Car Brake

When you explosively deploy the skirt, won't you blow snot all over everything?

This is really "outside the skirt" thinking.

Why not a pogo stick to let you leap over the obstacle.?

"Why not a pogo stick to let you leap over the obstacle.?"

Like the powerful Mach 5?

Exactly.

Someone has alresdy stolen my concept?

They'll hear from Dewey, Cheatem and Howe first thing in the morning!

I confess that I had to Google Mach 5 before I knew what you meant.

Oh well.

How could you increase the efficiency of a brake?.

Drive slower.

I don't get it. Just seems like an unrealistic concept especially given that it would "save some people, but would kill more".

If I could shift gears (pun intended) here a moment on the subject, what do you see wrong with current day ABS breaking systems?

I know, I know, on an ice covered road the ABS would still allow you to slide but wouldn't the same hold true for your vacuum boot?

I drive an insane amount of miles every year in every type of weather, road surface, traffic pattern, speed, load, construction zones, other idiot drivers, you name it, I have probably driven in it.

If you drive with reasonable care, are always alert, use caution, and remain aware of what is going on ahead and around you at all times, I just can not see any need ever to deploy an exploding snot covered skirt to stop

Perhaps I am not fully understanding your concept, what advantage would your system have over modern day braking systems?????

I would just:

1. Drive a car with bigger/better/well maintained brakes and tires

2. Increase my following distances

3. Slow down

4. Stay alert

5. Drive defensively

If you do all of that you won't need a mucus laden plow with thermo-vacuum pulse jet retrorockets.

It would also be a lot cheaper.

I seems that I did not make it clear, as usual.

Braking (Decceleration) is measured in "g"s.

A car with tires capable of a CoF of 1.1 will brake a maximum of about 1.1g, no matter how good is your braking system.

If the atmospheric "Push" on the 1000 Kg car is of 24,000 Kg-force, then the braking could be as high as 24 g (You'll need to beef up your standard brakes).

This is an absolutely deadly decceleration.

The complete study of one scenario where all vehicles use this new brake is too complex. And much more complex if only some vehicles use it. It puts a new cause for accidents in the road.

The reason why I spent an excessive amount of time studying and designing this brake was my own research in real deadly accidents.

Practically always, the poor guys had enough time to see the Death coming. As evindenced by the usually long tire marks in the pavement. What if they had had a brake able to stop the car within these marks?.

Not so clear. The problem is of course the vehicles behind you.

It would be necessary to make a detailed study of all possible types of accidents. I would enjoy to see people in this thread considering it.

The final overall results could be possitive or negative.

The brake is really feasible.

BTW. The people that think "This is never going to happen to me" because they deem to be very good drivers, are a little silly.

Chorete

Well, I may not have made myself clear, either.

I submit to you that the brakes are not the problem (almost all of the time); the driver is the problem.

Your solution is to fix the brakes.

Mine is to fix the driver.

You wrote, "The people that think "This is never going to happen to me" because they deem to be very good drivers, are a little silly."

If they are a good driver then the risk of an accident drops considerably. Conversely, I don't care how good your brakes are, you can't fix stupid.

Also, if you really want good brakes, look at Formula 1. These cars stop with a braking force in excess of 4 Gs.

The last time I started having thoughts like this, I realized that I had my hat pulled down too tight around my head and it was cutting off the blood flow to my brain.

"BTW. The people that think "This is never going to happen to me" because they deem to be very good drivers, are a little silly."

I think you are a LOT silly. Your proposals are beyond comprehension.

Have one for me, whatever it is.

Many modern super cars (and even high performance sports cars) are fitted with ceramic brakes and even air brakes that produce a surprising increase in braking speed compared to standard disc brakes.

These are viable and proven solutions on both modern cars (and in the case of air brakes in aircraft also). Perhaps this would be a better area of study (especially if you want to try and get your ideas into the notoriously difficult automotive market). Very, very few technical and safety issues and only a slight drop in braking force compared to your ideas.

