EV Digest 5030
Topics covered in this issue include:
1) Re: refractometer vs hydrometer...
by Bob Bath <[EMAIL PROTECTED]>
2) Re: EV acceptance idea
by "Rich Rudman" <[EMAIL PROTECTED]>
3) Re: I want to build a PWM DC motor controller
by Stefan Peters <[EMAIL PROTECTED]>
4) Re: Warp 13/11 Cooling
by "Rich Rudman" <[EMAIL PROTECTED]>
5) Re: EV acceptance idea
by Stefan Peters <[EMAIL PROTECTED]>
6) Re: performance statistics (was EV acceptance idea)
by "Peri Hartman" <[EMAIL PROTECTED]>
7) Re: Units of EV merit
by "Rich Rudman" <[EMAIL PROTECTED]>
8) Ovonics licenses
by Reverend Gadget <[EMAIL PROTECTED]>
9) Re: EV acceptance idea
by [EMAIL PROTECTED]
10) Re: I want to build a PWM DC motor controller
by Lee Hart <[EMAIL PROTECTED]>
11) Re: 24ah 240vdc Li Ion pack.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
12) Re: Festiva or Metro
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
13) Re: Festiva or Metro
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
14) Re: Festiva or Metro
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
15) Re: I want to build a PWM DC motor controller
by Danny Miller <[EMAIL PROTECTED]>
16) RE: Hybrid motor mounting, was: RE: RPM, brushes and commutators,
by "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
17) RE: Small car, Big heart
by "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
18) RE: RPM, brushes and commutators, was: RE: CVT transmission for E
V
by "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
--- Begin Message ---
I _was_ using a refractometer, and am now back to a
hygrometer, due to incomplete charging. I agree,
stratification is the issue.
Is the wife's refractometer temp. corrected? The ones
for EVs are, and they scale between 1.000 and 2.000.
Presumably, one for ice cream, or ethanol might not
share the same scale?
0.02,
--- Dave <[EMAIL PROTECTED]> wrote:
> I was all set to order a misco refractometer because
> I was getting tired
> of spending 20-30 minutes once or twice a day to
> check my batts... Then
> I thought to ask my wife who has used refractometers
> in the lab, She
> said her experience has been they are difficult to
> read and the
> dilenation is not sharp more gradual from light thru
> grey and then dark
> requiring eperience/guesswork to interpolate the
> proper reading.
>
> So is anyone currently using a refractometer? How
> simple/difficult is
> it to read?
>
> One other downside it seems to me would be
> stratification of the acid in
> the battery. with a hydrometer I take my reading on
> the 3rd bulbful.
> whereas the refractometer uses only a drop or two of
> liquid and would
> only be reading the very top layer of acid...
>
> thanks,
> dave
>
>
'92 Honda Civic sedan, 144V (video or DVD available)!
www.budget.net/~bbath/CivicWithACord.html
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?
Are you saving any gas for your kids?
__________________________________________
Yahoo! DSL Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
--- End Message ---
--- Begin Message ---
Watt hours per mile is the excepted unit of measure, or the inverse is miles
per Kwhr.
I don't see what else is needed...
I do like the idea of a "Rudman"
Cute!! Golide has about 15 Rudmans....
Madman
----- Original Message -----
From: "Michaela Merz" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, December 27, 2005 2:17 PM
Subject: Re: EV acceptance idea
>
> > Typical? That can't be right... if the typical car was "full highway
> > use", they would all be parking lots. Since comments like these pop up
> > regularly, I think our little EV community is slanted towards those who
> > are not suburban (am I right?). Please realize that the vast majority of
> > people in this country live in a large city, close to work and services.
> > I haven't been on a highway (besides the in-laws for thanksgiving) for
> > over three years now. And I live outside of town.
>
> This is why I suggested we define a set of 'measurements' and maybe we are
> able to agree on something to define the 'range' as something like the
> distance a vehicle is able to travel on a set temp., on a flat hard
> surface with a defined speed until the battery reaches a defined DOD
> level.
>
> We should do it metric though. Here the example:
>
> 1 Rudman (Roden, Merz, Whatever) = Distance (in Km) travelled at 70 Km/h -
> 20 Degrees Celsius on a flat surface until battery reaches 50% dod. My 144
> V electric Nissan truck has about 55 Rudman (Roden, Merz, Whatever), while
> my 120 V S-10 currently has only 46 Rudman (...). Since I am about to
> upgrade the S-10 to 144 Volts, it will be interesting to see if I am able
> to reach those 55 (..) with the S-10 as well.
>
> Your input is appreciated.
>
> Michaela Merz
>
>
>
>
>
>
>
--- End Message ---
--- Begin Message ---
Danny Miller wrote:
I don't follow the reasoning against them, a uC can be built with
better protection than possible with discrete components. Modern uC
have features for detecting brownouts and execution errors and can be
made extremely reliable. Of course software bugs are still an obvious
additional problem.
That's what "watchdog timers" are for... If you don't ping them every so
often (time configurable), they can reset the processor. Any good
micro-controller will float all of the outputs during this time,
allowing you to set them as defaulting up or down with a couple of
resistors.
I would avoid using a micro, except perhaps as a remotely-mounted
system monitor. The noise levels are so high, and the consequences of
a computer "crash" so hideous that it is better to keep them OUT of
the main control loop.
Depends on the circuit used. An appropriate micro-controlled circuit
will do nothing without "supervision" (active inputs), so it's a
fail-off scenario.
