EV Digest 4313
Topics covered in this issue include:
1) Re: Contactor controller, Was:RE: Mechanical PWM Controllers
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Value of electric 7 EV?
by Victor Tikhonov <[EMAIL PROTECTED]>
3) Re: Trains an' Stuff
by "Dave" <[EMAIL PROTECTED]>
4) Re: Direct Drive Racing Driveline
by David Dymaxion <[EMAIL PROTECTED]>
5) Re: Value of electric 7 EV?
by Ryan Stotts <[EMAIL PROTECTED]>
6) Re: Got my taperlock hub off!
by Ryan Stotts <[EMAIL PROTECTED]>
7) Re: Trains an' Stuff
by Evan Tuer <[EMAIL PROTECTED]>
8) Chain primary drive
by Eric Poulsen <[EMAIL PROTECTED]>
9) Re: Direct Drive Racing Driveline
by Ryan Stotts <[EMAIL PROTECTED]>
10) Re: Direct Drive Racing Driveline
by Ryan Stotts <[EMAIL PROTECTED]>
11) Re: Chain primary drive
by Ryan Stotts <[EMAIL PROTECTED]>
12) Re: Value of electric 7 EV?
by "Philippe Borges" <[EMAIL PROTECTED]>
13) Re: Re EV watercraft, EV jet ski's and EV race cars was: Newbie
introduction
by D B <[EMAIL PROTECTED]>
14) Re: Direct Drive Racing Driveline
by "Dave" <[EMAIL PROTECTED]>
15) Re: Valence, etc.
by Reverend Gadget <[EMAIL PROTECTED]>
16) Re: Direct Drive Racing Driveline
by "Christopher Robison" <[EMAIL PROTECTED]>
17) Re: Trains an' Stuff
by Derrick J Brashear <[EMAIL PROTECTED]>
18) Re: Chain primary drive
by Eric Poulsen <[EMAIL PROTECTED]>
19) Re: Valence, etc.
by Victor Tikhonov <[EMAIL PROTECTED]>
20) Re: Got my taperlock hub off!
by "Philip Marino" <[EMAIL PROTECTED]>
21) Re: Direct Drive Racing Driveline
by James D Thompson <[EMAIL PROTECTED]>
22) Re: Pics of the Big Guy, mechanical questions (was Re: New EV Dragster)
by Seth Allen <[EMAIL PROTECTED]>
--- Begin Message ---
Stu and Jan wrote:
> Assuming I switch from 0 to: 12, 24, 36, and 48 V, is an additional
> first step with a resistor required for a soft start?
Yes. Assume you are using a series DC motor. It behaves like a resistor
whose value is proportional to RPM. At zero rpm, it has (almost) zero
resistance. So, the current will be very high no matter how low the
battery voltage. Starting directly at 12v will still produce quite a
lurch.
But, the torque a vehicle takes to move at a constant speed is roughly
constant. The speed of a motor is roughly proportional to voltage. So if
you start with 12v and no resistor, it lurches to a start and then
creeps along at low speed.
Take the opposite extreme. A PWM controller runs in current limit at low
motor speeds. This produces constant motor torque. When this torque is
more than the vehicle needs, you accellerate. So, the amount of current
directly controls your accelleration.
Now suppose you have only one battery voltage (48v), but a choice of
several starting resistors (high/medium/low resistance). At low speeds
where motor resistance is negligible, these resistors provide a
"constant" low/medium/high current. Thus they provide a nice, smooth,
slow/medium/fast accelleration. The resistors stabilize the current, so
your accelleration is just as smooth as a PWM controller.
The resistors would burn up a lot of energy while you are accellerating.
But when you reach full speed, of course you switch the motor directly
to the batteries (no resistors).
This is exactly how many older slow EVs were built. When the vehicle
spends most of its time travelling at a fixed (maximum) speed, and the
resistors are only briefly used to accellerate, this system works great.
The idea of switching battery voltages is how you efficiently select
your speed. The idea of the starting resistor(s) is to control how
smoothly you can change *between* those speeds.
--
"The two most common elements in the universe
are hydrogen and stupidity." -- Harlan Ellison
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
You probably mean $1.4/Wh, not per Ah, which works out to ~$5/Ah.
$1.4/Ah would mean the Kokam's are cheaper than TS ones,
and AXRC would be full of them by now...
Victor
Philippe Borges wrote:
The quote i had at EVS21 was about $1,4/Ah for low quantities.
