EV Digest 4301
Topics covered in this issue include:
1) Re: Fwd: Electric NASCAR fans
by Victor Tikhonov <[EMAIL PROTECTED]>
2) Re: Batt-Bridge monitor
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Problem with T-Rex throttle setting
by Lee Hart <[EMAIL PROTECTED]>
4) Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by "Christopher Robison" <[EMAIL PROTECTED]>
5) Re: about PHEV
by Rush <[EMAIL PROTECTED]>
6) RE: Batt-Bridge monitor
by "Jamie Marshall \(GAMES\)" <[EMAIL PROTECTED]>
7) Re: Problem with T-Rex throttle setting
by Nick Viera <[EMAIL PROTECTED]>
8) Re: about PHEV
by "ProEV" <[EMAIL PROTECTED]>
9) RE: New pictures of the Ghiamonster
by "Steve Marks" <[EMAIL PROTECTED]>
10) Re: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by Ryan Stotts <[EMAIL PROTECTED]>
11) RE: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by "Philip Marino" <[EMAIL PROTECTED]>
12) Re: motor connections
by "Roland Wiench" <[EMAIL PROTECTED]>
13) Re: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by Keith Richtman <[EMAIL PROTECTED]>
14) Re: Pics of the Big Guy,
mechanical questions (was Re: New EV Dragster)
by "Christopher Robison" <[EMAIL PROTECTED]>
15) Re: Pics of the Big Guy,
mechanical questions (was Re: New EV Dragster)
by "Christopher Robison" <[EMAIL PROTECTED]>
16) Re: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by Ryan Stotts <[EMAIL PROTECTED]>
17) Treadmill Motor I picked up & potential uses
by "Mark Ward" <[EMAIL PROTECTED]>
18) Re: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by Ryan Stotts <[EMAIL PROTECTED]>
19) :Bringing an EV to market. + Valence, etc.
by jerry dycus <[EMAIL PROTECTED]>
20) article: AquaGlider: Inflatable Watercraft
by Paul Wujek <[EMAIL PROTECTED]>
21) PV/EV Workshop on June 4
by Sherry Boschert <[EMAIL PROTECTED]>
22) RE: Wire Gauge questions
by "Bryan Avery" <[EMAIL PROTECTED]>
23) Re: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by Seth Allen <[EMAIL PROTECTED]>
--- Begin Message ---
The bank of assembled caps inside - my guess.
Never seen this before though.
Googled this: http://www.tavrima.com/products.html
Victor
Dave Cover wrote:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=98061&item=4543594255&rd=1
I'm not an EE but when I saw that ultra capacitor, I thought it was a
second motor. Is this a
common item? I'm more familiar with the form factor Victor used.
Dave Cover
--- End Message ---
--- Begin Message ---
Jamie Marshall (GAMES) wrote:
> I'd like to avoid using a relay system because I want the isolation
> to happen right at the battery, keeping traction voltage isolated
> to inside the battery box.
I agree. My Battery Balancer puts the relays right in the battery box. I
built an 8-relay board that has the sealed relays, fuses, and associated
parts on a PC board that I mounted in the battery box. A 9-wire isolated
control cable and two wires from the selected battery run back to the
central Control board.
I'd do the same with the opto-isolator scheme. Make a tiny little board
that would be potted, and mounted right at the batteries. In this case,
the wires from it are isolated.
--
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
-- Leonard Cohen, from "Anthem"
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
> Multi turn ports don't weather very well.
Especially the $1 cheapies that often get used!
You can get good potentiometers that won't wear out, but they are
expensive.
--
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
-- Leonard Cohen, from "Anthem"
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Ryan Stotts said:
> Any updates?
Eh, yes ... and no.
I've got some [fairly crappy] pictures of the Warp motors (11" and 13") on
my server (the website itself is still not "up" and only has some quickly
thrown-together content so far):
http://ohmbre.org/images/warp13_side.jpg
http://ohmbre.org/images/warp13_end.jpg
http://ohmbre.org/images/warp11.jpg
I did not take these pictures myself, as alas, I still don't have the
motor. I promise much better ones once I do. The reason I still don't
have it is something that perhaps some ME gurus here can help me with.
First of all, I know this motor is going to be capable of some incredible
torque. Although I know I won't have a platform to take advantage of all
of it right away, I'm determined to prepare for it from the start, so I
don't have to go back and have things redone.
>From the data I have from Netgain which shows a peak at nearly 900ft-lbs
at 1400A, I am projecting that at 2000A I should be getting torque
somewhere around 1100 ft-lbs. At 2500A with a controller bypass (future
plan, won't be implemented until I know what I'm doing), I am projecting
somewhere around 1300 ft-lbs. And due to some recent developments (a
change in design that will affect all future Warp 13s), the torque numbers
will actually be even higher though by how much no one's certain yet. The
motor is supplied with a 2" shaft of untreated 1144 steel (LaSalle calls
it "Stressproof").
