EV Digest 6465
Topics covered in this issue include:
1) Re: contactor controllers (was RE: EV bashing, RE: T-105 Sitcker
Shock)
by Lee Hart <[EMAIL PROTECTED]>
2) Re: contactor controllers (was RE: EV bashing, RE: T-105 Sitcker Shock)
by "damon henry" <[EMAIL PROTECTED]>
3) Warp, ADC, rehash, was Battery amps in Uve's EV Calculator
by Jeff Shanab <[EMAIL PROTECTED]>
4) RE: T-105 Sitcker Shock
by Mark Brueggemann <[EMAIL PROTECTED]>
5) RE: Charger tweaks
by Mark Brueggemann <[EMAIL PROTECTED]>
6) Re: Fixing Mark's S-10 EV
by Mark Brueggemann <[EMAIL PROTECTED]>
7) Re: [electric_vehicles_for_sale] (fwd) VECTRIX Demo Bike Now Available For
Te...
by "Charles Whalen" <[EMAIL PROTECTED]>
8) RE: Fully sprung 'direct drive' (was: Regenerative suspension)
by "Randy Burleson" <[EMAIL PROTECTED]>
9) RE: T-105 Sitcker Shock
by Cor van de Water <[EMAIL PROTECTED]>
10) Re: Fully sprung 'direct drive' (was: Regenerative suspension)
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
11) RE: Regenerative suspension
by Cor van de Water <[EMAIL PROTECTED]>
12) RE: Fully sprung 'direct drive' (was: Regenerative suspension)
by Cor van de Water <[EMAIL PROTECTED]>
13) RE: Fully sprung 'direct drive' (was: Regenerative suspension)
by Cor van de Water <[EMAIL PROTECTED]>
14) FW: I like this drag bike better than Killacycle
by Mike Willmon <[EMAIL PROTECTED]>
15) Commutators, was: Battery amps in Uve's EV Calculator
by Cor van de Water <[EMAIL PROTECTED]>
16) Re: Optima batteries
by "Chris" <[EMAIL PROTECTED]>
17) RE: Fully sprung 'direct drive' (was: Regenerative suspension)
by "Randy Burleson" <[EMAIL PROTECTED]>
18) Re: Regenerative suspension
by "Kaido Kert" <[EMAIL PROTECTED]>
--- Begin Message ---
From: Jack Murray
>I've been thinking of giving this a try, I got in the new $64 kilovac
>contactor, looks good, at that price you can use three or four of them,
>and use the micro to turn them on/off. The question is how much noise
>do they make, and how fast will they wear out using them this way?
Contactors built for EV service are usually rated for 100,000 operations at
rated load, and 1,000,000 operations at light load. This is many years of daily
driving.
They typically make a distinct "click" when they pull in, and "clunk" when they
drop out. You'll hear it if they are mounted in the open, or as something that
acts as a sounding board; but they're pretty quiet in an electrical box (and
you shouldn't be leaving them out in the open anyway, due to the shock hazard).
>It will definitely require having a battery balancing charger because
>the lower voltage bats in the pack are going to drain a lot more than
>the higher voltage bats.
Contactor controllers normally wire the batteries in series and parallel
combinations, so you always have all of them carrying an equal part of the
load. This also means *less* battery management is needed (at least with
lead-acid), because when they are in parallel they automatically tend to
equalize the charge between them.
A typical setup might have eight 12v batteries, which can be wired as:
- 4 groups of 2 in series, for 24v
- 2 groups of 4 in series, for 48v
- all eight in series, for 96v
Such a controller would have 5 steps:
1. off
2. 24v with starting resistor in series (to start motor without a jerk)
3. 24v direct to motor
4. 48v to motor
5. 96v to motor
Such a controller has ten SPST contactors (though it is more common to use
three DPDT, and two SPST).
Note that you don't need expensive high-voltage contactors like the Kilovacs.
With the above setup, most of the contactors never see more than 24v, or more
than half the motor current; this allows the use of much cheaper golf cart
contactors.
--
Lee Hart
--- End Message ---
--- Begin Message ---
From: Jack Murray <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: contactor controllers (was RE: EV bashing, RE: T-105 Sitcker
Shock)
Date: Fri, 23 Feb 2007 19:05:41 -0800
I've been thinking of giving this a try, I got in the new $64 kilovac
contactor, looks good, at that price you can use three or four of them, and
use the micro to turn them on/off. The question is how much noise do they
make, and how fast will they wear out using them this way?
It will definitely require having a battery balancing charger because the
lower voltage bats in the pack are going to drain a lot more than the
higher voltage bats.
