Damn that's really a clever solution 👌 Simple and effective. I didn't know yet that the castor had an angle at all, but then again I didn't look at that before... Thank you 😁👌 The animations are a bit weird though... And the car drives on the wrong side of the road 😜😏
Your animations make the learning process enjoyable. This kind of learning is so much effective than the ones at schools. Thanks a lot for your effort to make these videos.
I think this kind of mechanism also shows up when you are free handing in the bike. When you're turning the bike, the centripetal force acts in the pivot point with restoring torque due to the fact the the pivot point is in front of the patch area of a bike, therefore, provides a restoring torque
I think another perfect example is when you push a trolley. When the trolley is moving forward the front wheels is automatically adjusted towards the direction is heading.
Well explained. You get a first hand look at how this works by watching how wheels on a grocery cart follow where the cart is pushed, even though there is no active steering control. Castor provides a moment arm to rotate the wheel behind the pivot arm as the cart is pushed forward. Also note that when driving in reverse you don't get a stabilizing force to center the steering wheel....
@@kartikchoubisa Only if the wheel can rotate 180 deg so the wheel follows the pivot axis. That happens easily on a grocery cart but range of motion for a car wheel is more restricted. The same process happens with the rudder of a boat.
Above 80% people are visual learner's but in schools we are taught abstract language then abstract information and when we decode the words into a clear picture then we understand Your channel is at the top because of its visuals.
This is such a hard concept to grasp. When I first heard about it I kept getting bogged down by the fact that the tire basically is turning through the ground. Definitions really helped with this tricky concept. I'm still confused about the turning into the floor thing but at least i know about patch area and the axis not lining up with the patch area being the reason for that restoring torque...really cool stuff!
You're not turning into the floor, you're lifting that corner of the car by a little bit. That's part of the reason why caster angle increases steering force.
This video is actually awufk at explaining what is happening. Neither the words nor the animations clearly show what happening such that you can imagine it for yourself.
@@north-shoregcs3894 Two things. Either u weren't brought up well to interact with people respectfully which I wouldn't blame you for. Or you just decided to walk down this path which says alot about how you reason. Either ways, it's your problem. But Pls, don't pass this attitude to ur kids. The world needs less of such people in it. Lots of love
This feature can actually help you steer into (or out of) a slide. I was in a situation similar to those 'Sport Car Fails' where the driver fishtails uncontrollably. I was driving an older truck without power (assist) steering. I realized I was sliding and tried to steer into, but after a few fish tails I was not fast enough at the corrections. And, to my surprise, the steering wheel spun too fast for my hands - I pulled my hands back, and the truck did two more smaller fishtails and recovered.
You do not understand how long I've been searching for an answer to this. I knew it couldn't be as simple as a wheel just returns to a straight-line path automatically without some ingenuity behind it!
The term "patch area" is more commonly known, as far as I know, as the "tire footprint". The specific point in this footprint where the steering axis intersects has a huge bearing on handling and steering performance. Caster angle is not the only critical element. Proper alignment specs will differ between front-wheel and rear-wheel drive, as well as the manufacturer's geometry. It is important to know that changing tire/rim sizes or offset from the hub ("wide track" rims etc.) will change the designed steering/suspension intersection with the footprint and could cause unexpected and possibly severe handling or wear problems. Some immediate symptoms may be "bump steer", "oversteer" or "failure to centre". Stick to manufacturer's specs unless you know your suspension geometry!
There is also the matter of the spindle-to-pivot axis angle. The pivot axis is defined by the alignment of the top and bottom ball joints (for double a-arms or double wishbone suspensions), or lower ball joint and strut pivot line (for McPherson strut suspension). If you view the car from the front, the pivot axis is angled such that the pivot points is slightly shorter at the top between the 2 wheels, and longer at the bottom. In other words, the upper ball joints are closer to each other at the top between both front wheels. This causes the spindle to follow an arc as the wheel turns in such a way that the spindle will gradually point down on either a right or left turn. This causes the front end to lift up when the wheels are turned creating potential energy from gravity pushing the front end down, causing the wheels to straighten up once turning effort from steering input is released.
Doesn't cover nearly enough for a garage mechanic to be happy with. Simplistic to the extreme, suitable for novices only and, even then, only as an intro to the more complex concepts. If this were the only explanation for steering self entering, then steering fault diagnosis would be impossible.