A few parameters surrounding my dilemma:
A) Clearly, I *really* don't want the shaft to fail. 1. I'm planning on
splining the shaft, and twisting the splines will bind the slipyoke as it
attempts to travel toward the motor when hitting a bump. 2. Bending the
shaft will cause the driveshaft to impact the battery boxes, which will be
in close proximity to either side. This may even cause the rear wheels to
lock up, which is just all kinds of bad. 3. Breaking the shaft under full
power could cause the motor to instantly overspeed, unless the Zilla's RPM
limit can catch it fast enough. (Otmar?)
B) If it fails, I'm thinking I want it to break, rather than bend. An
overspeeding motor and exploding commutator are far less risk to me than a
jump-roping driveshaft. (If anyone disagrees, please let's discuss it --
your experience may be better than my speculation.)
c) I have a hunch that 1144 is not going to be strong enough for this
application. Especially given that the shaft will need to be narrowed at
the part where the splines are, to fit the yoke.
d) I'm not even sure what spline I want on the shaft -- Netgain has
suggested a spline from a chevy automatic transmission output shaft (since
yokes are readily available) but I do not have a frame of reference for
whether this is a good choice, nor do I have measurements for the diameter
of the shaft that would fit. I do know I need at least a 1350 U-joint,
possibly a 1410. I'm having a new driveshaft made and will be assembling
a new rear end, so I could go either way. I am assuming that I either
need a spline with as large a length and diameter as possible, or I need
to make sure I'm using a *very* strong steel in the shaft. If anyone has
a suggestion of a good spline standard to go with, please let me know.
This brings me to my main question ... from what should the shaft be made?
Should I choose a different material, or is 1144 sufficient? If I stay
with 1144, should I have it heat treated? If so, to what extent (what
hardness, etc)? How should dimensional instability during the hardening
process be handled?
John Wayland (who's doing a similar thing on his 13" motor) is going with
a hard stainless though I'm not exactly sure which alloy -- should I be
doing the same?
Influenced by recent stories of failed keyways and such, I have begun to
realize that torque is not my friend -- and I'll have to deal with a lot
more of it than one would experience from a gas engine of similar overall
power. I have tried finding help at the university here in town without
success, and have tried to find information in Machinery's Handbook and
various references online, but at this point, I could really use the help
of a mechanical engineer or someone with experience in metallurgy and
strength of materials...
--chris
>
>
> On 3/21/05, Christopher Robison <[EMAIL PROTECTED]> wrote:
>
>> >>the motor is in the queue at Warfield now.
>> >
>> > Any chance of posting some pics of it when you get it? I haven't been
>> > able to get a good look at that motor yet. It's very elusive.. (how
>> > many do they have queued up anyways and how long is it going to take
>> > them to "build it"? Who originally made the 13"? Or does Warfield
>> > cast/forge/machine the motor from raw materials themselves? ;)
>>
>> My understanding is that the Warp 13 is an original design intended
>> specifically for racing; it's not a rework of another motor, hence the
>> dual windings for series/parallel switching. Netgain has Warfield
>> making
>> them from scratch. I hope to get a website going soon; I'll post
>> everything including detailed motor pics as soon as the action starts.
>>
>> Also, Warfield is reportedly swamped with orders for Netgain motors.
>> Mostly 8's and some 9's. Lead times on any Warp motors are around 16
>> weeks, last time I checked (a couple weeks ago). As annoying as it
>> might
>> be if you're in a hurry (I'm certainly not), I can only consider such a
>> backlog to be the evidence of overall good news for Netgain.
>>
>> >
>> > Also not to be nosey or prying or anything..(that motor appeals to me
>> > too); where did you get it and how much was it? You don't have to
>> > answer that if you don't want too.
>>
>> No secrets here ... Netgain has several resellers around the country and
>> elsewhere. The closest one to me is Matches Motors
>> (www.matchesmotors.com)
>> and Mark Klemkosky has shown enormous patience in handling my somewhat
>> abnormal order. :o) Prices are on his site. The Warp 13 is officially
>> still "experimental" but that doesn't mean you can't buy one.
>>
>> >
>> >> the numbers I've gotten from Netgain look *very* impressive.
>> >
>> > Anything you can repost? Info seems non existent on it..
>>
>> I need to work out with Netgain what's public and what's not. They've
>> sent me some data that's confidential, so I will assume all of it is
>> until
>> I get some clarification. One way or another though, any testing I do
>> on
>> my finished vehicle will be posted on the website.