I have $1/Ah from other company (10Ah lipoly cells) but i'm still figuring
the cell quality (lots of questions not enought good answer for the moment)
Philippe
Et si le pot d'�chappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les v�hicules �lectriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "Victor Tikhonov" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, April 25, 2005 6:31 PM
Subject: Re: Value of electric 7 EV?
Mark Fowler wrote:
...
Li-Poly plus AC (I assume you've looked through Victor's site
www.metricmind.com or the Electric Imp site www.proev.com ) is going to
cost a large chunk of money - probably about double what the Lotus 7 kit
costs.
(Victor, were you selling 3.7V Kokams for about US$5 per Ah?)
I don't deal with Kokam's LiPs directly, if one wants to purchase
them, they should contact Kokam, pay to them, and the battery will be
shipped to them direcly from Korea. BTW, I don't make a dime on this.
Expect the cost to be ~$6/Ah, this is last quote I had year ago.
May be Kokam changed their prices, I haven't asked since then.
--
Victor
'91 ACRX - something different
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Ironic, no?
David C. Wilker Jr. USAF (RET)
Children need love, especially when they do not deserve it.
- Harold S.
Hulbert
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, April 25, 2005 11:37 AM
Subject: Trains an' Stuff
Interestingly enough the Bullet Train, with a perfect safety record , over
40 years!!! Hurrah! Japan National Railway!!I tip my hat to you folks as a
RR guy, myself!
--- End Message ---
--- Begin Message ---
I don't know how universally true this is, but for the Mustang guys
IRS weighs about 100 more pounds and is prone to wheel hop.
--- Christopher Robison <[EMAIL PROTECTED]> wrote:
> ...
> More importantly, is there any mechanical reason why IRS would not
> be as
> desireable on the strip? I know it's a liability with the
> off-road
> crowd, conversions to a solid rear axle are a fairly popular
> upgrade.
> ...
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Some more Kokam prices:
"The 70 amp/hr battery is $362.60 each. The 40 amp/hr battery is
$207.20 each. These prices are FOB South Korea so shipping is not
included. Discounts are possible for larger orders."
http://www.proev.com/P1Batt.htm
How does one hook those batteries together with that style tab?
If I had a stack of them 1' high, wouldn't that be a lot of weight on
the bottom one? What about heat between them from being stacked up
like that?
How are those supposed to be mounted? All 90 something of them...
--- End Message ---
--- Begin Message ---
Will a puller like this remove the hub?
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/in_our_stores/loan_a_tool/pullers_specialized/timing_gear.jsp
I really don't want to hammer on the bearings..
--- End Message ---
--- Begin Message ---
On 4/25/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> is there a really GOOD argument for 25hz, today?? I know Amtrak has motor
> alternater
> substations rotery converters to MAKE 25hz, seems a lot of trouble, to me?
> The new stuff
> from NH to Bos is all a more mod 25k 25hz, put in 5 years ago.
I think that a lot of times, early electric machinery was running
directly from a dedicated power station. So, the frequency that they
ended up using would just be a function of the generator design - how
much current and voltage they needed, what was the power source etc..
To illustrate the point, I recently had a trip on the Flam railway,
which runs up the side of a very picturesque fjord in Norway. It's
seriously steep, and the feat of engineering involved in building it
is incredible! Anyway, the electrification was done in 1944, 15kV
overhead wires, and 16 and 2/3rd Hz!? A pretty odd frequency, but
when we passed the hydro station, half way up and on the edge of a
waterfall, I guessed that must have been what the generator produced
when they installed it back then. All still running now of course,
and at the same odd frequency.
--
EVan
http://www.tuer.co.uk/evs2
--- End Message ---
--- Begin Message ---
I've been mulling over the use of roller chain as a primary drive for a
motor --> transmission coupling on a motorcycle.
One major reason is to be able to tweak the motor --> transmission ratio
by using different sprockets.
Here's the assumptions:
1) An enclosed oil bath will be necessary for a #60 chain operating at
motor speeds.
2) Changing sprockets will often mean a change in chain length.
Sometimes the new length needed won't be a multiple of 2 rollers; when
you shorten or lengthen a chain, you have to remove or add two links.
The questions:
A) Can an idler sprocket be safely used to take up the "slack"? My
intuition says "yes," but ...
or
B) Must the shaft-shaft distance be modified to take up the slack?
C) Would a smaller pitch (#40) double or triple width chain be better?
If (A) is true, will the idler sprocket be okay when used in reverse,
assuming it's on the "slack" side of the chain for normal forward operation?
