Electric motor with no tranny for conversion

[Peter VanDerWal]

It is technically possible to connect the motor directly to the drive
shaft, but it is MUCH more expensive and generally less efficient.

Without the torque multiplication provided by the transmission, you need
to have a motor and controller capable producing the huge amounts of
torque need for hills, acceleration, etc.

This means that you need a larger motor, a much more powerful controller
and  possibly some kind of external cooling for the motor, since it will
often  be running at low RPMs where it's internal fan doesn't provide much
cooling.  If you combine low RPMs with high torque (i.e. climbing a hill)
then you will quickly overheat the motor without external cooling.

Also, while electric motors are very efficient over a wide band of RPMs,
efficiency tends to fall of quickly at very low and very high RPMs. So
around town driving will be less efficient without the tranny.
High current and low RPMs is VERY inefficient, as well as causing over
heating problems, so climbing hills without a tranny is extremely
inefficient.

Bypassing the tranny (which usually comes free with most conversions) will
almost double the cost of the motor & controller, and possibly reduce your
range.

It's been done, drag racers frequently go this way, but most folks that
have done it wouldn't recommend it for a commuter vehicle.

>
> My wife and I are trying to figure out the necessity for having a tranny
> to
> do an ICE to electric conversion on a 65 mustang.  Is the tranny required
> for the conversion or can we have an adapter to go directly to the drive
> shaft (or rear end)?  Would the ratio (gearing?) be too low?  What would
> be
> the potential problems by not having the tranny?  It would save us some
> weight and $1000 for the adaptor plate.
> Thanks!
> --
> View this message in context:
> http://www.nabble.com/Electric-motor-with-no-tranny-for-conversion-tp17254470p17254470.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
> _______________________________________________
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[chazersize]

My wife and I are trying to figure out the necessity for having a tranny to do an ICE to electric conversion on a 65 mustang.  Is the tranny required for the conversion or can we have an adapter to go directly to the drive shaft (or rear end)?  Would the ratio (gearing?) be too low?  What would be the potential problems by not having the tranny?  It would save us some weight and $1000 for the adaptor plate.
Thanks!

[Roland Wiench]

Input your data into:

http://www.geocities.com/hempev/EVCalculation.html

and see what happens.

In the gear ratio section.  Input a 1 to 1 gear ratio and run the program
and keep increasing the gear ratio until:

The gear ratio is the overall gear ratio of a transmission gear times the
axle gear.

Run the program and increase the gear ratio until the motor ampere is at the
maximum continuous rating for the motor you are going to use.

My Warp 9 has a 199 amp continuous duty and has a service factor of about
2.0 for about a minute, meaning 200 amps x 2 = 400 amps for this short of
acceleration time.

Try different voltage and hp motors in this program.  My best results was
the highest voltage rating motor.

Also look at the battery amp vs the motor ampere.  Depending on what kind of
controller.  The ratio between these two amperes could be 200 motor amperes
while you are pulling 75 battery amps if you have a controller like a Zilla
or equal to.

>From this data, you can tell what axle ratio you would need without a
transmission or a combination of a transmission and axle ratios, for what
speed, motor and battery ampere you want to attain.

Roland


----- Original Message -----
From: "chazersize" <chazebs@...>
To: <ev@...>
Sent: Thursday, May 15, 2008 8:25 AM
Subject: [EVDL] Electric motor with no tranny for conversion

>
> My wife and I are trying to figure out the necessity for having a tranny
> to
> do an ICE to electric conversion on a 65 mustang.  Is the tranny required
> for the conversion or can we have an adapter to go directly to the drive
> shaft (or rear end)?  Would the ratio (gearing?) be too low?  What would
> be
> the potential problems by not having the tranny?  It would save us some
> weight and $1000 for the adaptor plate.
> Thanks!
> --
> View this message in context:
> http://www.nabble.com/Electric-motor-with-no-tranny-for-conversion-tp17254470p17254470.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[storm connors]