Jack
Actually contactor controllers balance the batteries for you if you put them
together properly. For simplicity sake lets say you have 4 12volt batteries
in three steps. The lowest speed puts all for batteries in parallel for 12
volts across the motor. The next step gives you two sets of two batteries
in parallel for 24 volts across the motor. Your top speed comes when you
put all four batteries in series for 48 volts across the motor. In the two
steps that have batteries in parallel there is some natural battery
balancing going on between the batteries connected in parallel.
damon
_________________________________________________________________
Don’t miss your chance to WIN 10 hours of private jet travel from Microsoft®
Office Live http://clk.atdmt.com/MRT/go/mcrssaub0540002499mrt/direct/01/
--- End Message ---
--- Begin Message ---
I didn't mean to sound like I was netgain bashing, I wasn't. In truth, I
think it is just the way the industry has gone. Netgain has those motors
built and they have to work with what is offered. The only gripe I may
of had was the Hype was more than the reality.
I have been mulling over how to upgrade my EV this summer and had 2
senario's for you Jim, and wanted to get your thoughts. Might as well
ask in the open for all to get the benifit.
Base Vehicle is the 300zx, heavy, poor choice, but I like it and there
are no hills here.
The tranny is sounding rather poor and this may be a source of energy
loss. Geting tires of shifting anyway, I'd like to eliminate the tranny.
As this vehicle is heavy, I think my high amperage starts are wasteing
large amounts on energy fighting the advance of the motor. I would like
to play with an adjustable brush rigging. I think this condition exists
because it certainly has a different curve than before and it comes to
life at about 2000rpm. But this is seat of the pants stuff, so I need
ABR to play with. :-) (I "need", ROTFL)
Concept 1
Get a siamese 9 donateing my existing 9 to the mix. Drop it down in
the tunnel. While this is easiest for me I requires all the contactors
and a good way to move both ABR's hasn't come to me.
Concept 2
This vehicle has an independent rear suspension. Drop it out and
make a sub mounting plate that contains a gearbox with roller chain or
belt and put these two motors side by side, behind the diffy in,
ironically, the fuel tank area. Now the brush ends are side by side for
easy rigging and the motors are closer to the powered wheels.
What do ya think? Can wee build a rigging that goes from -90 degrees
(reverse) to +18degrees(full advance)? like a fwd and a reverse position
and then an advance for the 18degrees. Then I only need the S/P contactors.
--- End Message ---
--- Begin Message ---
--- Don Cameron <[EMAIL PROTECTED]> wrote:
> Lots of people are offering solutions to your complaints,
> but you seem like you are not interested.
1. I am not complaining. I was stating my observations.
As individual to me and my EV as they may be, I did not
make them up.
2. Other than a suggestions of alternate battery sources
and brands, there have been no other practical solutions
offered. Because there really aren't any. I didn't expect
a magic answer, I was just trying to sanity check the price.
> What is it that you are after?
Input about battery prices from those that may be better
informed as to why I got the quote that I did. I don't
buy batteries very often, and don't watch that market.
> Is it simply to say that EVs don't work for you?
It works fine for me. Never said it didn't. Wouldn't
it seem kind of odd for me to show up after almost 10
years and 50k miles to say they don't work?
> Are you trying to convice others to avoid EVs?
Nope. Quite the contrary, I have assisted dozens of others
on construction of their EV's over the years. Some may
still be on EVDL.
> If you have a specific EV need that you want truly want
> solved, then post your question.
Question was posted, and answered.
I find it curious that my position has been transformed
from stating EV's aren't cost effective to "anti-EV"
and "EV bashing" in the thread's subject line. Lighten
up folks, I'm not the enemy. I just reported my observations
and experiences. Sorry if they're not as upbeat as you'd
like to hear. If you've got a better way of doing it, let us
know so we can all benefit. Look at it this way- if you can
convince me, you can convince anyone.
Mark Brueggemann
Albuquerque, NM
S-10 EV
--- End Message ---
--- Begin Message ---
--- Cor van de Water <[EMAIL PROTECTED]> wrote:
> use either a 6V transformer with two separate secondary windings
> or two 6V transformers,
Yeah, I guess as long as you keep it balanced you're OK. Problem
would be coming up with two identical 30A 6V transformers. By
the time I go through all that, and incorporate appropriate
control I might as well just replace the whole thing.
> Alternative is to remove wiring at the primary side to
> cranck up the ratio,
I've also read about dinking with the capacitor but that also
comes with negative side effects. It's been a wonderfully
reliable system (albiet a bit inefficient), I'd hate to
compromise that. Thanks for the advice though.
Mark Brueggemann
Albuquerque, NM
S-10 EV
--- End Message ---
--- Begin Message ---
--- jerryd <[EMAIL PROTECTED]> wrote:
Hi Jerry;
> I'd start by replacing the cab, front with an RX-7
> front 1/2, saving about 500lbs, next replace the bed with a
> composite aero one, saving about another 125 lbs.
I agree with your weight estimates, but somehow I don't
think an RX-7 would fit over what's already there. An
S-10 front clip/cab is a lot taller. It would be a difficult
retrofit, if even possible. The idea of an RX-7
pickup conjurs an interesting image, I'll grant you
that.