The steering wheel is supposed to return to center ? WoW ! I have been driving bent beaters that either pull to the left or pull to the right for the past 40 years. This return to center deal sounds like a luxury to me.
Omg, I did not understand clearly the video and the "rotation" there was going on but the example with the bike is genius and it made it clear. Thank you !
That’s a different mechanism. Shopping cart wheels are dragged from the front. They follow whatever direction they are pulled to. The mechanism on a bike or car is totally different.
This is the clearest and most brilliantly simple way of explaining castor angle. (Something that I thought involved complex mathematics before). Now, I finally understand it well enough to explain it to someone else.
This is enlightening. I always thought the the front wheels were castered the opposite way -- like a caster under a mobile workbench -- so that they would easily track and not squirm to hunt to stay parallel with the vehicle's longitudinal access. Thanks for correcting my misunderstanding
This definitely makes sense, but the textbook I'm reading about it (CDX Fundamentals of Automotive Technology 2nd Ed) is saying it actually has to do with the body roll of the vehicle pushing the stub axles. The wheel turning out causes body rise and the one turning in causes body fall/lowering. When you let go of the wheel, the side that rose will push back down and, working with the caster angle, push the wheel straight again. I imagine the whole answer is a combination of these two concepts, as this one helps to explain how shopping carts get crazy when you push them really hard. They seem to lean into a turn on their own, even if you pushed fairly straight. The centripetal force is then in front of the steering angle (due to negative caster on the rear caster wheels) and would reinforce the turning in of the wheel.
The combined effect of castor angle and kingpin inclination helps the self centering of the steering wheel.Only castor angle cannot do the same.... Castor gives directional stability.
Fun fact. There are actually cars that return the wheel even at stand still. Lookup "Diravi" that was used on Citroën SM, CX and the V6 model of XM. I know you at least got the SM model in the US. Amazing system.
you'd find that as you begin to make a turn, the steering wheel will turn very easily, it would continue to turn, until it hits its limit, and would be difficult to get back straight again. Basically, it would be very dangerous!
One thing is missing to say in this video and is worth to mention, it's maybe not fully related but needed to point out. A suspension with 0° caster angle make the suspension more rigid while driving. Giving this light caster angle also help the suspension crumble upon front(forward driving) impact. One place where this light castle angle help is when you go into a parking lot and have to drive on a sidewalk that is a bit elevated. Or when your wheel fall in a pot hole.
The most significant part is 0:26 where you can see that when the car is in a curve the centripetal force induces torque in the caster angle direction. This is because the where the tire meets the ground and where the tire is connected to the axle form a moment arm.
Very good explanation. It would be great if you make more videos on steering geometries like camber angle, toe-in/out, Ackerman steering, Suspension. I am interested to see videos! Thanks!
incredible video. the visuals are a massive help to understand these concepts (since most of us don't have a physics degree, lol), .ive been doing a ton of research on front end suspension in an effort to save some coin on my older car, and this has helped immensly, thank you ! twf- mb,canada
The engineers probably applied the castor angle to overcome the body roll loss of traction due to centrifugal forces, the return to zero of the steering was perhaps a added bonus which came as a surprise to the benefit.
One correction: in the animation the pivot point is in front of the patch area not behind as the narrator says. The animation is correct. If the pivot point was behind the patch area there would not be the torque to center the wheels.
You called what should have been "steering axis inclination" caster angle. Caster is the angle of the lower ball joint to the upper ball joint in the side view of the car (longitudinal) not laterally as you described
One small addition to the excellent illustration, the car with zero castor angle will still have some steering return or self aligning torque due to the pneumatic trail in the tire. As point of application of the net lateral force is a bit behind the tire contact patch. Hence the pneumatic trail will add to the steering self return.
Typical US centred video who have never heard of Citroen. Citroen in a typically French way did use complicated springs and valves and hydraulics to return the wheel to straight ahead. The car in question had zero castor, trail or camber. The wheels pivoted to steer on a vertical axis exactly vertically through the centre of the wheel. All "feel" to the steering was applied artificially as seen on the original DS and the SM.
when the caster angle = 0, the friction force at the point of contact of the tire acts at the same point through which the steering axis of the wheel passes. Since the points coincide, the leverage of the force is 0, and therefore the torque is equal to 0. When the caster angle is greater than zero, the point of application of the friction force and the pivot axis of the wheel do not match. The distance between the point of action of the force and the projection of the turning axis on the road is the lever of force. And the product of force on the lever gives torque, which seeks to align the wheel in a neutral position.