>>
>>
>> > voltage and batteries are you planning on using? Are you just going
>> > to mount them all in the bed?
>>
>> Planning for 348V, under the bed and under the hood. As much weight
>> between the axles as possible. Empty bed, hopefully with some capacity
>> left over for a little bit of hauling capability, but of course this is
>> probably wishful thinking.
>>
>>
>> > Got any pics of the truck in progress?
>> I'm looking forward to the truck being in progress. :o) Nothing's
>> happened with the truck yet; I'm still driving it on the ICE for trips
>> to
>> Home Despot and such. Again I'm planning to set up a website for it,
>> which
>> will happen Really Soon Now. Since for some reason I couldn't resist
>> keeping the tradition of shamefully cheesy, inexcusably punful EV names,
>> the truck is going to be called the Ohmbre (har har ... groan) and the
>> website will be at www.ohmbre.org. Not that there's anything there now
>> but the registrar's parking page.
>
>
--- End Message ---
--- Begin Message ---
Rich,
As I said before, I apologize.
My sword, as you say, has always been sheathed.
Being a newbie, I don't know everything and that is one of the reason's that I
am on this list, to learn.
I had no idea that everybody knew that Marc was employed by Valence, I guess I
just never saw any posts of his that were Lithium related (and there certainly
have been a lot of them), but I obviously know he is one of their employees
now... been told by several people...
But, in passing I will point out that it seems also the there are more
knowledgeable and long term members on the list that think that Marc's
treatment of the other battery manufactures was unfair.
As I said in the beginning, the sword was never unsheathed, that is just your
opinion, which I will fight to the death to uphold...
Do I have your blessing to stay...<G>
Rush Dougherty
Tucson AZ
www.ironandwood.org
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Thursday, April 21, 2005 12:56 PM
Subject: Re: about PHEV
> Hey Rush....
>
> Please stop attacking a solid list member.
> We all know Mark and his current employer.
> And are really glad to have him on this list keeping the Lion Claims in the
> real ball park.
>
> Try not to attack with such aggressiveness...
> There is no reason to cross examine everything he says.
>
> Getting nasty in the first few weeks your name appears on this list is a
> great way to get Kicked off it.
>
> Sheath your sword or leave.
>
> Rich Rudman
> Manzanita Micro.
> My opinions ARE corporate policy.
>
>
>
--- End Message ---
--- Begin Message ---
Right now I just want to read the battery voltages. I think it'd be
usefull for my own education to watch things happen under load. By
capturing all the data on the PC, I can also compare it to the telemetry
from the Zilla and see when any one battery starts to sag, and adjust my
settings on the Zilla to fit my pack as it ages.
Eventually it would be cool to use some of those extra outputs from the
DAQ (most of them have 16 or more I/O bits) to also trigger bypass loads
on the batteries. This would be an upgrade to the per-battery isolation
circuit.
Currently I have Ed Ang's regulators installed, and they seem to be
doing pretty well, so substituting my own for them is not a high
priority.
-Jamie
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Victor Tikhonov
Sent: Thursday, April 21, 2005 1:45 PM
To: [email protected]
Subject: Re: Batt-Bridge monitor
I'll get my system done quite soon, where opto-isolation
is done right at the battery. It is basically just waiting
for big enough order to make production worthwhile.
What are you planning to use the data for? Just look at it
or feed into other hardware to do something?
Victor
Jamie Marshall (GAMES) wrote:
> I'd like to avoid using a relay system because I want the isolation to
> happen right at the battery, keeping traction voltage isolated to
inside
> the battery box. I'd be worried about a relay shorting out and frying
> my PC (or frying me).
>
> I'm looking at USB based low-cost DAQs like this:
> http://www.measurementcomputing.com/pmd.html
>
> -Jamie
--- End Message ---
--- Begin Message ---
Hi,
Rich Rudman wrote:
Multi turn pots??? That would make the problem worse. SNIP But... the
pot doesn't wear, and you never have open scratchy pots. This is
truley a better throttle sensor than a PB6 or wound wire pot. SNIP
Multi turn pots don't weather very well. compared to a Steel slug in
a plastic tube inside a 200 turn coil.
Rich, you mis-understood what I was saying. I was suggesting that it
would have been nice if the "MAX THR" and "I" potentiometers on the
Raptor/T-Rex controllers were the multi-turn type. I was *not* talking
about the throttle switch nor about changing it from an inductive pickup
to a potentiometer.
--
-Nick
http://Go.DriveEV.com/
1988 Jeep Cherokee 4x4 EV
---------------------------
--- End Message ---
--- Begin Message ---
Hey Rush....
Please stop attacking a solid list member.
We all know Mark and his current employer.