> Your EV weighs 4600 lb - 1600 lbs batteries weighs
> 3000 lbs.
It did with T-125's. About 4150 with T105's. I think
your original weight estimate is closer to being correct.
This might be a grand idea if you're building from the
ground up, but this is a running vehicle. Seems you'd
be better off scrapping the S-10 and building an RX-7
EV with the parts, no? I understand where you're coming
from and pretty much agree with your assesments, but
I think it would be a lot more work to retro an RX-7
body onto an S-10 frame then just make a lighter, better
aero EV out of the RX-7 to begin with.
> to be honest, pick ups are not known for safety either.
Lots safer than wood and epoxy trikes, methinks.
Something I should mention is I'm kind of a stickler on
the safety aspect of EV's. I would probably never do
as you propose, even if it was mechanically possible
because you're severely compromising the crash integrity
of the vehicle. I suppose a roll cage is an option,
but not terribly practical in a daily driver. I know
you're a big fan of lightweight ultra efficient EV's,
but I don't see them as practical transportation. The
common sense check I use is, is this vehicle something
I would entrust the lives of my son or daughter to?
It's one thing if you want to assume that risk personally
(as I do riding a motorcycle) but I wouldn't endorse
building ultralights as a transportation solution. It's
bad enough on the roads as it is, and in a homebrew you
don't stand a chance in the event of even a minor collision.
And, I don't think it does a lot for the image of EV's when
the public sees you riding around in a science project.
Just my opinion though (as if everyone hasn't heard
enough of mine already).
> As for driving fast, one can drive smart like drive
> 1/2 mile ahead to be in the correct lane, not speeding to a
> red light, less slowing, stopping and still get there as
> fast or even faster on much less energy than many driving
'fast'.
Techniques one learns early on in EV ownership. I rather
enjoy playing 'tag' with the ICE racers on the commute
to work, watching them as the zip and zag through traffic
so they can beat everyone to the red light, while I plod
along and coast up right back next to them.
Mark Brueggemann
Albuquerque, NM
S-10 EV
--- End Message ---
--- Begin Message ---
Hi Mike,
No, I haven't yet taken delivery of the bike I've had on order for almost 3
years now. I've been given a tentative delivery timetable of sometime this
spring and currently have an email into the company seeking an update on
that. I have seen final production version bikes up close but have only
ridden several of the earlier prototypes a few years ago, which I did take
up to the top speed of 62 mph. Acceleration was brisk and regen powerful on
those earlier prototype bikes I rode, never once had to use the friction
brakes. I've heard unofficial range figures of around 50 miles at 45 mph in
extensive range testing in New Bedford on the final production version
bikes, but I'll withhold judgment until I get my own bike and see what kind
of range I actually get out of it, although my range might be greater here
in pancake-flat, warm South Florida than elsewhere. Build quality of the
pilot production bikes looked good upon cursory inspection, but again I'll
withhold judgment until I get my own.
But I'm certainly not the right person to give a credible, unbiased,
objective opinion because I am an investor in the company. So I'll leave it
to others to take my bike (whenever I get it) and other Vectrix bikes around
the country for test rides and then report back to the list as they see fit
and call it as they see it, good or bad. Yet I have always been pretty open
and frank about what I see as some of the bike's shortcomings for the US
market and improvements I'd like to see for this market here (in this
country), as the bike was specifically designed for and is targeted
primarily at the Western European urban commuting market, where speeds are a
good bit lower than here. Specifically, the 62 mph top speed may work fine
for urban commuting in Western Europe, but I would have liked to see Vectrix
turn the controller up to 75 mph for this market here. That's one of the
biggest questions I get -- can we hack the controller and turn up the top
speed? I wish it were that easy, but I for one wouldn't be smart enough to
be able to figure that out, although I wouldn't put it past some people on
this list to be able to manage that. The bike is sort of
nominally/marginally "freeway capable", but what I tell people here is that
I only consider it "freeway capable" in US metropolitan areas during rush
hour traffic, otherwise I myself won't be taking this bike on the highway at
non-rush hour times and wouldn't consider it safe to do so with that 62 mph
controller-limited top speed. The company has always said -- well, we don't
want to turn the controller up that high because everyone will be tempted to
drive at that higher speed (or ... people are going to drive it at whatever
the top speed is, no matter how high you set it), which will bring down the
range unacceptably. My answer is that they shouldn't be making that choice
for the customer but rather should let the driver make that choice. We
EVers are smart enough to understand the trade-offs, which is something that
I do every day with my RAV4-EV. When I have to make a 100-mile leg on the
highway between charging stations, I drive at 55mph in order to ensure that
I will make it with enough margin to spare to give me some comfort. But
there are times, such as when I am merging on the highway, or when others
are doing so into the right-hand lane where I am driving, that I need to
briefly take the car up to 70 or 75 mph for safety reasons. Then when I've
gotten out of a jam and the coast is clear, I ease it back down to 55mph.
