The red lid you took off the superglue, there’s a sharp point inside the top of it - use that to pierce the new superglue rather than the metal tool you used.

I love how natural you presented the process, including (1) sliiight size mistake, (2) superglue getting on your fingers (3) oops should've used gloves (4) oops should've sanded _before_ mounting (5) okay this is not turning smoothly as I wanted (6) some things are dropping/disassembling themselves. Dang. It's clear you're One of Us 😄 Great video 👍🏼

This is a wild coincidence. I've been having issues with my automatic transmission that I rebuilt. To wrap my head around how it's really working and what the problem is, I've been modeling it to 3D print a small replica. I've got two of the planetary sets done, but I need to figure out a one way clutch and how to manipulate the regular clutches. It's a big project, but will be awesome fully printed. (well somewhat small). A U140e transmission (plagued with problems).

The ring gear is also known as an annulus gear.

Monster trucks use these inside the wheels so the planet carrier is fixed, the sun gear is attached to the axle, and the ring gear is bolted to the wheel since it puts so much stress on the engine to rotate the huge tires.

I think the table is misleading. Those ratios only work for a planetary gear systems with the same number of teeth on each gear. I made a clock with a planetary gear system and the sun to plant ratio (with the ring stationary) is a 6:1 ratio

When I was an automatic transmission tech back in the 90's, I thought (and still do) that the coolest transmission was the 700r4 (the same gearsets used in the 4T60, 4T60E and 4T65E). Using only two planetary gearsets, it achieved 4 forward speeds (4th as overdrive) and reverse, and was the most compact 4 speed transmission of the 90's.

The leaking superglue was a plot twist i did not see coming. Out of left field. Really threw me for a loop. This is great cinematic storytelling. Nice little subplot to the overarching narrative.

Adding electric motors to the gearbox effectively turns it into a cvt. A thing toyota made in their hybrids. It works by spinning two of the 3 components in various directions and ratios to acheive infinitely variable gears. It is also probably the most reliable transmission ever created, as there is no friction material, nor a torque converter, just gears and electric motors.

I think making inner handles' ends longer than the outer ones would make it more comfortable to rotate.

I don't know how it works in fusion 360 but in onshape there's a setting for backslash in the gear tool which makes it really easy to change the tolerances... Great video btw!

When John Deere came out with their power shift on the tractors, the 6 to 7 or 7 to 8 shift was very harsh. The dealer advised that was because one of the planetary gears, had to switch its direction of rotation, to complete the shift. Now it all makes more sense.

On heavy truck in the UK this gearing is used in the drive axle hubs, we call them double reduction hubs, it reduces the size of the crown wheel and pinion, thus giving the axle a higher ground clearance. 🇬🇧

This a cool project, but I still have a couple of questions... How did super-gluing my gloves to my hands assist the gears? How do I remove the gloves now? (You did that bit off-camera!)

Thank you for this video. It is informative and inspiring. For 40 years, I've wanted a special planetary gear design, made from lightweight materials. With modern technology, software and 3-D printing, maybe I can now make it myself.

BUDDY!... I have been in automotive business my entire life and have increasingly seen this gear setup used in one more places over the years. Due to the detail and explanation in this video I can totally see why! For the first time! Brilliant! Thank you so much - so very sincerely

This is very helpful for the turbojet engine that I am designing, I need the intake fan to be spinning much slower than the compression fans. A planetary gear set is perfect for it.

Great video. I had a gear system like this in an old drill I took apart. I threw the drill away but kept the gears for ages as it was just a cool thing 😃

I've always preferred to use other adhesives like contact cement over superglue. IME superglue is *exceedingly* effective at sealing its own container shut, and it's nowhere near as good at adhering anything else.

Your model and explanation are the most clear i have ever seen! I am going to show this to my children so they can understand this powerful concept

I've had 5 or 6 different bicycles with different hub gears. I've also worked repairing pneumatic tools including their planetary gearboxes. This is by far the best explanation and demonstration on how they work I've ever seen! The energy flows of planetary gear boxes can be hard to understand but you made it easy. Thanks!