If you drive a modern car, you are already trusting your life to a
couple of micro-controllers. If you work in a modern factory, you might
owe your life to some of them as well, and not even know it. How to make
them safe in industrial control applications has become a matter of
record these days.
I am a fan of well-tested older technology, Lee. I even like the newer
analog/linear stuff (BEAM robots, etc.) But I think I would feel more
comfortable with the many layers of failure protection possible with a
well supervised analog circuit under digital control. I can inspect each
line of code, too bad I can't inspect each semiconductor junction ;)
--- End Message ---
--- Begin Message ---
How does one go about... taking about %10 of the electrical power that you
dump into that motor... and then extract that Wattage without letting
anything get above 200 f.
That is the art of drive train cooling.
Most of us have about 10Kwhr of battery on board that is useable... so we
have to dissapate 1 Kwhr of waste heat without damaging anything.
Starting with a Stone cold... Zero Deg C motor that weighs about 150 lbs ...
makes the first part rather easy.
Madman
----- Original Message -----
From: "Don Cameron" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, December 27, 2005 5:49 PM
Subject: Warp 13/11 Cooling
> I am looking at a Zilla/Warp 13 or 11 as an inexpensive alternative high
> torque motor, but my concern is that this motor is not liquid cooled. The
> compartment where the motor will be installed is nearly enclosed. I can
> have approx 250CFM of electric ventilation for the motor and (Li-poly)
> batteries through a 4" diameter opening.
>
> Will this be adequate? How does one go about calculating the cooling
> requirements for something like this?
>
> thanks
> Don
>
> Victoria, BC, Canada
>
> See the New Beetle EV Conversion Web Site at
> www.cameronsoftware.com/ev/
>
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
Watt hours per mile is the excepted unit of measure, or the inverse is miles
per Kwhr.
I don't see what else is needed...
I do like the idea of a "Rudman"
Cute!! Golide has about 15 Rudmans....
Madman
Isn't that just a measure of efficiency? (How much power is needed to
travel a given distance) You would need to combine it with storage
capacity and the dreaded "P" factor to find potential range.
--- End Message ---
--- Begin Message ---
Wow, that's a cool website.
I think more grade testing would be helpful. For example, if EVs without
transmissions will be sold, I would want to know if they can make it up
hills or accelerate reasonably entering a freeway.
I would add:
- time to accelerate to 25mph on 20% grade
- time to accelerate to 60mph on 6% grade
- max grade to sustain 10mph
Also, I think people are more used to 60mph than 50mph for benchmarking,
thus:
- time to accelerate to 60mph on level
Keep the various energy and power metrics associated with each test - great
stuff.
Would people be interested in creating a standard test suite where
contributors could add test results to the evalbum?
Peri Hartman
----- Original Message -----
From: "Ron Archer" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, 27 December, 2005 16:08
Subject: Re: EV acceptance idea
I've found the Idaho National Laboratory vehicle tests to be very helpful.
http://ev.inel.gov/fsev.shtml
Performance Statistics include: Acceleration 0-50, Max Power, Max Speed
1/4 mile and 1 mile, Range @ 45 mph and 65 mph; including Energy Used,
Average Power, Efficiency (Wh/mile) and Specific Energy. There's also
Braking, Handling and Gradeability.
When stating range, it would be important to know Depth of Discharge.
...just my opinion, it's free and worth every penny :)
Ron
Michaela Merz wrote:
>
This is why I suggested we define a set of 'measurements' and maybe we
are
able to agree on something to define the 'range' as something like the
distance a vehicle is able to travel on a set temp., on a flat hard
surface with a defined speed until the battery reaches a defined DOD
level.
We should do it metric though. Here the example:
1 Rudman (Roden, Merz, Whatever) = Distance (in Km) travelled at 70
Km/h -
20 Degrees Celsius on a flat surface until battery reaches 50% dod. My
144
V electric Nissan truck has about 55 Rudman (Roden, Merz, Whatever),
while
my 120 V S-10 currently has only 46 Rudman (...). Since I am about to
upgrade the S-10 to 144 Volts, it will be interesting to see if I am able
to reach those 55 (..) with the S-10 as well.
Your input is appreciated.
Michaela Merz
--- End Message ---
--- Begin Message ---
Why???
Just to waste some time????
Storage Cap, and potential are so nebulas, and over calculated.... and well
so... un scientific....Un less you have about 12 data points, you have a
WAG.
1 Rudman is defined as one mile of range on a hot summer day in Seattle.
That's 68 Deg F
Sealevel 760 Torr.
No elevation gained or lost
55 miles per hour.. no stops no starts..Ok one each...
less than .25 G to get there....and back
NO rubber smoke.. DARN!
Storage cap... are you kidding... Who is going to measure that? on every
EV. and be honest about it.
Potential range... er Gee if I only could have had hotter batteries, If I
used a wind mill over there on the windy part of the course....If I only had
better cable ends, shorter wires, bigger wire... a better controller....
less wind drag... a harder push from my buddy...
Am I making some points here?
All our measuremnts can be made using normal units.
so lets keep them that way.
I we need to convert.. great most of us here can use a calculator.. our our
toes... What ever.
The big point is if you claim some kind of range or preformance... please
include your raw data. That way, we can see for ourselves what you did, and
how you did it.
What we can measure is how much power it took to go so many miles/Km, and
how much we CAN get out of our packs.
lets keep it simple folks... or else loose the whole concept.
Rich Rudman
----- Original Message -----
From: "Stefan Peters" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, December 27, 2005 9:42 PM
Subject: Re: EV acceptance idea
> Rich Rudman wrote:
> > Watt hours per mile is the excepted unit of measure, or the inverse is
miles
> > per Kwhr.
