EV Digest 6409
Topics covered in this issue include:
1) Re: A123 pictures
by Ray Wong <[EMAIL PROTECTED]>
2) Re: Brake Pressure Multiplier?
by Doug Weathers <[EMAIL PROTECTED]>
3) Re: Brake Pressure Multiplier?
by David Dymaxion <[EMAIL PROTECTED]>
4) Re: Vacuum pump running constantly
by "Peter VanDerWal" <[EMAIL PROTECTED]>
5) Re: Brake Pressure Multiplier?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
6) Re: Brake Pressure Multiplier?
by "FRED JEANETTE MERTENS" <[EMAIL PROTECTED]>
7) Re: Looking for a 12 V / 5 Amp minimum isolated charger for AGM batts
by "David Roden" <[EMAIL PROTECTED]>
8) RE: Vacuum pump running constantly
by "David Roden" <[EMAIL PROTECTED]>
9) Re: Personal Electric Transport
by Jack Murray <[EMAIL PROTECTED]>
10) A/C Motor voltage?
by "MG" <[EMAIL PROTECTED]>
11) RE: Vacuum pump running constantly
by "Claudio Natoli" <[EMAIL PROTECTED]>
12) Re: A123 pictures
by Ray Wong <[EMAIL PROTECTED]>
13) RE: Brake Pressure Multiplier?
by "Phil Marino" <[EMAIL PROTECTED]>
14) Battery temp question
by "John O'Connor" <[EMAIL PROTECTED]>
15) Re: Brake Pressure Multiplier?
by "Bob Rice" <[EMAIL PROTECTED]>
16) Re: Brake Pressure Multiplier?
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Vacuum pump running constantly
by "Roland Wiench" <[EMAIL PROTECTED]>
18) Re: A/C Motor voltage?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
19) Calgary electric trains
by "Tim Gamber" <[EMAIL PROTECTED]>
20) Re: Battery temp question
by "Peter VanDerWal" <[EMAIL PROTECTED]>
21) BMS tips (was: A123 pictures)
by Bill Dube <[EMAIL PROTECTED]>
22) Cost to drive a EV
by "Tim Gamber" <[EMAIL PROTECTED]>
23) Re: Personal Electric Transport
by "jmygann" <[EMAIL PROTECTED]>
--- Begin Message ---
I want to build the pack in flats of 4x6 cells. It give each flat about 13.2
volts, 12 volts under load, with 6 buddies per cell. 10 flats will give me 132
volts 13.8AH with up to 600 amps. Pack weight about 50 lbs.
It looks like the vented pos end can create some difficulty. If I keep as
many of the Dewalt tabs intact at the pos end, it should not be too difficult
to spot weld or solder to the case on the neg end. I am not sure what kind of
alloy was used by Dewalt for their tabs. The tabs seem to take solder if they
are sanded.
Thanks for your suggestions.
EZESport
Bill Dube <[EMAIL PROTECTED]> wrote:
I'm not sure what you mean when you say "4X6X10".
You may be able to "unfold" the DeWalt packs to give you nice 10 cell
strings. At that point, you would just need to attach parallel tabs
between them to parallel up all the cells. These parallel wire/tabs
need not be very stout and can be soldered onto the center of the
existing tabs.
Since you don't have a proper welder, you should do all you can to
use the existing tabs on the cells.
Bill Dube'
At 05:49 PM 2/11/2007, you wrote:
>Thanks for the offer of help. I am in Edmonton, Alberta, Canada,
>basically too far away from any help. But that has never stopped me before.
>
> I have a few ideas to make a jig that might work on the A123 cells.
>
> EZESport
>
>"[EMAIL PROTECTED]" wrote:
> Ray or Bill,
>GoWheel.com and crew will help any way we can too.
>We're in Orange County, California
>Gary, Ryan, Jay, Randy, Ed, Robert, Don, Lou, & crew
>-------------------------------
>--- Bill Dube wrote:
> > Ray,
> > You didn't say were you were located. If
> > you are near
> > Denver, contact me and maybe we can help you get
> > these welded together.
> > Bill Dube'
> >
> > At 12:41 PM 2/10/2007, you wrote:
> > Hi Bill, I hope you can help or anyone else on
> > the list.
> > I finally got hold of enough A123 cells to put
> > together a small
> > > pack. (many Dewalt packs) In the past you
> > mentioned it took a
> > > very expensive spot welder to assemble the
> > Killacycle pack.
> > What kind of problems would be caused by a
> > standard spot welder
> > with small tips. Do you have a source for the
> > tabs that protect
> > the vent hole. Is there an alternative you might
> > suggest, something cheaper.
> > I don't want to solder onto the batteries
> > althought the RC guys say it works just fine.
> > Pack is a 4x6x10. I want to build two of these
> > 1.8kwh packs.