Another amazing feature of the planetary gearbox is the amount of torque it can withstand,due to the large amount of contact of gear teeth.

Very well done! Easy to see the concept! And it's a good concept to see! This concept was deployed in many of the earliest and most successful transmissions of many early cars. Ford loved this configuration and used it with great success on the Model T.

Awesome demonstration and well explained! Thanks so much for sharing this with us! I found that you cut 24 Teeth into the Sun Gear and 48 Teeth into the Ring Gear. Take the sum of the Sun and Ring Gear to use as the value for the Planet Carrier (72 Teeth). The Ratios are easy to figure after that.

What clearance are you using for the things to rotate when printing? Like how much gap is there between the pins in the planet carrier and the inside of the planet gears for them to spin freely without much friction?

The thing that people don’t understand about the gear wars is it really was never about the gears

Planetary gearsets are very cool . I learned about them in my 4th year apprenticeship of auto mechanics . Most newer transmissions use a double planetary gearset . Very cool stuff .

i work with alot of related gearboxes like this on electric bikes and shimano nexus, this was a really good way to explain it. deffnitly gonna get one these printed for everytime i have to try to explaine how a planetary gearbox works to someone. going to save me so much time =)

Good design. I would try to incorporate ball bearings, and make the gear teeth helical for smoother and quiter operation.

That 2:3 ratio you were getting is actually how the Ravigneaux gear set gives the 33% Overdrive on the Ford AOD transmission...It's a very simple design and works really well if maintained properly.

This is by far the best planetary gear system explanation I've ever seen

Thank you for the video. I've been watching transmission teardown videos for a while and couldn't figure out how a planetary system created the different gear ratios. Your video made it make sense for me.

Nice video and explanation. Always impressed when KZfaqrs just design and 3d print a model as a part of the demonstration. I thought that automatic transmissions worked with fluid dynamics? Always like a day at the library.

You have created one out of four axles on a monster truck or the back half of an automatic transmission. The part after all the fluid has done the work. That is pretty cool I wish they had 3D printing when I was in school to help people visualize and understand things like that. Instead we had a cutaway of an old transmission😀

The Ford Model T had this simple gearbox as well. The Model T didn't have the standard pedal layout we know today, it had one pedal for first and second gear, a pedal in the middle for the reverse, and another pedal for brakes c: I hope that's right.

When I was training to be a helicopter mechanic at Fort Rucker in Alabama, I had the opportunity to see the planetary gearbox of the UH-1 helicopter. It was a beautiful thing to behold. The intricately machined parts fit inside each other with incredible precision.

1:01 thanks for the information

Genius. I am infatuated with Unimog trucks and for 15 years I've wondered how their drive train works. And now I understand about 75% more than I did Thank you

Wonderful explanation of something that I have never totally understood until now and I’ve worked on them in hydraulic winches and only had a vague understanding of them until now

Made a set of these at work not to long ago but had no idea how they were applied. Nice work

Consider using dichloromethane (DCM) instead of superglue for PLA or acetone for ABS. This gives a much stronger and more reliable bond

Great demo! Thanks, it's helped me understand how planetary gears work. I also see its not just me who gets themselves in somewhat of a mess with superglue. I would've somehow got myself stuck to the inside of the glove too!

We have all had things go wrong when building something. What matters most is the end result and yours is amazing!

Tip: the end of the glue tube cap can be used to pierce the new tube. In fact, the cap is designed to do so. Great job with the gears.

Wonderful experience and thanks you 😊 Your experiment is priceless

Working in the automotive field it ain't pretty when these fail. Mostly because of not changing the transmission oil at service intervals or neutral drop shift.

I've always found it hard to understand planetary gears, but this video helped me!

After taking apart and reassembling several automatic transmissions, I didn't know some stuff from this video. Nicely done.

