# [EVDL] mail delivery



## EVDL List (Jul 27, 2007)

Since you do not need high speed, you can increase
the torque by adding extra down-gearing, an AC motor
is actually pretty bad in peak torque so in case of AC
it will be *required* to have a reduction, in case of
direct drive DC it is possible to push the motor into
saturation and get more torque at the cost of the risk
of over-heating it at low speed.

Additional gearing is easy with either a (replacement)
manual gearbox (my AC drive truck used the original
manual transmission *without* stick, it was simply
permanently locked in 2nd gear to provide the needed
reduction from the max 9k motor RPM to the proper input
of the diff to top out at 72 MPH.

If you want to go to permanent connection, you can use
a chain or belt to get your reduction.

I think a look at "Gone Postal" may give more ideas.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water XoIP: +31877841130
Tel: +1 408 383 7626 Tel: +91 (040)23117400 x203 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Willie McKemie
Sent: Saturday, November 19, 2011 12:27 PM
To: Electric Vehicle Discussion List
Subject: [EVDL] mail delivery

A friend was talking to me a while back about the possibility of
converting his wife's rural mail delivery RHD Jeep. I haven't seen it,
but I think it is a surplus post office vehicle. Her route is 60-62
miles, so I told him lithium, not lead. Probably ~20kwh. Both the
engine and manual transmission are worn out and he was talking about
direct drive. I said no, that is not likely to work well with low speed
and a DC motor. But, I've been mentally revisiting the problem. 
Would one of those low end AC setups be likely to work direct drive for
this situation? I guess DC direct drive might work if a real low
rear-end could be found. I would guess top speed needs to be no greater
than 40-50 mph. Ideas solicited.

--
Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 4 days 55 min minutes

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## EVDL List (Jul 27, 2007)

> Willie McKemie wrote:
> > A friend was talking to me a while back about the possibility of
> > converting his wife's rural mail delivery RHD Jeep. I haven't seen it,
> > but I think it is a surplus post office vehicle. Her route is 60-62
> ...


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## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> 
> > Willie McKemie wrote:
> >> A friend was talking to me a while back about the possibility of
> ...


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## EVDL List (Jul 27, 2007)

The idea is not to keep the 4x4 after conversion ? Just RWD ?

Why would not standard, well oversized, secondhand (and dirty cheap)
industrial AC do the trick ? Could fit in the transmission tunnel.

I know many has taken this road earlier and so far no big success, but
industriel components have also got smaller and lighter.

Cheap 600-800 VDC Battery pack does not exist (?). But the
controllability (regen) and 2nd sources for replacement parts would
maybe be the positive side of the deal.

Would weight be an issue ? I did not yet check the vehicle data but
for the 60 mi range Li-Lead compensation should already allow added
motor weight. Could it take 600-800 lbs of motor ?

-akkuJukka

http://www.google.com/profiles/jarviju#about



2011/11/20 Martin WINLOW <[email protected]>:
>
>


> Lee Hart wrote:
> >
> >> Willie McKemie wrote:
> >>> A friend was talking to me a while back about the possibility of
> ...


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## EVDL List (Jul 27, 2007)

On Sun, Nov 20, 2011 at 01:38:57PM +0200, Jukka J?rvinen wrote:
> The idea is not to keep the 4x4 after conversion ? Just RWD ?

I haven't seen the vehicle but I have assumed that it is rear wheel 
drive only. Post office vehicles are almost all two wheel drive. It 
is driven from the right side to facilitate servicing road-side mail 
boxes in our "drive on the right side of the road" part of the world.

> Why would not standard, well oversized, secondhand (and dirty cheap)
> industrial AC do the trick ? Could fit in the transmission tunnel.

The goal would be to have a reliable and cost effective vehicle. It 
seems to me that going down a not well beaten path would likely lead to 
un-reliability. I don't know anything about "industrial AC" but am 
eager to be educated.

-- 
Willie, ONWARD! Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime 4 days 17 hours 47 minutes

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| Please take those discussions elsewhere. Thanks.
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## EVDL List (Jul 27, 2007)

> Willie McKemie wrote:
> A friend was talking to me a while back about the possibility of
> converting his wife's rural mail delivery RHD Jeep. I haven't seen
> it, but I think it is a surplus post office vehicle. Her route is 60-62
> ...


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## EVDL List (Jul 27, 2007)

> Roland Wiench wrote:
> >
> > Not enough info to do a design specifications for this unit. What is the
> > route terrain like, dead flat all the way or hills, type of pavement, road
> ...