I would see what Otmar who makes the Zilla controller has to say.
http://www.cafeelectricpress.com/blog/?p=22

On Thu, May 15, 2008 at 4:03 AM, Peter VanDerWal <evdl@...> wrote:
> It is technically possible to connect the motor directly to the drive
> shaft, but it is MUCH more expensive and generally less efficient.
>
>



--
http://www.austinev.org/evalbum/1059
http://stormselectric.blogspot.com/
Storm

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[Mark Eidson]

I've been considering doing this with my 1970 Mustang using a
TransWarp9 and a Zilla 1klv with a 144V battery pack. I have a 4.11:1
differential and I could hook this motor directly to my existing drive
shaft.  This would give me 75MPH at about 4000RPM.  Since my driving
is on flat terrain this combination should be OK.  If you have steep
hills to deal with this might be a problem.  me

http://www.go-ev.com/TransWarP.html#TransWarP_9






On 5/15/08, chazersize <chazebs@...> wrote:

>
> My wife and I are trying to figure out the necessity for having a tranny to
> do an ICE to electric conversion on a 65 mustang.  Is the tranny required
> for the conversion or can we have an adapter to go directly to the drive
> shaft (or rear end)?  Would the ratio (gearing?) be too low?  What would be
> the potential problems by not having the tranny?  It would save us some
> weight and $1000 for the adaptor plate.
> Thanks!
> --
> View this message in context: http://www.nabble.com/Electric-motor-with-no-tranny-for-conversion-tp17254470p17254470.html
> Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[Randy Eckert]

You will save money and have more simple wiring because it gives you reverse
and you only need the little 3 speed,
and you still have to build something to hang the motor on any how unless
you plane on putting it over and on the rearend. you don't really need the
clutch/fly wheel

On Thu, May 15, 2008 at 9:25 AM, chazersize <chazebs@...> wrote:

>
> My wife and I are trying to figure out the necessity for having a tranny to
> do an ICE to electric conversion on a 65 mustang.  Is the tranny required
> for the conversion or can we have an adapter to go directly to the drive
> shaft (or rear end)?  Would the ratio (gearing?) be too low?  What would be
> the potential problems by not having the tranny?  It would save us some
> weight and $1000 for the adaptor plate.
> Thanks!
> --
> View this message in context:
> http://www.nabble.com/Electric-motor-with-no-tranny-for-conversion-tp17254470p17254470.html
> Sent from the Electric Vehicle Discussion List mailing list archive at
> Nabble.com.
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[Roland Wiench]

So far, nobody has mention what you need to go in reversed with no
transmission.  This requires a reversing contactor that is a double pole
contactor that is mechanical and electrical interlock, so one is off while
the other is on.  You also need a main contactor, so you can completely turn
off the positive battery  power from the battery.

The main contactor could be a two pole contactor that completely cuts off
both the negative and positive power from the battery, or use another
separate contactor on the negative side with is normally call a back up
safety contactor.

You will still need a Forward-Off-Reverse control switching mechanism which
are normally made with a cable operated straight line shifter, or peddle
shifters that can operated micro switches.

If you take too much time in the off position when shifting from forward to
reversed, you may have to precharge the controller each time you make this
change.

Another method we use for reversing some motors, is the use of two large L
frame circuit breakers that do not have the overload trips in them, making
them a enclose transfer switch.  They can be remotely operate by a motorize
circuit breaker kit, that is also electrical interlock.  The placement of
the circuit breakers with the load ends buss bar together, provides the
mechanical interlock.