Has anyone ever used superglue without a drop somehow getting on your finger?

The latest example of using a planetary gearset is in the design of a Toyota/Lexus hybrid transmission. It's nothing more than the internal combustion engine (ICE) driving one of the planetary cranks and an beefy electric motor driving another crank, with the third crank tied to the wheels. Either the ICE or the motor or both can spin to drive the wheels, and by using a computer and a gigantic 600v battery the motor can actually spin backwards, as needed, in order to match the desired ICE rpms to the wheel rpms. The whole thing is brilliant and totally transparent to the driver, and since it's nothing more than just a planetary gearset it's indestructible. And no "shifting" per se--instead, the computer just directs different motor and ICE rpms to meet the wheel rpm needs. Toyota calls it a Continuously-Variable Transmission (CVT) but it has nothing in common with the old-fashioned CVTs that used cone-shaped pulleys and a steel drive belt that would eventually fail.

I love the gearing on the champion hand crank forge blower. One turn of the handle, turned the about 60 revolutions.

It's why I prefer internal gear hubs for my bicycles. Everything critical is enclosed. If you make sure the shift cable is properly adjusted and give them some oil now and then they run almost forever with very few problems.

This is basically the Toyota Hybrid transmission. The car's wheels and large electric traction motor are attached to one shaft, the gas engine to a second, and a smaller electric motor is attached to the third shaft. It's much simpler and more durable than using a belted CVT and it allows lots of different modes of operation. The gas engine can idle at a stoplight to charge the battery or provide cabin heat, or the transmission can allow the car to be driven by the electric traction motor while the gas engine is off. Mechanically, the system is simple and robust, but it takes a lot of advanced high-power electronics and computers to make it run smoothly.

The "Power Split Device" in a Toyota Hybrid Synergy Drive E-CVT transmission, is a planetary gear set, just like depicted in this video. In the Toyota Prius, the original application for HSD, The Sun Gear is splined to a 30hp, 3-phase synchronous motor called MG1. The Planet Gear Carrier is splined to the gasoline engine, and the Ring Gear connects two ways, to the front wheels and via the Differential gear set, and to a 70 hp synchronus motor, MG2. The genius in this system is provided by the software that controls the overall flow of power to and from the gasoline engine and the two motor generators. MG1, the smaller, 30 hp unit, has two jobs: to reclaim kinetic energy when the vehicle needs to slow down, via "regenerative braking", and to control and limit the speed of the gasoline engine. At any given vehicle speed, the computer can adjust power flow to MG1, and thus control how fast the sun gear is spinning, or even make it spin backwards, and this indirectly controls how fast the gasoline engine is spinning. The computer is programmed to try and keep the gasoline engine running within it's most fuel efficient range of rotation speeds (1,000 to 2,500 rpm), and to limit the maximum speed of the engine to about 4,200 rpm. While the gasoline engine is being controlled by the computer via MG1's spin on the Sun gear, the computer is simultaneously controlling power supply to the 70hp MG2 motor. How much power can be delivered by this motor is influenced by the state of charge in the traction battery, temperature and power limitations in the inverter and motor stator, the power demand by the driver or cruise controll, steepness of the terrain, altitude and oxygen supply in the air intake to the gas engine, and several other factors. The computer makes thousands of decisions every second, and is programmed to optimize all of the components in the power train to deliver the maximum fuel efficiency, and minimize tailpipe emissions to keep the Government happy. It's not just Toyota, of course: many manufacturers sell Hybrid cars, and most of them use technology similar to the Toyota HSD, in which a planetary gear device is central to marrying one or more electric motors, a large battery, and a gas or diesel combustion engine in a unified powertrain that uses electricity from the battery to propel the car whenever possible, and use as little fossil fuel as possible.

that large black sheet you were working on looks like what came with my Ender 3. And its what I put down on the table when I superglue as well!

Man, reduction gearbox in a T-56 has a planetary gear system with 5 planetary gears. Was one of the coolest things to study in tech school.