> >
> > I don't see what else is needed...
> >
> > I do like the idea of a "Rudman"
> > Cute!! Golide has about 15 Rudmans....
> >
> > Madman
> Isn't that just a measure of efficiency? (How much power is needed to
> travel a given distance) You would need to combine it with storage
> capacity and the dreaded "P" factor to find potential range.
>
--- End Message ---
--- Begin Message ---
A while back there was a post talking about the
limitations of the Ovonics licenses for nickel metal
hydride batteries. I believe the post said that the
licenses limits the size of batteries to those too
small for use in BEV's if you wrote the post or
remember who did, please email me off list ASAP. or
call me at 310-908-0604
Thanks in advance
Gadget
visit my websites at www.reverendgadget.com, gadgetsworld.org,
leftcoastconversions.com
--- End Message ---
--- Begin Message ---
<<<Okay, so how badly does going high speed hurt the efficiency of an EV?
Is there a rule of thumb I could use to say that at 35 mph I'll get X
range and if I take the same car 65 mph, I'll get X*someRatio? Or a
better wa of saying that would be what's the percentage loss at a
given speed? Then it can easily cummulate with other things (like
running accessories if not separate, hills, etc.).
Thanks,
-joel>>>
The EVA test of the '98 Ranger EV got:
57.9mi at 60mph
86.9mi at 45mph
a 2x run-time difference.
Commuting 49mi means keeping mine between 50-55mph, even slower up grades but in
neutral downhill (5+mph > the 75mph governed limit); in fact, my time shifted
into "N" can be over 12 of those 49 miles! This includes coasting down instead
of braking, often making regen 'moot' (below 20mph, might as well stick to
regular brakes). I can have >10mi of range left on some days, but just a few
more mph for very much of the trip, and it's "yellow light time" before I get
home. A heavy vehicle with poor aerodynamics isn't the best example, but it's
generally true of other BEVs.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>>> I would avoid using a micro, except perhaps as a remotely-mounted
>>> system monitor. The noise levels are so high, and the consequences of
>>> a computer "crash" so hideous that it is better to keep them OUT of
>>> the main control loop.
Danny Miller wrote:
>> a uC can be built with better protection than possible with discrete
>> components.
If you believe this, then you don't understand circuit design!
When safety is critical, engineers can design fail-safe circuits, where every
known
failure mode leads to a safe condition. You can prove that no conceivable
failure
will do something dangerous. It's harder to do, and it requires a great deal
more analysis and testing; but at least it is possible.
This is simply not possible in any computer. The number of possible failures is
so
astronomically large that it is impossible to verify that they all lead to safe
conditions.
The only you can use a computer in a fail-safe design is if you make it
physically
impossible for the computer to do anything dangerous, even if it were running a
"mad terrorist" program that is *trying* to do something unsafe. Basically, that
means there is external hardware, not part of and not controllable by the
computer,
that is doing the safety critical operation.
Stefan Peters replied:
> That's what "watchdog timers" are for... If you don't ping them every so
> often (time configurable), they can reset the processor.
Yes; there are lots of marketing features that salesmen will tell you will make
their
micros crashproof. They help, by eliminating some of the gross errors; but they
do
*not* fix the problem. Here are just a few that I've run across in my years
designing
furnace controls:
1. Watchdogs that can be turned off by the software, by bits in some control
register.
2. Watchdogs that rely on external parts to provide their clock and/or timing.
If these parts fail, the watchdog is defeated.
3. Programmers leave a "trap door" routine in the code that defeats the watchdog
so they could test or debug their program. The trap door code gets
inadvertently
executed to create a dangerous condition.
4. The watchdog gets reset by some naturally recurring event, such as in an
interrupt handler, so the main program is totally nuts but the watchdog is
still
being kept quiet by the interrupt handler.
5. The micro's clock fails, due to a shorted or open clock input pin. Even if
the
watchdog tries to reset the micro, without a clock, nothing happens anyway.
6. A bad bit in memory can make the micro think an output is "off" when it is in
fact "on". Micros usually have "write-only" locations for I/O, which can't
be read
to verify that they are actually working.
7. Most micros blindly continue to execute programs even when the chip is too
hot
or too cold, the supply voltage is too high or too low, or the clock
frequency is out
of bounds. This can make out-of-spec conditions appear normal, or cause
totally
erroneous operation.
8. An output bit gets stuck low due to being static zapped, or other hardware
failure.
9. Most micros have "factory test" modes so they can test the chip even with
some
customer's program in it. Noise or circuit faults can stumble into one of
these "test"
modes, causing the outputs to thrash around insanely.
10. High-current pulses on a micro's output (from noise or a momentary short)
can
cause parts of the chip to "latch up" in a temporary mode where the
on-chip logic
will not function predictably. Watchdogs or resets won't fix it; you have
to actually
remove power from the chip and re-apply it to recover.
>If you drive a modern car, you are already trusting your life to a
>couple of micro-controllers. If you work in a modern factory, you might
>owe your life to some of them as well, and not even know it. How to make
>them safe in industrial control applications has become a matter of
>record these days.
Yes; and the people designing such critical safety systems know HOW to do
fail-safe
design. But they do NOT do it with off-the-shelf micros, standard circuits, and
garden
variety C compilers! I'm not kidding; you will KILL someone if you do this!
My key point is that the casual programmer doesn't know how to write or test
fail-safe
software. It is a very specialized, very time-consuming process. So, he
shouldn't try!
