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model T conversion help please

2243 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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You have no compression braking in an EV, so it's a soapbox derby car going down 600 feet - pretty much totally faded brakes and a safety hazard, if not death trap at the bottom with your escarp-go. Your use model requires regen, which also substantially reduces battery size.

All if your choices for your build are horrible. Carry on, eh.
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The Niagara Escarpment is a cliff. It's what Lake Erie falls off of (Niagara Falls).

I don't care if it has carbon fiber discs from a Lamborghini, brakes work by dissipating energy (potential and kinetic) as heat into a mass (the rotors) until the temperature rises to a point where there is no more heat sink to dump into (brake fade), and riding them down a cliff with ZERO compression brake is reckless by design and a massive liability problem, imo. The mere fact that this is now an awareness makes ignoring it likely negligent.

I believe the contraption being proposed, being a public conveyance, also has to be signed off by a PE. Good luck finding one that will sign off on no other form of braking down a 600 foot cliff other than riding the brakes.

And, yes, you can plug brake...down a hill, which means a LOT more/heavier battery, and even more potential energy to dissipate down the cliff AS HEAT.
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All of your pals are using compression braking. Nobody is throwing it in neutral and riding the brakes down a 600 foot hill. There's no question you can stop from 30 mph. The question is riding the brakes, as if in neutral, all the way down the escarpment and THEN being able to safely stop from 60mph (runaway condition).

Now you are talking about regen in your posting - not with a DC brushed forklift motor. You can plug brake, but that's a bigger battery being carried, which increases the plug braking need, which increases the battery size, which...

Then you have to get back up the hill. More battery needed...
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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.
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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...
According to Duncan's fairly correct energy calcs, you'll need a 12kW oven element to dump into, then...

Lets see...240V oven, that's 50A. Make that two or 240V.

Yeah, bicycle, lol.

Meanwhile, find an Ontario Professional Engineer who is willing to work with you and sign off because it's illegal to transport the public in a homemade contrivance that has safety implications.
The resistor needs to dissipate ~12kW if Duncan's assumptions are correct (they're in the ballpark, imo) - about the size of the heating element in a household electric furnace...
Or...tow a trailer full of household hot water heaters and have 400 gallons of hot tea at the bottom of the escarpment.
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