Pneumatic trail in addition to mechanical trail (caster) are the components responsible for steering wheel return. At low lateral accelerations (low tire slip angles), the pneumatic trail is at a maximum. As lateral acceleration increases (increasing tire slip angles) the center of the lateral force moves forward, reducing the pneumatic trail, and thereby reducing the aligning moment that causes steering wheel return. At very high slip angles, the pneumatic trail can change sign, and the 'aligning moment' is now acting to increase the steer angle. This change in pneumatic trail will change the steering wheel torque perceived by the driver, and can be a signal to the driver that the limit of adhesion is approaching (and quickly.....)
Hello,It is so simple but the angle depends on the car segment and the tire width and aspect ratio.You even can watch it when you turn your steering as much as you can,you can see the angle.But the shown steering mechanism is not true nowadays steering is provided by hydraulic pump or EPS system,but it was interesting.
Simple. The "caster" part. The easiest explonation is that you actually lift your car a little bit everytime you turn the steering wheel. Or maybe more like "bending" it up So it´s gravity that makes the wheels get back to center. Look at how a bicycle behaves. The lowest part for the system is at center and therefore the weight of the car want´s it back to center.
@@michaelheimbrand5424 no, you are making a wrong logic out of it, it might be very much instinctive and I also had to give a bit of thought to it, but tilting the axis of rotation won't elevate the front part of the car just think about it.....the wheel is circular so...
For a moment to occur about a point (in this case the pivot point) you need a force acting perpendicular to that point at a given distance. By moving the pivot point forward (as a result of the castor angle) the friction force is now a given distance away from the pivot point meaning a moment(torque) can occur which acts to turn the wheel back to the straight position.
i am an engineer 47 year old. i have been working as a professional Machine designer for 25 year. i did many models and simulations to find answer to the same question what you are dealing. in four wheelers we are using the akier-man steering gear mechanism and 'amber' is the inclination that takes the turning axis's centre to the rotating wheel centre where the wheel touches the ground. when you look from the front the axises of the front wheels seem to be like the letter 'A' (this much visible in form trackers) . caster angle is being used in 2wheelers which gives a counter force that stabilizes the vehicle upright while in motion.
@LearnEngineering You should have also noted that the friction on the patch area under the front wheels will be acting backwards (since it is driven, not driving). This will also contribute to the restoring torque and will dominate the centrepital force for low steer angles.
I heard another explanation, the angles are not the same, if you turn right the right wheel makes a larger angle than the left wheel. That makes that, assuming the forces of friction parallel to the length of the car are the same on both wheels, the left wheel generates more torque than the right. The angles are not the same because the arms are not parallel but form a regular trapezoid.
Definitely our own 2017 Ford "ferd" Super duty needs a positive caster on the next alignment in hope to eliminate the small wobble we get when hitting bumps on the road.
Thus I can understand why front wheels look a little weird (in the patch area front wheels are not touching %100 smooth with the road) when turning the steering wheel. The answer was caster angle. The video is great and very helpful. Thank you. But why there is a restoring force when patch area is behind the pivot point?
Old cars didn't have that caster angle so you could just get out the car and it would keep turning. Demonstrated very well in Chevrolet's 1937 video about their invention of differential steering.
In fact, there is still a restoring (a.k.a. aligning) torque even if the caster angle is zero. That is so because the lateral force does not pass exactly through the center of the contact patch (patch area) in moderate speeds.
In a more simple way, the concept is very similar to that of a shopping trolley where the wheels are off centre from the swivel connecting each wheel to the trolley frame, so when you push the trolley in a straight line the wheels will align in that direction.
There are kits to implement adjustments that the manufacturer did engineer into the design. The most common is a camber kit. On a strut system the strut mount holes can be elongated to create a caster adjustment. This is usually required when there is collision damage that either the body shop can't fix or the customer doesn't want to pay for.
www.patreon.com/LearnEngineering - Patrons are our strength, please be a proud supporter of Learn Engineering.
Could you please add some videos regarding the steering angles and their effects
Could you please make a video about sewing machine
Please make a video on Camber angle.
