EV Digest 6741
Topics covered in this issue include:
1) Tube Frames and Skins (RE: DD, Cog Calcs, aero)
by "Randy Burleson" <[EMAIL PROTECTED]>
2) RE: Jay Leno no friend of electric cars.
by "Randy Burleson" <[EMAIL PROTECTED]>
3) Re: Jay Leno's quote - how it really happened
by "Michael Perry" <[EMAIL PROTECTED]>
4) RE: EV on a dyno in CA?
by "Myles Twete" <[EMAIL PROTECTED]>
5) RE: DD, Cog Calcs, aero
by "Randy Burleson" <[EMAIL PROTECTED]>
6) RE: DD, Cog Calcs, aero
by "Randy Burleson" <[EMAIL PROTECTED]>
7) Re: 1994 Toyota 2WD conversion
by Frank John <[EMAIL PROTECTED]>
8) Re: 1-Wire Expertise
by Rod Dilkes <[EMAIL PROTECTED]>
9) Re: EV on a dyno in CA?
by "Mike Phillips" <[EMAIL PROTECTED]>
10) Re: AGNS takes 96 volt motorcycle record
by "Bob Rice" <[EMAIL PROTECTED]>
11) Re: Jay Leno no friend of electric cars.
by "Bob Rice" <[EMAIL PROTECTED]>
12) Re: FW: Jinxed! ( Now - Belktronix)
by "Timothy Balcer" <[EMAIL PROTECTED]>
13) PFC-20
by <[EMAIL PROTECTED]>
14) Re: Jay Leno's quote - how it really happened
by "Timothy Balcer" <[EMAIL PROTECTED]>
15) Re: 1-Wire Expertise
by Steve <[EMAIL PROTECTED]>
16) Re: PFC-20
by "Roland Wiench" <[EMAIL PROTECTED]>
17) Re: AGNS takes 96 volt motorcycle record
by Bill Dube <[EMAIL PROTECTED]>
18) Jay Leno and RAV4-EV
by JS <[EMAIL PROTECTED]>
19) Over voltage in a pack
by "Timothy Balcer" <[EMAIL PROTECTED]>
20) Re: Jay Leno's quote - how it really happened
by "Bob Rice" <[EMAIL PROTECTED]>
21) Re: FW: Jinxed! ( Now - Belktronix)
by "Bob Rice" <[EMAIL PROTECTED]>
22) Re: Jinxed! ( Now - Belktronix) LINK
by Mark Dutko <[EMAIL PROTECTED]>
23) Re: Jinxed! ( Now - Belktronix) LINK
by "Timothy Balcer" <[EMAIL PROTECTED]>
24) Re: DD, Cog Calcs, aero
by Lee Hart <[EMAIL PROTECTED]>
25) Re: 1-Wire Expertise
by Lee Hart <[EMAIL PROTECTED]>
26) RE: AGNS takes 96 volt motorcycle record
by "Myles Twete" <[EMAIL PROTECTED]>
27) Re: EV on a dyno in CA?
by John Fisher <[EMAIL PROTECTED]>
28) Re: DD, Cog Calcs, aero
by John Fisher <[EMAIL PROTECTED]>
29) Re: 1-Wire Expertise
by Danny Miller <[EMAIL PROTECTED]>
--- Begin Message ---
> Hey stick to DOM tubing as you say...
Definitely for proof of concept. I may do successive 'drafts.'
> The sand rails use fabric to make skimpy little body panels.
> It looks pretty good, perhaps you've seen them? I am going
> to try it, as its ultra-light and cheap.
Yup, I have a little experience with rails... and a good bit more with
their beefier cousins, rock buggies. Both are weight-sensitive but built
stout to survive a tumble -- there are certainly ways to optimize
strength out of panels, if you know the loads exactly, but for quickness
of build and toughness, tube frame is tough to beat.
There are multiple options for 'skinning' a tube frame:
- fabric (can be stretched with elastic, or doped to shrink like they
did on old planes)
- thin plastic or metal panels
- fiberglass/composite
I'm open to other lightweight ideas... keeping panels in tension within
-- or over -- a tube frame is pretty simple. Getting stiffness out of
them is a good bit more challenging.
Rolling in beads helps prevent 'oil-canning' but I expect to be
challenged by the 'floor.' The classic 'production' way around this is
to stamp-form enough contour to enhance stiffness, but since I'm looking
to get a flat bottom out of my floor, that'll be a challenge. I'll burn
this bridge when I get to it, but some sort of 'glass/foam sandwich
composite makes some sense, perhaps with wood, aluminum, and/or
honeycomb composition. Actual loads can be kept pretty minimal -- seats
and battery boxes will mount to the tube frame. It will need to support
ingress which will be sit-pivot-and-drop a' la Wrightspeed, Ariel Atom,
Lotus Elise 340R, etc. A tougher load-case is the opposite egress
process -- that's the only real load the floor will be subjected to...
