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Who's (most) right as of right now, with current technology?

  • My dad

    Votes: 1 11.1%
  • Me

    Votes: 3 33.3%
  • Neither

    Votes: 5 55.6%
  • Both

    Votes: 0 0.0%
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Discussion Starter #1
Once again my dad and I are in a debate. It's been a while but I'm sure some guys around here remember the last one. He thinks they should make an electric car with a motor at each wheel; 2 propelling the car and 2 as generators... effectively creating perpetual motion.

I disagree... the friction of the bearings, internal motor parts, wind resistance, road resistance, the resistance of going uphill will deplete the battery, as well as accessories (radio, HVAC, idiot lights). Not to mention that some of the energy will be dissapated as heat energy.

I think a diesel-electric or a gas-electric setup (think an automobile sized setup like in a locomotive) would be much more practical. I've seen some guy do an AMC Eagle/Concord up with a briggs engine and a generator, and a motor powering the wheels out back, just too lazy at the moment to do an online search.

What's your take?

Thanks, Matt
 

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Race The Truck
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ChevelleSS_LS6 said:
Once again my dad and I are in a debate. It's been a while but I'm sure some guys around here remember the last one. He thinks they should make an electric car with a motor at each wheel; 2 propelling the car and 2 as generators... effectively creating perpetual motion.

I disagree... the friction of the bearings, internal motor parts, wind resistance, road resistance, the resistance of going uphill will deplete the battery, as well as accessories (radio, HVAC, idiot lights). Not to mention that some of the energy will be dissapated as heat energy.

I think a diesel-electric or a gas-electric setup (think an automobile sized setup like in a locomotive) would be much more practical. I've seen some guy do an AMC Eagle/Concord up with a briggs engine and a generator, and a motor powering the wheels out back, just too lazy at the moment to do an online search.

What's your take?

Thanks, Matt
LOL, They have both I believe in popular science is where I saw them. the debate as to which is best is still undecided. which one will be used the cheaper one like anything else.

Craig
 

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You got a leaky spark tube...
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killerformula said:
I think you should stop debating your dad and move out on your own.
Ha ha, that's funny. Poncho is right, perpetual motion isn't going to happen. You can do a little experiment yourself and show that it won't work. Buy two small electric motors and connect them to each other. Hook a small batter up to one and watch it run, measure the voltage at the going into the motor then measure the voltage coming off of the one acting as the generator. The output is going to be significantly lower.

Is it possible that your dad just says stuff like that to get you to think? You know, playing the Devils Advocate.
 

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Ford Man to the bone!!!
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If he disconnects the generators during acceleration and accelerated slowly, then used the generators as his ONLY braking, then he could replace part of the battery juice. Using gears to spin the generators fast enough and stopping quicker could be the answer in order to completely replace the juice. However, it might mean starting out like your grandma and braking like an F1 car on a road course. What a ride. In theory the power used to begin moving the car if applied slowly (Low G's) could be replaced by the rapid slowing of the car (High G's). Whatever juice/energy is lost to heat/friction/wind resistance while starting and cruising must be regained by stopping faster.

Tell him to create a closed system with a battery,an electric motor,a real heavy flywheel (to simulate a vehicle) and a generator/Alternator. Attach a tach to the flywheel and time how long it takes to reach a certain speed. then kill power to the motor and use only the generator/alternator to stop the flywheel. The proper ratio of motor size to flywheel could be achieved using a small 12 volt motor and a flywheel off a diesel truck. He could hang the flywheel with starter gear ring down in a tub of heavy weight oil to simulate air resistance. An adjustable gear ratio transmission attached to the gen/alternator would be needed to get the most from the stopping effect. Start stopping at 300:1 and progress to 1:300 as you reach a stand still. Measuring the power lost and then gained from this would mean starting and stopping several times.


OK... tell your dad he got me too. Tell him thanks, it was good brain exercise. :thumbup:
 

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You got a leaky spark tube...
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You'd still never be able to recoup all of the power used during the accel/cruising portions of the drive. Also, since an electric motor can work as either a motor or a generator you could make all four motors act as generators during the braking phase and use only two motors (to conserve energy) for the acceleration/cruise phase.

FordMan1951 said:
If he disconnects the generators during acceleration and accelerated slowly, then used the generators as his ONLY braking, then he could replace part of the battery juice. Using gears to spin the generators fast enough and stopping quicker could be the answer in order to completely replace the juice. However, it might mean starting out like your grandma and braking like an F1 car on a road course. What a ride. In theory the power used to begin moving the car if applied slowly (Low G's) could be replaced by the rapid slowing of the car (High G's). Whatever juice/energy is lost to heat/friction/wind resistance while starting and cruising must be regained by stopping faster.

