EV Digest 6957
Topics covered in this issue include:
1) Ebay Fun Reading
by Tom Gocze <[EMAIL PROTECTED]>
2) Re: Testing Torque Cabilities
by "Roland Wiench" <[EMAIL PROTECTED]>
3) Re: Make it
by "John G. Lussmyer" <[EMAIL PROTECTED]>
4) Re: silicon batteries
by Chip Gribben <[EMAIL PROTECTED]>
5) Re: ft-lbs or lbs-ft
by Bill Dennis <[EMAIL PROTECTED]>
6) Re: ft-lbs or lbs-ft
by "Phil Marino" <[EMAIL PROTECTED]>
7) RE: ft-lbs or lbs-ft
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
8) Re: Cheap
by Tony Hwang <[EMAIL PROTECTED]>
9) Chains and belts (was Re: ft-lbs or lbs-ft
by "Peter VanDerWal" <[EMAIL PROTECTED]>
10) Re: ft-lbs or lbs-ft - Now considerations for sprocket/sheave sizes
by "Phil Marino" <[EMAIL PROTECTED]>
11) RE: AGM vs Gel
by "Alan Brinkman" <[EMAIL PROTECTED]>
12) Re: Chains and belts (was Re: ft-lbs or lbs-ft
by Eric Poulsen <[EMAIL PROTECTED]>
13) Re: Chains and belts (was Re: ft-lbs or lbs-ft)
by Christopher Robison <[EMAIL PROTECTED]>
14) EV air conditioning, how to connect motor?
by Christopher Robison <[EMAIL PROTECTED]>
15) Re: EV air conditioning, how to connect motor?
by "Randall" <[EMAIL PROTECTED]>
16) Re: Faking Tach signal for 92 VW Cabriolet
by Eric Poulsen <[EMAIL PROTECTED]>
17) Re: Make it
by "Peter Gabrielsson" <[EMAIL PROTECTED]>
18) Re: EV air conditioning, how to connect motor?
by Christopher Robison <[EMAIL PROTECTED]>
19) RE: EV air conditioning, how to connect motor?
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
20) Re: Manly EV's, RE: EV are for girls blog
by "Loni" <[EMAIL PROTECTED]>
21) RE: ft-lbs or lbs-ft
by "Alan Brinkman" <[EMAIL PROTECTED]>
22) Re: Manly EV's, RE: EV are for girls blog
by "Kaido Kert" <[EMAIL PROTECTED]>
23) Re: AGM vs Gel
by "Tehben Dean" <[EMAIL PROTECTED]>
24) Re: EV air conditioning, how to connect motor?
by Danny Miller <[EMAIL PROTECTED]>
25) Re: regarding the Solectria Sunrise
by "damon henry" <[EMAIL PROTECTED]>
--- Begin Message ---
I am thinning the library.
Thought this might be of interest to someone on the list. Bid often!
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?
ViewItem&ih=020&sspagename=STRK%3AMESE%
3AIT&viewitem=&item=300124434584&rd=1,1
--- End Message ---
--- Begin Message ---
Hello Rob,
Just search the WEB on Torque measurements. You can build a simple machine
that can read a torque of a rotating shaft. I remember there was one where
you bolt the motor down so it will not move and connect a smooth sheave
which is the type that does not have any belt V grooves in it to the motor,
engine, or any shaft you want to test.
Then you have a large beam or something like a 4 x 4 timber that one end is
fasten to a support with a single bolt so it can hinge. On this beam, a
large brake shoe is connected to it, so when it is lower it makes contact
with the sheave.
Now the length of distance from the other end of the beam to sheave is about
four feet, where you apply down ward pressure at that end, which puts
pressure on the sheave of the rotating shaft.
Here the length is four feet, so if you put on 20 lbs of weight on the end
of this lever, it will be about equal to 80 ft-lbs on the the shaft because
4 feet times 20 lbs = 80 lbs. You could call this 20 4-ft-lbs to be equal
to 80 ft-lbs.
You also have to add the weight of the beam. You can do this by using a
spring scale at the end of the beam to see how much it weighs. Lets say it
weights 20 lbs and if it takes another 20 lbs of weight to stop the shaft
from rotating or about to stop, then you then add the weight of the shaft
which is 20 lbs + 20 lbs = 40 lbs.
Then because if your brake contact point is about 4 feet from the shaft,
then you take 4 x 40 = 160 ft-lbs.
Now let say you made the lever only 2 feet long, then the force at two feet
would be about 80 lbs or 2 x 80 = 160 ft-lbs at the shaft.
At 1 foot from the shaft, it would be 1 x 160 = 160 ft-lbs.