Well, I think it would save some people, but it would kill more.

What do you think?.

Well I wouldn't close with that during a presentation if you plan to try and market it.

6º Have the heaviest parts of your car spring loaded to the Chassis and shot them up at danger, braking with the wheels.What about the destruction caused by heavy stuff falling from above?.

7º The same but shooting forwards. Similar problems. No need to use the brakes.

I just had the mental image of two cars during a head-on collision ejecting their engines at each other.

Most people incorrectly believe that those big disks and calipers make a super car's stopping distance shorter than your Buick.

Nothing can be further from the truth. The factors that determine stopping distance has more to do with the tires and their compound. Really sticky tires do the lion's share of the work. Suspension, brake bias, and weight distribution do the rest.

The only advantages to big brakes and ceramic rotors and pads are their ability to repetitively brake again and again without incurring brake fade and/or boiling away their brake fluid.

You can put very sticky tires on any car and get much better stopping distance, but the cost is ridiculous and chances are you loose wet weather traction and stopping power. A lot depends on how your suspension is tuned, as well.

To try to answer your initial question on "how to increase the effiency of a brake" and disregard the rest of your post - I will relate an 'experiment' we had at my previous place of employment - from my understanding at the time' the project was considered as propietary and to be confidential.

Therefore, since I am not currently employed there for over a year to the present, I feel that I can disclose only the basic concepts of that endeavor.

It was named the 'Drisk', which by the name kind of self explains itself, was a combination of a 'Disk' rotor cast together with a 'Drum' style alloy assembly, the purpose of which was to attempt to bring together the best of both worlds.

To best describe it best, imagine a drum brake with a disc rotor and caliper shoes in one.

As far as I was allowed to know about this concept at that time, was that our lab was trying differing alloys, (differing combinations of nickel and aluminum and copper -molybdinum with other exotic composites, etc.), and heat treating and rapid cooling processes over a duration of cycles in our furnaces and cyrogenic atmospheric clean rooms.

Then we would break apart the samples and prepare them for analysis in our lab to see how the materials stood up over the extreme conditioning cycles.

As far as I am aware of, this was a development of one of the 'Big 3" N.A. automakers, ^{me thinks it was Ford} and they were to be responsible for 'real world' testing including some endurance and racing duty cycles.

Then the whole idea was never mentioned again, so I don't know if the process proved itself out through testing, cost/benefit analysis. or whatever.

I tried "Gooooooooooogling' "Drisk brakes', but nothing came up besides disk brakes and associated parts and repairs. (I have thought that the idea had some promise of concept.) - Loupy.

Wouldn't a "Drisk" require a "Dire" of exceptional traction to apply the farce to the ground?

"Dire Straights" - I'd better get my front end alignment checked ASAP - too many POTHOLES. (and while I'm in the shop, I'll get my Drisks checked out as well) - Loupy

If the dire goes dflat from dloss of the dair, I would have to say drat, drat, drat, that damn drisk has made me drink.

"drat, drat, drat....." - that's the very same noise my 'dires' make, when driving over those stupidly placed, insane embedded and raised/embossed chevron road speed reducing bumps in safety zones, (like in front of schools, hospitals, homes for the aged, police stations, etc.) whilst driving at speed.

T.G. I've got my new improved Drisks™® installed just recently, in order to stop safely enough in time to slow down and take proper aim at all those drunks, wandering onto the roadway . - Loupy

Get racing tires made from a softer compound. I had a pair once and the just happened to save me twice. Once was a virtually instantaneous lane change at 80mph. On the down side, they didn't last a year. Everything's a trade off.

Drive a hybrid car then you can add regenerative braking to your conventional brakes.

Alternatively drive cars on rails then you can add magnetic brakes as used by modern trams. (I've been in one when it did an e-stop, you've never seen so many people in the front carriage).

So you think only number 5º is farfetched

Some cars now have automatic braking activated by sensors like reversing sensors: what about combining that idea with an air bag that deploys out of the front of the vehicle.

