does handle more temperature, and fiber nylon is an upgrade of the nylon that’s more expensive as well more stronger, for the fiber inside it...
@@SianaGearz ahhhhh... I play around with my 3d printer, somehow I made parts with nylon for handling strength. Guess what, the shape tolerance changed after 1 day... 😂, that’s what I mean too soft, it doesn’t handle, and will mess up the accuracy... but as well, it is strong in some ways other than the stiff pla😂
Great videos Bro¡¡ How do you get that accuracy? especially the inner and outer of circles. It is almost impossible to achieve that in my 3d printer. Could you give some tips? Thanks
Correction: Spur gears are the strongest type of gear and are used in high torque, low speed applications such as automotive gearboxes.This is because tooth to tooth contact area is the largest. Downside is noise or gearbox 'whine' from sudden tooth to tooth contact especially when some wear has occurred. Helical or "herringbone" gears are used more in relatively low torque high speed applications. They are weaker than spur gears as the tooth contact area is minimal but have the advantage of smoother operation because tooth interaction is a more progressive rolling type. Horses for courses.... 😉
Spur gears are weaker than helical gears because the loads are transmitted over fewer teeth. They are also highly susceptible to damage/wear since the entire surface area of the tooth is always in contact with it's opposing tooth. The reason sports cars use spur gears as opposed to helical gears is because they aren't concerned about longevity or noise. Spur gears also produce no axial force which reduces loads on output shafts an bearings. Hence higher efficiency, at a cost.
@@thehardwareguy Apologies, but I have to disagree. With two gears of the same size, width and number of teeth, one spur, the other a single helical gear, the tooth to tooth contact area is wildly different. The "strength" of a gear in terms of its ability to transmit power depends of tooth face to tooth face contact. At any given moment, the spur gear teeth make contact across the entire width of the tooth face distributing the load across the entire width of the tooth. In the helical gear the contact is more like a point contact that rolls across the tooth face from one side of the gear to the other and the load is concentrated only on a relatively small portion of the tooth. There may actually be several such points of contact over a number of helical teeth that continuously roll from one side of the gear to the other, thereby helping to distribute the load, but the fact remains that the total contact area at any given moment is still far less than in the spur gear and so is inherently less capable of transmitting power without failure because the stresses on the individual teeth are more concentrated. Thats why nearly all gearboxes, if they don't fully employ spur gears, employ them at least near the final output shafts where torque is high and speed is relatively low. At the input end they might use helical gearing as the torques are relatively low and speed is high. Spur gears have to have at least one advantage over other gear types and this is it. Horses for courses... 😉
Good job!! I have successfully printed gears of modules as small as 1 mm. With herringbone gears, the teeth are not coming out very well. I often struggle with bed adhesion since the profile of teeth are so tiny. I have a couple of questions. 1. Your gears seem to have smaller module. What's the smallest module have you successfully printed with? Was it with 0.4 mm nozzle? 2. What's the backlash you keep if? I print gear assembly in one part (when its not physically possible to assemble as in the case of a double helical planetary box.). So what is the clearance you target for the teeth to not fuse together?
Thank you! My module is 1mm. Pressure angle is 14.5 degrees and helix angle is 40 degrees! The meshing distance can be calculated properly using a formula, check out my FreeCAD spur gear tutorial, I go into detail there!
Nice build. Good advice. Just a note Herringbone gears are actually quite a bit stronger than helical, because the teeth have that corner in the middle.
I would suggest two rows of ball bearings instead of roller bearings. Two rows will add rigidity and reduce the operating temperature from the increased friction of the roller bearings. This is only a suggestion. Great video.
I am pretty sure that straight cut gears are stronger than helical ones. For example, race car transmissions use straight cut gears. And forces there are much higher. Disadvantage of straight gears is that they are much louder, that is why street cars use helical gears. But sometimes even street car transmissions have straight cut rear gear - which is also cheaper and loudness doesn't matter.
I agree on this. Was thinking exactly the same when watching this video. Straight cut gears are stronger because they put all the force into the next gear, the helical ones does put some of the force in the axial direction. But yes helical are smoother, less noise. These fishbone helical gears does not put any axial loads, only internal in the gearwheel iself, not on any bearings and so on :) Maybee straightcut gears are weaker then helical when they are 3Dprinted in plastic material?