There is another way to measure how many pounds it takes to stop a shaft,
like they did way back in time. This time they use a rope pulley on the
shaft and another one on a overhead beam which had one or move rope grooves,
something like a block and tackle. If the pulley is a double groove type,
then you have four runs of line. If you are lifting up 100 lbs of weight,
then it takes only 100/4 runs of line = 25 lbs force.
You add weight to the end of the pull rope, until the rope around the
sheaves on the rotating shaft starts to slip. That will be about, and its is
about the pounds require to stop the shaft.
To convert this to foot pounds, it requires a pivot lever at the end of this
line like the above lever unit.
Roland
----- Original Message -----
From: "Rob Hogenmiller" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, June 27, 2007 5:57 AM
Subject: Testing Torque Cabilities
> I have a motor that I can't find any specs on and can't find any
> information
> from the manufacturer or on the internet. I was wondering how I might test
> it's torque capabilities?
>
> If I hooked it up to a torque wrench that would give me an idea but then
> it
> would be near it's stall very quickly too.
>
> Any ideas how I might test it's capabilities?
>
> God bless
>
>
> ----- Original Message -----
> From: "John A. Evans - N0HJ" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Wednesday, June 27, 2007 6:46 AM
> Subject: Re: ft-lbs or lbs-ft
>
>
> > Ft-lbs (foot pounds) are the units of torque. If you had a lever arm,
> > say
> > like a crescent wrench on a bolt and the arm was one foot long, applying
> > a
> > pound of force at the end of that arm would result in a foot pound of
> > torque being applied to the bolt.
> >
> > Hope this helps,
> > john
> >
> > Rob Hogenmiller wrote:
> >> What does a ft-lbs mean?
> >> Does a foot-lb, mean that something has the ability to move something
> >> one
> >> foot that weighs one pound?
> >>
> >>
> >
> >
>
>
--- End Message ---
--- Begin Message ---
At 08:35 AM 6/26/2007, Philippe Borges wrote:
please boys, pleeeeeeeease don't feed the troll !!!
let this guy (Dan) talking with himself, smart as he claim he is,
he's going to learn lots of things this way :^)
He's still posting? More people ought to learn about email
filters. I don't see his posts anymore.
There was an interesting study some years ago (hmm, I need to find my
copy). The jist of it is that Incompetent people not only don't
realize they are incompetent, but they are completely unable to
recognize competency in others. So they always "know" they are
right, and anyone that disagrees with them is obviously stupid.
Sound familiar?
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
The E-Max and Kasea 48 volt scooters are using them. They are running
two parallel packs for a capacity of 40 Ahrs.
I work on those scooters but don't own one personally. However, I'm
using two of those batteries in parallel on my Black and Decker mower
and it has plenty of power to mow the whole yard and then some. My
lot is about 12,000 square feet. So there is something to be said for
their capacity.
I do have a customer that needs a new set after they've had their
scooter for a year. So that has me concerned. It could be the charger
since some of those that came with the scooters have had bad diodes
or it could be a bad set of cells in this particular scooter. But I
haven't heard complaints about the batteries from my other customers
running E-Max scooters.
These batteries are heavy. 8 of them in scooter brings the weight up
to 300 pounds, both scooter and batteries so they are heavy for 20
amp hour batteries.
They are sealed.
Chip Gribben
http://ElectroScooterWorks.com
On Jun 26, 2007, at 11:41 PM, Electric Vehicle Discussion List wrote:
From: Aaron Richardson <[EMAIL PROTECTED]>
Date: June 26, 2007 7:59:16 PM EDT
To: ev@listproc.sjsu.edu
Subject: silicon batteries
I have not seen this battery discussed in this group. It appears that
the electric scooter market is moving to these batteries. They are
claiming better life cycles, higher current (charge and discharge),
and
better temperature range over lead (sealed??). Anyone have anything
good or bad to say about this type of battery?
thanks,
Aaron
--- End Message ---
--- Begin Message ---
If you've got a belt- or chain-driven setup for say 5:1, and you want to
reduce the ratio to 4:1 or 3:1, does it matter whether you increase the
diameter of the sprocket on the motor shaft vs. decreasing the diameter
of the sprocket on the wheel? Mathematically they seem to be
equivalent, but are there other factors to consider?
Thanks.
Bill Dennis
John A. Evans - N0HJ wrote:
Ft-lbs (foot pounds) are the units of torque. If you had a lever arm,
say like a crescent wrench on a bolt and the arm was one foot long,
applying a pound of force at the end of that arm would result in a
foot pound of torque being applied to the bolt.
Hope this helps,
john
Rob Hogenmiller wrote:
What does a ft-lbs mean?
Does a foot-lb, mean that something has the ability to move something
one foot that weighs one pound?
--- End Message ---
--- Begin Message ---
Yes - there are other things to consider:
1. Chain speed. A larger motor sprocket means the chain speed ( ft/sec)
will be higher. There is a maximum speed rating for the chain - make sure
you don't exceed that.