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## EVDL List (Jul 27, 2007)

On 11/20/11 7:48 AM, Willie McKemie wrote:
>


> Roland Wiench wrote:
> >> Not enough info to do a design specifications for this unit. What is the
> >> route terrain like, dead flat all the way or hills, type of pavement, road
> >> and ambient conditions.
> ...


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## EVDL List (Jul 27, 2007)

Hello Willie,

Ok then you will have to test the stop and go driving with a transmission in 
a gear ratio or in the 1.0:1 gear leaving the motor drop to 0 rpm at the 
stops and see what the motor ampere is when you have to accelerated back up 
to speed.

The next test is that you let up on the accelerator to coast to a stop, 
shift it in neutral which leaves the motor rotating, and then see what the 
motor ampere is when you accelerated again. I find that my motor ampere is 
less.

The next test I did, was taking out the manual transmission and put in a 
direct drive shaft that went to a GM TH-400 automatic transmission that was 
converted to a manual shift that had 15.3175:1 overall gear ratio in 1st 
gear. This did not work, because the starting force from a 0 rpm motor was 
very violent. Motor ampere went over 600 amps. This direct drive type of 
set up is normally using for racing.

Replace the direct drive shaft with a 12 inch torque converter that had a 
stall speed at 400 rpm (which the EV will not move) and a full lock on at 
1800 rpm which is lower than a normal transmission.

The torque converter adds another ratio of 1.8 at 400 rpm and varies to 0.0 
at 1800 rpm. This gives a smooth start and a overall gear ratio of 27.57:1 
at 400 rpm which varies to 15.3175:1 at 1800 rpm.

The WarP 11 motor has it sweet spot at about 1800 rpm at 10 mph which at 
that point produces the maximum HP and Torque at that rpm. Motor ampere now 
ranges from 50 to 200 amps.

I then shift to 2nd gear which the transmission varies from 15.3175:1 to 
9.9:1 and accelerated to 20 mph which again is 1800 rpm. My motor ampere 
ranges from 250 to 150 amps.

I then shift to 3rd gear which the transmission varies from 9.9:1 and 
accelerated up to 30 mph which the motor is at the sweet spot again in a 
overall gear ratio of 5.57:1 with a motor ampere of 200 amps.

Therefore I design the overall gearing where as to keep the motor rpm close 
to the sweet spot and at the maximum continues ampere rating of the motor.

You will have to have a motor controller that allows you to have a idle 
point and allows you to either not idle or idle. You will find that the 
motor idle time will be less motor ampere than the 0 rpm start up motor 
ampere.

With my manual transmission, it was common to pull about 500 to 600 motor 
amperes to start moving again using about 4.8 AH per mile. With the TH-400, 
I now in the 3.5 AH range for a 7000 lb EV.

There are some new electronic transmissions that have about a 4.0:1 gear 
ratio in high performance vehicles that now out performs the manual 
transmission. This would give a 40.0:1 overall starting gear ratio that 
would vary down to 2.78:1.

Roland




----- Original Message ----- 
From: "Willie McKemie" <[email protected]>
To: "Electric Vehicle Discussion List" <[email protected]>
Sent: Sunday, November 20, 2011 8:48 AM
Subject: Re: [EVDL] mail delivery


>


> Roland Wiench wrote:
> > >
> > > Not enough info to do a design specifications for this unit. What is
> > > the
> ...


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## EVDL List (Jul 27, 2007)

> Martin WINLOW wrote:
> > Hi Lee. I'll have to disagree with the 9" option as my van which had a 4.44
> > diff really struggled in 4th gear (1:1 in the gearbox) and it only had
> > 12" wheels and this was with 800A controller. I'm guessing the jeep
> ...


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## EVDL List (Jul 27, 2007)

> John G. Lussmyer wrote:
> 
> > That rating system confused me for quite a while, until I found out
> > something.
> ...


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## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> 
> > I pulled out my literature; the AM General direct drive EV Postal Jeeps
> > had a 5.89:1 differential ratio, and used CR78-15 tires. And it had an
> ...


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## EVDL List (Jul 27, 2007)

On 11/20/2011 3:21 PM, Willie McKemie wrote:
>


> Lee Hart wrote:
> >
> >> I pulled out my literature; the AM General direct drive EV Postal Jeeps
> >> had a 5.89:1 differential ratio, and used CR78-15 tires. And it had an
> ...


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