Damn that's really a clever solution 👌
Simple and effective.
I didn't know yet that the castor had an angle at all, but then again I didn't look at that before...
Thank you 😁👌
The animations are a bit weird though... And the car drives on the wrong side of the road 😜😏
@@thekingin3128😜?
Your animations make the learning process enjoyable. This kind of learning is so much effective than the ones at schools. Thanks a lot for your effort to make these videos.
I think this kind of mechanism also shows up when you are free handing in the bike. When you're turning the bike, the centripetal force acts in the pivot point with restoring torque due to the fact the the pivot point is in front of the patch area of a bike, therefore, provides a restoring torque
I think another perfect example is when you push a trolley. When the trolley is moving forward the front wheels is automatically adjusted towards the direction is heading.
Veritasium made a video about that very thing!
Deez
nuts
@@dockwonder2278 inside
3:51 That car's gonna need new side skirts.
And also they need a tyre change because they are backwards lol
I think its fine
@@3xcelsi0r10 no they're not?
@@lintonfr the tyre profile is in the wrong direction
@@lintonfr Tyre profile are pointing Inwards
Well explained. You get a first hand look at how this works by watching how wheels on a grocery cart follow where the cart is pushed, even though there is no active steering control. Castor provides a moment arm to rotate the wheel behind the pivot arm as the cart is pushed forward. Also note that when driving in reverse you don't get a stabilizing force to center the steering wheel....
Shouldn't driving in reverse still give a restoring torque? :/
@@kartikchoubisa Only if the wheel can rotate 180 deg so the wheel follows the pivot axis. That happens easily on a grocery cart but range of motion for a car wheel is more restricted. The same process happens with the rudder of a boat.
sir does this issue relate which cars move idly even though i don't give it any gas?
@@wizahxx8065 No, unrelated issue. Torque converter dislocates the drive train from the engine, something there. It could be as simple as a high idle.
@@spelunkerd what about weight contribution? plus caster angle the car will move forward thus stabilize the two wheels?
Please make a video on car suspension..
gorav dyan th-cam.com/video/e_EAWKGvSp0/w-d-xo.html
Yes I also have the same request
Me too
Me too... 🇧🇼🇧🇼
What do you think this was?
TLDW: There are multiple slave dwarfs constantly adjusting your steering wheel.
Religion trying to explain cosmos in nutshell.
I believe that
haha
Now this makes much more sense !
They are trying to hide the truth of the dwarfs.... LET IT BE KNOWN.
Above 80% people are visual learner's but in schools we are taught abstract language then abstract information and when we decode the words into a clear picture then we understand
Your channel is at the top because of its visuals.
This is such a hard concept to grasp. When I first heard about it I kept getting bogged down by the fact that the tire basically is turning through the ground. Definitions really helped with this tricky concept. I'm still confused about the turning into the floor thing but at least i know about patch area and the axis not lining up with the patch area being the reason for that restoring torque...really cool stuff!
Nic
You're not turning into the floor, you're lifting that corner of the car by a little bit. That's part of the reason why caster angle increases steering force.
This video is actually awufk at explaining what is happening. Neither the words nor the animations clearly show what happening such that you can imagine it for yourself.
skill issue lol
"its obvious that.." "it is clear that..." no, its not so obvious and clear why r u making me feel stupid haha
😂. I can relate. For the most part of the video, I was lost especially with those physics terms.
You are stupid if you couldn’t understand that, just look at the diagram when he is talking....
@@north-shoregcs3894 Two things. Either u weren't brought up well to interact with people respectfully which I wouldn't blame you for. Or you just decided to walk down this path which says alot about how you reason. Either ways, it's your problem. But Pls, don't pass this attitude to ur kids. The world needs less of such people in it. Lots of love
@@Fur_gene lol weirdo
@@north-shoregcs3894 😂. I guess we both are weirdos
This feature can actually help you steer into (or out of) a slide. I was in a situation similar to those 'Sport Car Fails' where the driver fishtails uncontrollably. I was driving an older truck without power (assist) steering. I realized I was sliding and tried to steer into, but after a few fish tails I was not fast enough at the corrections. And, to my surprise, the steering wheel spun too fast for my hands - I pulled my hands back, and the truck did two more smaller fishtails and recovered.