2. Chain tension - a smaller motor sprocket will result in higher chain
tension for the same motor torque. Again - there is a maximum rated chain
tension.
3. Number of sprocket teeth. When sprockets get very small, the number of
teeth can get low enough to cause problems - rough running, and high tooth
and/or chain wear. Again - the manufacturer's info can help guide you here.
So - the number of teeth on the sprockets is always a compromise. You want
sprockets that don't have the chain speed too high, don't have too much
chain tension, and don't have too few teeth on any sprocket.
Phil
From: Bill Dennis <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: ft-lbs or lbs-ft
Date: Wed, 27 Jun 2007 08:08:05 -0600
If you've got a belt- or chain-driven setup for say 5:1, and you want to
reduce the ratio to 4:1 or 3:1, does it matter whether you increase the
diameter of the sprocket on the motor shaft vs. decreasing the diameter of
the sprocket on the wheel? Mathematically they seem to be equivalent, but
are there other factors to consider?
Thanks.
Bill Dennis
John A. Evans - N0HJ wrote:
Ft-lbs (foot pounds) are the units of torque. If you had a lever arm, say
like a crescent wrench on a bolt and the arm was one foot long, applying a
pound of force at the end of that arm would result in a foot pound of
torque being applied to the bolt.
Hope this helps,
john
Rob Hogenmiller wrote:
What does a ft-lbs mean?
Does a foot-lb, mean that something has the ability to move something one
foot that weighs one pound?
_________________________________________________________________
Who's that on the Red Carpet? Play & win glamorous prizes.
http://club.live.com/red_carpet_reveal.aspx?icid=REDCARPET_hotmailtextlink3
--- End Message ---
--- Begin Message ---
RPM would be the only consideration. You want to stay in the most
efficient RPM for the motor you are using.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Bill Dennis
Sent: Wednesday, June 27, 2007 10:08
To: ev@listproc.sjsu.edu
Subject: Re: ft-lbs or lbs-ft
If you've got a belt- or chain-driven setup for say 5:1, and you want to
reduce the ratio to 4:1 or 3:1, does it matter whether you increase the
diameter of the sprocket on the motor shaft vs. decreasing the diameter
of the sprocket on the wheel? Mathematically they seem to be
equivalent, but are there other factors to consider?
Thanks.
Bill Dennis
John A. Evans - N0HJ wrote:
> Ft-lbs (foot pounds) are the units of torque. If you had a lever arm,
> say like a crescent wrench on a bolt and the arm was one foot long,
> applying a pound of force at the end of that arm would result in a
> foot pound of torque being applied to the bolt.
>
> Hope this helps,
> john
>
> Rob Hogenmiller wrote:
>> What does a ft-lbs mean?
>> Does a foot-lb, mean that something has the ability to move something
>> one foot that weighs one pound?
>>
>>
>
>
>
--- End Message ---
--- Begin Message ---
I've done something like using nickel fuses. From testing, I'm using a 0.003"
thick, maybe 1/16" wide piece of nickel battery tab as a 10+ amp fuse (very
very inaccurate "blowing" current!). The cell is rated for max 4 amps
discharge, but they are massively in parallel, so the fuse should work fine.
The tabs are 1/8" wide, I just cut a little bit of it in the middle, so that
the whole tab isn't high resistance. Also my thinking is that by having the
"fuse" part of the tab in the middle, it's farther from the cells, so it will
heat up more on high current draws?
- Tony
----- Original Message ----
From: Shaun Williams <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Sent: Wednesday, June 27, 2007 2:32:24 AM
Subject: Re: Cheap
On 6/27/07, Roger Stockton <[EMAIL PROTECTED]> wrote:
> As Lee notes, automotive fuses would probably not be a good choice,
> though I suppose it is fair to observe that they do seem to work fairly
> reliably in 12V automotive systems and until the last of your fuses on a
> given module fails, they will be operating at a single cell voltage (so
> <4.5V).
Good point.
>
> I think the more practical approach (that Bill Dube has mentioned) is to
> use tabs welded between each cell and the module common bus
> bars/planes/etc. as fusible links. If a cell fails shorted and
> N-neighbours dump their full current through it, the fault current will
> be significantly greater than the normal operating current, so the
> fusible link does not have to be particularly precise in the current
> required to open it.
Thanks Roger, can you suggest an off-the-shelf product that could be
used for this? That is, a fusible material that could be spot welded
to either the cell-end or existing cell-tab, or is it simply a case of
make it thin enough and it will give?
> I doubt the benefit of being able to identify that a particular cell had
> failed would justify the cost and complexity of the monitoring required
>With most cells available now, the number in
> parallel is dictated by the required capacity, not the required peak
> current capability.
Nicely put.
>The result is that, again, one can lose a fair
> number of cells in any module before any of the remaining cells are
> going to be stressed particularly by carrying the full load current on
> their own.