Last year I’ve learn the formulas and calculations to know the gear ratios depending on the number of gears and which handle you turns. It’s quite a mess but a nice mess in the end.

Simple but looks amazing

Good explanation and well demonstrated. Also I liked that you do not edit out your errors or sticky finger problems.

The ZF 8hp transmission utilizes this design. Absolutely love the trans, 8hp75, in our Wrangler rubicon ecodiesel.

The gear ratios don't depend on the number of teeth on the planetary gears. Just the sun gear and ring gear. I know that your ring gear has 2x as many teeth as your sun gear because it produces a 2:1 ratio when the planetary gears are held still.

When I'm printing parts that will fit together I generally print the outer part with a 101 or 102% scale. It fits better without losing it's properties.

Needed this for a reminder on how gas turbines achieve counter-rotating blades in designs where turbines rotate at a different ratio (and different direction) to compressor blades.

Can you model a v8 engine block with pistons and crankshaft?

Always wondered exactly how the ratios were achieved. Now I have to find something else to always wonder about.

@3dprinteracademy Which orientation is best to print the ring gear? I am having difficulty with supports

Thank you for the video! I was curious how my excavator planetary drives work and I think this satisfies it!

If you vary the speed of individual handles you get a continuously variable gear ratio. This is what Toyota uses for their hybrid transmissions.

Can we see it being use with some kind of motor?

Now this is satifying to watch it can also give a perfect explanation on how time itself works

I got to learn a little bit about these when helping fix a crane at work. There's what's called a planetary gearbox that uses hydraulics to spin the gear and make the crane rotate. I had to disassemble and clean it up. It was a Linkbelt crane. All together, I'd say it weighed 300 pounds.

Can you please make a tutorial about modelling this planetary gear in Fusion 360 for 3d printing like you did? *Everyone who agrees with me leave a like.

Engineers will save the world. No idea who came up with the automatic transmission, but thanks to them, the whole world can drive instead of shifting through their own gears. Some people will never be able to learn manual transmissions. Even guys.

In the process of rebuilding the transmission in my car, this 3 pinion planetary gear set is also in Chrysler A727 transmissions, later transmissions had a 4 pinion planetary gears. Gear reduction ratio in first gear is very similar to this model of 2.23:1

Boy did this bring back memories... a VERY long time ago when I was a young teenager I taught myself how to rebuild Ford(1949-1954) 3-speed transmissions with a Borg-Warner overdrive. An interesting fact about those overdrive units is... when the O/D was manually selected, but not engaged you would be in a 'free-wheeling' situation so when you let up on the gas the engine would simply go to idle. When you got up to around 30mph and let off the gas momentarily, a solenoid would engage the O/D. The free-wheeling was necessary when you were running down the road so there was no load on the O/D gears during the shift. The really interesting part was... (lets say you wanted to pass) when you floored the gas pedal it would depress a switch mounted under the gas pedal. That would actually short out the engine coil (just like you turned the ignition off), which would in turn remove any load on the gears, then the unit would shift out of O/D. If you did not want the O/D to engage at all (town driving) you would manual select 'no O/.D'. That would lock up the planetaries on the sun gear. Fun memories I have not thought about for a very long time.

Excellent video, very good information density per unit time.

I'm super early for this one. 😁😁

Holy schnikey's that's insane! I knew the basics of how a planetary gearbox created reduction but I had no idea you could get multiple ratios out of one set of gears like that

I worked at a company that attempted to develop a planetary gearbox to drive a turbo compressor from an aircraft engine propeller drive shaft mounting pad. They attempted to use the propeller output as a power source for compressed air instead of engine bleed air for air condition and cabin pressurization. The effort was design was to take a low output shaft speed and step it up to mid 40,000 rpm. The gearbox harmonics and bearing inputs was amazing and I don't recall if they ever did get the design solidified. The price of aviation fuel fell soon afterwards and the effort was cancelled.