As usual I seem not to explain things properly.

I should not have called my brake this way but an emergency stop system to be used once in a lifetime, just as airbags.

People forgets that no matter how good is your brake it is limited by the maximum friction of tire/road.

Somebody mentioned F1 cars having a friction of 4.0. I believe that the figure is rather 1.5.

My system has a virtual friction of 16.0 to 24.0.

So we are in a different game.

My braking proposed schemes are, of course, a joke, except the last one, which is crazy but feasible.

I loved the idea of the pogo stick.

Also the idea of the fullbody airbag for the car is excellent though a little bit farfetched.

Unfortunately nobody addresses my main question about what would happen if the power of all the car emergency brakes were increased from 1.0 (Standard efficiency) to 24.0. Stopping distances would be reduced to a few meters.

Would statistics show less or more deaths?.

chorete

Just another crazy suggestion - by some electrical / electronic system - switch from forward to revers e gear???

As someone has pointed out - ultimately it is the quality of tyres that really matter.

Use wider tires to increase contact patch. Install ceramic pads. And as a last resort use a heavy chain around the wife as an anchor.

I browsing through the net for magnetic brakes. It is used on trains. But why is it not used in cars for regular use- as a non-contact braking system. It will minimise/ eliminate wear and tear of braek liners. I want to sincerely understand from experts - why this is not adopted.

Weight, cost, and heat.

Stopping a car is all about converting kinetic energy into some other form of energy, i.e., heat.

Magnetic brakes would weigh far more than a conventional disk and increase complexity, which translates to a higher probability of failure over the life of the car.

A train has the luxury of a large amount of space to mount large components, huge reservoirs of energy to drive systems, and the ability to carry huge weight. A car does not.

Money! Current standards require auxiliary braking systems on many emergency vehicles. Telma retarders were used by some of the vehicles in our fleet a few years back. They dramatically reduced the replacement of brakes on the vehicles, but the trucks did not stop any faster, because of the limited friction between tires and road. And the cost of retrofitting was huge, because to make an effective magnetic brake required large amounts of electricity fed into a large copper windings. This had to be supplied by large expensive batteries that would be maintained by large expensive alternators. All of these components cost money. Especially the components made with copper.

I wonder if it would be possible to design a magnetic braking system with aluminium discs and magswitches instead of electromagnets.

The retarders relied on switchable electromagnets restricting the cast iron disc from spinning with the drive shaft. The magswitches might be able to be substituted for the electromagnets, but the disc would still need to be iron to react to the magnets.

Neither copper nor aluminium are magnetic as such: but, try dropping a magnet through a copper tube. The changing magnetic field induces eddy currents in the copper and the current opposes movement of the magnet.

That's how the brakes on some fairground rides work: fixed permanent magnets on the "cars" which move either side of vertical aluminium plates towards the end of the track.

This ride also has plates at the start of the track which pop up after the launch just in case the cars don't go over the top.

Thanks. I now have to try that.

Yes, no.

The big problem with magnetic brakes is they will not stop you, only slow you down. You need a set of conventional brakes to do that, but magnetic assist is possible.

However, what is possible is not necessarily practical.

Stopping quickly or in the shortest distance is much less about the brakes than the tires. Small brakes will stop a car in X feet. Putting larger calipers and brake rotors will not change that stopping distance, but it will allow you to perform that stop repeatedly without boiling away your brake fluid or warping your brake disks. Same applies for braking down hills while towing a trailer.

Bottom line is, magnetic brakes will not make the car stop sooner. Just about any braking system has enough power to lock up the wheels, so the actual brakes are not the limiting factor.

Thanks AH.

I was really responding to this part of Bob's post:-

And the cost of retrofitting was huge, because to make an effective magnetic brake required large amounts of electricity fed into a large copper windings. This had to be supplied by large expensive batteries that would be maintained by large expensive alternators.