I'm thinking that should a module's capacity become severely depleted
due to multiple blown cells it could be detected under load with a
voltage comparison to other modules.
Thanks,
Shaun
www.electric-echo.com
--- End Message ---
--- Begin Message ---
If you are looking for maximum efficiency, then you want to use the
largest sprockets possible. Otherwise it doesn't matter.
Using larger sprockets means that the chain/belt has to flex less going
around it and this causes less friction, resulting in higher efficiency.
> If you've got a belt- or chain-driven setup for say 5:1, and you want to
> reduce the ratio to 4:1 or 3:1, does it matter whether you increase the
> diameter of the sprocket on the motor shaft vs. decreasing the diameter
> of the sprocket on the wheel? Mathematically they seem to be
> equivalent, but are there other factors to consider?
>
> Thanks.
>
> Bill Dennis
>
> John A. Evans - N0HJ wrote:
>> Ft-lbs (foot pounds) are the units of torque. If you had a lever arm,
>> say like a crescent wrench on a bolt and the arm was one foot long,
>> applying a pound of force at the end of that arm would result in a
>> foot pound of torque being applied to the bolt.
>>
>> Hope this helps,
>> john
>>
>> Rob Hogenmiller wrote:
>>> What does a ft-lbs mean?
>>> Does a foot-lb, mean that something has the ability to move something
>>> one foot that weighs one pound?
>>>
>>>
>>
>>
>>
>
>
--
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 ---
And, a couple of other things to think about for a belt drive:
1. If the sheaves are small, you will need more belt tension to prevent
slipping. That would mean more side load on the bearings, which could
eventually be a problem. And more chance of a broken belt.
2. For belt drives, you always want as much "wrap" angle around the sheaves
as possible. So, avoid having two sheaves of very different diameters be
close together. In that case, the wrap angle of the smaller sheave would be
much less than 180 degrees, and the belt would more easily slip on that
sheave. You could increase the belt tension to compensate, but now you
would have more belt wear, and bearing wear.
If you need to use a small and a large sheave, try to space them as far
apart as you can manage, for that reason.
Phil
From: "Phil Marino" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: ft-lbs or lbs-ft
Date: Wed, 27 Jun 2007 10:29:52 -0400
Yes - there are other things to consider:
1. Chain speed. A larger motor sprocket means the chain speed ( ft/sec)
will be higher. There is a maximum speed rating for the chain - make sure
you don't exceed that.
2. Chain tension - a smaller motor sprocket will result in higher chain
tension for the same motor torque. Again - there is a maximum rated chain
tension.
3. Number of sprocket teeth. When sprockets get very small, the number of
teeth can get low enough to cause problems - rough running, and high tooth
and/or chain wear. Again - the manufacturer's info can help guide you
here.
So - the number of teeth on the sprockets is always a compromise. You want
sprockets that don't have the chain speed too high, don't have too much
chain tension, and don't have too few teeth on any sprocket.
Phil
From: Bill Dennis <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: ft-lbs or lbs-ft
Date: Wed, 27 Jun 2007 08:08:05 -0600
If you've got a belt- or chain-driven setup for say 5:1, and you want to
reduce the ratio to 4:1 or 3:1, does it matter whether you increase the
diameter of the sprocket on the motor shaft vs. decreasing the diameter of
the sprocket on the wheel? Mathematically they seem to be equivalent, but
are there other factors to consider?
Thanks.
Bill Dennis
John A. Evans - N0HJ wrote:
Ft-lbs (foot pounds) are the units of torque. If you had a lever arm,
say like a crescent wrench on a bolt and the arm was one foot long,
applying a pound of force at the end of that arm would result in a foot
pound of torque being applied to the bolt.
Hope this helps,
john
Rob Hogenmiller wrote:
What does a ft-lbs mean?
Does a foot-lb, mean that something has the ability to move something
one foot that weighs one pound?
_________________________________________________________________
Who's that on the Red Carpet? Play & win glamorous prizes.
http://club.live.com/red_carpet_reveal.aspx?icid=REDCARPET_hotmailtextlink3
_________________________________________________________________
Need a break? Find your escape route with Live Search Maps.
http://maps.live.com/default.aspx?ss=Restaurants~Hotels~Amusement%20Park&cp=33.832922~-117.915659&style=r&lvl=13&tilt=-90&dir=0&alt=-1000&scene=1118863&encType=1&FORM=MGAC01
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--- Begin Message ---
Tehben,
I researched Optima batteries a few months back and found the following:
The yellow tops were all deep cycle.
The blue tops had one model that was for starting, and the rest were
deep cycle.
All the red tops were for starting.
Each top color has about 3 to 6 different models in terms of capacity
and size.
Prices have come up a lot in the last year.