You do not understand how long I've been searching for an answer to this. I knew it couldn't be as simple as a wheel just returns to a straight-line path automatically without some ingenuity behind it!
The term "patch area" is more commonly known, as far as I know, as the "tire footprint". The specific point in this footprint where the steering axis intersects has a huge bearing on handling and steering performance. Caster angle is not the only critical element. Proper alignment specs will differ between front-wheel and rear-wheel drive, as well as the manufacturer's geometry. It is important to know that changing tire/rim sizes or offset from the hub ("wide track" rims etc.) will change the designed steering/suspension intersection with the footprint and could cause unexpected and possibly severe handling or wear problems. Some immediate symptoms may be "bump steer", "oversteer" or "failure to centre". Stick to manufacturer's specs unless you know your suspension geometry!
I know it as contact footprint
In the racing world, in almost every resource I've studied, it's referred to as the contact patch.
One of the best Engineering channels out there. I have learnt so much here, something which is very difficult for a book to portray with imagination.
There is also the matter of the spindle-to-pivot axis angle. The pivot axis is defined by the alignment of the top and bottom ball joints (for double a-arms or double wishbone suspensions), or lower ball joint and strut pivot line (for McPherson strut suspension). If you view the car from the front, the pivot axis is angled such that the pivot points is slightly shorter at the top between the 2 wheels, and longer at the bottom. In other words, the upper ball joints are closer to each other at the top between both front wheels. This causes the spindle to follow an arc as the wheel turns in such a way that the spindle will gradually point down on either a right or left turn. This causes the front end to lift up when the wheels are turned creating potential energy from gravity pushing the front end down, causing the wheels to straighten up once turning effort from steering input is released.
I guess this ( what is called as king pin inclination) is the dominant reason for self correcting steering 👍
This seems to be simple mechanism to understand for any car repair garage mechanic. Very informative! Very well explained.
Doesn't cover nearly enough for a garage mechanic to be happy with. Simplistic to the extreme, suitable for novices only and, even then, only as an intro to the more complex concepts. If this were the only explanation for steering self entering, then steering fault diagnosis would be impossible.
Great video. Lot of work put in the animations. Very helpful. Good job keep it up 👍👍👍👍👍
The steering wheel is supposed to return to center ? WoW ! I have been driving bent beaters that either pull to the left or pull to the right for the past 40 years. This return to center deal sounds like a luxury to me.
and that's why bicycles moves without falling when we're not handling its handle.
Omg, I did not understand clearly the video and the "rotation" there was going on but the example with the bike is genius and it made it clear. Thank you !
And the wheels on the shopping carts align themselves too
That’s a different mechanism. Shopping cart wheels are dragged from the front. They follow whatever direction they are pulled to. The mechanism on a bike or car is totally different.
@@Engineer9736
yup! i agree for shopping cart but not for difference between bike and car.
Yes, that’s what i meant. Bike and car are same, shopping trolley not.
Another great video in addition to the wheel alignment video. Thank you for explaining these simple but essential concepts.
TH-cam at 3 am: You wanna know how does the Steering Wheel automatically returns to its center?
Sleepy me who can barely open his eyes: Interesting.
It's not as "random" of a concept one might wonder about. Stop posting in every video the title of the video as if it was funny
This is the clearest and most brilliantly simple way of explaining castor angle. (Something that I thought involved complex mathematics before). Now, I finally understand it well enough to explain it to someone else.
This is enlightening. I always thought the the front wheels were castered the opposite way -- like a caster under a mobile workbench -- so that they would easily track and not squirm to hunt to stay parallel with the vehicle's longitudinal access. Thanks for correcting my misunderstanding
This definitely makes sense, but the textbook I'm reading about it (CDX Fundamentals of Automotive Technology 2nd Ed) is saying it actually has to do with the body roll of the vehicle pushing the stub axles. The wheel turning out causes body rise and the one turning in causes body fall/lowering. When you let go of the wheel, the side that rose will push back down and, working with the caster angle, push the wheel straight again. I imagine the whole answer is a combination of these two concepts, as this one helps to explain how shopping carts get crazy when you push them really hard. They seem to lean into a turn on their own, even if you pushed fairly straight. The centripetal force is then in front of the steering angle (due to negative caster on the rear caster wheels) and would reinforce the turning in of the wheel.