Describing this, I find myself thinking of some sort of aluminum
slatting for stiffness, with lightening holes cut as needed.
> I am right with you on the steel tube bumper on the sides.
I'm thinking of it more as a 'door beam' or 'crash bar,' but we're
otherwise in synch.
Randii
--- End Message ---
--- Begin Message ---
> I think his opinion that electrics haven't come very
> far is reasonable, if you're comparing to ICE development.
> But to me that means the development is still ahead of us,
> not all played out.
AWESOME last sentence, Marty -- it is exciting to think about what
opportunities lie ahead!
Randii
--- End Message ---
--- Begin Message ---
"The electric car is dead" has been attributed to Edison... except the year
the note was supposedly passed changes with the teller of the story. It
might well be an urban legend.
As I recall, it was somewhere around this time (1896) when one of the
world's great scientists proclaimed that there was nothing worthwhile left
to invent.
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Saturday, May 05, 2007 10:25 AM
Subject: Re: Jay Leno's quote - how it really happened
> Mark Grasser wrote:
>
> I read the article while flying last week. The quote is at the end of the
> article. Thomas Edison passes a note to Henry Ford at the dinner table.
"The
> Electric car is dead"
>
> I would like to know the true context, was it because Edison drove the
> electric car to dinner and ran it dead to needing a charge? Another
> question, did Popular mechanics edit the article and in doing so inject
into
> Leno's article how they feel about electric cars?
--- End Message ---
--- Begin Message ---
Here in Portland, I'm working on my 1911 Hupp-Yeats Electric at a shared
workshop called "Shop People"---metal, wood, ceramics, forge, jewelry,
glasswork and more all in one facility---very lively atmosphere to be
working in. I'm also doing some of the blasting/paint prep work at a more
distant shared workshop that is specifically geared towards vintage car
work. The concept is good. There're a few of these shared places around
here that I know of---mostly woodworkers sharing the rent.
-Myles
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John Fisher
Sent: Saturday, May 05, 2007 7:51 PM
To: ev@listproc.sjsu.edu
Subject: Re: EV on a dyno in CA?
I live in Santa Barbara. Been talking about shared workshop space for
years, never done anything about it.
In this town it's probably hopeless due to cost of space, but its fun to
dream. It would work great down in the Valley though, not that that
would help me.
JF
Jeff Shanab wrote:
> John Fisher, Where in central Ca? I just asked if they had one close to
> fresno and I checked the "willing to manage" box.
>
> I worked in a moldmaking shop for years. I am almost suffering withdrawal.
>
>
--- End Message ---
--- Begin Message ---
> > It is simple for me to work in steel, and 2 pounds per
> > foot of .120-wall one-and-three-quarter tubing just
> > doesn't seem that much...
> How many ft of tubing will it take? How much would the body, floor
weigh?
Dunno yet. My 'fat' estimate allots 400lbs for chassis, but I'm having a
tough time seeing how I could possibly use more than 100' of tubing on
the outside (swingarm included) ... add the VW front axle.
> Air drag starts to get ahold of it just as the motor's power
> curve starts dropping so acceleration drops with it's single
> speed. I used 1/2 field weakening to move the torque curve up
> the rpm range so go to 60 mph but my use was in town so 45 mph
> was fine for it with more range. It would also go to 60 mph with
> a 48vdc pack instead of 36vdc and field weakening with better
> acceleration.
Excellent reference points -- I'm playing catch-up on the electrons side
of the business, so I'll need to experiment... thanks, as always for
giving me a GREAT head-start!
> You can find out the weight by listing all the parts, tubing,
> ect and adding the weight up!!
Dunno what's on that list, yet. Twiddly little stuff always adds up --
steering column, wiring, lighting, seats... I can't list what I don't
have but will try to keep a running tally.
> VW bug front ends weigh 165lbs complete without tires/rims.
Is that drum or disk?
>>>> 2f1r tadpole/tail-dragger profile should help (decrease drag)
>>> Not if you are a convertible or open top.
>> Tonneau should assist with this -- using a shorty windscreen
>> like the speedster can't hurt, either, but certainly there will
>> be unavoidable turbulence.
> That turbulance is THE problem, taking you from a say .25cd to a
> .40-.45cd.