Roland


----- Original Message -----
From: "storm connors" <stormconnors@...>
To: <evdl@...>; "Electric Vehicle Discussion List"
<ev@...>
Sent: Thursday, May 15, 2008 9:52 AM
Subject: Re: [EVDL] Electric motor with no tranny for conversion

> I would see what Otmar who makes the Zilla controller has to say.
> http://www.cafeelectricpress.com/blog/?p=22
>
> On Thu, May 15, 2008 at 4:03 AM, Peter VanDerWal <evdl@...>
> wrote:
> > It is technically possible to connect the motor directly to the drive
> > shaft, but it is MUCH more expensive and generally less efficient.
> >
> >
>
>
>
> --
> http://www.austinev.org/evalbum/1059
> http://stormselectric.blogspot.com/
> Storm
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>

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[Peter VanDerWal]

>  >> My wife and I are trying to figure out the necessity for having a
>  >> tranny to do an ICE to electric conversion on a 65 Mustang. Is the
>  >> tranny required for the conversion or can we have an adapter to go
>  >> directly to the drive shaft (or rear end)?  Would the ratio gearing
>  >> be too low? What would be the potential problems by not having the
>  >> tranny? It would save us some weight and $1000 for the adaptor plate.
>
> Peter VanDerWal wrote:
>> It is technically possible to connect the motor directly to the drive
>> shaft, but it is MUCH more expensive and generally less efficient.
>
> Peter is correct, but includes way to many "very"s and other adverbs.
>
> Essentially all vehicles built as EVs from scratch have no transmissions
> (electric cars, trains, buses, golf carts, fork lifts, etc.)

We aren't talking about Golf Carts, or even purpose build EVs.  We are
talking about converting a MUSTANG and connecting the electric motor
directly to the differential.
In THIS situation, the adverbs apply.

> Yes, you do
> need a bigger motor and controller when there's no transmission. But the
> extra size and weight, higher cost, and lower efficiency in the motor
> and controller is more than offset by eliminating the size, weight,
> cost, and efficiency of the transmission.

In this situation, I dissagree.
At 30 mph, the motor is going to be turning at about 1,000 rpm or less
(depends on the exact diff ratio)
Assuming a 9" ADC or equivelent, and given the lower voltage needed at 30
mph, this low RPM will only be about 65% efficient (not counting the extra
power required by the cooling fan)

Bypassing the transmission gains about 5% efficiency, but you loose 10-15%
in the motor.
At lower speeds it gets even worse.

>
> However, most EV conversions already have a transmission, so it's
> "free". The mechanical design is such that it's harder to remove the
> transmission than it is to keep it. Given that you're keeping it, you
> can save some money by using a smaller motor and controller.
>
>> Without the torque multiplication provided by the transmission, you need
>> to have a motor and controller capable producing the huge amounts of
>> torque need for hills, acceleration, etc.
>
> The extra torque needed without a transmission is about 2:1. You can get
> this by going up a size or so in the motor or controller. For example,
> an 8" motor and 500 amp controller with a transmission, versus a 9"
> motor and 1000 amp controller without one.

Assuming you never need to climb hills.  If you do have any hills you'll
need closer to 3:1 (i.e the typical difference between 1st/2nd and
4th/5th)

> Note that you will need to replace your differential gears to go
> transmissionless. A typical ICE car differential ratio is around 3:1.
> The differential for a transmissionless EV is more like 5:1.

Or 10:1 as found in many purpose built EVs

-snip-

>> Also, while electric motors are very efficient over a wide band of RPMs,
>> efficiency tends to fall off quickly at very low and very high RPMs.
>
> Yes; except that your driving time at very low and very high speeds is
> generally quite low.

Unless you drive in traffic.

>> around town driving will be less efficient without the tranny.
>
> In fact, I leave my EV in 2nd gear for almost all around-town driving,
> because it's *more* efficient than shifting.

Try leaving it in 4th, since that is effectively we are talking about.
If he goes transmissionless he won't HAVE a second to shift down into.

It's easy to win an arguement by changing the basic assumptions.