I have one blue top in a travel trailer and do not use it enough to say
any more than I am happy with it.
The red tops in my ICE cars perform well, and I have left them in when I
sell the cars so I do not know what they do after my five or so years
with them. When I did have a marginal red top in the first year, I
brought it back to Costco and it was replaced without any test or
hassle.
Alan Brinkman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tehben Dean
Sent: Tuesday, June 26, 2007 9:20 PM
To: ev@listproc.sjsu.edu
Subject: Re: AGM vs Gel
What about Optima's? They seem fairly popular on the evalbum, 27% of the
AGMs.
For the breakdown:
Optima 27%
Hawker 18%
Deka 8%
...something like that anyways ;\
What is the difference between blue and yellow tops?
Would you recommend these/
Any comments
--
TEhben
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
If you are looking for maximum efficiency, then you want to use the
largest sprockets possible. Otherwise it doesn't matter.
Using larger sprockets means that the chain/belt has to flex less going
around it and this causes less friction, resulting in higher efficiency.
Also means less actual tension on the belts themselves. 100 Ft-lbs on a
12" sprocket is 200 lbs tension. 100 Ft-lbs on a 6" sprocket is 400 lbs
tension.
--- End Message ---
--- Begin Message ---
On Wed, 2007-06-27 at 08:34 -0700, Eric Poulsen wrote:
> Peter VanDerWal wrote:
> > If you are looking for maximum efficiency, then you want to use the
> > largest sprockets possible. Otherwise it doesn't matter.
> >
> > Using larger sprockets means that the chain/belt has to flex less going
> > around it and this causes less friction, resulting in higher efficiency.
> >
>
> Also means less actual tension on the belts themselves. 100 Ft-lbs on a
> 12" sprocket is 200 lbs tension. 100 Ft-lbs on a 6" sprocket is 400 lbs
> tension.
>
Also gives you more contact length with the sprockets. Could be
important when using a belt, and may prolong the life of a chain as
well.
As a downside, larger sprockets and a longer belt/chain also would
increase rotating mass. Maybe not enough to matter, but that is
dependent on the design.
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
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--- Begin Message ---
Has anyone connected a relatively modern car A/C compressor to a motor,
inline? The discussion about belts and chains is reminding me that I
need to figure this out, and I'd like to avoid a belt if I can --
amongst other reasons, I've still not found a good source for small
lightweight K-section ribbed pulleys to fit on a standard keyed shaft or
bushing. So, I'd like to have the motor somehow directly coupled to the
compressor.
Though I haven't taken one apart to verify, I've been told by someone
knowledgeable that removing the pulley from an automotive compressor
won't work, since the pulley actually supports the bearing in some way.
I'd hoped to remove the pulley so I could couple directly from the motor
shaft to the compressor shaft, but if he was right then this won't work
without some detailed machine work to replace the pulley's bearing seat
surfaces.
So... I'm thinking more along the lines of bolting or welding something
to the existing pulley and shaft end, and welding the clutch closed. Am
I nuts? Is there a better way to do this?
BTW, the inline idea would be ideal in my case, not only for efficiency,
but also because I have a very long, narrow space where the setup would
fit well. The vehicle in question is a 2001 Saturn SL.
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
--- End Message ---
--- Begin Message ---
I had always heard that you could connect a 1 or 2hp electric motor directly
to the input shaft of the compressor and have that motor be triggered by the
same input wire that would trigger the clutch.
----- Original Message -----
From: "Christopher Robison" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, June 27, 2007 12:09 PM
Subject: EV air conditioning, how to connect motor?
Has anyone connected a relatively modern car A/C compressor to a motor,
inline? The discussion about belts and chains is reminding me that I
need to figure this out, and I'd like to avoid a belt if I can --
amongst other reasons, I've still not found a good source for small
lightweight K-section ribbed pulleys to fit on a standard keyed shaft or
bushing. So, I'd like to have the motor somehow directly coupled to the
compressor.
Though I haven't taken one apart to verify, I've been told by someone
knowledgeable that removing the pulley from an automotive compressor
won't work, since the pulley actually supports the bearing in some way.
I'd hoped to remove the pulley so I could couple directly from the motor
shaft to the compressor shaft, but if he was right then this won't work
without some detailed machine work to replace the pulley's bearing seat
surfaces.
So... I'm thinking more along the lines of bolting or welding something
to the existing pulley and shaft end, and welding the clutch closed. Am
I nuts? Is there a better way to do this?
BTW, the inline idea would be ideal in my case, not only for efficiency,
but also because I have a very long, narrow space where the setup would
fit well. The vehicle in question is a 2001 Saturn SL.
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
--- End Message ---
--- Begin Message ---
Also, look at "air core meter driver" ICs. These are the chips found in
tachometers. They have two separate circuits on-chip. One is a F-to-V
charge pump, and the other section is the meter driver itself. There's
no reason these functions can't be used separately; in fact, the data
sheet often shows you how. You could use the F-V circuit as an input
filter to the existing tach.