Wonderful animated explanation! Thanks for the effort you took in making these videos👏🏻👍🏻
The combined effect of castor angle and kingpin inclination helps the self centering of the steering wheel.Only castor angle cannot do the same.... Castor gives directional stability.
Absolutely brilliant explanation. I’ve always wondered how this happens, thank you!!!!
Fun fact. There are actually cars that return the wheel even at stand still. Lookup "Diravi" that was used on Citroën SM, CX and the V6 model of XM. I know you at least got the SM model in the US. Amazing system.
2:25 Wow that's a lot of understeer
The caster angle is very noticeable on my MB W124, I was wondering why it was built that way, now I know! Thanks
But what happen when negative caster is given????
probably a lot of oversteer because the centripetal force acting on the patch area will generate a torque in the opposite direction.
It would simply turn the steering wheel into the turn.
It'll pull the car to one side
you'd find that as you begin to make a turn, the steering wheel will turn very easily, it would continue to turn, until it hits its limit, and would be difficult to get back straight again.
Basically, it would be very dangerous!
So that's why driving backwards fast in a car can cause abrupt steering.
One thing is missing to say in this video and is worth to mention, it's maybe not fully related but needed to point out.
A suspension with 0° caster angle make the suspension more rigid while driving.
Giving this light caster angle also help the suspension crumble upon front(forward driving) impact.
One place where this light castle angle help is when you go into a parking lot and have to drive on a sidewalk that is a bit elevated.
Or when your wheel fall in a pot hole.
The most significant part is 0:26 where you can see that when the car is in a curve the centripetal force induces torque in the caster angle direction. This is because the where the tire meets the ground and where the tire is connected to the axle form a moment arm.
Thanks bro! Your comment actually cleared my misconception that why does the torque produce I was missing the moment arm thing
This is a kind of video i would watch in 3 am but hey its a really informative and good animation
Is there any other uses for castor angle apart from returning the steering?? Doesn't it improve the cornering?
The caster angle affects the dynamic camber of sterling inputs. It can be beneficial to help with turn in feel and reduce understeer in FWDs,
Yeah I think it does the same sort of thing as a negative camber angle, but is only applied during the turn
Thanks LEARN ENGINEERING for clearing my doubt.🙏
Very good explanation. It would be great if you make more videos on steering geometries like camber angle, toe-in/out, Ackerman steering, Suspension. I am interested to see videos! Thanks!
0:03 probably something an actual bmw driver would do
*Asian BMW driver XD
@@jessiequinton9974 American BMW driver*
*basically any asshole
@@gamechep Do you drive a BMW?
I love how you like the e86.
This makes sense and is very accurate because there are no turn signal stalks.
I have literally watched all the videos of this channel ,now what i want is my graduation degree lol:)😂
to bad, this is elementary school knowledge
@@peepa47 yeah that's right you studied theory of relativity when you were peeing in your cradle right?
Ok, before you get your degree, you must pass the exam. And your exam question is "How automatic transmission works?" 😂😂😂
@@peepa47 bro in what kind of elementary school did you study??
Explainig the full physics of how a bycicle works would be also interesting. Balance, cornering without the hands on the handlebar, etc.
incredible video. the visuals are a massive help to understand these concepts (since most of us don't have a physics degree, lol), .ive been doing a ton of research on front end suspension in an effort to save some coin on my older car, and this has helped immensly, thank you ! twf- mb,canada
Cool video! Kyle engineers would be happy! Happy new year !
Wow something i always have wondered for a looooooooooooong time. 😊
happy new year 2019 Learn Engineering bahi
Interior looks top notch
I like Kimi Raikkonen so much that I can't hear "steering wheel" without thinking about him
The engineers probably applied the castor angle to overcome the body roll loss of traction due to centrifugal forces, the return to zero of the steering was perhaps a added bonus which came as a surprise to the benefit.
One correction: in the animation the pivot point is in front of the patch area not behind as the narrator says.
The animation is correct. If the pivot point was behind the patch area there would not be the torque to center the wheels.
"pivot point behind patch area"
Auto steer mechanism for decreasing radius turns
Mind blown
You called what should have been "steering axis inclination" caster angle. Caster is the angle of the lower ball joint to the upper ball joint in the side view of the car (longitudinal) not laterally as you described
Well this explains why old tractors( with hydraulic steering) don’t do this
One small addition to the excellent illustration, the car with zero castor angle will still have some steering return or self aligning torque due to the pneumatic trail in the tire. As point of application of the net lateral force is a bit behind the tire contact patch. Hence the pneumatic trail will add to the steering self return.