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[Lee Hart]

 >> My wife and I are trying to figure out the necessity for having a
 >> tranny to do an ICE to electric conversion on a 65 Mustang. Is the
 >> tranny required for the conversion or can we have an adapter to go
 >> directly to the drive shaft (or rear end)?  Would the ratio gearing
 >> be too low? What would be the potential problems by not having the
 >> tranny? It would save us some weight and $1000 for the adaptor plate.

Peter VanDerWal wrote:
> It is technically possible to connect the motor directly to the drive
> shaft, but it is MUCH more expensive and generally less efficient.

Peter is correct, but includes way to many "very"s and other adverbs.

Essentially all vehicles built as EVs from scratch have no transmissions
(electric cars, trains, buses, golf carts, fork lifts, etc.) Yes, you do
need a bigger motor and controller when there's no transmission. But the
extra size and weight, higher cost, and lower efficiency in the motor
and controller is more than offset by eliminating the size, weight,
cost, and efficiency of the transmission.

However, most EV conversions already have a transmission, so it's
"free". The mechanical design is such that it's harder to remove the
transmission than it is to keep it. Given that you're keeping it, you
can save some money by using a smaller motor and controller.

> Without the torque multiplication provided by the transmission, you need
> to have a motor and controller capable producing the huge amounts of
> torque need for hills, acceleration, etc.

The extra torque needed without a transmission is about 2:1. You can get
this by going up a size or so in the motor or controller. For example,
an 8" motor and 500 amp controller with a transmission, versus a 9"
motor and 1000 amp controller without one.

Note that you will need to replace your differential gears to go
transmissionless. A typical ICE car differential ratio is around 3:1.
The differential for a transmissionless EV is more like 5:1.

> external cooling for the motor, since it will often  be running at
> low RPMs where it's internal fan doesn't provide much cooling.

"Often" depends on how and where you drive. If you expect to be climbing
lots of big hills at low speeds, an external blower will be needed. A
blower is also needed if you don't have a high enough differential ratio.

> Also, while electric motors are very efficient over a wide band of RPMs,
> efficiency tends to fall off quickly at very low and very high RPMs.

Yes; except that your driving time at very low and very high speeds is
generally quite low.

> around town driving will be less efficient without the tranny.

In fact, I leave my EV in 2nd gear for almost all around-town driving,
because it's *more* efficient than shifting.

--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in    --    Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net

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[Jeff Shanab]

After driving with a zilla 1k connected to the stock transmission, the
feel I got was that 2 9"s with just the rear end reduction would be the
same as the one 9 that I drive in 2nd and third/fourth only.

The single 9 and stock tranny provides reverse, a 2:1 2nd and a 1:1 4th.

Dual motors with series parallel switching provides Double the torque at
the same amps up to 1/2 speed and double the torque as 1 9" at the upper
half of the speeds.(1/2 the torque at twice the speed times 2 motors).
Reverse is provided by the contactors that handle S/P plus a few.

If I had to do again, I would try for dual 9's instead of adapting to
the tranny.


In Fact, Two motors look like they would fit in the space of the fuel
tank, which in the 300zx was right behind the diffy. If I could put it
back there then I could put bateries under the hood in two layers and
get rid of the driveline entirely. (The 300zx has IRS so the diffy
doesn't move up and down. Use a boat v-drive or just remove the ring and
pinion and replace with an extension box, a chain ring mounted in place
of the ring!



ascii art warning.

  original
   diffy_    _____________________
    /    |  |                     |
===/     |  |  old gas tank       |
         |  |                     |
===      |  |                     |
   \     |  |                     |
    \    |  |_____________________|
     \___|



becomes                                       rear view
     ____eeeeeeeeeeeeeeeee        
    /    ccccccccc       /          MMMMMMMMMeeeeeeeeeMMMMMMMMM
===/  ccc        c      /           MMMMMMMMMe   c   eMMMMMMMMM
     c       c         /            MMMMMMMMMe===S===eMMMMMMMMM
===  c   c            /             MMMMMMMMMe   c   eMMMMMMMMM
   \  cc     eeeeeeee/              MMMMMMMMMe       eMMMMMMMMM
    \       /                                e       e
     \___ee/                                  eeeeeee

Where e is the extension case, C is a dual roller motorcycle chain and
the MMM are the motors on each side like "gone postal"
This would be partially filled with oil however.