That may indeed be a show-stopper, then -- I'm not going to flex on the
roadster design for Phase One. It allows a simpler, lighter design (no
doors, windows, or roof) that has easy rigidity.
> If you want range at speed, you need an aero roof or a hump
> behind you to gather the air back together and feed it cleanly
> aft. It's the purpose of the original head backrests on old
> racing cars, bigger than the helmet if worn, rounded front
> corners, gently curving inward to bring the air together aft...
This may be something I can explore later... it sounds like a tradeoff
of effective vs. attractive, IMHO. I definitely appreciate the continued
practical suggestions, Jerry.
> The Vortex was originally an EV and available in both
> versions.
Were the EV versions shorter, or did they have the same basic footprint?
Randii
--- End Message ---
--- Begin Message ---
> Have you read the book "How to Build a Cheap Sports
> Car"?
Not yet, Peter, but I'll add it to the reading list for my next overseas
flight. Thanks!
> This car uses a frame made from square steel tubing
> and the design is light enough for the author to hold
> the complete frame above his head.
I might have said this elsewhere, but IMHO the trick to lightweight is
knowing what your loads are, and building just to them... Google Altair
Computing and OptiStruct for the fullest example of that. Since I am
coming to this from a practical space, I'm building stronger across a
wider range... I doubt I'll be holding my frame overhead!
I'm definitely familiar with Riley's writings, plans, and techniques.
Good stuff, but I don't trust my foam-sculpting abilities.
Randii
--- End Message ---
--- Begin Message ---
Hi Adrian,
Battery placement (T125 GC size) will be very similar to the S-10: four on each
side of the driveshaft between the frame rails, eight behind the rear axle,
four up front (three where radiator was and one off to the side). That gives a
120 VDC system. To get more I'd have to have a "top row" immediately behind
the cab but there's room for seven batteries there (with a hole in the stock
bed for clearance). I'm considering only four batteries behind the rear axle
and using the top-row concept to move weight forward but that would complicate
maintenance with floodies. I have rear air bags to be installed and am
upgrading brake pads. I'm also thinking about making a flatbed with
lightweight materials but that's down the road. Phil Knox's aerodynamic mods
are very intriguing to me and homemade cargo area fits in with this concept.
These vehicles have a dynamic brake balancing arrangement (changes as rear ride
height drops) and I may bypass this for heavier full-time
braking at rear while maintaining stock ride height.
It's a tight fit between the frame rails as the driveshaft is offset to the
passenger side, shock mounts are splayed (one fore and one aft) and the
differential casting protrudes more on the driver's side but my louan box model
tells me it will work. I just ordered the mount steel so will know better in a
couple of weeks. I'd also like the idea of insulated boxes (I live in Maine)
but without heaters there's not much point. I'm not sure exactly how I'll
construct the boxes but might try to incorporate a bit of insulation where I
can.
Having two first names gives you a second-chance with missing hotel
reservations. :)
have fun!
----- Original Message ----
From: Adrian DeLeon <[EMAIL PROTECTED]>
To: "ev@listproc.sjsu.edu" <ev@listproc.sjsu.edu>
Sent: Sunday, May 6, 2007 12:34:31 AM
Subject: 1994 Toyota 2WD conversion
Frank John (John Frank?),
What is your battery layout going to look like? What type of battery?
I'm just starting a '93 Toyota (22RE) conversion and am still working on
battery type/placement. My goal is 26 T-105/125/145 OR 25 Group 31 AGMs.
Insulated boxes are a bonus..
So far I've had the upholstery fixed, upgraded to a speedo cluster WITH
tach, and I'm working on the tilt bed thing. A passenger side mirror may
be next.
Adrian
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--- Begin Message ---
Message-ID: <[EMAIL PROTECTED]>
Date: Sun, 06 May 2007 14:24:31 -0500
From: Danny Miller <[EMAIL PROTECTED]>
MIME-Version: 1.0
To: ev@listproc.sjsu.edu
Subject: Re: 1-Wire Expertise
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Well, it's completely possible to make a PIC with a software 1-wire on
an optically isolated bus. It requires 2 pins off the PIC to drive the
one bus and this is fairly straightforward.
It is technically possible to take a hardware device that already does
1-wire and make it isolated, but it requires quite a number of
components and may have some funky "gotchas". Basically not really
practical.
The PICs will need their own power supply relative to the battery
voltage they're reading. A 3rd power wire for the 1-wire bus can't
serve this purpose since all the devices need different voltages for
their + and - power wires.
