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model T conversion help please

2246 Views 34 Replies 9 Participants Last post by  Duncan
I started with a 23 T where the engine needed rebuild. I was offered this 300 lb caterpillar forklift motor ,sweet spot 1800 rpm ,series wound motor that i have mounted in the car,direct drive no clutch engine plate is shown it came from a 15 000 caterpillar forklift machine. the T nets out at 1500lb with the ice components removed original speed 35 mph at 1500 rpm. the electrics should balance out to 1500 pounds aftermarket disc brakes stop like a normal car.
I have run the motor direct drive to the driveshaft at 750 rpm on a `12 volt battery . I am anticipating 48 volts to give me just over 35 mph of 50 Km/hr this is a much as I wish to go on 100 yr old wooden wheels.
the batteries are nominal 48 volt from a bmw 130i which at 3500 lbs gave a 200 mile range. there are 8 units 4 under the floor as shown and two under the front seat replacing the gas tank ,two under the back seat cushion.
I have watched the videos from benjamin nelson, scotty vw van and garcia vw van.
nelson and scotty are using lead acid batteries.
The motor i got from a forklift mechanic who now being self employed has no time. a second tech said the same thing and a third does not want the liability. i found an octogenarian who has built 4 electric vehicles SLA and does not want the unknown liability of working with Lithium . the new crop of enthusiasts want AC motors regen and computer algorithms.
I have a main contactor, throttle box. 48 volt 12 volt converter throttle pedal and hydraulic brake pedal mounted to the front floorboard.
i bought a forklift that has a suppex motor and controller that are not compatible with a series wound motor.
I am acutely aware of the need for compatible components.
what i need is for someone to tell me what model controller to buy as well the bits and pieces. what i don't want to do is acquire bits and pieces from various sources that are not compatible. the choices are dizzying. i can sorta figure it out but lack the assurance that my thinking is correct.
I am well aware of what i can fabricate but humble enough to admit my limitations.
I live in the niagara falls canada area. [email protected] 905 9888648

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Lets have a quick look at this in terms of the energy that your brakes have to convert to heat and radiate away

600 ft - 200 meters x 10 x mass in Kg - 2,000 joules per kg
60 mph stop - 27 m/sec - 1/2 x 27 x 27 Joules per kg - 364 Joules per kg

In energy terms the 600 ft is about six times as much as the 60 mph stop

In terms of "power" the 60 mph emergency stop should take less than 3 seconds - the descent would take what 10 minutes?? - 600 seconds

So the "power needs" for the descent are about one seventh of the braking needs
for a 700 kg vehicle we are talking about 85 kW for the braking and 12 kW for the descent

85 kW is a very very low figure for power dissipation of any modern disc brake system
I would NOT expect a continual 85 kW to overheat a disc brake system

The standard for a modified vehicle here (NZ) is that it should be able to pull the vehicle up from 60 mph - SIX times in a row without fading
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If the seventh time is an allowed fade, you have no brakes at the bottom of that 600 foot hill because you are maintaining speed all the way down in your calcs.
Maintaining speed is only 12 kW - not likely to overheat any modern brakes
The total energy could overheat the brakes but its over 20 times the time period
It's 12kW applied for ten minutes. Ten glowing hot space heaters trained on that disc of metal for ten minutes.

Look at your 6x energy-needed analysis, which coincidentally plugs right in to the 6 stops NZ regs...
On that disc of metal in a nice cool 100 kph breeze

Correction on those four discs of metal in a cool 100 kph breeze
Or...tow a trailer full of household hot water heaters and have 400 gallons of hot tea at the bottom of the escarpment.
We have 2000 Joules per kg - and a 700 kg car - so 1,400,000 Joules
It takes 4,000 joules to heat 1 kg of water 1 degree
So to heat from 20C to 100C for tea is 320,000 joules per kg
So we can heat about 4.3 liters about one gallon of water (its in Canada so we use proper gallons) for our cup of tea
Sounds like a plan to me

Four 3 kW kettle elements in a five liter container
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