If (B) is the case, this is easy enough to accomplish if your chain
isn't enclosed, but when it's inside it's own little housing with oil,
how do you adjust one of the shafts to be closer or farther to the other
shaft?
Notes:
The Gates "PolyChain" belts used by Harleys can be dry, and easy to
re-tension, but these are expensive and large.
I am aware I can go tranmissionless, but that's not the point.
--- End Message ---
--- Begin Message ---
David Dymaxion wrote:
> I don't know how universally true this is, but for the Mustang guys
> IRS weighs about 100 more pounds and is prone to wheel hop.
Here is a picture of a Corvette differential:
http://img254.echo.cx/img254/1899/mvc007s9am.jpg
Late model Mustang:
http://img254.echo.cx/img254/5476/thmbondollymark3bm.jpg
Drag racing is not one of those differentials strong points..
--- End Message ---
--- Begin Message ---
> Christopher Robison wrote:
> 9" is the current plan.
Have you seen that drop in 12 bolt center section that is available for the 9"?
http://www.strangeengineering.net/catalog/64.html
> I've mentioned, the thing that's stalling me here is that I have never cut
> an axle housing before, and I'm not sure I know what I'm doing.
What exactly are you referring too?
> though, then it should extend about 6 or 7 inches or so, I figure. This
> will be dictated in part by the slip yoke. At the moment, the challenge
> seems to be to find a slip yoke with a large enough internal spline.
I think one of those drive shaft places should be able to set you up
with a slip yoke.
--- End Message ---
--- Begin Message ---
Eric Poulsen wrote:
> I've been mulling over the use of roller chain as a primary drive for a
> motor --> transmission coupling on a motorcycle.
>
> 1) An enclosed oil bath will be necessary for a #60 chain operating at
> motor speeds.
Why not just use a standard motorcycle chain and then it wouldn't need
an "oil bath" system?
http://www.ekchain.com/sport.htm
--- End Message ---
--- Begin Message ---
ouch sorry my mistake for Kokam
though second price source is good one ;^)
cordialement,
Philippe
Et si le pot d'�chappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les v�hicules �lectriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "Victor Tikhonov" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, April 25, 2005 8:51 PM
Subject: Re: Value of electric 7 EV?
> You probably mean $1.4/Wh, not per Ah, which works out to ~$5/Ah.
>
> $1.4/Ah would mean the Kokam's are cheaper than TS ones,
> and AXRC would be full of them by now...
>
> Victor
>
> Philippe Borges wrote:
>
> > The quote i had at EVS21 was about $1,4/Ah for low quantities.
> > I have $1/Ah from other company (10Ah lipoly cells) but i'm still
figuring
> > the cell quality (lots of questions not enought good answer for the
moment)
> >
> > Philippe
> >
> > Et si le pot d'�chappement sortait au centre du volant ?
> > quel carburant choisiriez-vous ?
> > http://vehiculeselectriques.free.fr
> > Forum de discussion sur les v�hicules �lectriques
> > http://vehiculeselectriques.free.fr/Forum/index.php
> >
> >
> > ----- Original Message -----
> > From: "Victor Tikhonov" <[EMAIL PROTECTED]>
> > To: <[email protected]>
> > Sent: Monday, April 25, 2005 6:31 PM
> > Subject: Re: Value of electric 7 EV?
> >
> >
> >
> >>Mark Fowler wrote:
> >>...
> >>
> >>>Li-Poly plus AC (I assume you've looked through Victor's site
> >>>www.metricmind.com or the Electric Imp site www.proev.com ) is going to
> >>>cost a large chunk of money - probably about double what the Lotus 7
kit
> >>>costs.
> >>>(Victor, were you selling 3.7V Kokams for about US$5 per Ah?)
> >>
> >>I don't deal with Kokam's LiPs directly, if one wants to purchase
> >>them, they should contact Kokam, pay to them, and the battery will be
> >>shipped to them direcly from Korea. BTW, I don't make a dime on this.
> >>
> >>Expect the cost to be ~$6/Ah, this is last quote I had year ago.
> >>May be Kokam changed their prices, I haven't asked since then.