Also, you could probably just buy an old bolt-on tach from Ebay cheap,
remove the driver board, and wire it to the existing tach meter movement
(provided it's an air-core meter).
Phil Marino wrote:
Erik
One way to get from a pulse train to an analog voltage ( I'm assuming
you want a voltage that is proportional to the frequency of the pulse
train) is to use an IC called a "frequency to voltage converter".
National's LM 331 ( or 231 if you want the low-temperature-tolerant
version) is available at digi-key. You do need a few external
components, but I have used one successfully in my EV to create a tach
voltage signal from a sensor that sends out pulses.
It will run from just a single positive 12V supply, so it's easy to
use from that standpoint.
Phil Marino
From: "Sarah & Erik" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev <ev@listproc.sjsu.edu>
Subject: Faking Tach signal for 92 VW Cabriolet
Date: Tue, 26 Jun 2007 23:51:30 -0500
Hi all,
I spent a couple good hours looking at the VW wiring diagram and
finally found what I think is the right wire. I hooked it up to my DCP
Raptor 600, which I think outputs a normal signal for a 4 cyl tach,
drove around the block, and the tach didn't budge the whole time.
Not too long ago, another AustinEV member told me that VW tachs expect
a linear voltage signal. Anyone have any insight into VW tach signals?
Also, is an integrator circuit with an op-amp the right way to go
about making a voltage out of a pulse train? Usually when I think
about something I learned in a circuits class there is a better and
cheaper way to do it with a single part from Mouser or Digikey (or
Miser and Digikrime as Bob said once =), but all I came up with were
Transimpedance/Switched Integrators.
If I go the DIY circuit route are there any special needs for the
parts? A special cap maybe?
Thanks!
Erik
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--- Begin Message ---
There was an interesting study some years ago (hmm, I need to find my
copy). The jist of it is that Incompetent people not only don't
realize they are incompetent, but they are completely unable to
recognize competency in others. So they always "know" they are
right, and anyone that disagrees with them is obviously stupid.
Sound familiar?
Yes, I used to work for that guy!
--
www.electric-lemon.com
--- End Message ---
--- Begin Message ---
On Wed, 2007-06-27 at 12:24 -0400, Randall wrote:
> I had always heard that you could connect a 1 or 2hp electric motor directly
> to the input shaft of the compressor and have that motor be triggered by the
> same input wire that would trigger the clutch.
That's exactly the plan. A relay triggered by the clutch signal, driving
a 2hp motor I have that runs at 3600rpm, which should be about the right
speed for decent performance from the compressor.
The question is how I should physically connect the two, without a belt
if possible. Anyone done this kind of direct drive arrangement, or seen
it done?
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
--- End Message ---
--- Begin Message ---
You can get a direct motor coupler from www.mcmaster.com All you would
have to do is take off the clutch from the AC compressor and bolt the
coupler between the electric motor and the compressor.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Christopher Robison
Sent: Wednesday, June 27, 2007 12:09
To: ev@listproc.sjsu.edu
Subject: EV air conditioning, how to connect motor?
Has anyone connected a relatively modern car A/C compressor to a motor,
inline? The discussion about belts and chains is reminding me that I
need to figure this out, and I'd like to avoid a belt if I can --
amongst other reasons, I've still not found a good source for small
lightweight K-section ribbed pulleys to fit on a standard keyed shaft or
bushing. So, I'd like to have the motor somehow directly coupled to the
compressor.
Though I haven't taken one apart to verify, I've been told by someone
knowledgeable that removing the pulley from an automotive compressor
won't work, since the pulley actually supports the bearing in some way.
I'd hoped to remove the pulley so I could couple directly from the motor
shaft to the compressor shaft, but if he was right then this won't work
without some detailed machine work to replace the pulley's bearing seat
surfaces.
So... I'm thinking more along the lines of bolting or welding something
to the existing pulley and shaft end, and welding the clutch closed. Am
I nuts? Is there a better way to do this?
BTW, the inline idea would be ideal in my case, not only for efficiency,
but also because I have a very long, narrow space where the setup would
fit well. The vehicle in question is a 2001 Saturn SL.
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Kaido Kert" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, June 27, 2007 3:03 AM
Subject: Re: Manly EV's, RE: EV are for girls blog
On 6/27/07, Loni <[EMAIL PROTECTED]> wrote:
I thought of doing similarly, but two motors seem heavy and difficult to
package in a volume-produced motorcycle. On the other hand, a pair of
siamesed AC pancake motors might make a sweet little compact arrangement.
Anyone ever heard of such a beast? Sure sounds like an idea worth looking
into.