It is much easier to build fail-safe hardware circuits instead.
--- End Message ---
--- Begin Message ---
Yep.
----- Original Message -----
From: "Rod Hower" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, December 24, 2005 4:40 PM
Subject: RE: 24ah 240vdc Li Ion pack.
The prices on their website where $465 for a 24V,
24Ahr battery pack and a $100 charger. Perhaps he was
thinking you just put 10 packs in series?
--- Don Cameron <[EMAIL PROTECTED]> wrote:
Lawrence, you had me going a bit crazy. The subject
of the email said
"240V" $4600 for 24Ah 240V would change the face of
EVs overnight!
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On
Behalf Of Lawrence Rhodes
Sent: December 24, 2005 11:12 AM
To: Electric Vehicle Discussion List
Subject: 24ah 240vdc Li Ion pack.
http://www.cyclone-usa.com/Cyclone%20Data%20Sheet%2011-01-2005.pdf
The pack
would be really light. The pack is 4600 dollars the
charger 1000 dollars.
Does that make sense for a small electric vehicle?
Lawrence Rhodes
Bassoon/Contrabassoon
Reedmaker
Book 4/5 doubler
Electric Vehicle & Solar Power Advocate
415-821-3519
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
http://www.festivamotorsport.com/ Here is a Festiva/Aspire after market
parts supplier. Lawrence Rhodes.....
----- Original Message -----
From: "Roger Stockton" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, December 26, 2005 2:30 PM
Subject: RE: Festiva or Metro
[EMAIL PROTECTED] wrote:
I think the Festiva with the 9" motor and 14 x 12 V AGM
batteries and a 1k Zilla controller locked in 2nd gear
would make a great car. I think better than a comparable
Metro which would be limited to a 8" ADC and 12 x 12 V
batteries (I've heard space issues).
Anyone need to correct me?
Sure. ;^>
Have a look at this Metro conversion by Canadian Electric Vehicles:
<http://www.canev.com/Conversions/Geo/Geo.html>
ADC 9", Auburn MPC 600 controller, and 192V pack of Optima G31s. Tranny
locked in 2nd.
You may still prefer the Festiva, but be aware that the Metro is capable
of accepting the same sort of performance bits that you envision.
In favour of the Metro/Swift might be that you ought to be able to find
parts easier, expecially performance-oriented things like stiffer sway
bars, shocks/springs, heavier duty clutches, etc.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I've done an Aspire which is the Festiva is the predecestor of. Plenty of
room for batteries under the back seat and I got 756 pounds of Delphi
batteries in the car without affecting interior space or moding the car.
1200 pounds with a rear battery box. These cars are plenty strong & can
handle a lot of weight. Lawrence Rhodes...
----- Original Message -----
From: "Andrew Letton" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, December 26, 2005 2:38 PM
Subject: Re: Festiva or Metro
OK, I'll take the counterpoint and list some advantages to the Metro:
(FYI, the Metro is designed/built by Suzuki and has existed under various
names since about '85, including Suzuki Swift, Pontiac Firefly, Chevy
Sprint, Geo Metro, Chevy Metro, and has been sold in 2-door and 4-door
hatchback as well as 4-door sedan and 2-door convertable models.)
- For the '89-'94 versions, there is a pocket rocket version sold as the
Suzuki Swift GT/GTi which has 14" wheels, disc brakes all around, "sport
suspension", and some aerodynamic/styling add-on bits. There are
performance parts available, including springs, struts, strut tower
braces, anti-roll bars, etc. Very Fun Cars!
- I believe that the 4-cylinder models (some '89+ Swifts as well as some
'95+ Metros) will fit a 9" ADC motor (without tailshaft), but don't take
this as gospel - find and measure one!
- Both Electro Automotive and Canadian EV offer Geo Metro kits and have
experience with many conversions.
- At least in the USA, I believe that there are far more Metro variants on
the road than Festivas, so replacement and salvage-yard parts should be
more available.
- Not sure about the Festiva, but on the Metros, the rear struts are not
located inside the rear coil springs, so it is easy to add air-bag helpers
to the rear suspension. (I can look up the Air-Lift bag p/n if you need
it; I've put them in two different 'zukis.)
- The Suzuki Swift GTi has an (aero drag) CdA of 6.15 ft^2, compared to
the Festiva's of 7.3 ft^2. (Std '92 Geo Metro's is 6.78 ft^2) See:
http://www.mayfco.com/tbls.htm
- I've known Geo's with as many as 20 golf cart batteries. Not
recommended, but doable. (Yes, it uses up the back seat area, but the
back seats are hardly usable in either of these cars anyway, if the front
seat passengers are tall.) 16 is a better number and gives a car with a
pretty solid 60 mile range.
- I think that the limiting factor in either of these cars will be the
transmission/clutch, not the size of motor you can fit between the tranny
and the wheelwell. An 8" ADC motor will kill either of these
transmissions and smoke their clutches, given enough amps.
Hope that helps your decision; let me know if you have any specific Suzuki
(variant) questions.
cheers,
Andrew (...with close to half a million (mostly ICE) miles in 'Zuki
variants.)
[EMAIL PROTECTED] wrote:
If you were converting a "small car" today, would you rather used a late
model Ford Festiva or Geo Metro. I looked at both cars earlier today and
I believe the Festiva to be a superior conversion candidate. But, I am
interested in what others have to say, and why other people aren't
choosing the Festiva.
In my opinion, advantages of the Festiva:
There is at least 2.75" more length to fit a motor which opens up a lot
more options than the 8" ADC.