> > The EZESport bike is getting A123 batteries and
> > a Zilla 1K
> > upgrade. The goal is to be able to keep up around
> > town with other
> > 600cc ICE sports bike with a 20 to 30 mile range.
> > EZESport
>
>
>
>
>____________________________________________________________________________________
>Any questions? Get answers on any topic at www.Answers.yahoo.com. Try it now.
>
>
>
>
>---------------------------------
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--- End Message ---
--- Begin Message ---
On Feb 12, 2007, at 7:06 PM, David Dymaxion wrote:
I think the only ways you can argue drum brakes are better are:
* Drum brakes take less pedal effort
* It takes less force to do a parking brake with a drum brake
Do drum brakes have less drag than disc brakes? I recall hearing this
somewhere.
If true, then drum brakes have a significant advantage on an EV.
--
Doug Weathers
Las Cruces, NM, USA
http://www.gdunge.com/
--- End Message ---
--- Begin Message ---
Good point, I've heard that, too. In my experience, though, I haven't been able
to tell drum brakes were easier to turn by hand.
----- Original Message ----
From: Doug Weathers <[EMAIL PROTECTED]>
To: [email protected]
Sent: Monday, February 12, 2007 7:55:30 PM
Subject: Re: Brake Pressure Multiplier?
On Feb 12, 2007, at 7:06 PM, David Dymaxion wrote:
> I think the only ways you can argue drum brakes are better are:
>
> * Drum brakes take less pedal effort
> * It takes less force to do a parking brake with a drum brake
Do drum brakes have less drag than disc brakes? I recall hearing this
somewhere.
If true, then drum brakes have a significant advantage on an EV.
--
Doug Weathers
Las Cruces, NM, USA
http://www.gdunge.com/
____________________________________________________________________________________
Food fight? Enjoy some healthy debate
in the Yahoo! Answers Food & Drink Q&A.
http://answers.yahoo.com/dir/?link=list&sid=396545367
--- End Message ---
--- Begin Message ---
ANother possibility just occured to me. Perhaps a bit of debris got into
the vacuum lines from the vent connection and has lodged in the vacuum
switch.
Seems unlikely, but might be possible.
> Cool - lots of things for us to try. Folks on this list are the greatest!
> Glad to know I can drive it, but on my nutso interstate commute I'll be
> hanging way back.
>
> To clear up a few points asked:
>
> Yes, I did remove the vent hose and put the plug back in. That worked for
> about 1 minute.
>
> Also, I think I can eliminate the switch because we put some hose clamps
> in
> a couple of places to try to find the leak. That worked for about 2
> seconds
> - then the pump "burped" on a few times, then was on solid again. BTW, it
> has been "burping" (is there a technical term for that?) every 10 seconds
> or
> so since I got it. Figured I had a slow leak, but was not motivated to
> look
> for it until now.
>
> On 2/12/07, Peter VanDerWal <[EMAIL PROTECTED]> wrote:
>>
>> Even without vacuum the brakes still should work (just takes a lot more
>> effort).
>>
>> You may or may not have a vacuum leak. It might just be that the vacuum
>> sensor switch is shorted/welded. Vacuum switch failure is actually
>> fairly
>> common.
>> Check to see if your vacuum switch is internal or external to the pump.
>> An external switch will be wired to the pump and connected to the vacuum
>> lines.
>>
>> The best way to see if you have a leak is to use a vacuum guages, but
>> I'm
>> going to assume you don't have one.
>>
>> Do you hear a hissing sound? If so that's your leak, try to find it.
>> If not, pull of a vacuum line while it is running and see if you hear it
>> at the line. If so, try plugging it with a finger and see if you feel
>> any
>> suction.
>>
>> If everything is good so far, disconnect the vacuum line immediately
>> after
>> the switch (if the switch is inside the pump, disconnect right at the
>> pump. Plug the line here and see if the pump will draw enough vacuum to
>> activate the switch. If not and you have good vacuum from the pump,
>> then
>> the problem is the switch.
>> If it does switch off, then keep adding back vacuum line and plugging
>> the
>> far end until you find one that doesn't switch off. That line is your
>> problem.
>> If all the lines check out, hook them back up to your brake booster (big
>> round thing on the master cylinder). If the problem comes back when you
>> add the booster, then your booster has a leak. You can either rebuild
>> it
>> or replace it.
>>
>> > I am a newbie owner of an older Voltsrabbit conversion (
>> > http://www.austinev.org/evalbum/1020 ). I am not mechanically
>> inclined
>> > (I'm
>> > a EE but so far no electrical problems!) so my husband works on the
>> car
>> > when needed - but he's not tremendously experienced with cars either.