One of my friends is a keen carpenter and bought one of the feathering boards from magswitch. The way they work is astonishing: you can hold the unit up to a filing cabinet, and feel no magnetic force at all; turning the knob/switch is effortless, but, then there is no way you can pull the thing off the cabinet; undoing the switch takes a little more strength (I only really noticed because I was trying to work out how the thing worked), but then the unit simply falls off the cabinet. They only use permanent magnets, so, require no power.

Everything in your post is still of course valid.

Your response is exactly the results we had with 23 units. Great savings in brake wear, not stopping distances.

Finally!. An excellent well thought answer.

So I am right to have sent this project to the Never Files. I am pretty sure that, using my design properly developed, cars would brake at 16-24 g. But even so, there are so many problems that, as you say, the system is not worth spending much more design time.

Thanks

Chorete

Want to make a real difference? Become a driving instructor. The life you save may not just be your student, but may be your own, too! ;-)

Remember, good drivers get hit by bad drivers, too.

Then you can search around for your eyeballs when they fall out, and pop them back in.

They'll still see you coming.

I am not very happy at not having been able to solve this problem.

We, engineers as a profession, have changed the World during the last Centuries, and now it is our duty to try to solve the serious problems we have created

Let me try for a second time something crazy, farfetched and stupid, but practically feasible.

Pease check my elementary calcs, I am nearly always mistaken

See if we can use greatly "diminished" ejection seats.

Assume a car at 120 Km/h, aprox 33 m/s

Suddenly the driver sees a deadly obstruction at 100 m.

At a response time of 1.5 s, he has travelled about 45.5 m, so he has 44.5 m left

Let us assume, for simplicity that "g" = 10 m/ s2 and that we have a brake capable a decceleration of one "g". The car will hit the obstacle at about 14 m/s, about 50 Km/h. A dangerous speed.

Our seats would have a rocket system capable of:

1º- Vertical lift at about 2-3 g, after explosive release of the roof. As soon as the seat clears the car's roof, the lift is switched to one "g" just to maintain it hovering at a few meters over the surface.

2º- Horizontal rearwards push to deccelerate it just enough to stop before hitting the obstacle. In our example, 1.123 g.

3º- At the moment of complete loss of forward velocity, the system should be capable of a soft landing of the seat.

4º- As it is not a good idea to land just behind the crash zone, the system should be capable of deviating, at a sufficient elevation, the seat to one side of the road before landing.

All this would have looked excessively comic-ese a few years ago. Now it looks very feasible, although expensive. The means to do it exist today..

The deployment should be automatic, with the need to concentrate on solving the control problems. A lot of Artificial Intelligence would be needed

The worst part seems to be the automatic deviation to one side during flight. Ejection and braking seem to be single tasks.

For example: Danger of hitting buildings or trees in the side deviation path

As the rockets burn mostly in the doomed car's swept area, there is no danger of harm to persons or property. Except in the deviation path.

chorete

No, this might not be so crazy, farfetched and stupid. I think I have seen something like this before.

Is this the one where the Coyote decides to mount the ejector seat on a rocket, and eject just a little bit at just the right moment (as you suggest), to finally catch the Roadrunner?

As I recall, it didn't work too well for the Coyote.

Don't eject under a bridge or in a tunnel.

How about this system installed in a 15 passenger van?

A real 4th of July spectacular.

Chorete; here's something for you to to munch upon, while we all await for your next post: http://www.archinode.com/Archcar.html - Loupy. Bubblewrap anyone - all you can carry away and apply with duct tape.

