# etec motors?



## major (Apr 4, 2008)

Jamie EV said:


> Anyone ever used twin etec motors at the wheel for direct drive? 10 hp each apparently at 48 volts for "hyper speed" whatever that is...
> 
> 
> 
> http://www.ebay.ca/itm/DC-MOTOR-GEN...ltDomain_0&hash=item460870b754#ht_8182wt_1398


Bad idea.


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## Jamie EV (Oct 3, 2012)

Care to elaborate on that?


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## major (Apr 4, 2008)

Jamie EV said:


> Care to elaborate on that?


That is a wimpy motor for a car even if you use two and will fall short of performance expectations or fail in short order. And it would seem you intend to try the wheel motor approach which is another bad idea. And the person selling those on eBay is an idiot.


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## Jamie EV (Oct 3, 2012)

I know I'll be sorry but I have to ask:

How do you know what my performance expectations are? How do you know it will fail? How do you know he's an idiot? 

Anyone ELSE want to weigh in on this? I'm not sure I'm getting objective feedback here.


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## major (Apr 4, 2008)

Jamie EV said:


> I know I'll be sorry but I have to ask:
> 
> How do you know what my performance expectations are? How do you know it will fail? How do you know he's an idiot?


I've been around for a long time. I know about the Etek motor. Unless you intend to convert a car and expect 25 mph with sluggish acceleration, my statement has a high probability of truth. And anybody who would post that wiring diagram is an idiot.

You ask for advice. Take it or leave it. It's your project. Good luck


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## Jamie EV (Oct 3, 2012)

Using parallel versus series as a speed control is not idiotic. In fact it's how the ElectroVette from GM was wired initially. I suppose you know better though. After all you live in an age of Mosfets and IGBT and don't have need of creativity...

Your statement about the required hp might be correct but since I've seen other 20 hp motors used in conversions, I think it's fair to ask why not 2 10 hp instead.

Does anyone else have some solid numbers on HP requirements? How much at the dogbone do I need?


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## major (Apr 4, 2008)

Jamie EV said:


> Using parallel versus series as a speed control is not idiotic. In fact it's how the ElectroVette from GM was wired initially. I suppose you know better though. After all you live in an age of Mosfets and IGBT and don't have need of creativity...


I don't have to be creative to know that diagram is not parallel versus series switching.



Jamie EV said:


> Your statement about the required hp might be correct but since I've seen other 20 hp motors used in conversions, I think it's fair to ask why not 2 10 hp instead.


I made no statement about hp.


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## Jamie EV (Oct 3, 2012)

I beg your pardon, I didn't look hard enough at the diagram, from first glance it looked like series parallel...which would work btw...although not great.... his would drain batteries unevenly...mind you I don't think he built the motors....I doubt he's got the where with all.


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## Jamie EV (Oct 3, 2012)

You made no statement about HP....ok....but you said they were whimpy motors....if not in HP, what do you mean? Please....I crave your condescension.


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## muffildy (Oct 11, 2011)

hes talking about the problem of motors like etek having magnets which can overheat and demagnatize probably.
which can be a problem if these motors are going to be used close to their peak performance for too long.
my project the pmac is mostly there to help acceleration so im not going to be relying on it to get from A to B so it should have time to cool off between uses, but i wont know for sure until i get this thing built.
those particular eteks arent very good though - their max voltage is too low so they are less efficient than the 72-96v versions of the etek style.


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## Jamie EV (Oct 3, 2012)

Yeah I saw the 96 volt versions. They look a lot more robust...not a lot cheaper than Warp 9s though...I am not disagreeing with original response substance...but I'm a peculiar sort. When someone is flip, I'm flip.

Etec would not specifically be my favourite choice either of course. 


But to the HP, am I wrong to think something like 10 hp continuous could run direct at the wheel if I paired it with another? I'm told you need about 6 hp for every 1000 lbs roughly....so 20 hp would give you approx. 3300 lbs capacity. No?


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## frodus (Apr 12, 2008)

Maybe that 20hp is what it takes to go a continuous 50-60mph, but how much do you think it takes to accelerate the vehicle to that speed? Is the motor rated for that kind of HP at that amount of time? IMHO the etek style motors are for motorcycles, scooters, go-karts.

You could use 2 motors on each wheel (8 total) and have a working vehicle that goes maybe 60mph (limitations due to direct drive with a 48V motor), that's up to you..... or you could use ONE more coupled to the original transmission and a matching controller. You'll likely spend the same amount of money getting it working and eliminate mechanical and electrical complexity.


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## muffildy (Oct 11, 2011)

dont forget that a vehicle going up a grade of 5% just about doubles the HP required to maintain speed.
30-40HP is the bare min i would build for(2000#car); 60 is more comfortable, 100 or more is pretty typical though. increase the HP if you increase the weight.
directly connecting to the wheels isnt terrible, better than hub motors, but using a transmission would be more efficient when attempting to accelerate; it will also allow you to go up steeper grades with a lower HP motor than otherwise is possible.


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## Jamie EV (Oct 3, 2012)

muffildy said:


> dont forget that a vehicle going up a grade of 5% just about doubles the HP required to maintain speed.
> 30-40HP is the bare min i would build for(2000#car); 60 is more comfortable, 100 or more is pretty typical though. increase the HP if you increase the weight.
> directly connecting to the wheels isnt terrible, better than hub motors, but using a transmission would be more efficient when attempting to accelerate; it will also allow you to go up steeper grades with a lower HP motor than otherwise is possible.


Ok I need to establish some understanding here. Do yhou mean 100 HP peak or 100 HP continuous? Big difference of course. 100 HP continuous ius a monstrous motor.


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## muffildy (Oct 11, 2011)

depends on where you live and how heavy the car is and how fast/aerodynamic or not.
if you lived in the mountains, i could see a 100hp continuous motor being necessary if your car was say 4000# or so and you drive fast and had a brick for a car.
100hp is mainly typical because of acceleration (peak)

if you had a 2000# car that was very aerodynamic and you didnt drive over 65 mph, then you would need around 12kw continuous, 24kw for going up grades, and the more HP the better for acceleration.


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## MalcolmB (Jun 10, 2008)

This motor is a knockoff of the original Etek, so quality is unknown. I used an original Etek on my motorbike at 72V, total weight 200kg, geared down around 4:1. Performance was reasonable to about 60 mph. With two of the original Etek motors running at a similar ratio I wouldn't attempt to drive a vehicle weighing much more than 500 kg fully loaded. Direct drive to the wheels won't work unless you have very small wheels, since the motor needs to rev to 3500 rpm to develop 10 hp.

You can't compare this motor directly with the series wound motors that most people here are using, as the design and thermal mass of series motors allows them to be pushed well beyond their nominal rating for short periods. If you try the same with the Etek knockoff it will quickly melt down.

You could drive a very small car with a pair of Agni motors, if you get the gearing spot on and limit the time at high current since they have very good efficiency, so generate less heat, but as mentioned their efficiency and low weight comes at a price.

Major knows what he's talking about, by the way


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## Jamie EV (Oct 3, 2012)

I never for a minute doubted that he knew what he was talking about. I didn't go out and buy the things. Just throwing that out there.


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## Salty9 (Jul 13, 2009)

Check http://www.diyelectriccar.com/forums/showthread.php?t=65753&highlight=luigi

Rikard explored the limits (and beyond) of an Agni in a Fiat 500. Interesting thread.


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## frodus (Apr 12, 2008)

Should be mentioned that Agni motors are some of the most efficient PM DC motors out there, but also some of the more expensive (usually over $1400 for one).


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