But I know that if I drive the car continuously at 75 mph, my range is going
to be shot and I won't make it to my destination. Vectrix should let its
customers have the same flexibility and decision-making capability to manage
the speed/range trade-off curve themselves, and especially to have that
extra headroom and margin of safety to take it up to higher speeds when
necessary. As one sage old EV pioneer here in Florida told me recently, the
company will get the message pretty quickly when their US dealers start
giving them this feedback and telling them this.
The other thing I am disappointed about is the big sticker-shock $11k price,
which caused me to gasp and almost fall out of my chair when I first heard
about it last summer. But as was explained to me, the price of nickel (the
main element in the NiMH batteries) had tripled over just the previous 9
months prior to setting the MSRP, and there were also sharp increases in a
number of other metals and commodity prices that make up the bike's raw
material inputs, all of which forced a big upward adjustment in the final
MSRP over previous years' estimates.
Other than that, what can I say?, seems like a great bike! :-) And indeed,
I am looking forward to getting it soon. I will report back on my
speed/range experience. One positive is the 10-year life on the NiMH
batteries, which those of us who already drive NiMH-powered EVs -- ranging
from 5 to 9 year old packs -- are getting pretty comfortable accepting as
well tested.
The first Vectrix dealer in the US to have a demo bike now available for
test rides is BMW Motorcycles of Scottsdale, Arizona:
BMW Motorcycles of Scottsdale
14870 N. Northsight Blvd., Suite 100
Scottsdale, AZ 85260
A few of Vectrix's other US dealers are:
Vespa Soho
13 Crosby St.
New York, NY 10013
Vespa Miami
2010 Biscayne Blvd.
Miami, FL 33137
Vespa Ft. Lauderdale
2601 N. Federal Hwy.
Ft. Lauderdale, FL 33306
Vespa Palm Beach
1609 S. Dixie Hwy.
W. Palm Beach, FL 33401
Bentley, Lamborghini, and Lotus San Francisco
999 Van Ness Ave.
San Francisco, CA 94109
Rockridge Two Wheels
5291 College Ave.
Oakland, CA 94618
Vespa Walnut Creek
1813 Mt. Diablo Blvd.
Walnut Creek, CA 94596
More dealer announcements will follow in the next few weeks.
US sales and deliveries will start in the second quarter of this year, in
limited quantities.
Vectrix continues to do Ride 'n Drive events around the country, including
one at 2pm tomorrow afternoon, Saturday Feb. 24, in Atlanta at Georgia
Power's headquarters, courtesy of Don Francis, who was kind enough to
arrange it and secure permission on short notice.
Charles Whalen
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: <ev@listproc.sjsu.edu>
Sent: Friday, February 23, 2007 4:28 PM
Subject: Re: [electric_vehicles_for_sale] (fwd) VECTRIX Demo Bike Now
Available For Te...
Attn: Charles Whalen
Did you take delivery of the Vectrix that you had on order? If so what can
you share with us about this machine? Did it measure up to the promises in
terms of range, top speed, build quality, etc.?
Mike Bachand
Denver Electric Vehicle Council (DEVC) - Colorado Chapter of the EAA
1994 Kawasaki Ninja EV
--- End Message ---
--- Begin Message ---
Thanks, Michael, for the real-world verification of my suppositions!
I've eyeballed the Freeway setup before with interest.
> The motor "fed" a counter-shaft, which drove the rear wheel.
> There were several problems, mostly in that the counter-shaft
> wasn't quite on the pivot point. <snip> Climbing the killer hill,
> torque would lift the rear of the car, causing the belts to ratchet.
Ratchet -- meaning slip and catch, slip and catch, and so on? I'm
picturing a not-so-enjoyable pogo-ing of suspension jacking, belt slip,
and gravity.
> Reverse the polarity and you had to use a velvet foot or the
> suspension would "crash" to its upward position... with a
> scary crunch.
I need this in smaller chunks. *grin* What do you mean by "reverse the
polarity?"
> Mount the motor near the pivot, or perhaps on the opposite side of the
pivot.
Clever neutralization of sprung weight, though I think the mass probably
still pays the piper.
I like it just from the simplified two-cog drive, which should be pretty
simple to prototype in steel. Agreed that a pillow block would help
minimize shaft deflection stress at the motor.
> I think up to 50% of my power was lost through the system I used.
To clarify, that seems like a huge loss -- is that through belt slip,
shaft deflection, need for adjustment, and cogged belts?
Randii
--- End Message ---
--- Begin Message ---
Mark,
Did you contact the battery dealer or the manufacturer directly?
My batteries (12V 110Ah AGM) are retailing over $200 but when buying from
the manufacturer in bulk,
they were about $85 for the order, before the price increase - now about
$100 each.
So I got a pack last year for $2200 with higher capacity as others who were
not scouting around and paying $5000.