Hold on there Rich,
I did not know Marc or realize who was his current employer despite being on
this list for years. I would have remained in ignorance except for Rush's
post.
Marc writes:
<It is a general conseption that representatives of battery manufacturers
seem to exagerate their product's performance. Many would question my
statement if I made it with my title stamped behind it. I posed the
statement as a person who has been told, by customers, that that is what
they are seeing.>
I read this statement as Marc saying he did not identify himself because
many would question his statement if they knew he worked for Valence. Is
that a valid reason for not identifying himself?
Marc's original message also said:
<And unlike almost every other battery out on the market today, I've heard
that
you actually get out the AH rating (or more) on the Valence units.>
Should his job title effect people's evaluation of this statement? I have
been involved in the testing of Kokam Lithium Polymer batteries. Of the 97
EV size cells that we tested, every one made more than their rated AH. Is
Kokam the only other battery that has made it's rated AH? What about SAFT,
Sony, etc.? Are they all accuracy challenged<G>? Inquiring minds want to
know!
Now Marc also makes some very valid points about the difficulty between
sharing personal knowledge on the list and working for a public company. I
hope he will continue to try to find that balance that makes information on
this list so useful.
Cliff Rassweiler
www.ProEV.com
Sponsored by Kokam batteries!
--- End Message ---
--- Begin Message ---
> > *****
> > Do you think 1/2 inch aluminum will be sufficient?
> Only if it's really good aluminum 6061-T5. Anything less will
bend.
> Nasty is 7075-T6. This you won't break, and it's stronger than Steel
lb
> for
> lb. I would ask your machinist. With all that air in the lightening,
> having really good Alum is cheap compared to the
> Cost of failure.
The builder builds custom VW drag racers for a living so I have a lot of
confidence he knows what he's doing. My only concern is that he
wouldn't believe me when I told him what kind of torque we were talking
about. After a visit to the NEDRA site and a talk with John Wayland,
however, he's become a believer ;o)
> That would be worth the plane ticket....
> You do this right, and single digit times will arrive with Lions....
Did you have a particular set of Lions in mind? Which ones have better
power densities than SVRs and Hawkers and are available to mere mortals?
Steve
The information contained in this email message is being transmitted to and is
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--- End Message ---
--- Begin Message ---
Christopher Robison wrote:
> I'm planning on splining the shaft
Are you not running a transmission? Is this going to be a trailered
to the track drag truck?
> jump-roping driveshaft.
You should really install a "drive shaft safety loop" so that if the
front u-joint fails, or the yoke or weld fails, the drive shaft won't
drop to the pavement and pole vault the truck into the air.
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=4123&prmenbr=361
You can easily fabricate your own. Get a copy of the NHRA rulebook
for the dimensions and placement of it.
> d) I'm not even sure what spline I want on the shaft -- Netgain has
> suggested a spline from a chevy automatic transmission output shaft
A pic of various ones:
http://www.moserengineering.com/moser_interior/products.asp?CatID=11
> Influenced by recent stories of failed keyways and such, I have begun to
> realize that torque is not my friend
Unless slicks will be used, radial tires won't be breaking anything.
What are your plans with this truck? Are you going to be keeping it
on the street?
--- End Message ---
--- Begin Message ---
From: "Christopher Robison" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Pics of the Big Guy, mechanical questions (was Re: New EV
Dragster)
Date: Thu, 21 Apr 2005 15:55:47 -0500 (CDT)
e.
The
motor is supplied with a 2" shaft of untreated 1144 steel (LaSalle calls
it "Stressproof").
This brings me to my main question ... from what should the shaft be made?
Should I choose a different material, or is 1144 sufficient? If I stay
with 1144, should I have it heat treated? If so, to what extent (what
hardness, etc)? How should dimensional instability during the hardening
process be handled?
"Stressproof" 1144, at least according the the only references to it I could
find, is a LaSalle Steel trademark, and is not "untreated" but is coldworked
to a yield strength of 100 kpsi, and a tensile strength of 120 kpsi, and a
Rockwell hardness of C23.
This is already a moderately high strength steel - roughly double the
strength of untreated low carbon steel.
If you have a reasonable idea of the maximum torque expected, you could
bring your design ( or, even, just a sketch of your ideas) to a mechanical
engineer - preferably a stress analyst , to try to get a prediction of what
will happen under load. ( and, what strength steel you need, if 1144 is not
adequate.)
Try contacting the mechanical engineering department of a local university (
if any) - you may get some leads as to who can help with this.
Phil Marino
_________________________________________________________________
Don�t just search. Find. Check out the new MSN Search!
http://search.msn.click-url.com/go/onm00200636ave/direct/01/
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: [EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Thursday, April 21, 2005 1:50 PM
Subject: Re: motor connections
So, does this hold true if you're down under in Australia or Brazil ?