>> > Last
>> > time I drove the car, the vacuum pump started running constantly. The
>> > brakes still worked OK, but I drove straight home and haven't driven
>> it
>> > since. We have looked for leaks, but there is nothing that we can
>> find
>> so
>> > far. I am wondering how is the best way to find a leak (assuming
>> that's
>> > what it is) so we can fix it up and get back on the road?
>> >
>> > I take it that it's not safe to drive it in this condition?
>> >
>> > This might (or might not) be coincidental: but the previous time I
>> drove
>> > it
>> > was to the local EAA meeting where we worked on a member's car at a
>> local
>> > shop. There happened to be a mechanic there who moonlights on Rabbits
>> > that
>> > took a look at my car. After I mentioned getting pretty cold from the
>> > fresh
>> > air vents, he said he thought he could fix it. It was a pretty simple
>> fix
>> > -
>> > the vent is held closed by vacuum, and there was a disconnected hose
>> from
>> > the vent that ran right over to the larger hose coming from the vacuum
>> > pump. It was hanging loose, and there was a plug on a obvious
>> connection
>> > point for the vent vacuum hose. When we connected it up, there was a
>> leak
>> > in the hose to the vent. The Rabbit guy fixed that leak in the
>> smaller
>> > vent
>> > hose and it all seemed great - drove home with no cold air on me for
>> 15
>> > miles. Several days later when the vacuum pump started running
>> > constantly,
>> > I of course replaced the hose with the plug that had been there
>> before,
>> > but
>> > that only fixed the vacuum pump from running for less than a mile.
>> >
>> > I appreciate any ideas I can get!
>> >
>> > De
>> >
>> >
>>
>>
>> --
>> If you send email to me, or the EVDL, that has > 4 lines of legalistic
>> junk at the end; then you are specifically authorizing me to do whatever
>> I
>> wish with the message. By posting the message you agree that your long
>> legalistic signature is void.
>>
>>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Properly adjust drums have no drag from the pads, so that's another point
in their favor.
>
> On Feb 12, 2007, at 7:06 PM, David Dymaxion wrote:
>
>> I think the only ways you can argue drum brakes are better are:
>>
>> * Drum brakes take less pedal effort
>> * It takes less force to do a parking brake with a drum brake
>
> Do drum brakes have less drag than disc brakes? I recall hearing this
> somewhere.
>
> If true, then drum brakes have a significant advantage on an EV.
>
> --
> Doug Weathers
> Las Cruces, NM, USA
> http://www.gdunge.com/
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
to elimnate drag on disc brakes what if one put a small spring between the 2
discs ?
----- Original Message -----
From: Lee Hart<mailto:[EMAIL PROTECTED]>
To: [email protected]<mailto:[email protected]>
Sent: Monday, February 12, 2007 8:07 PM
Subject: Re: Brake Pressure Multiplier?
From: Peter VanDerWal
>...it seems to me that until you experience brake fade, drum brakes will
> provide more stopping power per pedal effort on un-assisted brakes
> (due to the self-actuating feature).
>
> ...sports cars went to disc brakes (even un-assisted disc brakes) because
> racing involves LOTS of slowing down... This kind of driving is NOT typical
> for most EV commuters. I'm thinking that drum brakes might actually be
> better than discs in a commuter type EV.
I agree. Drums don't require power assist, which saves power and weight. They
are also easier to adjust so they don't drag.
If an EV has regenerative braking, the quality of the regular friction brakes
are much less important. You're more likely to use regen down a long hill.
One area where disks still excel is in wet braking. Drum brakes can fade
badly if they get wet. This can be alleviated somewhat with the proper choice
of brake linings.
--
Lee Hart
--- End Message ---
--- Begin Message ---
On 12 Feb 2007 at 0:00, Lee Hart wrote:
> However, be aware that [Guest chargers] are not particularly reliable.
A couple of list members tried Guest chargers for modular charging about 10
years ago. IIRC, they found them far too unreliable; they were reversing
batteries that hadn't been properly charged.
I might be remembering incorrectly, but it seems to me that Bill Dube' was
one who tried them back then. If so, he might have some thoughts.
David Roden - Akron, Ohio, USA
EV List Administrator
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--- Begin Message ---
Insert a tee in one of the vacuum lines and connect an automotive vacuum
gauge to it. Shut off the pump and, without touching anything, see how
quickly the vacuum falls. It should stay strong for at least a few minutes.
If it dissipates quickly, you have a leak. Then it's a matter of
disconnecting and plugging different hoses until you find it.
If the pump itself won't hold vacuum, the diaphram may have developed a
leak. IIRC, there are diaphram replacement kits for the Gast pumps often
used in conversions. Sometimes just opening the pump up and cleaning things
up a bit, making sure the reed valves seat well, is all it needs.
David Roden - Akron, Ohio, USA
EV List Administrator
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--- End Message ---
--- Begin Message ---
Thanks for that link, you are right, the motorcycle makes the same
racket as the aspire does, too loud and annoying for me!