For two pallets worth (combining my order and two other EV'ers in the area)
it was certainly worthwhile to go through this hassle.
Success,
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mark Brueggemann
Sent: Friday, February 23, 2007 9:33 PM
To: ev@listproc.sjsu.edu
Subject: RE: T-105 Sitcker Shock
--- Don Cameron <[EMAIL PROTECTED]> wrote:
> Lots of people are offering solutions to your complaints, but you seem
> like you are not interested.
1. I am not complaining. I was stating my observations.
As individual to me and my EV as they may be, I did not make them up.
2. Other than a suggestions of alternate battery sources and brands, there
have been no other practical solutions offered. Because there really aren't
any. I didn't expect a magic answer, I was just trying to sanity check the
price.
> What is it that you are after?
Input about battery prices from those that may be better informed as to why
I got the quote that I did. I don't buy batteries very often, and don't
watch that market.
> Is it simply to say that EVs don't work for you?
It works fine for me. Never said it didn't. Wouldn't it seem kind of odd
for me to show up after almost 10 years and 50k miles to say they don't
work?
> Are you trying to convice others to avoid EVs?
Nope. Quite the contrary, I have assisted dozens of others
on construction of their EV's over the years. Some may
still be on EVDL.
> If you have a specific EV need that you want truly want
> solved, then post your question.
Question was posted, and answered.
I find it curious that my position has been transformed
from stating EV's aren't cost effective to "anti-EV"
and "EV bashing" in the thread's subject line. Lighten
up folks, I'm not the enemy. I just reported my observations
and experiences. Sorry if they're not as upbeat as you'd
like to hear. If you've got a better way of doing it, let us
know so we can all benefit. Look at it this way- if you can
convince me, you can convince anyone.
Mark Brueggemann
Albuquerque, NM
S-10 EV
--- End Message ---
--- Begin Message ---
HI-
why not replace the swing arm pivot with the motor it's self.
press into the arm.a custom double end shaft with long enough
bearing surfaces to hold two bearings on each end of the motor.
then attach the swing arm to the outer bearings.
FT.
> [Original Message]
> From: Michael Perry <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Date: 2/23/2007 9:25:00 PM
> Subject: Re: Fully sprung 'direct drive' (was: Regenerative suspension)
>
> How do you avoid squat? That's one of the considerations on most MC's.
Even
> using drive shafts, bikes do squat under power. It's even worse when full
> power is reversed... something 2 wheel MC's don't encounter.
>
> As you say, hub motors don't have this problem, since the thrust is
against
> the center shaft. What you get there, even with bicycle sized rigs, is
that
> the forks must be strong enough to withstand the torque. A bike with
> standard forks may not be strong enough to withstand even the small force
of
> accelerating a bicycle. The hub may actually spread the fork and escape.
> (Nothing so much fun as having a front hub motor escape, leaving your with
> front forks digging into the pavement at 25MPH!)
> ----- Original Message -----
> From: "Jeff Shanab" <[EMAIL PROTECTED]>
> To: "Electric Vehicle Discussion List" <ev@listproc.sjsu.edu>
> Sent: Friday, February 23, 2007 8:58 PM
> Subject: Fully sprung 'direct drive' (was: Regenerative suspension)
>
>
> > Actually that is to be avoided at all costs. You must maintain balanced
> > forces or the power will effect the suspension and make it almost
> > undriveable.
> >
> > Even on moutain bikes with rear suspension, pains are taken to make sure
> > the tension on tha chain doesn't cause a squat or a hiking of the
> > suspension.
>
--- End Message ---
--- Begin Message ---
Hi Perry,
No problem, I like a discussion as I am no expert on handling of a car. Like
many here, I am EE and need to dig deep into my memory for the physics
lessons at school (for some reason, EE's got the same math as the math
programs and in addition the same physics as the physics studies programs,
before getting into the EE subjects. Kind of a double whammy.)
My feeling is that it won't work the way you described, so let me try to
build an argument, then others can fire away and shoot holes in it:
Sure you can reduce the regen on the wheel for the stroke back after the
bump, but then the wheel is:
a. not dampened, it has only the spring, so it will bounce once it hits the
street
b. since the spring is weaker than normal, the force is lower and thus the
time it takes to move back is longer, so the wheel will not follow the
(sharp) bump, but lose contact with the road and for a short distance the
wheel is airborne.
So, eventually it will be back on the road, but it will take longer because
of the weaker spring and it may bounce if it is not dampened, making the
road contact even worse.
That is why I referred to electronic suspension, which will counter-act all
of this by using sensors and actuators, but then you are feeding power to
the suspension, not getting it back.
In essence, I think that it could be possible to retrieve a positive energy
flow from the suspension - at least in theory, but in practice I see lots of
pitfalls and possible handling problems, so I rather not mess with the
suspension. To me it is more a safety thing, I know what to do to the wheels
to optimize range and how to optimize the toe of the wheels to reduce
friction, but I doubt that suspension is a good area to gain much from,
while the opportunities to do harm are very large, so this does not look
like a good trade-off to me.