- You could even easily fit a Warp 9" for some serious
performance.
Battery mounting appears to be easier, especially if you take out the rear
seat, which is very easy
Currently, you may be able to get a donor car pretty inexpensively
In my opinion, disadvantages of the Festiva:
No off the shelf kit, as far as I know
Few examples to work from
Parts availability - 5 years from now - is questionable
The cars are generally older and more difficult to find in low mileage
Stock brakes seem a little small - from what I could tell from the
disassembled car
I would like to know what others think, and why they decided to go with
the Metro rather than the Festiva. I think the Festiva with the 9" motor
and 14 x 12 V AGM batteries and a 1k Zilla controller locked in 2nd gear
would make a great car. I think better than a comparable Metro which
would be limited to a 8" ADC and 12 x 12 V batteries (I've heard space
issues). Anyone need to correct me?
--- End Message ---
--- Begin Message ---
I'll agree that Honda's are superior vehicles but if you want a comfortable
ride you don't have to squat down to get into the Aspire is superior for
back seat leg room. A bit narrower but it is a nice sit up car compared to
the low wide Honda. Not very good for passengers. I've owned both. I
prefer the Aspire to the Honda as an EV. Lawrence Rhodes.
----- Original Message -----
From: "Bob Bath" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, December 26, 2005 4:14 PM
Subject: RE: Festiva or Metro
I'd still say the 92-95 Honda Civics are a far
superior candidate to either of the rigs mentioned.
It simply has a huge spare tire well that shrieks,
"I'm MADE for flooded USBatts!" I also consider it a
safer roll cage in the event of accident, and the fact
is, there were, and still are, 20-25,000 running off
the line PER MONTH. You will have spare parts,
aftermarket parts, etc. for a _very_ long time.
The biggest hassle (as is with other cars, too), is
yanking the heater core, and swapping the power rack
for a manual one.
Newbies, if you're interested, inquire about the
DVD/VHS.
I'd start making a kit available, (contactor mount,
controller mount, throttle mount, motor/vac. pump
mount, heater relay mount), but I'm just not convinced
there is a market at the ready, yet. And I use DCP
DCDC converter and controller, which don't quite exist
anymore.
peace,
--- Don Cameron <[EMAIL PROTECTED]> wrote:
Nothing wrong with blazing a new trail. My New
Beetle EV is only one of
three in the world.
What is nice about the Metro is that there is a lot
more expertise available
if you want parts or advice. Before I did the New
Beetle conversion, I
purchased a 96 Metro, and it has enough room to
accommodate a 9" ADC motor.
good luck.
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On
Behalf Of [EMAIL PROTECTED]
Sent: December 26, 2005 1:36 PM
To: [email protected]
Subject: Festiva or Metro
If you were converting a "small car" today, would
you rather used a late
model Ford Festiva or Geo Metro. I looked at both
cars earlier today and I
believe the Festiva to be a superior conversion
candidate. But, I am
interested in what others have to say, and why other
people aren't choosing
the Festiva.
In my opinion, advantages of the Festiva:
There is at least 2.75" more length to fit a motor
which opens up a lot more
options than the 8" ADC.
- You could even easily fit a Warp 9" for
some serious performance.
Battery mounting appears to be easier, especially if
you take out the rear
seat, which is very easy Currently, you may be able
to get a donor car
pretty inexpensively
In my opinion, disadvantages of the Festiva:
No off the shelf kit, as far as I know
Few examples to work from
Parts availability - 5 years from now - is
questionable The cars are
generally older and more difficult to find in low
mileage Stock brakes seem
a little small - from what I could tell from the
disassembled car
I would like to know what others think, and why they
decided to go with the
Metro rather than the Festiva. I think the Festiva
with the 9" motor and 14
x
12 V AGM batteries and a 1k Zilla controller locked
in 2nd gear would make a
great car. I think better than a comparable Metro
which would be limited to
a 8" ADC and 12 x 12 V batteries (I've heard space
issues). Anyone need to
correct me?
'92 Honda Civic sedan, 144V (video or DVD available)!
www.budget.net/~bbath/CivicWithACord.html
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering
wheel? Are you saving any gas for your kids?
__________________________________________
Yahoo! DSL - Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
--- End Message ---
--- Begin Message ---
I'm not sure where you're getting your information, but much of this is
inaccurate at least for modern parts.
I don't mean to dog the point but from our previous discussions, have
you actually used a microcontroller itself? I know you did a lot of
work with the BASIC Stamp things. I certainly don't want to revamp the
argument over their value but using their interpreted system is far
isolated from working with the controller itself which may be a source
of misunderstanding. Funny I can make my own top list of potential uC
problems but they don't coincide with this list much as all... maybe I
should to be fair. And this isn't supposed to be competition here so I
suppose I should do that tomorrow.
I wouldn't automatically say that a uC, ASIC, or discrete design is best
for a task. I'm just saying most of what's stated here as issues has
little validity. And the problems in using an ASIC and/or discretes are
not mentioned. Wired boards with more components are generally more
susceptible to noise and vibration, for starters. The uC can carry more
features. An ASIC/discrete design can have more features added with the
addition of more components but this brings up new avenues of noise and
component reliability issues.
I do agree with the big transistor module instead of paralleling a ton
of little cheap ones. Reliability would be far better. And the cost in
mounting issues alone makes up for the difference in component cost.
Lee Hart wrote:
1. Watchdogs that can be turned off by the software, by bits in some control
register.
That's one good reason not to use the softWDT feature. This is a known
tradeoff. But even if softWDT were used it's phenomenally unlikely that
it would be cleared by a random electrical event.