John
> So for the 1231C, you'd wire in either FWD or REV, depending on the
> direction that your tranny needed to turn (e.g., Honda turns one way
> and
> other manufactures turn the other way)?
Yea, that right. If you go south of the equator the motor has to be rewire
for reversed so you can go forward. Water drains the other way, don't it?
We sent a team of electrical workers to Australia one time and perform a
experiment in what direction a light switch has to be in for the light to come
on.
We had one of the guys wire a mercury single pole light switch which is not
mark with the words ON and OFF. Had him connected it up to a light and had him
mark it with ON and OFF up here in the States.
In Australia we had him wire up the switch to a light, and it had to be in
the OFF position for the light to come on. We told him that the DOWN position
is towards the equator which would be the OFF on the switch.
Of course we rig the switch to do this.
Roland
--- End Message ---
--- Begin Message ---
I am not a mechanical engineer, but I will be in December.
Here are my numbers:
Torque = 1600 ft-lb = 19200 in-lb
Polar Moment of Inertia (J) = (pi*dia^4)/32 = 1.57
Outer Radius = 1"
Shear Stress = (T*r)/J = (19200 * 1)/1.57 = 12.2 ksi
I do not know the stress concentration factor for splines (and I am sure
it depends on the style), but we'll say 2 for now. The yield stress for
1144 steel is ~90 ksi.
Shear Yield Strength = .577 * Tensile Yield Strength = .577 * 90 = 51 ksi
Safety Factor = Strength / (Stress * Stress Conc. Factor) = 51/(12.2*2)
= 2.09
Unless you can better quantify the materials, loads, and the effect the
spline has on the peak stress I wouldn't trust the shaft as is. Easiest
option is to find better steel, but you could also find a way to attach
the drive shaft that doesn't involve a spline (queue Seth to mention
Loctite 620).
Keith
Philip Marino wrote:
From: "Christopher Robison" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Pics of the Big Guy, mechanical questions (was Re: New EV
Dragster)
Date: Thu, 21 Apr 2005 15:55:47 -0500 (CDT)
e.
The
motor is supplied with a 2" shaft of untreated 1144 steel (LaSalle calls
it "Stressproof").
This brings me to my main question ... from what should the shaft be
made?
Should I choose a different material, or is 1144 sufficient? If I stay
with 1144, should I have it heat treated? If so, to what extent (what
hardness, etc)? How should dimensional instability during the hardening
process be handled?
"Stressproof" 1144, at least according the the only references to it I
could find, is a LaSalle Steel trademark, and is not "untreated" but is
coldworked to a yield strength of 100 kpsi, and a tensile strength of
120 kpsi, and a Rockwell hardness of C23.
This is already a moderately high strength steel - roughly double the
strength of untreated low carbon steel.
If you have a reasonable idea of the maximum torque expected, you could
bring your design ( or, even, just a sketch of your ideas) to a
mechanical engineer - preferably a stress analyst , to try to get a
prediction of what will happen under load. ( and, what strength steel
you need, if 1144 is not adequate.)
Try contacting the mechanical engineering department of a local
university ( if any) - you may get some leads as to who can help with this.
Phil Marino
--- End Message ---
--- Begin Message ---
Ryan Stotts said:
> Are you not running a transmission? Is this going to be a trailered
> to the track drag truck?
Street/strip - I'll be driving it, and racing it when I can. There will be
some decisions I'll be making that will compromise its effectiveness as a
dragster; the ultimate goal will not be the lowest ETs possible (since I
know I can't afford that anyway), merely a respectable level of
performance in a truck I can take to mainstream car shows.
I figure I'll eventually go with a transmission. For the moment I'm
focusing my money on a decent rear end and driveshaft. I've talked about
my reasoning concerning the transmission before; I won't repeat it here.
> You should really install a "drive shaft safety loop" so that if the
> front u-joint fails, or the yoke or weld fails, the drive shaft won't
> drop to the pavement and pole vault the truck into the air.
I've thought about ways to do this. Battery boxes will be to either side,
bridging across the bottoms of the boxes under the shaft with a strip of
metal would be an easy way to keep from dropping a broken shaft I think,
and could at the same time be part of the flat bottom surface for reducing
drag. Good idea? Too heavy (use a normal loop of webbing and do the
bottom with coroplast instead)?
>> d) I'm not even sure what spline I want on the shaft -- Netgain has
>> suggested a spline from a chevy automatic transmission output shaft
>
> A pic of various ones:
>
> http://www.moserengineering.com/moser_interior/products.asp?CatID=11
The pics are nice, but does anyone have the actual dimensions of the
transmission output shafts they're designed to fit to? These all look
skinnier (and shorter) than what I was hoping for.