Interesting subject though.
<Your opinion may vary>
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Michael Perry
Sent: Friday, February 23, 2007 6:38 PM
To: ev@listproc.sjsu.edu
Subject: Re: Regenerative suspension
I am trying to figure this out. Forgive me if I'm being dense here, but...
If you use a light spring, you'd get lots of travel. I can see that. What I
don't see is why it would not allow the wheel to move back into contact with
the street.
As I recall, some shocks (most?) have a valve in them that can vary the
resistance of the stroke, depending on the direction the shock is traveling.
I don't see why this system couldn't do the same. If the windings were
playing against a fixed magnet, you'd get more resistance as the shock
traveled quickly... but if the magnet was similar to an alternator, you
could vary the field. If returning the wheel downward quickly was the goal,
couldn't you simply eliminate (or reduce) the field voltage?
----- Original Message -----
From: "Cor van de Water" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, February 22, 2007 11:36 PM
Subject: RE: Regenerative suspension
> What I see as a severe problem in "regenerative suspension" is that it
will
> not very well... regenerate.
>
> Oh sure, it will initially generate a burst of power when a bump is hit,
but
> if you try to tap that power to the max, this means that the spring must
be
> very weak. Now, your wheel will move *up* the bump, but not back, so you
> lose contact with the road after the bump and you may crash.
--- End Message ---
--- Begin Message ---
The (anti-) squat is not so strange, if you conside that the rear wheel is
the driven wheel,
so on acceleration the rear wheel's contact patch on the road pushes the
vehicle, which is a forward/upward move,
which will tilt the vehicle forward, especially if the centre of gravity is
low (batteries near the front axle).
All cars tilt backwards, because the wheels try to accelerate the bottom of
the car forward, so it tilts backward around its centre of gravity. If cars
had a swing-arm and a (high) pivot point, then a rear wheel driven car would
also tilt it forward.
Tilting backward while braking has to do with the force from the rear wheel
on the road, pulling the wheel with a force in flat rear direction. The
wheel can only exert a force via the swing arm which gives a counter-force
in forward/upward direction. The forward and rearward forces cancel out (the
wheel does not move relative to the swing arm) but the upward force remains,
so the wheel compresses the spring more to counter-act that force and the
swing arm "digs in" on braking.
This way of movement is actually very natural, you need to lean backwards
when decelerating to maintain good balance and forward when accelerating, a
4-wheel car handles opposite to normal in that respect. The axle loading of
a 3-wheeler (or any vehicle with rear wheel drive on swing arms) will stay
better balanced than a normal 4-wheeler.
Regards,
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Randy Burleson
Sent: Friday, February 23, 2007 6:58 PM
To: ev@listproc.sjsu.edu
Subject: RE: Fully sprung 'direct drive' (was: Regenerative suspension)
> * anti-squat upon acceleration (swing-arm pushes the tail end up) and
> * squat upon deceleration (swing-arm pulls the tail end down) I think
> this is backwards for chain driven rear wheels, after all thats how we
> do wheelies.
It is counter-intuitive, but true. Wheelies are more about weight transfer
than squat/antisquat. Long ago, I two-wheeled almost exclusively, but a
combination of skills atrophy and California traffic finally led me to
retreat from two wheels. From long distant recollection, IIRC, Keith Code
well-explained the various rear-wheel forces at work in "A Twist of the
Wrist" book.
> > I guess that I need to white-board a vector diagram out, ...
> I have the URL of a calculator for all this at home I can post later.
Please post it -- I fear that I may be getting lost in the forest, staring
at tree roots.
> Perhaps I am just chicken little.
I'd rather read the concerns here, and consider them, than experience them
later on my own, as I slide along the pavement. Been there, and done that...
one of the other reasons I retired from two wheels.
> > > nor would I want to deal with the effect of adding unsprung
weight.
> > Definitely a concern, but negative effects should be reduced ... by
> > anchoring the motor close to the swingarm pivot.
> This I agree with ;>)
Whew, I'm not totally in the ozone. :p
> I'd very much like to hear your battery-motor-weight calcs, as I am
> penciling out various options now.
I'm not even to the point of penciling weights yet... though I'm more than a
few pages into a new design notebook. I'm currently rewiring the dash on my
hobby 4x4 to work with the SEFI Ford 302 I swapped into it.
If anyone is curious, there are some truly bandwidth-abusive ICE swap
pictures at: http://staff.4x4wire.com/randii/motor/
Some type of ultra-efficient vehicle is the next project. I started thinking
it would be based off an ICE economy car, but I believe that the good folks
on this list are to blame in ensuring that it will likely be an Electric
Vehicle.
Randii
--- End Message ---
--- Begin Message ---
Well, the solution to avoid squat is really simple.