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[Ian Hooper-3]

I agree with Peter's comments on the subject. The only time I'd  
recommend considering direct drive is for racing applications, where  
the motor is big enough that it can handle the equivalent of setting  
off in 4th gear and working hard up hills. Doubling the motor and  
controller seems a pretty reasonable approximation.

That said, I love the elegance of direct drive and believe it may  
actually be slightly more efficient while cruising on flat road -  
maximum efficiency of a series DC motor is typically seen around  
2000rpm which happens to equate to normal cruising speed of ~40mph  
(depending on diff ratio and wheel size of course), with no gearbox  
losses. And lastly, large motors may have so much torque that they  
would damage the existing gearbox anyway.

For interest, here's the photo journal of my MX5 conversion which is  
direct drive:

http://www.zeva.com.au/conversion_blog.php?vehicle=1

-Ian

On 15/05/2008, at 4:03 PM, Peter VanDerWal wrote:

> It is technically possible to connect the motor directly to the drive
> shaft, but it is MUCH more expensive and generally less efficient.
>
> Without the torque multiplication provided by the transmission, you  
> need
> to have a motor and controller capable producing the huge amounts of
> torque need for hills, acceleration, etc.
>
> This means that you need a larger motor, a much more powerful  
> controller
> and  possibly some kind of external cooling for the motor, since it  
> will
> often  be running at low RPMs where it's internal fan doesn't  
> provide much
> cooling.  If you combine low RPMs with high torque (i.e. climbing a  
> hill)
> then you will quickly overheat the motor without external cooling.
>
> Also, while electric motors are very efficient over a wide band of  
> RPMs,
> efficiency tends to fall of quickly at very low and very high RPMs. So
> around town driving will be less efficient without the tranny.
> High current and low RPMs is VERY inefficient, as well as causing over
> heating problems, so climbing hills without a tranny is extremely
> inefficient.
>
> Bypassing the tranny (which usually comes free with most  
> conversions) will
> almost double the cost of the motor & controller, and possibly  
> reduce your
> range.
>
> It's been done, drag racers frequently go this way, but most folks  
> that
> have done it wouldn't recommend it for a commuter vehicle.
>
>>
>> My wife and I are trying to figure out the necessity for having a  
>> tranny
>> to
>> do an ICE to electric conversion on a 65 mustang.  Is the tranny  
>> required
>> for the conversion or can we have an adapter to go directly to the  
>> drive
>> shaft (or rear end)?  Would the ratio (gearing?) be too low?  What  
>> would
>> be
>> the potential problems by not having the tranny?  It would save us  
>> some
>> weight and $1000 for the adaptor plate.
>> Thanks!
>> --
>> View this message in context:
>> http://www.nabble.com/Electric-motor-with-no-tranny-for-conversion-tp17254470p17254470.html
>> Sent from the Electric Vehicle Discussion List mailing list archive  
>> at
>> Nabble.com.
>>
>> _______________________________________________
>> For subscription options, see
>> http://lists.sjsu.edu/mailman/listinfo/ev
>>
>
>
> _______________________________________________
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[Stephen West-2]

Roland wrote:
> My Warp 9 has a 199 amp continuous duty and has a service factor of about
> 2.0 for about a minute, meaning 200 amps x 2 = 400 amps for this short of
> acceleration time.

Interesting. Do you know if that 2.0 service factor applies after running
continuously at 200 amps?

Steve


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[Peter VanDerWal]

> Do the reasons not to go direct drive change, if we're talking about an
> AC system?

Yes, mostly. Though even an AC system could gain some benefit from a two
speed transmission.  But, I'm not aware of any AC system that would
provide even moderately acceptable performance with the motor connected
directly to the differential in a Mustang.