Jack
David O'Neel wrote:
To get an idea of typical chain noise, you could watch some videos on
Google
of other people's electric motorcycles:
http://video.google.com/videosearch?q=electric+motorcycle&hl=en
I think most people are surprised at how noisy they are. It not as
noticeable when there is a gas engine screaming you along.
Dave O.
On 2/11/07, Jack Murray <[EMAIL PROTECTED]> wrote:
I'd really like to know how much noise the chain drive makes.
Jack
David O'Neel wrote:
> Wow, I'm having a really hard time NOT making immediate plans to put in
an
> order for one! $3-4000 is really not bad at all especially for
ground-up
> design. I always liked the Gizmo as well. I could see adding a rear end
to
> it though, if for nothing else, to boost the aerodynamics a little. I
guess
> I will have to just go and have a look
>
> I wonder what the implications would be for hopping it up a bit,
although
> for most, 50mph top speed is actually plenty. Any more than that, and
you
> are competing with sparrows!
>
> Excellent..
>
> On 2/8/07, jmygann <[EMAIL PROTECTED]> wrote:
>
>>
>> http://blueskydsn.com/BugE_Concept.html
>>
>> ADvanced DC 4001 series wound motor.
>>
>> Chain drive; 6/1 ratio.
>>
>>
>>
>
>
--- End Message ---
--- Begin Message ---
Hi All, I'm back for a little while. I started a new position at work and it
is keeping me busy.
But now to the point. I have always wanted to use an A/C motor in my
conversion and it appears as though I may be able to do so with some help
from a new contact at the motor controllers design facility.
He mentioned to me to use an 80 volt controller with a lower voltage motor
to help with the bemf issues.
My question: If I use a 36 volt A/C motor on an 80 volt invertor do you
think I could damage the motor?
Also: How will the torque output of the motor be affected with the different
voltage?
I realize the voltages are unusual but they are what is available to me.
Any input is welcome.
Thanks in advance.:)
Mike G.
--- End Message ---
--- Begin Message ---
Deanne Mott writes:
> BTW, it has been "burping" (is there a technical term for that?)
> every 10 seconds or so since I got it. Figured I had a slow
> leak, but was not motivated to look for it until now.
Many pumps don't actually hold a vacuum very well when they aren't running, as
they leak air out of the exhaust (compression) side; couple that with a small
reservoir and/or small hysteresis on the vacuum switch, and it'll "burp" (as
good a term as any :-) every few seconds.
Is it a Thomas? Mine certainly leaked in this manner.
If it isn't a Thomas, it might still be worth a check. Let the pump build up a
partial vacuum in the vacuum system, and then turn it off. Carefully feel if
air is being drawn in from the exhaust side (on the Thomas, if you remove any
attached filter, you'll feel the suction if you block the exhaust side with
your finger or palm).
If so, putting a suitable check value between the pump and the vacuum reservoir
will correct this aspect of your vacuum pump problems.
Cheers,
Claudio
--- End Message ---
--- Begin Message ---
Each Dewalt pack has a BMS. There is a single thermister and a tap from every
cell going to the BMS module. Unforturnately, the module is potted so I cannot
give any details.
So far I have just put the BMS modules aside and worked directly with the
cells. The A123 cells put out a lot of current and recharges at a very high
rate. I don't think the Dewalt BMS will be suitable for EV use.
The A123 cells have a clean charge cycle. You can charge at up to 5C (10+
amps) into a single string at about 3.6 volts per cell. The cell voltage stays
very constant until the cell is full and then spikes up rapidly. If the cells
are fairly consistent, it should not be too hard to monitor for the first cells
to reach full capacity. I need to do some more bench tests to see what might
work to top up the cells, or the cells may be good enough that you do not need
to do a top up, just protect the cells from overcharge.
Maybe Bill can share with the group what is on the Killacycle BMS.
EZESsport
"Osmo S." <[EMAIL PROTECTED]> wrote:
What does the BMS (or "BMS") unit of the DeWalt-pack do? Over voltage
protection only? Temperature? Is it good enough to offer the minimal
protection (whatever it is) for larger packs? You can just attach the
DeWalt packs and that´s it?
terveisin,
Osmo
Ray Wong kirjoitti 12.2.2007 kello 2.49:
> Thanks for the offer of help. I am in Edmonton, Alberta, Canada,
> basically too far away from any help. But that has never stopped
> me before.
>
> I have a few ideas to make a jig that might work on the A123 cells.
>
> EZESport
>
> "[EMAIL PROTECTED]" wrote:
> Ray or Bill,
> GoWheel.com and crew will help any way we can too.