> >>
> >>--
> >>Victor
> >>'91 ACRX - something different
> >>
>
> --
> Victor
> '91 ACRX - something different
>
--- End Message ---
--- Begin Message ---
Aloha All: Did I miss something when the surf was up? Could you point me
to it please? I only subscribe to lurk and acquire info for
electric-powered ultralights and electric powered surfboards/boogie
boards. I obtained a model jet pump made in Gernmany with a 55 mm
diameter rotor for use in a self-powered waterproof surf camera, but the
RPM's required to generate thrust caused too much vibtration and lack of
effectiveness in dragging a swimming body through the water. We worked
on an electric radio controlled boogie board to allow surfing by blind
or handicapped children (controlled by a therapist), but the funding
never came through. We figured that batteries, motors, controllers and
small pumps would all be improving over time, we had the ocean for
passive cooling, and the combined medical/rich kid market would create a
large demand. We're still waiting, and my wife told me to build a Lanai
instead.
I think that the giant surf site "JAWS" (Peahi, Maui - 50 foot + old
style of measuring), which is now only surfed by tow-in behind a jet
ski, could be ridden by a self-powered rhino chaser that was limited to
a 30 second burst of high power to get in the wave and then a 20 second
burst of low power to get out. The board would be exchanged with a caddy
boat outside the surf, where the batter would changed out and charged.
Now that a (very very noisy) two stroke powered surfski is avaiable
(with a claimed 48 HP), a far larger and better size jet pump is
available, as it is bigger than mine but smaller than the smallest
production pump (the old and original Kawakai 300 and 440 pump at 4
3/8"), but I don't know the actual size. A jet pump may not be the best
choice for low speed cruising on a three person craft as opposed to the
ETEK outboard. I'm sure that the IHPVA can provide insights to higly
efficient watercraft, which I think included hydrofoil carried
"sinkers", SWATH-style submerged bouyant twin hulls, kayaks, etc.
I'm just started testing an ETEK with a drone propeller (so as not to
load it up too much at first) direct drive as a pusher. I'm still trying
to decide on a controller; we're using battery switching now, starting
off with 12, then 24, etc. We're using old 12 and 24 volt aircraft
batteries which won't hold a chrage, but can give us flash readings. My
electron guru moved to the mainland, so thing are going slowly. As has
always been clear, only certain niche markets or design concepts with
highly unique capabilities which compensate for the lack of power
density. I'm trying to get battery information on thd new GP3700 NIHI
cells that can puke out 200+ amps for a short period of time; I can't
find voltage charts for anything over a 40 amp load.
has anyone done the numbers for an EV prop-pack, as are currently being
used with parasails, now usually powered by a noisy gas engine?... seems
like the energy density on LiP might give it a functional range...
I'm just started testing an ETEK with a drone propeller (so as not to
load it up too much at first) direct drive as a pusher. I'm still trying
to decide on a controller; we're using battery switching now, starting
off with 12, then 24, etc. We're using old 12 and 24 volt aircraft
batteries which won't hold a chrage, but can give us flash readings. My
electron guru moved to the mainland, so thing are going slowly. As has
always been clear, only certain niche markets or design concepts with
highly unique capabilities which compensate for the lack of power
density. I'm trying to get battery information on thd new GP3700 NIHI
cells that can puke out 200+ amps for a short period of time; I can't
find voltage charts for anything over a 40 amp load.
We'll test it on a Trike, not a paraglider. Paraglider wings are still
far too inefficient when compared to either a flexible or a ridgid
hangglider. We fly a single-seat trike at Makapu'u, where it takes less
than one minute get fly up into the ridge lift from the ground or
nothing to jump off from the top. The Trike is heavy and requires about
25 HP to accellerate quickly (<100 feet take off roll into a nomral
trade wind) and climb out steeply, but only about 10-12 HP to fly in
level flight at best L/D. The engine it at idle and cleared occasionally
when soaring in ridge lift, and warmed up only incase of a balked
landing. The 170 lb. empty (370 gross) Trike is totally non-optomized
for low powered flight; it is heavy and draggy, but its a baseline.
This is a profile even a pure electric could achieve with a longer
take-off run, a lower rate of climb and a larger engine. A hybrid system
might prove more practical (STOP THE FLAMES) in aircraft applications,
but I know that a practical pure electric can now be built and flown
without the expense of LiPoly.
MANU IWA: An Easy Riser based hybrid ultralight cross-country motor-glider.
The Easy Riser is a swept wing, positive stagger biplane hangglider that
weighs about 55 lbs with metal ribs and 53 lbs with foam/wood ribs.