>
> Unless slicks will be used, radial tires won't be breaking anything.
I plan to ultimately have a separate set of wheels and tires for the
strip, as well as a separate differential center section with racing gears
preconfigured, so it's an easy swap to set them up.
At first though, you're absolutely right. Initially I won't have as much
chance of breaking anything, or fully taking advantage of the capabilities
of the motor. Eventually, some drag slicks here, a bypass there, throw in
a Lenco once I decide the inability to downshift is worth the extra torque
... then maybe I'll be ready to join the Electric Drivetrain Carnage Club.
--chris
--- End Message ---
--- Begin Message ---
Keith Richtman said:
> I am not a mechanical engineer, but I will be in December.
>
> Here are my numbers:
I won't respond to these immediately, as I need more time to absorb... In
any event, thank you for the input -- this is the sort of data I have so
far been unable to find on my own, and for which I was looking to the
university for help.
> spline has on the peak stress I wouldn't trust the shaft as is. Easiest
> option is to find better steel, but you could also find a way to attach
> the drive shaft that doesn't involve a spline (queue Seth to mention
> Loctite 620).
I'd like a better option than using a spline and a slipyoke, but the only
alternative I can think of is a telescoping driveshaft. These are much
heavier, and are built for the off-road and rock-crawling markets rather
than for racing. I could be wrong, but I just don't see a good fit for my
purposes.
Since I'm not willing to do away with the rear suspension, are there any
other alternatives, that would still allow for suspension travel?
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> drive shaft that doesn't involve a spline
Have a look at this Top Fuel differential:
http://www.strangeengineering.net/catalog/110.html
Various ways to attach a transmission directly to a differential:
http://www.strangeengineering.net/catalog/105.html
A two piece coupler with a little blueprint showing how it's installed:
http://www.strangeengineering.net/catalog/104.html
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I just picked up a treadmill motor rated at 90V DC and 1.5 hp. It is rated
at about 15 amps.
What kind of applications would this be good for? I am thinking a power
steering pump? Air conditioner?
What say ya all?
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Christopher Robison wrote:
> I'd like a better option than using a spline and a slipyoke, but the only
> alternative I can think of is a telescoping driveshaft. These are much
> heavier, and are built for the off-road and rock-crawling markets rather
> than for racing. I could be wrong, but I just don't see a good fit for my
> purposes.
>
> Since I'm not willing to do away with the rear suspension, are there any
> other alternatives, that would still allow for suspension travel?
Think about a normal rear wheel drive shaft setup. When the
differential travels up and down, the yoke on the front of the drive
shaft slides in and out of the back of the transmission.
Will you have a long enough splined shaft out of the back of the motor
to allow this to happen?
A "two piece" drive shaft will hold the front of the drive shaft in
place and not let it fall off the motor shaft.
Here is(or was) White Zombie's drive shaft:
http://www.austinev.org/evalbum/035p.jpg
http://www.austinev.org/evalbum/035.html
This company should be able to set you up with a proper drive shaft setup:
http://www.dennysdriveshaft.com/
Some quotes from their site(their caps lock not mine):
"1350 SERIES...VIRTUALLY UNBREAKABLE"
"IF YOU EVER TWIST THIS TUBING OR BREAK OUR WELDS...WE WILL REPLACE
THE ENTIRE DRIVESHAFT FOR FREE."
Some good info on this page too:
http://www.dennysdriveshaft.com/html/faq.html
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Hi Phillippe and All,
--- Philippe Borges <[EMAIL PROTECTED]>
wrote:
> Interesting price question,
> we was talking about strange starting price on Ev
> business with a friend
> last week(for all the parts in fact), let me try to
> explain (translate) my
> point of view here:
>
> The automotive industry want to launch another car
> (ICE), they design, test
> then sell it.
> Initial price is not the car value, the company
> can't put the first 1000
> batch at $100 000 each, so they fix a commercial
> strategie:
> our car price target is for "this" market, others
> brand are sold $XXX, we
> want to have 1/5 of this market fast so we fix our
> new car at $XXX-1 and
> wait until we win money (fast in fact because this
> is the way to win money
> and they are aware of and specialist in the wining
> money business...)
>
> Now they make EV (they try...or seems to...):
>
> Initial price similar to ICE version or even cheaper
> to open the market ?
> NO !
> instead they fix high initial price, why ?
> are they scared to sell just a few ?
> maybe but even selling only 10 000 EV initial price
> should be lower than
> what we had seen, so where is the problem ?
They are scared for some reason to do it.
Maybe because you need to think outside the tiny
box they are in! First they need to get away for
steel!!!
I'm trying to do it by completely changing the
whole way of doing things, much more like Ferrari than
GM. Mostly because I don't have the money to do it
GM's way amoung other reasons.