Make sure that the line from rear wheel contact patch with the road, via the
pivot point of the swing arm, goes through the centre of gravity of the rest
of the vehicle.
That way, no matter how hard you accelerate, the vehicle will be balanced
around the force vector and not move up or down.
With batteries low, this means that the swing arm pivot must be low as well,
possibly barely above the bottom of the vehicle. Stiff springs help too, in
case you did not get it exactly right.
NOTE that a little anti-squat during acceleration and a little squat during
braking may be helpful to keep the vehicle straight, as the front suspension
will come up during acceleration as well and upon braking it will dig in, so
it helps if the rear suspension is making the same move.
Regards,
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John Fisher
Sent: Friday, February 23, 2007 8:03 PM
To: ev@listproc.sjsu.edu
Subject: Re: Fully sprung 'direct drive' (was: Regenerative suspension)
Hey Randy see interspersed comments.
Randy Burleson wrote:
>> * anti-squat upon acceleration (swing-arm pushes the tail end up) and
>> * squat upon deceleration (swing-arm pulls the tail end down) I think
>> this is backwards for chain driven rear wheels, after all thats how
>> we do wheelies.
>>
> It is counter-intuitive, .... Keith Code well-explained the various
> rear-wheel forces at work in "A Twist of the Wrist" book.
>
Ahem.
I don't know Keith personally, but I do know lots of people who do, and
people who are physicists who do, and lets just say he's not a scientific
authority, even to people who like him. He has some good pointers in the
books, and the school is deemed worthwhile by people I respect, though I'd
go elsewhere.
But I am frequently befuddled so I'll look it up in Tony Foale's book. I may
have the definition reversed....
>>> I guess that I need to white-board a vector diagram out, ...
>>>
>> I have the URL of a calculator for all this at home I can post later.
>>
> Please post it -- I fear that I may be getting lost in the forest,
> staring at tree roots.
>
http://www.tonyfoale.com/ has his book and his software. Said to be
very helpful over on the mc chassis list. The book is very good.
> I'd rather read the concerns here, and consider them, than experience
> them later on my own, as I slide along the pavement. Been there, and
> done that...
me too just last weekend. but on some hard dirt. Getting old and slow
sux except for the alternative. ;>)
> Whew, I'm not totally in the ozone. :p
>
Who knows? I am having fun. Maybe we'll each have something built one day.
>
> I'm not even to the point of penciling weights yet... though I'm more
> than a few pages into a new design notebook. ...
>
> Some type of ultra-efficient vehicle is the next project.
>
maybe we should compare notes off list. I am planning a fairly extensive
web site with details on the various options, EV and otherwise. I just
re-joined this list, but saw a post that someone has a lot of experience
with 3 wheelers and ultralights. Anybody out there?
John Fisher
--- End Message ---
--- Begin Message ---
My buddy found this today.
Someone tell me its actually an electric bike.
I can't quite make out the batteries.
From: Shawn Fitzpatrick
Sent: Fri 2/23/2007 4:37 PM
To: Mike Willmon
Subject: I like this drag bike better than Killacycle
http://community.webshots.com/album/96409308RfIrlb
--- End Message ---
--- Begin Message ---
This reminds me of an old motor I saw sitting outside a farm nearby.
To my astonishment, I noticed that the brushes were mounted directly under
the face of the motor, the rears almost sticking out of the face. Huh?
Then I noticed that it had a commutator *disk* so the brushes were pushing
against the bars (triangle-shaped) in the flat disk, this means that the
brush face was flat and that over-revving this motor should not result in
the bars flying or bending out...
Regards,
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jeff Shanab
Sent: Friday, February 23, 2007 7:04 AM
To: Electric Vehicle Discussion List
Subject: Re: Battery amps in Uve's EV Calculator
I dissassembled a warp 9's commutator and it was the cheapest,weakest type.
copper bars have little feet in the mica filled plastic. There are no
risers, just the windings welded to the bar. These "stacked" windings and
the fact that the welding probably compromises the plastic underneath if
done wrong leads to a failure-mode where the windings lift out the bars. In
my case the plastic just gave way, not 1 of the 59 bars broke the copper
nubs off in the plastic. In a pure case on irony, the ADC comms were better.
It annoys me that manufactures try to save a few bucks relative to the
overall sale price. At one time, I checked into a commutator manufacturer
and if 5 of us got together we could get the steel mica and copper v-ring
style commutators for about $110 each.
Jim Husted had pictures of my disassembled commutator up on his web site at
www.*hi**torque**electric*.com in the oops category, but I can't get to the
site this morning to check.
--- End Message ---
--- Begin Message ---
Sorry for just chiming in.
In this paper, there is an infra-red image of an Optima with an
internal short in an Optima
http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/evs_17paper.pd
f
The image is near the start of the paper, I wonder if this is the
sort of 'shorted heating' being referred to ? The paper has a lot of
other interesting Optima related information , but there is no
suggestion of fire, but the usual caveats must apply regarding
enclosed spaces and buildup of heat.