Lon Hull,
Portland, OR
Take a look at this:
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/16-810January--IAP--2007/Projects/index.htm
See the VDS, Powertrain - Electric Hub Motor design documents down the
page.
In essence, these guys designed a 10KW, axial air gap 3-phase PM motor
( sorta like
brushless ETEK, only bigger )
The important optimized design variables they came up with through
modelling:
8 poles, 18 stator slots, NeFeB magnets, 1mm air gap and 0.82mm wire.
now, where can i buy one ? ;)
-kert
Single rotor, dual stator, $9393. Ingenious, but ouch. That's why sometimes
it's just better to buy it from someone rather than design it yourself,
folks!
Lon Hull,
Portland, OR
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--- Begin Message ---
Bill,
Belts have a limit as to how much they can bend and not be damaged.
Also, you need contact area to transmit power from a flat surface of a
belt, or from the teeth on a timing belt. You may want to go larger on
the motor pulley here.
For a chain I would be tempted to go larger on the small motor sprocket
as you would limit the maximum bend in the chain and limit the friction.
However, larger on that end means more speed and more friction. What is
the maximum speed and power rating of the chain?
Someone else could tell you which pulley or sprocket on the motor would
give less side force if you were worried about wear on the bearings.
Clearance could be an issue. Do you have room to change one pulley
larger?
What is available in the size you need? The person at the parts counter
may tell you what is available, and that is your only choice to get to
say 4:1.
Cost moved me from timed belt drive to chain, standard motorcycle rear
sprocket choices, and the motor sprocket was the smallest available.
Alan Brinkman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Bill Dennis
Sent: Wednesday, June 27, 2007 7:08 AM
To: ev@listproc.sjsu.edu
Subject: Re: ft-lbs or lbs-ft
If you've got a belt- or chain-driven setup for say 5:1, and you want to
reduce the ratio to 4:1 or 3:1, does it matter whether you increase the
diameter of the sprocket on the motor shaft vs. decreasing the diameter
of the sprocket on the wheel? Mathematically they seem to be
equivalent, but are there other factors to consider?
Thanks.
Bill Dennis
John A. Evans - N0HJ wrote:
> Ft-lbs (foot pounds) are the units of torque. If you had a lever arm,
> say like a crescent wrench on a bolt and the arm was one foot long,
> applying a pound of force at the end of that arm would result in a
> foot pound of torque being applied to the bolt.
>
> Hope this helps,
> john
>
> Rob Hogenmiller wrote:
>> What does a ft-lbs mean?
>> Does a foot-lb, mean that something has the ability to move something
>> one foot that weighs one pound?
>>
>>
>
>
>
--- End Message ---
--- Begin Message ---
On 6/27/07, Loni <[EMAIL PROTECTED]> wrote:
----- Original Message -----
From: "Kaido Kert" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
> Take a look at this:
>
http://ocw.mit.edu/OcwWeb/Aeronautics-and-Astronautics/16-810January--IAP--2007/Projects/index.htm
> See the VDS, Powertrain - Electric Hub Motor design documents down the
> page.
> In essence, these guys designed a 10KW, axial air gap 3-phase PM motor
> ( sorta like
> brushless ETEK, only bigger )
>
> The important optimized design variables they came up with through
> modelling:
> 8 poles, 18 stator slots, NeFeB magnets, 1mm air gap and 0.82mm wire.
>
> now, where can i buy one ? ;)
>
> -kert
>
Single rotor, dual stator, $9393. Ingenious, but ouch. That's why sometimes
it's just better to buy it from someone rather than design it yourself,
folks!
That includes $3000 for engineer hours, $1650 for simulation
workstation and so on. As they say "this table includes one-time cost
of design, non-bulk cost of materials and machine-shop rates for
machines"
Contact these guys and offer to produce a small batch, and see how far
the price can drop..
-kert
--- End Message ---
--- Begin Message ---
On 6/26/07, David Roden <[EMAIL PROTECTED]> wrote:
On 25 Jun 2007 at 22:09, Tehben Dean wrote:
My question is, though, how often they'll really see that current. You're
talking about 120kW. Do you really expect to use that much power
frequently?
Victor says that the controller actually has a max current from
battery of 280amps.
Your inverter has 400A *rms peak* per phase output (motor) current.
The battery input limit for the inverter is 280A, you will never draw
more than that. In fact you will be hard pressed to see much more than
200A battery current. Dekas are perfectly fine battery for you.
Peter VanDerWal says:
Gel Cells are the worst.
AGMs perform the best in the cold, then floodeds and then Gel Cells.
I think I will stay clear of Gel Cells if they are the worst in cold weather.
--
TEhben
'hElix EV'
evalbum: http://www.austinev.org/evalbum/1225
--- End Message ---
--- Begin Message ---
You are underestimating the power requirements of a car A/C compressor.