As I see it you need to build them so by the time
you have built, sold 5 EV's, you are in the black with
debts paid off!!!
To do that you need to know how to do very low
volume profitably.
Luckily for me I come from a boatbuilding
background where 5 boats is a profitable success!!!
By doing EV's the same way in composites like the
Ferrari's, Fords new GT-40, ect, but using lower cost
composites instead of Carbon fiber, the tooling
cost's, first body and finishing it costs under $25k
doing most of the work myself!!! The tooling is
already paid for and part of the first body/frame too.
This way I can build 2 seat EV's that go about
100mile range and 75mph, though not at the same time,
on lead batteries! And sell it at $13k base price
making a nice profit at that by good design,
engineering and KIS.
Tooling will be done by the end of May. First
glider by the end of June and finished EV by the end
of July assuming the money is there!!!
The way it's done is going for very light weight,
low labor, low parts counts and using proven tech.
This keeps costs reasonable and without going deeply
in debt so is profitable very quickly.
Options will be AC and long range generator so you
will only need 1 EV instead of a car and an EV.
But this kind of thinking is against everything
auto companies know so no way they will do it.
While I'll do much of the work, I couldn't do it
without a great group of EV'ers on the EVProduction
list that makes this all possible!!!
> we all know why...so let's shift to batteries
>
> The batteries are expensive: yes !
> Lead is mass producted and so cheap, ok but nicad is
> also mass producted,
> Saft and others have production lines for them BUT
> they don't want to sell
> cheap, they want us to pay the added value, nicad is
> better than lead acid
> so you pay for it period.
If you design the EV as an EV from the start, lead
batts are perfectly okay with good range and
performance. How to do it was like the Selectria
Sunrise or GM Impact!!
But as Mark said, the only thing holding Li-ions
back now is ramping up the chemical plants to make the
materials needed in the quanities needed as they are
basicly cheap so the price can easily come down to the
same price as lead on a kwhr basis. And 1/3-1/4 the
weight!!
We are coming to another economic downturn which
will leave a surplus of li-ion marerials so the costs
should drop nicely over the next 2 yrs to affaordable
levels for us.
As my design, the Freedom EV, is designed for
ease of service, upgrading, switching to any new batt,
motor, controller will be very easy. You can replace
anything in it in 5-30 minutes!! A product of my being
a repair tech much of my life.
Ni-cads are a good choice for those wanting a 20
yr battery and now cheaper than AGM lead batts over
10yrs and if made in larger quanities could be equal
in cost to golf cart batts over 15 yrs easily.
But the way it looks now, by the time 1 set of
lead batts are used up, li-ions will be ready to be
put in at reasonable prices and their lighter weight
will increase performance nicely.
HTH's,
Jerry Dycus
>
> Lithium technologie is way better BUT there is a
> problem, you have 4 X nicad
> capacity for 2/3 weight, 1/2 volume, no servicing,
> so it's now 10X lead
> price, impossible to start an EV business with such
> batteries price, period.
> Noboby is selling at price it should be to launch EV
> market !!!
>
> THIS IS THE PROBLEM, they all want big money fast !
> but they are wrong !
>
> remember my automotive exemple,
> Why we shouldn't see Lithium at same $/ah price than
> nicad/nimh, they are
> not more complicated to produce, in fact material
> cost less.
> So what ?
> i think batteries company are making a big mistake,
> specialy which who are
> producing Ev batteries, they should give better
> price to launch their
> product and help EV market in same time THEN grow up
> the price.
>
> just my 1wh
>
> Philippe
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
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Electric inflatable watercraft, unfortunately only available for British
kids:
http://www.gizmodo.com/gadgets/gadgets/vehicles/aquaglider-inflatable-watercraft-100498.php
--
Paul Wujek ([EMAIL PROTECTED])
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Please forward to anyone in the San Francisco area who
doesn't yet have that EV grin...
JUNE 4: SOLAR POWER + ELECTRIC VEHICLES WORKSHOP
Why buy gas and drive a polluting car when you could
be in a zero-emission electric vehicle that
essentially runs on sunshine? Adding solar
photovoltaic (PV) panels to your home and using an
electric vehicle (EV) is a winning combination for
both your wallet and the planet.
Learn more and ride in an EV at a free PV/EV Workshop
on Saturday, June 4, from 10 a.m. to 12 noon at The
San Francisco School (a solar-powered school), 300
Gaven Street between Boylston and Bowdoin in the
Portola neighborhood.
Please r.s.v.p. to [EMAIL PROTECTED]
Solar PV panels create clean electricity. The monthly
payment for a PV system can be lower than your
previous electricity bill, saving you money instantly.