Tell him to create a closed system with a battery,an electric motor,a real heavy flywheel (to simulate a vehicle) and a generator/Alternator. Attach a tach to the flywheel and time how long it takes to reach a certain speed. then kill power to the motor and use only the generator/alternator to stop the flywheel. The proper ratio of motor size to flywheel could be achieved using a small 12 volt motor and a flywheel off a diesel truck. He could hang the flywheel with starter gear ring down in a tub of heavy weight oil to simulate air resistance. An adjustable gear ratio transmission attached to the gen/alternator would be needed to get the most from the stopping effect. Start stopping at 300:1 and progress to 1:300 as you reach a stand still. Measuring the power lost and then gained from this would mean starting and stopping several times.


OK... tell your dad he got me too. Tell him thanks, it was good brain exercise. :thumbup:
 

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Ford Man to the bone!!!
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Blazin72 said:
You'd still never be able to recoup all of the power used during the accel/cruising portions of the drive. Also, since an electric motor can work as either a motor or a generator you could make all four motors act as generators during the braking phase and use only two motors (to conserve energy) for the acceleration/cruise phase.
He got you too, huh? I did not talk much about cruising because that would mean eating the dash during braking. :pain: Just drive it like you stole it. Mash the gas until you have to mash the brakes.

As Matt's dad said, "Think about it!."
 

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Ford Man to the bone!!!
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OK... let us look at what you said...

First:
Blazin72 said:
...since an electric motor can work as either a motor or a generator you could make all four motors act as generators during the braking phase and use only two motors (to conserve energy) for the acceleration/cruise phase.
Using only two motors will use less energy but will produce less work. So... he would accelerate slowly and using all four to stop he would stop faster. Might work. Although we might need more stopping than that. How about we use 1 motor to start and 16 to stop. We need to do a little lab work to find out the best results. You got any 12 volt motors we can use to build a prototype? :mwink:
 

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You got a leaky spark tube...
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I wasn't suggesting using four generators (vs two) to make the car stop faster. I was suggesting he use four generators because that would generate more electric current than using two would.
 

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I think we all out to go out and work on our rides. Matt's dad is like me with my boys...knows which button to push!!! Ha, Ha This is what happens when you forget to take out the trash.

Good to think about, but I don't have enough time to work on the one I got much less to start a prototype.

Have a great day!

Pappy
 

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EFI Rules and Carbs Drool
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Your thinking of the Toyota Prius.

Oh wait, you can recoupe energy with a Prius, just not your money :welcome:
 

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Another disagreement with the old man

I think your all Missin the Point here ! Electric motor's are Almost Instantaneous Torque . Hybrids Gas / AKA electric Car's Could have, the Potential Too Come out of the Hole Much faster than Conventional Gas Engine automobiles. Letts Stay Focus'ed here on more important issue's ? Like What would make a Better E- Ticket Ride ? Solveing Perpetual motion Would just take the fun out of every thing ! He. He, Ha, Ha, Haaa, Snicker , Snicker :D ! Sean
 

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ChevelleSS_LS6 said:
I disagree... the friction of the bearings, internal motor parts, wind resistance, road resistance, the resistance of going uphill will deplete the battery, as well as accessories (radio, HVAC, idiot lights). Not to mention that some of the energy will be dissapated as heat energy.

I think a diesel-electric or a gas-electric setup (think an automobile sized setup like in a locomotive) would be much more practical. I've seen some guy do an AMC Eagle/Concord up with a briggs engine and a generator, and a motor powering the wheels out back, just too lazy at the moment to do an online search.

What's your take?

Thanks, Matt
Your comments are close to the real world of doing it. There was a group that took an old mail delivery van and used electric motors to power it. They were actually drag racing it to establish power parameters and capabilities.

I work with electric motors and both AC and DC variable speed drives. You ONLY need a single motor with dual output shafts to power the real axle. The single motor, when you apply power will turn the wheels. This is a better physical packaging method When you remove the power, to slow, the motor actually generates electricity. This is called re-generation and is used in industry all the time. The controller draws energy from the motor, now acting like a generator, and can use it to power other loads including providing charging power to the batteries. Using an engine-generator will provide sufficient power to keep things going.

Electric motors can produce 150% of their rated torque at locked rotor albeit they are energy hogs doing so. Some thing an engine cannot do. As the vehicle gains speed, the mass of the vehicle will help to maintain speed and lower the power requirements of the motor. During deceleration, your motor will help to brake the vehicle to a stop. Under the right setup this could make the brake pads last longer.

My $00.0000002 on this matter.
 

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The big haul trucks in the mines use an electric motor on each rear wheel. They also have a big diesel electric set to make the juice. However if this is the most efficient way to transfer power for them there might be something to be learned.
I think a good combination of several theorys mentioned here might be a starting point. Electric motors at least on 2 wheels, all 4 might be better for electric braking. So motor/generators on the wheels, generate electricity while braking, some battery storage, small constant speed diesel electric generator, and possibly a roof full of solar panels.
Now you could recapture energy during braking, have battery reserve for accelerating, generate enough power for cruising and get some free from the sun.
Now quit arguing with your father of goofy stuff and get out on your own.
 
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