MIT is one of the best concentrations of human intelligence. I used to have some friends there.
Now they join their best mechanical designers with the best Architect in curved shapes to get the best car for the Future.
But inventiveness is a delicate flower that grows well in the wild forests and not in sophisticated greenhouses.
Joining the best brains in a single project does not usually produce the best results.
Take this Car for the Future. They start by defining a box to contain two people seated side by side and another two (Or one) passengers seated just behind them.
This is a prerrational decision and this is probably where they make their first mistake.
The definition of what is a vehicle to transport people and things is as old as the invention of the wheel.
I am pretty sure that from the very beginning in Mesopotamia, people decided the dimensions of a vehicle, specially the track width.
This is a mysterious number (Track width) that has been kept practically unchanged since then, deciding the dimensional geometry of Cities and roads
Even MIT guys cannot get free of its spell.
The "Magic" 1.5-1.7 meter, was later translated to railways. And to everything else.
But in a completely "Rational" design of a land vehicle to transport people the modern designer must ask himself if the side by side seat layout is only a human desire or a real necessity.
Needless to say that I prefer to have passengers to my side and not ahead or behind me. But shall I impose this desire on the designer's mind?.
A large frontal crossection or width is a serious impediment to efficiency not only by increasing the drag, but even worse, by increasing the surface of thousands of Kilometers of roads.
A rational design for two people plus luggage should come to a vehicle of 0.65x1.50x2.00 meters.
This is what I designed and built in 1950 just after leaving Engineering School.
Spain was still living in the aftermath of devastation of the Civil War.
There were scarce cars and roads were just a long file of potholes.
I thought that we were in a good position to start a new philosophy of "Designing for scarcity".
Soon, the facts showed that I was absolutely wrong and that I miscalculated the frenzy of the common people to acquire goods as large as possible and to waste energy.
But it seems that time is working in my favor. There are signs that waste of Prime Materials and Energy should no longer be allowed
The Tiny Car I made had so many engineering problems, that up to date, nobody has solved all of them.
The worst is that due to its intrinsic narrowness it must lean in the curves.
And to do this in a safe way it needs complex tilting mechanisms.
A group of dedicated engineers and inventors has been lately working hard on the subject. But, up to date, nobody has evolved a perfect design.
So, as you can see, the Car of the Future would not be the MIT's one but these very narrow vehicles, invented and designed by intelligent individuals, not rich teams of engineers- architects.
BTW. One of the best conceived of these very narrow vehicles, Narrow Streets designed by Roy Gardiner of UK has recently lost a great opportunity of being mass produced in a Spanish factory ( Previously making Land Rovers and Suzukis) due to rampant political corruption A real pity!.
Being, by historical hazard, a pioneer in this Field, my opinion is that these new very narrow vehicles should be designed to avoid the sense of being a depreciation of the automobile.
The automobile is the clear descendant of the carriages of the nobility. (This is why the present feeling of "My car, my castle")
But, in the same way that a modern motorcyclist does not feel any shame in front of a Ferrari or Rolls (Copying from the ancient Cavalier on horseback)., people in these new vehicles should not have any sense of inferiority, simply because they'll be driving something superior in many aspects
PS. Do not mention what to do with heavy trucks!. Simply: They should not be allowed in the roads. Long range transportation should be by Rail or Sea.
Local delivery: To be studied. For example, delivery tubes and so.
Nevertheless, the study of a mixed traffic of narrow and wide vehicles is very interesting

As I read your lunatic ramblings, I have come to the conclusion that:

1. Your ideas are not practical

2. Your ideas are downright laughable

3. You must have a strong underlying desire get attention, even if it means ridicule.

I wonder why you can not put forth a practical solution to some real problem that might benefit mankind?

Dear Lyn.

Who cares if I am emotionally out of balance? Ideas should be judged by themselves.

They should be classified by their innovative base. To decide if they are practical or not is extremely hard. Only the pass of time will decide.

I sincerely believe that this time you may be wrong.

The idea that automobiles should be very narrow has been adopted by a lot of very good designers.

The mechanical problems to be solved are overwhelming, but they keep working hard and some of them are very close to mass production.

Please Google Yahoo Groups Tilting and from there you can reach other URLs and see the enormous amount of work being done on the subject.

You would like to see some idea in favor of Mankind.

OK. Here you can see one.

Forest Fire Fighting Machine.

But as this thread is now too crammed I will try to open a new one.

Thanks for your criticism, it has been good for me. For example I have seen that my Limpet Brake is not practical and that the Bolonkin bags do not float in the air.

chorete