1-Wire, like most all shared buses, has a tricky problem identifying
individual devices. If you have 20 devices, how do you know one from
another? In short they all have to have a unique ID number. In some
hardware 1-Wire or I2C devices, they might mfg 4 different parts with 4
different ID #s. Limits you to 4 of those devices at most, and an
annoying stocking problem- if you can't get all 4 of those you can't
build your system.
With a PIC you can come up with any number of ways to configure them.
DIP switches, jumpers, even solder jumpers on the board is one way.
Most PICs have a small nonvolatile EEPROM space that the code can write
and the data won't go away when you cycle power. You could designate a
write word that a dongel could send on the bus that would rewrite the
device ID and just hook them onto this programming rig one by one,
writing a different ID each time and put a sticker on the part "ID#xxxx"
so you know which batt is which.
Danny
Steve wrote:
>Hi,
>
> I have used various 1-wire devices for years, they are great devices.
>I have not used a voltage measuring device, which adds the
>complications of mixing the working supply and measured supply so I
>do not have an immediate answer. I assumme you are refering to the
>2760?
>
>
>
>>Subject: 1-Wire Expertise
>>
>>Anybody out there have experience with 1-wire devices? Maxim makes a
>>
>>nice 1-wire chip for monitoring voltage and temperature of a single
>>Li-ion cell. I've been looking at the possibility of putting one of
>>
>>those chips on each of my tracction pack cells and monitoring them
>>with
>>a Basic Stamp. In conversations with the Maxim's vendor support,
>>however, they told me that this plan wouldn't work, because the chips
>>
>>would all need a common ground, which wouldn't happen if each chip
>>were
>>on a different cell in a series string of cells. So I was wondering
>>if
>>the following would work:
>>
>>1) Basic Stamp is powered via an isolated 9V supply off of the 12V
>>system
>>2) Each Li-ion cell has chip on it, chip VSS tied to cell negative
>>and
>>chip VDD tied to cell positive
>>3) When the Stamp wants to read the cell's value, it energizes a
>>DPDT
>>relay that ties the chip's VSS to the Stamp's VSS, and the chip's DQ
>>line to a Stamp pin, with a 4.7K pull-up resistor to the Stamp's +5V
>>4) The Stamp then sends the appropriate commands to the chip to read
>>
>>the cell values
>>5) The Stamp deenergizes the relay and moves on to the next cell,
>>repeating the process
>>
>>Will that work? I realize that this would tie the Stamp to
>>successive
>>portions of the traction pack. But since the stamp is isolated, with
>>no
>>attachment to the chassis, I'm hoping this won't be a problem.
>>
>>
>
>Besides being way too complicated, it wouldn't work. The 1-wire device
>would loose it initialization during the period that the
>voltage supply was switched. The DQ line doesn't need to be switched,
>it is a bus arch, parts are all on the data line and addressed by a
>64bit ID. The chip wouldn't be attached to the voltage you wanted to
>measure at the time you commanded it to.
>
>
>
>>Subject: Re: 1-Wire Expertise and PIC
>>
>>
>>
>>>Technically, yes that would work. However, it's
>>>pointless.
>>>
>>>A PIC itself can measure voltage & temp for less $$$
>>>than that 1-wire
>>>device and far less than an array of DPDT relays!
>>>The PIC can have a
>>>serial port output (consisting of a single wire)
>>>that works just fine
>>>through a cheap optoisolator. If you're clever, the
>>>system can even
>>>share a single bus.
>>>
>>>
>
>Eliminate the relays, and a bus of 1-wires would probably end up
>cheaper. Assumming you want to monitor 30-40 devices, and about
>$2-3 each for the parts... (I haven't bought any of these for awhile,
>but when you deal with the right supplier they are cheap in quantity).
>
>Quick 1-wire lesson:
>
> Its actually 2/3 wire: GND and DATA, with optional 3rd dedicated
>power line (3rd line makes temp measurements faster).
>
> CAT5 cable (1 pair) for bus. Unbalanced "christmas tree" layout
>works fine. Lengths in the hundreds of feet OK.
>
> Each part has a unique address.
>
> RS-232 dongle available as part of the product line. I believe they
>have a USB dongle now also.
>
>Maxim site:
> http://www.maxim-ic.com/products/1-wire
>
>The part in question(?):
> http://datasheets.maxim-ic.com/en/ds/DS2760.pdf
>
>A temp monitor project I did years ago with 1-wire. Note that
>"Micro-lan" is the old name for 1-wire, used when it was a Dallas part:
> http://people.freebsd.org/~fsmp/HomeAuto/Therm.html
>
>---
>Steve
>
>
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--- End Message ---
