Can you please tell me what were the reasons for giving up this idea?There are many good technical reasons why this is a bad idea, and that's why it is uncommon. This has been tried with a gas engine as an assist device for an electric car, and while that's a bad idea I can see why people would want it... but why would you want an electric pusher?
It's unstable.Can you please tell me what were the reasons for giving up this idea?
Rear wheel drive vehicles are not hinged in the middle like the combination of a car and trailer, so they are driven by their own wheels, not pushed from behind - that's the important difference. Also, the rear wheels hold up about half the weight of the car, so they have traction; a trailer's tires carry only the trailer weight. The situation is very different.Some vehicles have front-wheel drive, others have rear-wheel drive.
We can say that they are pushed from behind.
True - but the result in the real world is not very much worse than towing a normal trailerRear wheel drive vehicles are not hinged in the middle like the combination of a car and trailer, so they are driven by their own wheels, not pushed from behind - that's the important difference. Also, the rear wheels hold up about half the weight of the car, so they have traction; a trailer's tires carry only the trailer weight. The situation is very different.
if you have extremely low drive force, and drive only on good surfaces (no ice or even rain), sure.True - but the result in the real world is not very much worse than towing a normal trailer
Towing things which are not driven is a very different situation... and even then it is not as stable as a single vehicle, but of course it's not a problem when done properly.Its more unstable than just a car - but I have towed all sorts of things for a lot of miles - just take care and you will be OK - most of the time
True. And an excellent illustration of an articulation mechanism - thanksThe only 'common' example of a road vehicle driving from the 'trailer' that i can think of is an articulated bus. They have a large 4 wheel bus for the front section, with a 'trailer' on a single axle that contains the engine and drive wheels. The connection between them is a solid engineered piece, Its nothing like a car trailer hitch.
With just a ball hitch, yes. Even the buses have problems in low-traction situations - articulated buses occasionally jackknife themselves as they try drive up hills in ice and snow, when the rear wheels of the front section slide sideways due to the force from the rear section. Currently in Canada transit operators are buying double-decker buses instead of articulated, despite the many problems of headroom and requiring people to take stairs, because the articulateds are such a pain.Trying to do this on a car is utterly stupid. It'll be unstable and difficult to drive, let alone pants shittingly terrifying if you were dumb enough to try drive it at highway speeds.
In the world of people who build this kind of crap, I think "it worked great" should be interpreted as "no one died"."Push Trailers" were all the rage 10-15 years ago for DIY EVers. Few got built.
I heard nothing but positive experience with them, but it might have suffered from evangelical blindness that many early EVers blathered on about.
But a trailer of any significant weight legally and rationally requires its own brakes, so the pushing force on the hitch is small. And even then, people lose control with trailers.It's no different than braking with trailer behind you.
All of this is about assisting an EV with some sort of trailer... but Pisoila wants to build a trailer with an electric motor. We still don't know why.A battery trailer is a poor solution in my eye. You're paying for all this extra capacity that you use a few days a year. No point. You'll never break even. Just rent a truck.
Towing a generator is another idea. It avoids the safety issues of a pusher trailer.
I saw a couple of pusher trailers that were literally just the front of a FWD car, cut off before the windshield. It has the advantage over a generator trailer in that you're not doubling up on the generator mass. It's just combustion to wheels.
Agan... why?I want a car trailer as small as possible but which to be equipped with an electric motor and to push the car.
Whoa whoa whoa. Let's not jump to conclusions. We have no information about what happened to all those trailers and the vitality of their owners. Only that while they were alive and still using them, they were highly regarded.In the world of people who build this kind of crap, I think "it worked great" should be interpreted as "no one died".
I dunno, a tent trailer doesn't have its own brakes, and plenty of times is loaded to 1-2 tons. Seems well within ability.But a trailer of any significant weight legally and rationally requires its own brakes
Hmm, yes, but, that's perhaps like saying "A t-shirt is not designed to be worn backwards!" true yes, but that only introduces the topic, it's not sufficient to say it's catastrophic to do it. Maybe, like a t-shirt, it's perfectly fine to push on the rear frame or on the pin or or on the ball, just as it's perfectly fine to pull on them. I myself don't see much of a difference or things that would be true one way or the other... but I don't have a good understanding of why it even might be an issue.so the pushing force on the hitch is small. And even then, people lose control with trailers.