Aluminum tubing forms front and rear spars at the leading and trailing
edges, with two bays/struts per side and drag rudder at each tip
trailing edge. All tubing is 1” 6061 T-6, including struts, and it folds
for transport. Flying wires are 7x19 aircraft cable, 1/8th I think. It
bolts together at the center section with four bolts, and hang tubes
control tip rudders. It has a 40” chord, and 26 foot span, and about 160
sq. ft. of total wing area. The wing tips are set 6’ further aft than
the center section nose, with both dihedral and washout; the swept back
wing makes for more pitch stability. It was a development of the Icarus
II hangglider designed by Taras Kicenick, had great stability, was
easily foldable, and was widely converted (by John Moody and others)
into a powered ultralight, with or without wheels. Attachments show the
basic hangglider and a powered variant with wheels.
I flew my machine with a McCulloch 101, a screaming beast with a 24”
prop turning at 10,000+ RPM and better suited to converting horse power
to noise than to thrust; we got about 45-55 lbs of thrust static, which
would barely fly me (then 180 lbs) but would fly a lighter (135 lbs)
pilot. Weight was about 75 lbs. We went to a reduction drive and larger
prop, and got 65-75 lbs of thrust, but weight was up to 82 lbs. I am
assuming based on those results that we will require 100 lbs of thrust
for take off and climb, and 55 lbs for cruise in dead air it a foot
launched version.
Larry Mauro (formerly of H-P prior to manufacturing Easy Riser kits)
started messing around with electrical power in 1973-74, starting with 3
Astro Flight 40’s driving a common propeller and mounted in the center
behind the pilot. It didn’t work too well, so a second one was built and
both were moved to the first bay out on each side. The motor pack was
mounted on the rear of a fore-aft tube (which carried the ni-cads) which
itself was mounted to the junction of the front and rear
flying/anti-flying wires in cleaner air. It didn’t work much better, but
it got a few of us off the ground from a running take off on flat ground
(on the Mainland in Sunnyvale), but I never got a chance to try it here
in Hawaii on a cliff launch or into a steady trade wind.
Later Larry built the Solar Riser, which featured landing gear, a “pod”
around the pilot, main landing gear made from a carbon fiber bow, a
helicopter starting nicad, and a motor designed to run a fan in Skylab
during the Apollo years. The solar panels were mounted on Styrofoam
between the ribs in the first three rib bays on each side. The aircraft
was covered with clear mylar rather than the normal doped fabric. It did
fly on solar power, albeit accumulated and stored in a larger battery.
It’s now in the EAA museum at Oshkosh.
An optimized “Carbon Easy” could weigh as little as 40 lbs without
landing gear but with a pilot fairing, and perform substantially better
if certain modifications are made, mainly by replacing aluminum with
carbon fiber tubing and composite ribs that would allow
semi-cantilevered construction. We’re looking to build a “breadboard”
basic proof-of-concept power system for bench testing, both of a pure
electric system for a foot-launched test aircraft to define thrust
requirements and parameters with minimal investment (as if two Neu 1500
serious, controllers and strings of GP 3700’s are minimal). I still have
a flyable Easy Riser hangglider which we previously flew (poorly) with a
chain-saw engine so we have a baseline.
Batteries are carried inside hang tubes and inner front wing spars.
Motors would be mounted on a span-wise structure behind pilot as
pushers, placing outboard motors either in the middle of the first bay,
or even at the strut itself (if a numerically high reduction ratio and a
very large diameter propeller) are used. Alternative mounting (assuming
rear spar flying/anti-flying wires cannot be eliminated in inner bay)
would be to mount outer motors on rear end of tube connected to junction
of flying/anti-flying wires at front and rear spar, with some batteries
inside tube, as Larry Mauro did in the 1970’s. Either way, propeller
size would be no less than 32” for a fixed pitch 6000 RPM prop (502
ft/sec tip speed) and possibly as large as 48” (with landing gear for
clearance) for a variable pitch 2500 RPM prop (514 ft/sec tip speed).
Either way, the propeller and reduction drive would be far lighter than
that required by a piston engine.
POWER SYSTEM OPTIONS.
Several power options considered possible with off-the-shelf parts, but
all have less than 6 KW ICE power and less than 9 KW take off/4 KW
continuous/ cruise. I'll only discuss the pure electric now, not the
various hybrid concepts. The concepts are based upn off-the-shelf model
technology, including Steve Neu's new motors (www.Neumotors.com) (at
2700 watt max) or the 4.0 KW under development. Thirty (30) seconds of
power from motors at 5.4 KW (2.7 KW each) from batteries (Li-poly or
more likely NMHI or NiCad). In climb-out, ICE power could be brought
back to cruise-climb (3/4 power) 4 KW electrical output. Motors act as
buffer with charge/discharge based on battery levels and flight power
required. 2 motors; 30 seconds of power from motors at 5.4 KW (2.7 KW
each), 30 seconds at 4.0 KW (2.0 KW each), and continuous at 2.6 KW (1.3
KW each), allowing both level flight in dead air and recharge of
batteries in flight or on ground.