Normally PIC's WDT is set by the fuse bits, that's the non-soft WDT. It
is not possible for the code to disable it because code can't rewrite
fuse bits.
2. Watchdogs that rely on external parts to provide their clock and/or timing.
If these parts fail, the watchdog is defeated.
Generally WDT do not use external osc for obvious reasons. So, duh,
don't set it up this way.
3. Programmers leave a "trap door" routine in the code that defeats the watchdog
so they could test or debug their program. The trap door code gets
inadvertently
executed to create a dangerous condition.
So don't do that. Duh. This would be foolish coding practice.
4. The watchdog gets reset by some naturally recurring event, such as in an
interrupt handler, so the main program is totally nuts but the watchdog is
still
being kept quiet by the interrupt handler.
Again, that's why you don't do this. Generally WDT should not be reset
by an ISR at all, that's a known bad practice.
5. The micro's clock fails, due to a shorted or open clock input pin. Even if
the
watchdog tries to reset the micro, without a clock, nothing happens anyway.
This may not be possible at all on a well featured micro. In any case,
you're bringing up what happens in a pin fails? How is this any
different than a pin on a more discrete controller?
6. A bad bit in memory can make the micro think an output is "off" when it is in
fact "on". Micros usually have "write-only" locations for I/O, which can't
be read
to verify that they are actually working.
No, the opposite is true. Been that way since forever as far as I know.
7. Most micros blindly continue to execute programs even when the chip is too
hot
or too cold, the supply voltage is too high or too low, or the clock
frequency is out
of bounds. This can make out-of-spec conditions appear normal, or cause
totally
erroneous operation.
Wow we're just grasping at straws now:
A uC generally can't overheat from its own power. MilSpec would allow
for any unreasonable external temp. You do probably want to detect
external temp which is easy to do. The uC will allow for an ideal
response to overheat as well as recording the event so you know what
went wrong.
A uC with an internal osc or an internal failsafe osc will not have this
problem. You seem to be assuming the osc for an alternative
implementation is going to be foolproof and nothing is further from the
truth.
8. An output bit gets stuck low due to being static zapped, or other hardware
failure.
And this is impossible in other chips and components?
9. Most micros have "factory test" modes so they can test the chip even with
some
customer's program in it. Noise or circuit faults can stumble into one of these
"test"
modes, causing the outputs to thrash around insanely.
Never heard of this. Seriously, what are you talking about? What part
ever did this?
10. High-current pulses on a micro's output (from noise or a momentary short)
can
cause parts of the chip to "latch up" in a temporary mode where the on-chip
logic
will not function predictably. Watchdogs or resets won't fix it; you have
to actually
remove power from the chip and re-apply it to recover.
Latch-up's a bitch, that's for sure. Been there, done that. And you're
right that WDT won't fix it which is not a well known liability to say
the least. But do you have a part that's completely immune to it?
Designing to protect the pins is a part of all design.
Yes; and the people designing such critical safety systems know HOW to do
fail-safe
design. But they do NOT do it with off-the-shelf micros, standard circuits, and
garden
variety C compilers! I'm not kidding; you will KILL someone if you do this!
They absolutely do work with OTS micros.
Working with C compilers or new, unproven devices does have issues and
risks. Assembly is recommended for critical apps.
My key point is that the casual programmer doesn't know how to write or test
fail-safe
software. It is a very specialized, very time-consuming process. So, he
shouldn't try!
It is much easier to build fail-safe hardware circuits instead.
No question failure-resistant design is challenging. But hardware is
hardly a cure-all alternative. If you're picturing the designer as
"casual", I'm not sure how letting him design hardware is going to be
failsafe either.
--- End Message ---
--- Begin Message ---
On my car the rear end pumpkin is bolted to the car. It has independent
rear suspension. My plan is to make a chain cog that will bolt to the
driveshaft flange and then the driveshaft will bolt to it. Basically it
will look like a chain cog with two driveshaft flanges on it. I will have
to shorten the driveshaft a little bit but I think it will be pretty
straightforward.
-----Original Message-----
From: James Massey [mailto:[EMAIL PROTECTED]
Sent: Tuesday, December 27, 2005 10:34 PM
To: [email protected]
Subject: Hybrid motor mounting, was: RE: RPM, brushes and commutators,
At 07:42 AM 27/12/05 -0500, Dewey, Jody R wrote:
>My question though is this:
>
>My plan is to connect my electric motor to my rear end pumpkin directly via
>a gear and chain.
Hi Jody
Is this an IRS setup, or are you intending to mount the electric motor off
the axle assembly?
If IRS, no problem, but if you are intending mounting off the axle assembly
you will have a challenge to mount it in such a way as the mass of the
motor doesn't rip itself off the axle with the bumps on the road. Doesn't
mean it can't be done, just more challenging.
I assume you've looked at driving from the gearbox output shaft? the
challenge there is the spline of the tailshaft inserted into the gearbox
moves in and out with the bumps of the road, but miniscule to what an axle
moves.
Of course if you are looking at a truck, many trucks have the slip-spline
(whatever its' real name is) in the tailshaft, so the gearbox output shaft
stays in its' orientation to the gearbox.
Hope this helps
James
--- End Message ---
--- Begin Message ---
A toyota MR2 would be a fun car for sure but you will have a hard time with
battery location. The car is tiny.
How about a toyota celica? Those are cool and a little bigger. If you get
a hatchback model you can take out the back seats and use that area for your
battery pack. Honda Civic hatchbacks would work for the same reason. Both
have plenty of aftermarket parts.