> We're in Orange County, California
> Gary, Ryan, Jay, Randy, Ed, Robert, Don, Lou, & crew
> -------------------------------
> --- Bill Dube wrote:
>> Ray,
>> You didn't say were you were located. If
>> you are near
>> Denver, contact me and maybe we can help you get
>> these welded together.
>> Bill Dube'
>>
>> At 12:41 PM 2/10/2007, you wrote:
>> Hi Bill, I hope you can help or anyone else on
>> the list.
>> I finally got hold of enough A123 cells to put
>> together a small
>>> pack. (many Dewalt packs) In the past you
>> mentioned it took a
>>> very expensive spot welder to assemble the
>> Killacycle pack.
>> What kind of problems would be caused by a
>> standard spot welder
>> with small tips. Do you have a source for the
>> tabs that protect
>> the vent hole. Is there an alternative you might
>> suggest, something cheaper.
>> I don't want to solder onto the batteries
>> althought the RC guys say it works just fine.
>> Pack is a 4x6x10. I want to build two of these
>> 1.8kwh packs.
>> The EZESport bike is getting A123 batteries and
>> a Zilla 1K
>> upgrade. The goal is to be able to keep up around
>> town with other
>> 600cc ICE sports bike with a 20 to 30 mile range.
>> EZESport
>
>
>
>
> ______________________________________________________________________
> ______________
> Any questions? Get answers on any topic at www.Answers.yahoo.com.
> Try it now.
>
>
>
>
> ---------------------------------
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>
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--- End Message ---
--- Begin Message ---
You're right, Cor.
I assumed ( and I should know what happens when you ass - u - me) that they
were presenting something novel - especially with their phrase " increase
brake pressure when you need it most". Still, their text doesn't seem to
agree wih their curves. Just marketing, I guess.
Phil
From: Cor van de Water <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: RE: Brake Pressure Multiplier?
Date: Mon, 12 Feb 2007 17:29:43 -0800
Phil,
Please see the graph on the page in the original link.
Output pressure is exactly 2x input pressure, so there
Is no gradual change, you may have been confused by
Their marketing term "stepped", which apparently only
Refers to the two connected pistons, the input having
Twice the diameter as the output piston, thereby
Increasing the pressure by a factor of 2.
This contradicts the text which talks about 150 to
160% but I did not make the graph and the text.
As I see it is simply two fixed connected cylinders
With two fixed connected pistons, so the output
Volume is half the input volume, which leads to a
Pressure multiplication, just as the subject says.
Regards,
Cor.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Phil Marino
Sent: Monday, February 12, 2007 8:41 AM
To: [email protected]
Subject: RE: Brake Pressure Multiplier?
Cor-
I think you missed the main feature of this particular device.
They claim that, by using stepped cylinders, it provides a
variable-leverage
system . They don't spell it out in this much detail, but my assumption is
that it behaves as a typical system for the first part of it's travel, and
then the ratio changes, so that, as you get to the "hard" part of the brake
pedal's travel, it supplies more hydraulic pressure in exchange for more
pedal motion - but just at the lower part of its travel.
If this is true, then it could do what it claims - supply substantially
more
brake force at the end of pedal travel- where you need it - with only a
little more total pedal travel than a conventional system.
So, your analogy is good, in that it works similarly to a pulley system (
like any hydraulic system) .
But, in this case it works like a pulley system whose configuration ( and
mechanical advantage) changes partway through its range of motion.
Phil
>
>Paul already provided the answer and the reference to the 914 forum has
>it in even more detail:
>- if your brake cylinder diameter increased with the disk brakes,
> then you have more stopping power (at the cost of larger
> pedal travel)
>- if your disk brake cylinders are the same diameter as the drums
> then they apply the same force to the brakes. It now depends on
> the pad material if you have higher friction or not.
>- if the disk brake cylinders have smaller diameter than the drums
> then the force on the brakes is now lower, so your stopping
> power has likely deteriorated, though you should have a very
> firm feeling pedal (little travel). The BPM can help you to
> increase force on the brakes at the cost of larger pedal travel.
>
>This BPM work in the same way as a pulley system can help you to lift
>2,000 lbs of weight with only 100 lbs of force, by making the travel of
>the chain twenty times larger than the lift provided on the 2,000 lbs
>object. The power reduces, the energy stays the same (force x distance)
>just like using different gears.
>
>Hope this clarifies,
>
>Cor van de Water
> On Feb 11, 2007, at 1:22 PM, Ryan Stotts wrote:
>
> > Is this the answer to our power brakes(i.e. no vacuum booster)?
> >
> >
>http://ecihotrodbrakes.com/brake_pressure_multiplier.html<http://ecihot
>rodbr akes.com/brake_pressure_multiplier.html>
>
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All the battery charging set points people refer to include
temperature compensation calculations, and I remember reading here
that this refers to the internal temp of the batteries not ambient
air temp.