And the slide toe-in setting
Typical US centred video who have never heard of Citroen. Citroen in a typically French way did use complicated springs and valves and hydraulics to return the wheel to straight ahead. The car in question had zero castor, trail or camber. The wheels pivoted to steer on a vertical axis exactly vertically through the centre of the wheel. All "feel" to the steering was applied artificially as seen on the original DS and the SM.
This video only covers cars that don't break down after a year of normal usage like French cars.
@@mitsako1 Ha, ha, ha, ha.
Caster isn’t ajustable but you can buy aftermarket parts to ad caster for specific scenarios such as pro drift cars
i lived in a lie.
What was the lie? That your car had shopping cart wheels?
Caster is adjustable on many modern cars. Typically via control arms if it's a wishbone suspension or the radius rods.
Is there a similar channel in german? My technicial english isnt that good.
Jaqenqt i have no clue bro
NO Shit ? You to ? Somethingx wronger!! Hylp ME and YOU two....
th-cam.com/video/DC6Opx_3EUo/w-d-xo.html
Brilliant engineering!
I can't understand can u kindly try explain still more clearly with basics too.
when the caster angle = 0, the friction force at the point of contact of the tire acts at the same point through which the steering axis of the wheel passes. Since the points coincide, the leverage of the force is 0, and therefore the torque is equal to 0. When the caster angle is greater than zero, the point of application of the friction force and the pivot axis of the wheel do not match. The distance between the point of action of the force and the projection of the turning axis on the road is the lever of force. And the product of force on the lever gives torque, which seeks to align the wheel in a neutral position.
Pneumatic trail in addition to mechanical trail (caster) are the components responsible for steering wheel return. At low lateral accelerations (low tire slip angles), the pneumatic trail is at a maximum. As lateral acceleration increases (increasing tire slip angles) the center of the lateral force moves forward, reducing the pneumatic trail, and thereby reducing the aligning moment that causes steering wheel return. At very high slip angles, the pneumatic trail can change sign, and the 'aligning moment' is now acting to increase the steer angle. This change in pneumatic trail will change the steering wheel torque perceived by the driver, and can be a signal to the driver that the limit of adhesion is approaching (and quickly.....)
2020 steering wheel
2009 speedo
2005 dash
2013 idrive
Wtf
2008 steering wheel, dash, speedo and idrive. It’s a Z4 interior
Hello,It is so simple but the angle depends on the car segment and the tire width and aspect ratio.You even can watch it when you turn your steering as much as you can,you can see the angle.But the shown steering mechanism is not true nowadays steering is provided by hydraulic pump or EPS system,but it was interesting.
How does the steering wheel automatically *RETURNS* to its center?
Watch this video and their previous steering video
@@arv1ndgr I think hes talking about a spelling error.
Simple. The "caster" part. The easiest explonation is that you actually lift your car a little bit everytime you turn the steering wheel. Or maybe more like "bending" it up So it´s gravity that makes the wheels get back to center. Look at how a bicycle behaves. The lowest part for the system is at center and therefore the weight of the car want´s it back to center.
@@michaelheimbrand5424 no, you are making a wrong logic out of it, it might be very much instinctive and I also had to give a bit of thought to it, but tilting the axis of rotation won't elevate the front part of the car just think about it.....the wheel is circular so...
Return
Caster also helps race cars turn into the corner, usually referred to as caster split, you can make the car easier to turn left or right...
2:50 Not the “effect of CENTRIPETAL force” but the effect of CENTRIFUGAL force
dstny09 centrifugal force doesn’t exist you’re an idiot
@@maxreddy2592 centrifugal force does exist. otherwise why would high speed roads be super elevated at curves?
Awesome man...nice way to make people understand theses things...
As a bmw owner, this is the most mutilated interior I have ever seen 😂😂
As an Audi owner, I feel sorry for you BMW owners :)
@@DaTT78 as bmw owner we don't think about VWs at all
@@GodKing804 I understand, no time to think about anything else except when the next breakdown will occur. :)
Thanks man, very well explained
Nothing new and def not a car engineers idea... Bicycles had it long before cars even existed!
good point, never even though of that until looking at my bike. Thought the front fork was at and angle because it looked cool when designed ha!