While it varies by make and model and I have no hard numbers, car A/C is
sized like a huge wall unit, people have said 20K-30K BTU equivalent
which would be something like 4 or 5 HP. The draw varies substantially
with temp differential as far as I know- I saw this powering a 6500 BTU
off an inverter, I got 80A @ 12V at start and it worked up to like 120A
eventually.
Doesn't a compressor require a substantial surge power to turn on? No
prob if it's just a mattor of not being within the motor's continuous
rating but if it exceeds the motor's max stall torque then the system
will never get turning in the first place.
Danny
Randall wrote:
I had always heard that you could connect a 1 or 2hp electric motor
directly to the input shaft of the compressor and have that motor be
triggered by the same input wire that would trigger the clutch.
----- Original Message ----- From: "Christopher Robison"
<[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, June 27, 2007 12:09 PM
Subject: EV air conditioning, how to connect motor?
Has anyone connected a relatively modern car A/C compressor to a motor,
inline? The discussion about belts and chains is reminding me that I
need to figure this out, and I'd like to avoid a belt if I can --
amongst other reasons, I've still not found a good source for small
lightweight K-section ribbed pulleys to fit on a standard keyed shaft or
bushing. So, I'd like to have the motor somehow directly coupled to the
compressor.
Though I haven't taken one apart to verify, I've been told by someone
knowledgeable that removing the pulley from an automotive compressor
won't work, since the pulley actually supports the bearing in some way.
I'd hoped to remove the pulley so I could couple directly from the motor
shaft to the compressor shaft, but if he was right then this won't work
without some detailed machine work to replace the pulley's bearing seat
surfaces.
So... I'm thinking more along the lines of bolting or welding something
to the existing pulley and shaft end, and welding the clutch closed. Am
I nuts? Is there a better way to do this?
BTW, the inline idea would be ideal in my case, not only for efficiency,
but also because I have a very long, narrow space where the setup would
fit well. The vehicle in question is a 2001 Saturn SL.
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
--- End Message ---
--- Begin Message ---
Well, that's the question isn't it? When is the Tbird not a Tbird anymore?
It's obviously no other kind of car the cop recognizes so you say you built
your own lightweight custom body, and oh by the way it's also electric now.
Take a look under the hood, can you believe the price of gas...
I guarantee that if it is John Wayland driving the "Tbird", not only will he
not get a ticket, but both the cop and the Tbird will end up in some kind of
wacky video posted on Plasmaboyracing.com :-)
I really don't know what the answer is, but it seems to me just as likely to
work and be legal as not. I have heard of people buying an old motorcycle
and just cutting off the neck where the VIN is stamped then building
something custom all the way around that one piece. Of course, I don't know
if that is true or legal either.
damon
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: regarding the Solectria Sunrise
Date: Wed, 27 Jun 2007 02:27:51 -0700 (MST)
Hmm, and if a cop should run your plates? They come back as belonging to
a T-bird (or whatever) and you're obviously not driving a T-bird... do you
think that might cause a bit of a problem?
> I think you miss my point. You register the donor vehicle when you buy
> it,
> then you build the kit on top of it keeping the license plates and VINs
> from
> the donor vehicle. So it is not a kit car, it is still considered the
> original vehicle. I've never done this type of thing before and don't
> know
> how this would fly in a particular state, but I was wondering out loud
if
> it
> could be this easy.
>
> When I had my motorcycle inspected in Washington, which was only
necessary
> because I had no title, I already had the gas engine out and the
electric
> motor mounted. The state trooper looked at it and casually remarked did
> you
> change the engine in this thing. I just told him yes, got my paperwork
> signed and have never had to do anything special, just treated it like a
> 1974 Suzuki GT250 in any ensuing paperwork.
>
> damon
>
>
>>From: "John A. Evans - N0HJ" <[EMAIL PROTECTED]>
>>Reply-To: ev@listproc.sjsu.edu
>>To: ev@listproc.sjsu.edu
>>Subject: Re: regarding the Solectria Sunrise
>>Date: Tue, 26 Jun 2007 15:46:36 -0600
>>
>>Speaking of my experience with Colorado and a kit trailer I assembled
>>(Harbor Freight), when I went to register it and get tags, they didn't
>> want
>>the VIN supplied by the chinese manufacturer since it was a KIT - so
they
>>issued me sticker with a state issued VIN and requested/required that I
>>remove the original VIN from the trailer. Sounds really silly in my
>>opinion, but that is the way it happened here.
>>
>>So for Colorado, I would say that a kit vehicle would get a different
VIN
>>rather than the underlying vehicle VIN.
>>
>>john
>>
>>damon henry wrote:
>>>I wonder if you can also use the VIN of the donor car to avoid DMV
>>>hassles.
>>>
>>>damon
>>
>
> _________________________________________________________________
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>
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