I believe one of the most interesting uses of this gear configuration is the differential in an automobile. The engine turns the planetary part I believe which will automatically distribute the energy to the two wheels unevenly if the car is turning (more speed to the wheel on the outer edge of the turn). If you ever have your car up on a lift, you can observe that spinning one of the drive wheels will spin the wheel on the other side of the car in the opposite direction.

Is it a setup like this that enables rotating radar antennas to maintain power without twisting the wires that feed them?

Radial aircraft engines , eg Pratt & Whitney's, have a planatary reduction gear built into the fron of the engine to allow the engine as well as the propeller to each work at it's most efficient rpm.

Very nicely done. The rotation is very cool. Was there a special reason to print the white base in 2 parts?

The best way to buy CA (Super) glue or epoxy is from a model aircraft supplier. You can buy much larger quantities for a lot less. You can also get CA glue in different consistencies - gel, for example - and epoxy glue with different drying times.

Could you take rotary power directly from the planet gear instead of passing it through the carrier...I mean if you use a flexible coupling may be a spring and Connect it to the planet gear face I think we could get another new ratio there

Dry graphite is usually a better choice of lubricant for this type of application. It doesn't degrade over time, and is incredibly effective (if slightly messy to apply).

Great video. One problem though, the ring gear doesn't have the right teeth form. No longer an involute form.

tell a combination in such a way that, regardless of the direction of the input, the output should always be in one direction

OMW. Yt algorithm wins again. Coming from eskate boards this is so relevant as gear drives are now being used as an alternative to belt drives and direct drives. Also need to learn how to 3D print components for my boards so this video is excellent. Great presentation and easily accessible. Thanks so much.

You need to take account of thermal expansion, and use an offset in horizontal expansion in the slicer for the tolerance

Great model and explanation. Thank you, brilliant work! 👍

this was the best video for explaining planetary gears that I've seen.

wow nice demonstration it's very clear to me now, they always used to confused me. This is so cool I never know what to make, guess I'll start making one for the kids for next Christmas! I better start now or I'll never finish in time lol.

IIRC a differential gear is also basically the same thing as the 1:1 (direct drive) case. Drive the "blue handle". Don't bother with the other handles, but use the "Sun gear" to drive one wheel and the outer gear to drive the other. If you're driving in a straight line, everything turns the same speed. If you're driving around a corner, the blue handle sets the average speed of the wheels - the inside wheel turns a bit slower as it travels a slightly shorter distance, and the outside wheel turns a bit faster - the two drive wheels can rotate at different speeds but you can still drive those wheels and you can still accelerate. In practice, the "handle" is another gear connecting to the drive shaft. One problem is that if you lose traction on one wheel, that wheel just spins freely so there's no force on the other. This can make it difficult to drive off of a patch of ice, for example. Modern cars do something about that, I think, but I don't know what.

I always wonders about the exact mechanics for the *Overdrive + Underdrive* on the rear of my old Willys CJ2 transfercase. Full Revs while in underdrive & 1st Gear is barely a walking pace, but the Torque is crazy for a 56Hp engine!we

try rotating 1 gear clockwise and another anticlockwise , list out the results into tabular colmun and post it here. Thanku for the amazing video

The Waen / Saturn overdrive used in vintage Jeeps uses a planetary gear set.

Cvt transmissions on ag equipment use a planetary gearset. The input is the planet carrier, the output is the sun gear, and there's two hydralic motors/pumps in a closed loop. One is on the sun gear, the other on the ring gear. By varying the speed and direction of the ring gear, you get forward and reverse speeds that can be anything from stationary to top speed. Ecvt transmissions in cars work the same way, only using electric motor/generators instead of hydraulic motor/pumps

This mechanism, Is great for , Spinning one thing and also if you want to spin two things! Except you might need a mechanism, Before it (Inside gear left movement attachment to right one, That’s used in vcr’s, Well the one I have.).

A very impressive demonstration. Thank you!