And if you drive an electric vehicle, your PV system
replaces not just household electricity but costly
gasoline, because EVs run on electricity. PV/EV
creates power without polluting and provides personal
transportation in non-polluting cars.
The PV/EV Workshop is part of the United Nations'
World Environment Day activities in San Francisco. The
event is sponsored by the San Francisco Electric
Vehicle Association (www.sfeva.org) and Occidental
Power Solar and Cogeneration, a licensed solar contractor.
Sherry Boschert
President
San Francisco Electric Vehicle Association
415-681-7731
www.sfeva.org
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
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>
> Have a look for heat shrink tubing it does come in several colors
> including
> orange
> yellow, white, black, blue, red. I've used the 3/4" ~18mm size which is
> common
> and there are some available which go much larger in size. Don't have to
> cover
> the entire cable in it but just put a few rings a few inches long on the
> cable
> with the ends near the connectors covered. Enough that you can look and
> see
> the
> cable is marked as the color. It's cheap and easy to use.
>
If you look for it, you can find orange electrical tape as well. Yes, it
would be a bit tedious, and use a lot of tape, wrapping all the HV cable in
electrical tape, but it is another option. A quick search comes up with one
site, http://www.brandsonsale.com/orange-electrical-tape.html, that appears
to offer 10-packs of orange electrical tape for $7.50.
Bryan Avery
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I did the mechanical engineering for the Super7 Kenworth hybrid at
Solectria. For the moment, not enough is known to say if 1144 is
acceptable. I can tell you that either an end milled or sled runner
keyway is not acceptable in that diameter and torque, regardless of
material.
I specified 4340 with a heat treat, but I had a slightly smaller
diameter. The input shaft on the transmission was a 10 spline at 1.75"
diameter made of some quite hard stuff, and it was rated for 860 ft-lb
for 500,000 miles. (This was a 32,000 lb hybrid with 1000 lbs of AC
induction motors) That's 860 ft-lbs but with lots of ripple that is
difficult to characterize. I can tell you what I did, the asssumptions
I made and what worked, what we tested and where the predicted failure
was. If you want. If I get sniped at then we can take it off list.
The vehicle:
http://www.solectria.com/news/17sept03.html
Seth
P.S. I think the F.O.S. for an involute spline is lower than 2, but I
don't recall off the top of my head what I did use or how I reached the
number I used.
On Apr 21, 2005, at 7:39 PM, Keith Richtman wrote:
I am not a mechanical engineer, but I will be in December.
Here are my numbers:
Torque = 1600 ft-lb = 19200 in-lb
Polar Moment of Inertia (J) = (pi*dia^4)/32 = 1.57
Outer Radius = 1"
Shear Stress = (T*r)/J = (19200 * 1)/1.57 = 12.2 ksi
I do not know the stress concentration factor for splines (and I am
sure it depends on the style), but we'll say 2 for now. The yield
stress for 1144 steel is ~90 ksi.
Shear Yield Strength = .577 * Tensile Yield Strength = .577 * 90 = 51
ksi
Safety Factor = Strength / (Stress * Stress Conc. Factor) =
51/(12.2*2) = 2.09
Unless you can better quantify the materials, loads, and the effect
the spline has on the peak stress I wouldn't trust the shaft as is.
Easiest option is to find better steel, but you could also find a way
to attach the drive shaft that doesn't involve a spline (queue Seth to
mention Loctite 620).
Keith
Philip Marino wrote:
From: "Christopher Robison" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Pics of the Big Guy, mechanical questions (was Re: New EV
Dragster)
Date: Thu, 21 Apr 2005 15:55:47 -0500 (CDT)
e.
The
motor is supplied with a 2" shaft of untreated 1144 steel (LaSalle
calls
it "Stressproof").
This brings me to my main question ... from what should the shaft be
made?
Should I choose a different material, or is 1144 sufficient? If I
stay
with 1144, should I have it heat treated? If so, to what extent (what
hardness, etc)? How should dimensional instability during the
hardening
process be handled?
"Stressproof" 1144, at least according the the only references to it
I could find, is a LaSalle Steel trademark, and is not "untreated"
but is coldworked to a yield strength of 100 kpsi, and a tensile
strength of 120 kpsi, and a Rockwell hardness of C23.
This is already a moderately high strength steel - roughly double the
strength of untreated low carbon steel.
If you have a reasonable idea of the maximum torque expected, you
could bring your design ( or, even, just a sketch of your ideas) to a
mechanical engineer - preferably a stress analyst , to try to get a
prediction of what will happen under load. ( and, what strength steel
you need, if 1144 is not adequate.)
Try contacting the mechanical engineering department of a local
university ( if any) - you may get some leads as to who can help with
this.
Phil Marino
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