Most (all?) of the currently available automotive AC systems have
relatively low torque and make their power at relatively high RPM.
The exact opposite of what you need for this particular case.

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[jerryd]

            Hi Peter and All,

----- Original Message Follows -----
From: "Peter VanDerWal" <evdl@...>
To: "Electric Vehicle Discussion List" <ev@...>
Subject: Re: [EVDL] Electric motor with no tranny for
conversion
Date: Thu, 15 May 2008 14:20:44 -0600 (MDT)

>>  >> My wife and I are trying to figure out the necessity
>>  >> for having a tranny to do an ICE to electric
>>  >> conversion on a 65 Mustang. Is the tranny required
>>  >> for the conversion or can we have an adapter to go
>directly to the drive shaft (or rear end)?  Would the ratio
>>  >> gearing be too low? What would be the potential
>>  >> problems by not having the tranny? It would save us
>>some weight and $1000 for the adaptor plate.
>> Peter VanDerWal wrote:
>>> It is technically possible to connect the motor directly
>>> to the drive shaft, but it is MUCH more expensive and
>>generally less efficient.
>> Peter is correct, but includes way to many "very"s and
>>other adverbs.
>> Essentially all vehicles built as EVs from scratch have
>> no transmissions (electric cars, trains, buses, golf
>carts, fork lifts, etc.)
>
>We aren't talking about Golf Carts, or even purpose build
>EVs.  We are talking about converting a MUSTANG and
>connecting the electric motor directly to the differential.
>In THIS situation, the adverbs apply.

        You can do it fairly easy without a problem if you
want.

>
>> Yes, you do
>> need a bigger motor and controller when there's no
>> transmission. But the extra size and weight, higher cost,
>> and lower efficiency in the motor and controller is more
>> than offset by eliminating the size, weight, cost, and
>efficiency of the transmission.
>
>In this situation, I dissagree.

         Surprise, surprise!! ;^D

>At 30 mph, the motor is going to be turning at about 1,000
>rpm or less (depends on the exact diff ratio)

         Several problems with this.
         First Lee said you'd need a high diff ratio and
4.11 or 4.56-1 ratios were common with up to 7-1 available.
I'd bet his Mustang has a 4.11 gear or can easily, cheaply
be replaced by swapping out the whole axle, very easy to do
on a rear wheel drive live axle car. Get better brakes too
so could be worth it just for them!
         So at 30 mph you are turning much higher rpm's than
1k rpm.
         Many motors are or can be made to run eff at
1000rpm and some forklift motors are 1100rpm stock rated
power, many under 2200rpm.  And if buying new, you can order
most motors at such low and eff rpm, just ask for it in your
spec's.
         One can use 2 motors giving the equivalent of a 2
speed transmission, doubling the torque for the same less
expensive controller. And even less expensive contactor
controller can be used for excellent power.
         Now add the 5% eff from not needing a trans and you
are ahead of the game.
         10-1 gears are only used in AC motors as you know
in road EV's to make up for their lack of torque. As series
motors make much more torque, they easily do in in less rpm.
         I see no reason to need to change basic
assumptions. As Lee said, almost ALL production EV's use
direct drive, Why?
         But other than these, Peter is right ;^D