Chris
--- In [EMAIL PROTECTED], "Roger Stockton" <[EMAIL PROTECTED]>
wrote:
>
> [EMAIL PROTECTED] wrote:
>
> > occassionally, the spirals will short out, causing the
> > batteries to internally heat up and catch your vehicle on
> > fire .... :-( Normally, this sometimes occurs under high
> > amperage loads, but can happen under normal loads (50-150 amps).
>
> This is a very interesting statement. Can you provide any examples
> where this has happened?
>
--- End Message ---
--- Begin Message ---
> > It is counter-intuitive, .... Keith Code well-explained the various
> > rear-wheel forces at work in "A Twist of the Wrist" book.
> I don't know Keith personally, but I do know lots of people who do,
and
> people who are physicists who do, and lets just say he's not a
scientific
> authority, even to people who like him.
He certainly researches the heck out of things, and I won't question his
coaching skills! He may not be a 'pure' scientist, but he's nearly a god
to motorcyclists. The link provided by jmygann seems to support
torque-driven antisquat.
I'm definitely interested in hearing what Tony Foale's book has to say.
You probably just killed my spare time for weekend reading -- lots of
good stuff at: http://www.tonyfoale.com/
> Who knows? I am having fun. Maybe we'll each have something built one
day.
I'm certain my wife would prefer that I just discourage myself. :p
> maybe we should compare notes off list.
I'm happy to, John... I'm not sure how much I have to add yet, but I am
dug in and learning as I go.
> I am planning a fairly extensive web site with details on the various
> options, EV and otherwise.
Sounds promising.
Randii
--- End Message ---
--- Begin Message ---
btw, regen suspension should work best on e-bikes first.
mountainbikes already have shocks, and they have battery-assist. now
with bike, when you hit the bumps it slows you down alot, and you
immediately feel how going gets much harder, i.e. you have to pedal
out more watts.
regen shcoks should help there by a bit. price of such system would
probably be out of range though for common buyers.
-kert
On 2/24/07, Cor van de Water <[EMAIL PROTECTED]> wrote:
Hi Perry,
No problem, I like a discussion as I am no expert on handling of a car. Like
many here, I am EE and need to dig deep into my memory for the physics
lessons at school (for some reason, EE's got the same math as the math
programs and in addition the same physics as the physics studies programs,
before getting into the EE subjects. Kind of a double whammy.)
My feeling is that it won't work the way you described, so let me try to
build an argument, then others can fire away and shoot holes in it:
Sure you can reduce the regen on the wheel for the stroke back after the
bump, but then the wheel is:
a. not dampened, it has only the spring, so it will bounce once it hits the
street
b. since the spring is weaker than normal, the force is lower and thus the
time it takes to move back is longer, so the wheel will not follow the
(sharp) bump, but lose contact with the road and for a short distance the
wheel is airborne.
So, eventually it will be back on the road, but it will take longer because
of the weaker spring and it may bounce if it is not dampened, making the
road contact even worse.
That is why I referred to electronic suspension, which will counter-act all
of this by using sensors and actuators, but then you are feeding power to
the suspension, not getting it back.
In essence, I think that it could be possible to retrieve a positive energy
flow from the suspension - at least in theory, but in practice I see lots of
pitfalls and possible handling problems, so I rather not mess with the
suspension. To me it is more a safety thing, I know what to do to the wheels
to optimize range and how to optimize the toe of the wheels to reduce
friction, but I doubt that suspension is a good area to gain much from,
while the opportunities to do harm are very large, so this does not look
like a good trade-off to me.
Interesting subject though.
<Your opinion may vary>
Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Michael Perry
Sent: Friday, February 23, 2007 6:38 PM
To: ev@listproc.sjsu.edu
Subject: Re: Regenerative suspension
I am trying to figure this out. Forgive me if I'm being dense here, but...
If you use a light spring, you'd get lots of travel. I can see that. What I
don't see is why it would not allow the wheel to move back into contact with
the street.
As I recall, some shocks (most?) have a valve in them that can vary the
resistance of the stroke, depending on the direction the shock is traveling.
I don't see why this system couldn't do the same. If the windings were
playing against a fixed magnet, you'd get more resistance as the shock
traveled quickly... but if the magnet was similar to an alternator, you
could vary the field. If returning the wheel downward quickly was the goal,
couldn't you simply eliminate (or reduce) the field voltage?
----- Original Message -----
From: "Cor van de Water" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, February 22, 2007 11:36 PM
Subject: RE: Regenerative suspension
> What I see as a severe problem in "regenerative suspension" is that it
will
> not very well... regenerate.
>
> Oh sure, it will initially generate a burst of power when a bump is hit,
but
> if you try to tap that power to the max, this means that the spring must
be
> very weak. Now, your wheel will move *up* the bump, but not back, so you
> lose contact with the road after the bump and you may crash.
--- End Message ---