Possible launch assist ground power line launch umbilical (i.e., short
(20 ft), fairly heavy power cords (uninsulated) going from ground
battery/APU/GPU source to aircraft. Line kept apart and attached to
break away (clothes pins?) at mid span each side (to keep from
touching). Back up 20 feet for foot or wheel launch, run/roll to and
then past ground power source, until power umbilical pulls out of each
side of lower wing, and batteries take over.
With the Neu (BAM motor). 2 motors; 30 seconds of power from motors at
7.0 KW (3.5 KW each), 30 seconds at 4.5 KW, and continuous at 3.0 KW.
Foot launch at 60 lb empty and 250 lb with pilot. Wing loading <1.3
lbs/sq.ft. Ability of use solar or excess lift to drive motors and
generate power a development possibility. Relies of soaring flight to
reduce flight power loads below zero so props drive motors as generators
(inefficient airfoil but light) during strong lift. Motor drag from
re-gen is used to turn aircraft rather than tip rudder drag.
Completely featherable or slightly reversible props (past feather, so
that propeller airfoil lifts in the correct direction even if motor
rotation must be reversed in air-driven charge mode) might give better
re-gen performance for less drag. Capability of charging batteries while
on ground in high wind (say all night) could make real cross-country
trips possible.
Strong point for electric propulsion is its over-boost ability, lack of
vibration, lighter reduction drive/propeller, larger-slower and more
efficient propeller, quiet operation, and ease of start, stop and ease
of speed control and computer control. Moreover, the efficiency of all
components of the system (batteries, motors, controllers, and chargers)
is being improved monthly or yearly, which can no longer be said for any
ICE systems. Drawbacks are very low power density, possible continued
need for reduction drives (although lighter), and the critcal cooling
requirements for motor, controller and batteries.
also,
with an electric system, there is the option of using many small
motors/props, providing greater range of power and attitude control than
single prop, which is not weight-practical using full-sized gas-burning
engines...
This is what aviation legend Burt Rutan said in a Road & Track article
on hybrid cars:
"Does he see any application of hybrid propulsion for airplanes? An
innocent question, although it leaves Rutan unusually silent. "Gee,
maybe I shouldn't disclose this in Road & Track. But at the risk of
someone else doing this first, let me tell you about an airplane that
would be really interesting to do. This is fascinating...."
Rutan leans back and stares into middle distance. "Visualize an electric
airplane with enough batteries to climb to about 500 feet. Actually, it
would have several small electric motors with small propellers scattered
all around the airplane—some on the tail, some on the wings—so if one
motor seized, it's just a nuisance. Plus, there's a phenomenal advantage
here: You wouldn't need control surfaces. Put a motor on a high part,one
on a low part and give the first power and the other negative thrust or
regen, and you pitch down, for instance.No elevator, no ailerons, no
rudder. "Okay. Now after climbing to 500 or 600 feet, the batteries are
pretty much puked. However, onboard would be this gas-powered generator
that would produce 10 to 20 percent more [electrical] power than you
need to cruise. The climb from 500 feet would be slow, but, the most
important part to climbing is the initial part, getting over the trees.
For landing, or even if something bad happens like the generator seizes
or you run out of gas, all the way down the props would be doing
regen,charging the batteries up for a controlled landing (altitude being
equivalent to potential energy). During the last part coming down, you
actually want drag anyway; a very efficient airplane needs flaps or
speed brakes to slow it down. "Here's a prediction: You may find that
within the next few years Burt Rutan will go off and build one of these."
Sounds like a Black military project to me.
Over the past 25 years I've put a lot of investigative time and design
conceptual work into newly-feasible electric aircraft types,
configurations and potentials; some are pure electric, some are hybrid,
and some (in the Lighter-than-air realm) are designed for long-distance
"sailing" or power sailing in the inter-island waters. Electric could
really come into its own in an LTA system to provide virtually a magic
carpet ride. Mahalo and I hope you start your project. David.
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The Mustang IRS looks very similar to the '92 T-Bird IRS I have.
David C. Wilker Jr. USAF (RET)
Children need love, especially when they do not deserve it.
- Harold S.