                           Jerry Dycus

>Assuming a 9" ADC or equivelent, and given the lower
>voltage needed at 30 mph, this low RPM will only be about
>65% efficient (not counting the extra power required by the
>cooling fan)
>
>Bypassing the transmission gains about 5% efficiency, but
>you loose 10-15% in the motor.
>At lower speeds it gets even worse.
>
>>
>> However, most EV conversions already have a transmission,
>> so it's "free". The mechanical design is such that it's
>> harder to remove the transmission than it is to keep it.
>> Given that you're keeping it, you can save some money by
>>using a smaller motor and controller.
>>> Without the torque multiplication provided by the
>>> transmission, you need to have a motor and controller
>>> capable producing the huge amounts of torque need for
>>hills, acceleration, etc.
>> The extra torque needed without a transmission is about
>> 2:1. You can get this by going up a size or so in the
>> motor or controller. For example, an 8" motor and 500 amp
>> controller with a transmission, versus a 9" motor and
>1000 amp controller without one.
>
>Assuming you never need to climb hills.  If you do have any
>hills you'll need closer to 3:1 (i.e the typical difference
>between 1st/2nd and 4th/5th)
>
>> Note that you will need to replace your differential
>> gears to go transmissionless. A typical ICE car
>> differential ratio is around 3:1. The differential for a
>transmissionless EV is more like 5:1.
>
>Or 10:1 as found in many purpose built EVs
>
>-snip-
>
>>> Also, while electric motors are very efficient over a
>>> wide band of RPMs, efficiency tends to fall off quickly
>>at very low and very high RPMs.
>> Yes; except that your driving time at very low and very
>> high speeds is generally quite low.
>
>Unless you drive in traffic.
>
>>> around town driving will be less efficient without the
>>tranny.
>> In fact, I leave my EV in 2nd gear for almost all
>> around-town driving, because it's *more* efficient than
>shifting.
>
>Try leaving it in 4th, since that is effectively we are
>talking about. If he goes transmissionless he won't HAVE a
>second to shift down into.
>
>It's easy to win an arguement by changing the basic
>assumptions.
>
>
>
>
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[Pestka, Dennis J]

Would it be possible and simpler to install a cheap/low voltage
controller just for reverse.
Turn it off and on with a switch.
With the infrequency of use, limited speed and power needed for reverse,
I was wondering if this would be a possibility.

Just an idea from someone who knows enough to be dangerous

Dennis

-----Original Message-----
From: Roland Wiench [mailto:ev_7@...]
Sent: Thursday, May 15, 2008 1:05 PM
To: Electric Vehicle Discussion List; evdl@...
Subject: Re: [EVDL] Electric motor with no tranny for conversion

So far, nobody has mention what you need to go in reversed with no
transmission.  This requires a reversing contactor that is a double pole
contactor that is mechanical and electrical interlock, so one is off
while the other is on.  You also need a main contactor, so you can
completely turn off the positive battery  power from the battery.

The main contactor could be a two pole contactor that completely cuts
off both the negative and positive power from the battery, or use
another separate contactor on the negative side with is normally call a
back up safety contactor.

You will still need a Forward-Off-Reverse control switching mechanism
which are normally made with a cable operated straight line shifter, or
peddle shifters that can operated micro switches.

If you take too much time in the off position when shifting from forward
to reversed, you may have to precharge the controller each time you make
this change.

Another method we use for reversing some motors, is the use of two large
L frame circuit breakers that do not have the overload trips in them,
making them a enclose transfer switch.  They can be remotely operate by
a motorize circuit breaker kit, that is also electrical interlock.  The
placement of the circuit breakers with the load ends buss bar together,
provides the mechanical interlock.

Roland


----- Original Message -----
From: "storm connors" <stormconnors@...>
To: <evdl@...>; "Electric Vehicle Discussion List"
<ev@...>
Sent: Thursday, May 15, 2008 9:52 AM
Subject: Re: [EVDL] Electric motor with no tranny for conversion


> I would see what Otmar who makes the Zilla controller has to say.
> http://www.cafeelectricpress.com/blog/?p=22
>
> On Thu, May 15, 2008 at 4:03 AM, Peter VanDerWal <evdl@...>
> wrote:
> > It is technically possible to connect the motor directly to the
drive

> > shaft, but it is MUCH more expensive and generally less efficient.
> >
> >
>
>
>
> --
> http://www.austinev.org/evalbum/1059
> http://stormselectric.blogspot.com/
> Storm
>
> _______________________________________________