With respect to flooded lead acid batteries, how does one go about
measuring the battery temp? Just stick a glass thermometer into the
cells? Do you have to worry about not touching anything in there?
If one failed to follow the advice of buying batteries last and have
them sitting around in a 45-50 degree F room, could one assume they
are at ambient air temp?
Thanks in advance.
John
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Doug Weathers" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, February 12, 2007 9:55 PM
Subject: Re: Brake Pressure Multiplier?
>
> On Feb 12, 2007, at 7:06 PM, David Dymaxion wrote:
>
> > I think the only ways you can argue drum brakes are better are:
> >
> > * Drum brakes take less pedal effort
> > * It takes less force to do a parking brake with a drum brake
>
> Do drum brakes have less drag than disc brakes? I recall hearing this
> somewhere.
>
> If true, then drum brakes have a significant advantage on an EV.
> Hi EVerybody;
Always liked drum brakes 'cuz they don't drag, when they are adjusted
right. They seem to take care of themselves pretty well.Discs? IF you drive
most every day, stay loose. BUT if the car isn't used for awile they 'crode
up, big time. When I resumed work on the 78 Datsun, or Nissan Sentra, it
took a pull with an other electric, the Rabbit in reverse to DRAG the damn
car out of the garage. Arent the wheels supposed to TURN? These just dragged
, locked, across the driveway. Said the hell with it, popped for 2 new
Niissan calipers. A session with the ":Brass Wrench"Acy. Torch, got them
loose and the NEW calipers released the discs just fine!Polished up the
roters with the 7 inch grinder with a sanding disc, let them spin while ya
grind. Don't breath that shit, rust, aspes-dose. Wear a face air filter.
Worse than smoking<g>!When yur done car will almost roll away.
Givin' ya a brake!
Bob
> --
> Doug Weathers
> Las Cruces, NM, USA
> http://www.gdunge.com/
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.411 / Virus Database: 268.17.36/681 - Release Date: 2/11/07
>
>
--- End Message ---
--- Begin Message ---
From: FRED JEANETTE MERTENS
> To eliminate drag on disc brakes, what if one put a small spring between
> the 2 discs?
You mean between the two pads?
This could help, but there are a number of problems. Typically, you have the
rotor, a free-floating caliper, and two pads. A single hydraulic cylinder
pushes one of the pads against one side of the rotor. The pressure from that
pad against the rotor makes the free-floating caliper slide in the opposite
direction, which presses the opposite pad against the other side of the rotor.
When you release the brake, the o-ring in the hydraulic cylinder is supposed to
pull back the piston (and its pad) from one side of the rotor. But often, this
o-ring is too weak; it pulls back to relieve the pressure, but the pad still
drags lightly on the rotor.
Meanwhile, the caliper is supposed to slide back to its free position. But
often, the pins that it slides on are dirty or rusty, and bind. So the caliper
continues to drag lightly on the other side of the disk, too.
Because the pressure is high, the movement of the pads is very small. Even if
the pads do pull back, there is very little clearance between pad and rotor. As
the rotor wears, it gets out of round. So it is common for runout and wobble in
the rotor to cause further binding.
--
Lee Hart
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--- Begin Message ---
I have this problem even with a new vacuum pump, new vacuum reservoir, new
double wall heavy duty vacuum hose and a new vacuum check value in the brake
booster.
A engine vacuum at high rpm may have a reading of 20 in.hg of vacuum in the
the brake booster which is held by the vacuum check valve that is plug into
the brake booster, but the line and engine it self reduce to lower than 10
in.hg of vacuum at low rpm or wide open acceleration.
In a electric or mechanical driven vacuum pump, and if you have the vacuum
switch before any check values, then as the vacuum pumps cycles off, you
will lose this vacuum very fast and the vacuum pump will short cycle.
Some vacuum pumps have a check value built into them to prevent bleed back.
Also there may be a check value that is plug into the vacuum reservoir to
prevent bleed back to the pump.
Also is you tap off this main line that goes from the vacuum reservoir to
the brake booster, for any other vacuum assist motors, than you need another
check value come off that main line to your accessory vacuum devices.
I have only one check value in this line at the brake booster and I could
get only two pumps of the brake before the vacuum pumps comes on again.
So I install another check value between the vacuum pump and reservoir and
now can get four pumps of the brake.
Finally I install another check value on my tap off the the accessories
vacuum motors and now it never drops below 15 in.hg.
I later got rid of the electric vacuum pump and install a GMC diesel vacuum
pump that is constant drive by either the pilot shaft of the main motor or a
electric motor. This vacuum pump has a built in cut out at 22.5 in.hg and
allows to drop to 16 in.hg for a differential of 6.5 in.hg. And there is no
pop, pop, pop noise because it is a radial type, not a diaphragm type.