-----Original Message-----
From: Ron Archer [mailto:[EMAIL PROTECTED]
Sent: Tuesday, December 27, 2005 7:16 PM
To: [email protected]
Subject: Re: Small car, Big heart
I've also been trying to determine a good donor for a system with your
specs. It would be fast/fun, but really I need it to have a 25 mile
range at 65 mph, 50% depth of discharge.
Any opinions about the 2000 Toyota MR2 at ~2,200 lbs?
Ron
Chris Buresh wrote:
> I've been trying to assess different vehicles to convert into a fun car
with surprising performance. Recently, the idea of a Metro, Festiva,
Aspire, etc. type vehicle loaded with excessive power has caught my fancy.
Range is not too big of a concern - 25 miles without having to baby it would
be fine. I could see upto 300V of AGMs using a Z1k and Warp 9. Obviously,
this setup may be overkill. I would tame it down (but not much) to fit the
application into the small donor. Loads of aftermarket detailling and mods
are options to get one of these ordinary rollerskates turning heads.
>
> My question to the list:
>
> Which car would be a good platform for this outcome? I know nothing about
the frame or suspension of these vehicles. Would I need to beef them up to
hold the battery weight and handle the power?
>
> --
> Chris Buresh
> St. Paul, MN
>
--- End Message ---
--- Begin Message ---
Ooooh I never thought of that. Not good. Also with the slipper clutch - no
reverse in EV mode. Not good. Probably stuck with a 1:1 chain driven ratio
using motorcycle sprockets and chain. That way I don't over rev the
electric while in gas mode and the creation of the driveline adapter is
greatly simplified. Maybe I could even get one CNC milled as one piece for
strength. I thought about an electric actuated clutch to disconnect the
motor from the driveline, maybe a clutch from an air conditioning
compressor. The drawbacks I see with that is it would have to take some
serious torque and also would draw power the entire time the car was in
electric mode. Not very efficient.
-----Original Message-----
From: Mark Grasser [mailto:[EMAIL PROTECTED]
Sent: Tuesday, December 27, 2005 1:42 PM
To: [email protected]
Subject: Re: RPM, brushes and commutators, was: RE: CVT transmission for
EV
I have already changed my mind on the slipper clutch thing. During
normal-electric operation if you are cruising say 30 mph and you take your
foot out of the throttle the motor stops. When you step on it again it revs
up then slams. BAD IDEA. Sorry I brought it up! Other options would be a
clutch or band. I think the easiest might be parts from a lower unit of an
out drive or outboard motor. They are called "Shift Dogs" purely mechanical
and controlled by cable.
Mark Grasser
----- Original Message -----
From: "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, December 27, 2005 11:51 AM
Subject: RE: RPM, brushes and commutators, was: RE: CVT transmission for EV
> Mark,
>
> That is my current thinking. Comet makes a CVT torque converter
> that will handle 200 HP. I think it will work but spending $400 for
> something that DOESNT work is kinda pointless. I have to do some serious
> research before forking over the dough.
>
> Jody
>
> -----Original Message-----
> From: Mark Grasser [mailto:[EMAIL PROTECTED]
> Sent: Tuesday, December 27, 2005 10:23 AM
> To: [email protected]
> Subject: Re: RPM, brushes and commutators, was: RE: CVT transmission for
> EV
>
>
> Why not create... or buy, a slipper clutch and let the electric motor be
> motionless when not being used. I don't know if they are comercially
> available but I do know that most automatics have them, I think in the 1st
> gear assembly. Don't worry they should be able to handle the torque, but
> you
>
> would have to design and build a suitable housing. Nice part about this is
> you could then gear it for higher motor rpm.
>
>
> Mark Grasser
> ----- Original Message -----
> From: "Roland Wiench" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Tuesday, December 27, 2005 9:57 AM
> Subject: Re: RPM, brushes and commutators, was: RE: CVT transmission for
> EV
>
>
>>
>> ----- Original Message -----
>> From: Dewey, Jody R ATC (CVN75 IM3)<mailto:[EMAIL PROTECTED]>
>> To: '[email protected]'<mailto:'[email protected]'>
>> Sent: Tuesday, December 27, 2005 5:42 AM
>> Subject: RE: RPM, brushes and commutators, was: RE: CVT transmission for
>> EV
>>
>>
>> My question though is this:
>>
>> My plan is to connect my electric motor to my rear end pumpkin directly
>> via
>> a gear and chain. The reason I am asking for max RPM is that I will be
>> running a gas motor at highway speeds. Right now it looks like my
>> driveshaft speeds will not exceed 5000 RPM but if I gear down the
>> electric
>> motor for good city driving the highway speeds will drive the electric
>> motor
>> to about 6 or 7,000 rpm. The electric motor will NOT be energized
>> during
>> this time but will be freewheeling. I just want to make sure the
>> electric
>> motor is not going to be damaged when in gas mode. I have thought about
>> using a comet torque converter. They have a model that can take 200 HP.
>> The only thought I have is can I adapt the driven pulley to have a
>> driveshaft connection on each end so I can bolt it to the pumpkin and
>> have a
>> PTO connection for the driveshaft of the gas engine.
>>
>> Your electric motor rpm will be lower then the engine rpm.
>>
>> Lets say the engine is at 4000 rpm and drive line is at 4000 rpm, if the
>> differential gear is 4 to 1 ratio, then the axle rpm is 1000 rpm.