Yes this is a weird use case.All of this is about assisting an EV with some sort of trailer... but Pisoila wants to build a trailer with an electric motor. We still don't know why.
Not legally behind a car in Alberta. And if you try to stop a two-ton trailer with a two-ton tow vehicle and only the tow vehicle's tire braking, you will have half the acceptable emergency braking ability and poor stability while braking. Lots of people do it, but lots of people do lots of stupid things.I dunno, a tent trailer doesn't have its own brakes, and plenty of times is loaded to 1-2 tons. Seems well within ability.
In other words, it's nearly useless and a terrible way to achieve more range. It might even not extend range at all.Again, performance-wise, you don't want any hard accelerating. And you definitely don't want it to be your main source of propulsion. And you don't want it to be something you use in situations with low traction.
But those are easily accommodated by only using it to maintain highway speed for longer range on the highway.
Not really. The dynamics of pushing forward on the ball and pulling back on the ball are very different. I can get into why... but so far I don't see a point. It's like getting into the details of a university physics course in a conversation started by the question "do you have to apply force to something to get it to move". Umm... yeah, and when the conversation gets way further ahead we can get into the fine details.Hmm, yes, but, that's perhaps like saying "A t-shirt is not designed to be worn backwards!" true yes, but that only introduces the topic, it's not sufficient to say it's catastrophic to do it. Maybe, like a t-shirt, it's perfectly fine to push on the rear frame or on the pin or or on the ball, just as it's perfectly fine to pull on them. I myself don't see much of a difference or things that would be true one way or the other... but I don't have a good understanding of why it even might be an issue.
Is it? I still don't know what the use case is. Is the vehicle driven by an engine, and if it is then is the engine on while the electric trailer is driving? Is the vehicle electric, and the electric trailer is another whole EV slaved to it? Where does the electrical power for the trailer's motor come from - a battery on the trailer, a generator on the trailer, the tow vehicle? None of these scenarios make sense, but why the idea is bad depends on which nonsensical design is being considered.Yes this is a weird use case.
Well, in one sense, it's building an EV with nearly zero modifications to the original vehicle, and zero conversion downtime.
That I agree with!Seems to be the worst tradeoffs, towing a trailer around in town all day long is my version of hell.
Yes, but that's an extreme situation. A pusher trailer is not going to be 2 tons. Braking with a trailer is a separate issue that can be resolved or addressed on its own.And if you try to stop a two-ton trailer with a two-ton tow vehicle and only the tow vehicle's tire braking, you will have half the acceptable emergency braking ability and poor stability while braking.
Not sure if you quoted the wrong part, but, an ICE pusher trailer is certainly going to be useful and massively extend range. EV pusher trailer, yeah, I'm having doubts.In other words, it's nearly useless and a terrible way to achieve more range. It might even not extend range at all.
I'll accept that there's unknown unknowns for me here, but I don't see how it's different than towing a trailer normally and braking.Not really. The dynamics of pushing forward on the ball and pulling back on the ball are very different.
I can't see anything different than towing a (much heavier) trailer, towing or braking downhill, with the weight of the trailer shoving the vehicle forward.For now, just think about the possible direction of the force on the ball, compared to the direction of motion of the tow vehicle and where it is pointed. Think about the vertical component, too.
Indeed.Is it? I still don't know what the use case is. Is the vehicle driven by an engine, and if it is then is the engine on while the electric trailer is driving? Is the vehicle electric, and the electric trailer is another whole EV slaved to it? Where does the electrical power for the trailer's motor come from - a battery on the trailer, a generator on the trailer, the tow vehicle? None of these scenarios make sense, but why the idea is bad depends on which nonsensical design is being considered.