Hulbert
----- Original Message -----
From: "Ryan Stotts" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, April 25, 2005 1:00 PM
Subject: Re: Direct Drive Racing Driveline
David Dymaxion wrote:
I don't know how universally true this is, but for the Mustang guys
IRS weighs about 100 more pounds and is prone to wheel hop.
Here is a picture of a Corvette differential:
http://img254.echo.cx/img254/1899/mvc007s9am.jpg
Late model Mustang:
http://img254.echo.cx/img254/5476/thmbondollymark3bm.jpg
Drag racing is not one of those differentials strong points..
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The price will probably stay high unless there is some
meaningful competition. It also depends on how the
manufacturers are set up to produce. If the production
line is set up for low volume, then it is hard to
drop the price. but if the line is set up for high
volume tnen sometimes the producer will drop the price
to raise the volume. A high volume line can lose money
at lower outputs. we just need someone who has the
money to set up production to get the prices to drop.
Reverend "fingers crossed" Gadget
--- Victor Tikhonov <[EMAIL PROTECTED]> wrote:
> The cost with volume can be *afforded* to be reduced
> by a manufacturer,
> but it is not a guarantee it will happen. Why lower
> the cost if the
> customers buying already? It is all supply/demand.
>
> Philippe already mentioned SAFT NiCds produced in
> millions but the
> price stay high and no sign of reduction so far.
>
> Victor
visit my website at www.reverendgadget.com
--- End Message ---
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Ryan Stotts said:
>> Christopher Robison wrote:
>
>> 9" is the current plan.
>
> Have you seen that drop in 12 bolt center section that is available for
> the 9"?
>
> http://www.strangeengineering.net/catalog/64.html
>
Saw it when you posted it last time. Interesting idea; my hesitation would
be regarding parts availability and the strength of the case. Their 9"
aluminum center section is considered "light duty" -- if you're drag
racing, go nodular. No mention of the issue with these aluminum centers.
Probably worth calling them to get their opinion.
I do like the shorter drop on the pinion ... I've heard that 9" rears are
noisy when running -- I wonder if the less severe hypoid mesh would have
the side effect of making the gears run quieter .. or would it make them
louder? Without a transmission, the rear end may end up being the loudest
part of the vehicle while in operation.
>> I've mentioned, the thing that's stalling me here is that I have never
>> cut
>> an axle housing before, and I'm not sure I know what I'm doing.
>
> What exactly are you referring too?
Taking a 9" axle housing and cutting/welding to make it narrower to fit
under a compact truck. I'm not entirely clear on how everything works at
the ends, how the brakes attach, how much clearance to allow for the
brakes given a particular wheel backspacing and so forth. I know there are
different standards in the end plates, and I know to avoid the smaller
older Ford standard. I also know I need to make one axle tube longer than
the other to allow for the off-center pinion. It's just the "doing" it
part ... I just have a feeling there's a lot more to it that I don't know
about yet.
--chris
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On Mon, 25 Apr 2005, Evan Tuer wrote:
On 4/25/05, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
is there a really GOOD argument for 25hz, today?? I know Amtrak has motor
alternater
substations rotery converters to MAKE 25hz, seems a lot of trouble, to me? The
new stuff
from NH to Bos is all a more mod 25k 25hz, put in 5 years ago.
I think that a lot of times, early electric machinery was running
directly from a dedicated power station. So, the frequency that they
ended up using would just be a function of the generator design - how
much current and voltage they needed, what was the power source etc..
Indeed, the earliest Pennsylvania Railroad electrification was DC only
near New York but when extended it was AC being fed from, for instance,
Safe Harbor Dam, and several sources claim commercial customers at the
time were fed 25hz power. The only real argument for it would be if there
were sufficient old equipment that required it, which I guess might be
Silverliners and Jersey Arrows. Everything back to E60s did dual frequency
tri voltage, right?
I'd guess, though, that this is really out of scope for this list. ?
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M/C chains are on the transmission --> wheel connection, which is
considerably slower than the motor --> transmission connection.
Ryan Stotts wrote:
Eric Poulsen wrote:
I've been mulling over the use of roller chain as a primary drive for a
motor --> transmission coupling on a motorcycle.
1) An enclosed oil bath will be necessary for a #60 chain operating at
motor speeds.
Why not just use a standard motorcycle chain and then it wouldn't need
an "oil bath" system?
http://www.ekchain.com/sport.htm
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Except that since "we" don't buy their NiCds now anyway,
setting competition will not impact or take away any busines
from SAFT, so their prices will stay just as high. They don't
care about local sales here from local suppliers - it would
not be "at their expence".