Roland
----- Original Message -----
From: "David Roden" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, February 12, 2007 8:28 PM
Subject: RE: Vacuum pump running constantly
> Insert a tee in one of the vacuum lines and connect an automotive vacuum
> gauge to it. Shut off the pump and, without touching anything, see how
> quickly the vacuum falls. It should stay strong for at least a few
> minutes.
> If it dissipates quickly, you have a leak. Then it's a matter of
> disconnecting and plugging different hoses until you find it.
>
> If the pump itself won't hold vacuum, the diaphragm may have developed a
> leak. IIRC, there are diaphram replacement kits for the Gast pumps often
> used in conversions. Sometimes just opening the pump up and cleaning
> things
> up a bit, making sure the reed valves seat well, is all it needs.
>
>
> David Roden - Akron, Ohio, USA
> EV List Administrator
>
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
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>
--- End Message ---
--- Begin Message ---
Assuming you don't over rev the motor or push too much current through it
and burn it out, higher voltage can allow you to maintain the same torque
you'd have at low RPMs up to a higher RPM level.
I'm assuming this is what you mean by the BEMF issues.
> Hi All, I'm back for a little while. I started a new position at work and
> it
> is keeping me busy.
> But now to the point. I have always wanted to use an A/C motor in my
> conversion and it appears as though I may be able to do so with some help
> from a new contact at the motor controllers design facility.
> He mentioned to me to use an 80 volt controller with a lower voltage motor
> to help with the bemf issues.
> My question: If I use a 36 volt A/C motor on an 80 volt invertor do you
> think I could damage the motor?
> Also: How will the torque output of the motor be affected with the
> different
> voltage?
> I realize the voltages are unusual but they are what is available to me.
> Any input is welcome.
> Thanks in advance.:)
> Mike G.
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Some C trains broke down today and caused huge delays for other trains. Does
anyone know why this happens when it gets cold out? We have two C train
models with a AC motor and a DC motor. Today it was -20C.
_________________________________________________________________
Free Alerts : Be smart - let your information find you !
http://alerts.live.com/Alerts/Default.aspx
--- End Message ---
--- Begin Message ---
I went to walmart and bought an digital automotive thermometer with an
external sensor (little puck of plastic on a 20 foot wire) and dropped the
sensor down between two batteries.
Of course if your charger has built in temperature compensation, you'll
need to purchase the appropriate sensor for the charger.
> All the battery charging set points people refer to include
> temperature compensation calculations, and I remember reading here
> that this refers to the internal temp of the batteries not ambient
> air temp.
>
> With respect to flooded lead acid batteries, how does one go about
> measuring the battery temp? Just stick a glass thermometer into the
> cells? Do you have to worry about not touching anything in there?
>
> If one failed to follow the advice of buying batteries last and have
> them sitting around in a 45-50 degree F room, could one assume they
> are at ambient air temp?
>
> Thanks in advance.
>
> John
>
>
>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
The A132 cells are very, very close to full at
3.4 volts. After they reach that voltage, it
doesn't take much to bring the voltage up to 3.8
volts, the maximum allowed. When you are
charging, you must voltage limit the cells
somewhere between 3.4 and 3.8 volts. Don't let them ever go over 3.8 volts.
If you are charging at high current, you can get
the cells to go over 3.4 volts without being
completely full. Thus, you might want to pick a
bulk charge trigger voltage of something closer to 3.8 volts, (but not over!)
There are a zillion ways of doing this. On the
version 1.0 KillaCycle BMS, Steve used a
micro-processor to monitor the voltages on each
of five cells in a group, and then would switch
on (PWM) by-pass resistors when a cell voltage
got over 3.4 volts. As a cell voltage approached
3.8 volts, the PWM would approach 100%.
Bill Dube'
At 08:45 PM 2/12/2007, you wrote:
Each Dewalt pack has a BMS. There is a single
thermister and a tap from every cell going to
the BMS module. Unforturnately, the module is
potted so I cannot give any details.
So far I have just put the BMS modules aside
and worked directly with the cells. The A123
cells put out a lot of current and recharges at
a very high rate. I don't think the Dewalt BMS will be suitable for EV use.
The A123 cells have a clean charge
cycle. You can charge at up to 5C (10+ amps)
into a single string at about 3.6 volts per
cell. The cell voltage stays very constant
until the cell is full and then spikes up
rapidly. If the cells are fairly consistent,
it should not be too hard to monitor for the
first cells to reach full capacity. I need to
do some more bench tests to see what might work
to top up the cells, or the cells may be good
enough that you do not need to do a top up,
just protect the cells from overcharge.
Maybe Bill can share with the group what is on the Killacycle BMS.