I wonder if an extremely tough TPU would have been good for the teeth, possibly shaping a cylinder with herringbone teeth on the outside and the parallel teeth of a typical spur gear on the interior surface, to snap/glue on top of the main body of the gear, also shaped accordingly but made out of a rigid thermoplastic; to make it short: like a tire.😅 I hypothesize that the elasticity mixed with the rigidity could have a chance at trasferring torque even better (when lubed properly). The end result should give the benefits of a belt drive to a direct transmission system, given the layers of TPU are properly fused together in a single and uniform volume (with 100% infill).🎉 I must try that now.😅 I sincerely thank you for the inspiration and the valuable information.😊
Thank you! the general consensus online is that PolyMax Polycarb is far superior to other Nylon filaments in regard to strength! That's not to say Nylon wouldn't work, I just haven't tried it yet! maybe an experiment for the future
@@thehardwareguy Yes I would usually say that too, however if you have a look at Polymaker's datasheets, their Polymide CF-6 is their strongest filament, even compared to their Polycarb. Either way, for gears I would definitely use their Polymide series, the self lubricating properties of nylon really makes a difference to smoothness!
I am not even close to expirianced in printing gears, but in my little experience I found it is a good idea to use rafts. This way you do not risk warps at the edges.
I am a newbie to 3DP. Regarding the couplers/drive-cups that you printed, what is the purpose of printing two separate halves and gluing together? Is there any way to print these type of parts as one piece? I need some similar plastic drive cups, except the ones I need have a hex extension with female threaded end for the wheels to attach directly. Any insights much appreciated.
What if you reversed one of the motors and made a longer driveshaft, so that the motors span opposed to one another and cancelled reaction torque? Might need to make the shaft a bit thicker to get rid of torque steer but i think it could make the whole thing more stable.
listen i just make the greatest art in the world but also this post is lit so thanks for sharing because i'm working on 3D printing some gears and machines and things like that but if you ever need any art you know who to call: time 🔮
It's interesting that we never see double-helix style gears in RC cars. Is it cost? Perhaps drag? Personally, I would be interested in QUIETER gears. My neighbors all come outside when I run my Arrma Kraton 6S down the street. That thing is sooo loud.
I need a worm gear that will resist being driven backwards. So the worm gear drives a herringbone system, but I need the herring bone system to not drive the worm gear. Is this possible?
This is great! Your work here would dovetail well with Makers Muse recent video testing different types of filament he was using spur gears and would benefit from your approach.
I'd suggest trying PC+PBT for the gears. It's available from Push Plastic, and probably other places. It's got the good strength from PC, but also has added self-lubrication features, and is a bit more ductile which might help on shock. I've had luck printing it on a PCB-heater bed, with an all-metal E3D V6, with just a trash back over my printer to keep the heat in. xD
Very interesting; I love what you did with the smaller gears by driving a screw through the center to reinforce them "along-the-printed-layers". However; since you have such a keen insight into the structural integrity of printed parts I was wondering why didn't you try the same thing with the dog-bones as you did with the smaller gears? Never the less; you are, definitely; someone to look forward to watching on youtube. Vantastic workmen ship and thank you for your brilliant insight on gears.
I know your Q was from years ago but I think he didn't need the support on the larger gears because they rotated at a much lower RPM so reinforcement wasn't needed.
Have you ever printed with Nylon ? I need to replace the drive wheel gear on my magneto ,on my motorcycle , it had a Bakelite plastic type gear as original and thats 40 years old ! So is nylon going to be better ? I could buy a new gear in the same bakelite but buying one would be no fun , and for the price I can buy 1 kilo of nylon filament and if lucky get a good one !! Or maybe two ! Great site by the way , thanks for the tips etc .
I agree a metal axle is probably best, but PLA is known to be brittle and easy to crack and break. You could use a different filament such as nylon. I wonder how a nylon axle and gears would hold up.
Any idea how 3D printed gears compare to 3D printed timing belt pulleys vis a vis strength? The large number of teeth in engagement with the latter make me curious.
I had no issues with strength when I tried the belted approach, main issue was belt slippage! Adding a tensioner to the design would've been quite awkward/clunky, but it could have potentially solved the problem
I bet a lot of people come to this video wanting to know about clearance and tolerance and haw to make gears fit like planetary gears with decent sizing, cos mine don't fit at all! i can't figure out the printre and slicer settings! cheers!
Not stupid, remelting the parts increases strength. Slightly melt in the oven or better submerging the print in fine sand or salt (props to the "salt method") and then heating it up. Vapor smoothing might give rather marginal improvements due to only affecting the outer layer
@@giedrius2149 I watched CNC Kitchen’s video, turns out smoothing can weaken and it only can penetrate outer perimeter walls. Remelting by Taiwanese RU-vidr looks interesting, need a ton of super super fine (icing sugar fine) salt, but the resulting look is mesmerizing for PETG.
Great tips, I found using nylon filament is better for strength and its much more forgiving and does not chip nearly as much as other filament I tried.