Very nice explanation of caster angle and patch area... Thanks
Am watching whie driving wish me luck.
Such a precious channel has only 5M subscribers, what a pitty.
*i dont get it*
its okay dude, me too
For a moment to occur about a point (in this case the pivot point) you need a force acting perpendicular to that point at a given distance. By moving the pivot point forward (as a result of the castor angle) the friction force is now a given distance away from the pivot point meaning a moment(torque) can occur which acts to turn the wheel back to the straight position.
Me too
@@eamonglavin2532 helpful comment, thanks
It’s called “Steering Axis Inclination Angle.” Also referred to as SAI included angle. A wheel alignment term.
Wait, at the beginning there os something severly wrong. The steering wheel is on the wrong sode of the car oO
i am an engineer 47 year old. i have been working as a professional Machine designer for 25 year. i did many models and simulations to find answer to the same question what you are dealing. in four wheelers we are using the akier-man steering gear mechanism and 'amber' is the inclination that takes the turning axis's centre to the rotating wheel centre where the wheel touches the ground. when you look from the front the axises of the front wheels seem to be like the letter 'A' (this much visible in form trackers) . caster angle is being used in 2wheelers which gives a counter force that stabilizes the vehicle upright while in motion.
I still do not understand to this :/
Then engineering or physics is probably not your cup of tea
Start with grade school.
you are not alone
Don’t worry and blame the “over engineered” video. It’s all about fancy graphics, but not explaining it well.
@LearnEngineering You should have also noted that the friction on the patch area under the front wheels will be acting backwards (since it is driven, not driving). This will also contribute to the restoring torque and will dominate the centrepital force for low steer angles.
Its not effective.
Great video but I would also like to see how the caster and chamber changes affect the driving dynamics of the car thank you
who is watching in 2018 ?
EAX 2019
Helpful for me tq
???9
2119
I heard another explanation, the angles are not the same, if you turn right the right wheel makes a larger angle than the left wheel.
That makes that, assuming the forces of friction parallel to the length of the car are the same on both wheels, the left wheel generates more torque than the right. The angles are not the same because the arms are not parallel but form a regular trapezoid.
What's with the engineer worshiping?
Oh praise dem engineers 🙏🏼
Hi übrigens 😂
@@elpedomasgrande1 ja oder. hast mich jetz zufallig als kommentar gesehen? 😂
xilefx ja haha, youtube’s Algorithmus weiß bescheid.
Die Hände am Anfang sind auch geil 😂
All hail the engineers. They have given us so much since they built the pyramids. Oh, wait, I'm thinking of Ancient Aliens.
Definitely our own 2017 Ford "ferd" Super duty needs a positive caster on the next alignment in hope to eliminate the small wobble we get when hitting bumps on the road.
I have got to tell u bro ur animations are ar so so cool ❤
2:36 there is an error in the picture. The radius of curvature should be the same line with rear axle.
Keep teaching us ...am an first year automobile engineering student....
amazing illustration
Wow ! I didn't know that ! You made it so simple
Brilliant. This was very informative. Great video.
Thus I can understand why front wheels look a little weird (in the patch area front wheels are not touching %100 smooth with the road) when turning the steering wheel. The answer was caster angle. The video is great and very helpful. Thank you. But why there is a restoring force when patch area is behind the pivot point?
Old cars didn't have that caster angle so you could just get out the car and it would keep turning. Demonstrated very well in Chevrolet's 1937 video about their invention of differential steering.
Awesome. I learnt a new thing today
In fact, there is still a restoring (a.k.a. aligning) torque even if the caster angle is zero. That is so because the lateral force does not pass exactly through the center of the contact patch (patch area) in moderate speeds.
In a more simple way, the concept is very similar to that of a shopping trolley where the wheels are off centre from the swivel connecting each wheel to the trolley frame, so when you push the trolley in a straight line the wheels will align in that direction.
Nice!! What happens if the caster angle is negative? I assume that the wheel will try to turn even more
There are kits to implement adjustments that the manufacturer did engineer into the design. The most common is a camber kit. On a strut system the strut mount holes can be elongated to create a caster adjustment. This is usually required when there is collision damage that either the body shop can't fix or the customer doesn't want to pay for.
Another nice video. I like it. By the way, happy new year for all