EZESsport
"Osmo S." <[EMAIL PROTECTED]> wrote:
What does the BMS (or "BMS") unit of the DeWalt-pack do? Over voltage
protection only? Temperature? Is it good enough to offer the minimal
protection (whatever it is) for larger packs? You can just attach the
DeWalt packs and that´s it?
terveisin,
Osmo
Ray Wong kirjoitti 12.2.2007 kello 2.49:
> Thanks for the offer of help. I am in Edmonton, Alberta, Canada,
> basically too far away from any help. But that has never stopped
> me before.
>
> I have a few ideas to make a jig that might work on the A123 cells.
>
> EZESport
>
> "[EMAIL PROTECTED]" wrote:
> Ray or Bill,
> GoWheel.com and crew will help any way we can too.
> We're in Orange County, California
> Gary, Ryan, Jay, Randy, Ed, Robert, Don, Lou, & crew
> -------------------------------
> --- Bill Dube wrote:
>> Ray,
>> You didn't say were you were located. If
>> you are near
>> Denver, contact me and maybe we can help you get
>> these welded together.
>> Bill Dube'
>>
>> At 12:41 PM 2/10/2007, you wrote:
>> Hi Bill, I hope you can help or anyone else on
>> the list.
>> I finally got hold of enough A123 cells to put
>> together a small
>>> pack. (many Dewalt packs) In the past you
>> mentioned it took a
>>> very expensive spot welder to assemble the
>> Killacycle pack.
>> What kind of problems would be caused by a
>> standard spot welder
>> with small tips. Do you have a source for the
>> tabs that protect
>> the vent hole. Is there an alternative you might
>> suggest, something cheaper.
>> I don't want to solder onto the batteries
>> althought the RC guys say it works just fine.
>> Pack is a 4x6x10. I want to build two of these
>> 1.8kwh packs.
>> The EZESport bike is getting A123 batteries and
>> a Zilla 1K
>> upgrade. The goal is to be able to keep up around
>> town with other
>> 600cc ICE sports bike with a 20 to 30 mile range.
>> EZESport
>
>
>
>
> ______________________________________________________________________
> ______________
> Any questions? Get answers on any topic at www.Answers.yahoo.com.
> Try it now.
>
>
>
>
> ---------------------------------
> Bored stiff? Loosen up...
> Download and play hundreds of games for free on Yahoo! Games.
>
---------------------------------
Everyone is raving about the all-new Yahoo! Mail beta.
--- End Message ---
--- Begin Message ---
Hey everyone just wanted to know what kind of EV your driving, what
components you used, and how much on average it cost for you to run your EV
per a certain distance including battery replacement?
_________________________________________________________________
http://local.live.com/default.aspx?v=2&cp=43.658648~-79.383962&style=r&lvl=15&tilt=-90&dir=0&alt=-1000&scene=3702663&cid=7ABE80D1746919B4!1329
--- End Message ---
--- Begin Message ---
would a fiber gear set help or better to go to a belt like
motorcycles or the EGO ?
--- In [EMAIL PROTECTED], Jack Murray <[EMAIL PROTECTED]> wrote:
>
> Thanks for that link, you are right, the motorcycle makes the same
> racket as the aspire does, too loud and annoying for me!
> Jack
>
> David O'Neel wrote:
> > To get an idea of typical chain noise, you could watch some
videos on
> > Google
> > of other people's electric motorcycles:
> >
> > http://video.google.com/videosearch?q=electric+motorcycle&hl=en
> >
> > I think most people are surprised at how noisy they are. It not
as
> > noticeable when there is a gas engine screaming you along.
> >
> > Dave O.
> >
> > On 2/11/07, Jack Murray <[EMAIL PROTECTED]> wrote:
> >
> >>
> >> I'd really like to know how much noise the chain drive makes.
> >> Jack
> >>
> >> David O'Neel wrote:
> >> > Wow, I'm having a really hard time NOT making immediate plans
to put in
> >> an
> >> > order for one! $3-4000 is really not bad at all especially
for
> >> ground-up
> >> > design. I always liked the Gizmo as well. I could see adding
a rear end
> >> to
> >> > it though, if for nothing else, to boost the aerodynamics a
little. I
> >> guess
> >> > I will have to just go and have a look
> >> >
> >> > I wonder what the implications would be for hopping it up a
bit,
> >> although
> >> > for most, 50mph top speed is actually plenty. Any more than
that, and
> >> you
> >> > are competing with sparrows!
> >> >
> >> > Excellent..
> >> >
> >> > On 2/8/07, jmygann <[EMAIL PROTECTED]> wrote:
> >> >
> >> >>
> >> >> http://blueskydsn.com/BugE_Concept.html
> >> >>
> >> >> ADvanced DC 4001 series wound motor.
> >> >>
> >> >> Chain drive; 6/1 ratio.
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >>
> >>
> >
> >
>
--- End Message ---