>>
>> If you connect a 3 inch sprocket on the drive line and a 9 inch sprocket
>> on the motor, this is a 3 to 1 ratio. For every 3 rpm that the driveline
>> rotates the motor will rotate 1 rpm.
>>
>> The maximum rpm of the engine at 5000 rpm would be 5000/3:1 = 1666 rpm.
>>
>> Therefore the overall gear ratio to the axles is 4:1 x 3:1 when motor is
>> running would be 12:1 ratio.
>>
>> The formula for speed of vehicle:
>>
>> RPM x Wheel Circumference
>> MPH = ---------------------------------
>> Overall Axle Ratio x 1056
>>
>> RPM is the electric motor RPM
>> Wheel Circumference is the rolling circumference in inches by marking
>> the
>> tire and rotate it one revolution on a
>> flat grade.
>> Overall Axle Ratio is the transmission gear ratio or any other gear
>> reduction
>> ratio times the differential gear.
>>
>> 1056 is a constant to convert the axle rpm which is in inches per
>> minute
>
>> to
>> feet per minute and than to miles per hour or:
>>
>> 5280 ft per mile x 12 inches per ft.
>> 1056 = ---------------------------------------
>> 60 minutes per hour
>>
>> Therefore the mph at 4000 electric motor rpm would be with a wheel
>> circumference of 85 inches using a 4:1 axle ratio and a sprocket ratio of
>> 3:1 would be:
>>
>> 1000 RPM x 85 inches
>> MPH = ----------------------------- = 6.7 Mph
>> 12:1 ratio x 1056
>>
>>
>> Therefore for every 1000 RPM, you have 6.7 Mph
>>
>> At 7000 electric motor RPM than you will have 7 x 6.7 = 46.9 Mph.
>>
>> In my EV, my 2nd gear ratio is about 13.5:1 which is about 35 Mph. I
>> therefore can shift from 19.5:1 1st gear to a 5.57:1 gear which gives me
>> about 92 MPH at 6000 Rpm with a 90 inch wheel circumference.
>>
>> I normally have to stay in 2nd gear for any speed under 35 mph which
>> keeps the RPM up and motor amperes down to 150 amps and battery amps to
>> 50.
>>
>> If your EV weight is at 3000 lbs than a 3:1 sprocket gear ratio for a
>> overall ratio of 9:1 will work for about 100 motor amperes. For every
>> 1000 lbs of weight its about a 3:1 ratio increase, so a 4000 lb EV should
>> be at 12:1 and 5000 lb at 15:1 and etc.
>>
>> Roland
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: James Massey [mailto:[EMAIL PROTECTED]
>> Sent: Friday, December 16, 2005 5:50 PM
>> To: [email protected]<mailto:[email protected]>
>> Subject: RPM, brushes and commutators, was: RE: CVT transmission for EV
>>
>>
>> At 06:23 AM 16/12/05 -0500, Jody wrote:
>> >What is the maximum RPM limit of the WarP 9" ???? Is the limit because
>> the
>> >brushes will pull away from the commutator or the bearings won't take
>> it?
>>
>> Hi Jody
>>
>> Your question reveals a misconception or a misunderstanding you seem to
>> have with brush/commutator assembly. If the commutator is not perfectly
>> round, or not 'true' to the rotation of the rotor, the brushes will
>> bounce
>> at speed, arc and die. This will happen very quickly, so a great deal of
>> effort is placed in making sure that the brushes do not bounce, i.e. the
>> commutator is truly round.
>>
>> Once the brushes are running on a round commutator, sheer speed cannot
>> harm
>> them, there is no centrifical or other forces being put onto the to the
>> brushes from the comutator. There comes a point where with enough volts
>> and
>> enough amps, the gaps between the commutator bars cannot clear the
>> energy
>> and then an arc occurrs that goes brush-to-brush over the surface of the
>> commutator.
>>
>> The commutator itself is the weakest link. It IS affected by centrifical
>> force, so that high RPMs are trying very hard to throw the commutator
>> (and
>> the windings, but they are held in a different, stronger, manner) away
>> from
>> the rotor.
>>
>> The voltage and power requirements of the commutator prevents the
>> commutator from being made in really small diameters, so we will always
>> have this limitation, one way or another.
>>
>> The limits to a commutators' RPMs are due to the material that it is
>> constructed from. In ye olde days of double-breasted sandshoes and
>> leather
>> flywheels (as my electronics instructor of 20-odd years ago used to put
>> it)
>> commutators were constructed mechanically. The commutator bars were
>> insulated with mica sheet and held in place by steel rings each end. The
>> limit on RPMs with this method is when the copper of the bar 'bows out'
>> enough to allow the mica to come loose or cause brush problems, or the
>> copper bar breaks.
>>
>> In more recent decades, commutator bars are held in by a hard plastic of
>> some description - generally 'bakelite' or a similar product. If this
>> gets
>> too hot, or exceeds its' mechanical strength, a single bar is loosened
>> first, and nothing is there to stop it flying out, so EVERYTHING gets
>> smashed, brush gear, all the other comm bars (which as soon as the first
>> bar is loose quickly follow).
>>
>> Madman pointed out on-list a couple of years ago that racer-EVers had
>> placed kevlar banding onto their commutators to prevent this wholesale
>> destruction in the event of comm failiure. I don't know how common this
>> method is, or how effective it is, so if anyone (Rich?) knows, please
>> post
>> it. Until Jim Husted recognised my commutator for a steel-ring type, I
>> had
>> planned on Kevlar banding my commutator, but there would be no benefit.
>>
>> Hope this helps
>>
>> James
>>
>
--- End Message ---