It's the people (OEMs) who *constantly* buys from SAFT can
impact SAFT's pricing policy if they (OEM) would have
alternative and decided to turn away from SAFT. Until then -
forget it.
Victor
Reverend Gadget wrote:
The price will probably stay high unless there is some
meaningful competition. It also depends on how the
manufacturers are set up to produce. If the production
line is set up for low volume, then it is hard to
drop the price. but if the line is set up for high
volume tnen sometimes the producer will drop the price
to raise the volume. A high volume line can lose money
at lower outputs. we just need someone who has the
money to set up production to get the prices to drop.
Reverend "fingers crossed" Gadget
--- End Message ---
--- Begin Message ---
Mike - is there some reason you can't put in two or three tapped holes in
these hubs ( at, for example, the same diameter as the pull-in screws) so
screws can be used to force the hub apart from the bushing. Is there a
flat surface on the bushing for these screws to push against? This way,
there would be no load on the motor shaft or bearings at all when taking the
hub off.
I know you've been doing this for a while, and it sounds like most of the
time, you have no problems getting these things apart, but I would be
nervous hammering either the pull-in screws or the end of the puller.
Either could damage the motor bearings.
Ball bearings ( inlike the bearings in most ICE engines) are not very
tolerant of impact loads, and the damage to the bearings may not be obvious
right away, but still cause a failure later on.
Phil
From: Electro Automotive <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: Got my taperlock hub off!
Date: Mon, 25 Apr 2005 10:42:32 -0700
The tapered bushings that we use have the tapped removal holes in the part
of the bushing that we machine off. We remove this part of the bushing
because there's no space for it, or reason in our applications. As part of
my quality control procedure, I fasten the hub and bushing to a keyed 1
1/8" shaft that is a duplicate of the motor shaft. It is fully locked to
the shaft, as it will be when it's put to use. To remove the assembly from
my test fixture, I take out the 10-24 pull-in cap screws, substitute two
cap screws that are about 1/2" longer than the pull-in screws, and rap on
them with a brass hammer to break the taper. This works every time, but
this is a new installation and has only been on the shaft a few minutes.
I've had motors in the shop that have been in service for a while that
needed to have the hub/bushing pulled for some reason, and this technique
sometimes doesn't work. All of my hubs are designed with at least a 3/4"
hole in the center to accommodate a gear puller. Put the screw drive of
the gear puller through the hole and put the arms on the flange of the hub.
Tighten the screw drive against the motor shaft as tight as you can get
it with a 1/2" drive breaker bar. This won't damage either the end of the
motor shaft or the flange of the hub. With everything nice and tight, and
all of the pull-in screws removed from the hub, give the end of the puller
a sharp blow with a large hammer. This should break the taper, and the hub
should separate from the bushing.
Mike Brown
Electro Automotive POB 1113 Felton CA 95018-1113 Telephone 831-429-1989
http://www.electroauto.com [EMAIL PROTECTED]
Electric Car Conversion Kits * Components * Books * Videos * Since 1979
_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today - it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
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More importantly, is there any mechanical reason why IRS would not be as
desireable on the strip? I know it's a liability with the off-road
crowd, conversions to a solid rear axle are a fairly popular upgrade.
Wheel hop, and the extra joints (failure points) are the main drawbacks.
A good clutch-type LSD will help with the first one, and upgrading the
sticks and stub axles will help the second one.
Also, what differential housings would be available for an independent
rear? Is it possible to cut a housing for a solid axle (eg. a Ford 9")
short enough to use it this way? Has anyone done anything like that?
Chopping down a solid axle isn't worth the trouble. Winters Performance
makes an IRS, and if you're on a budget the R230 pumpkin from a Nissan
Skyline or twin-turbo Z32 will get you the equivalent.
David Thompson
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Ok. I am familiar with end yokes and slip joints, not slip yokes.
You need to define a few more things:
How many times are you going to hit a contactor bypass torque of 1300
ft-lb? The fatigue equations I am using so far are based on infinite
life. And for some reason I seemed to be using 1600 ft-lbs based on
your speculation?
If we assume 1100 ft-lb for infinite life (street use) then that is a
different picture. 1600 ft-lb on a minor diameter of 1.625 (and no
stress concentration factor) at infinite life is about a unity factor
of safety. That is the dragstrip torque, not a street torque. But with
derating for street usage. Which means things look pretty good with
something like 4140.
Not knowing your spline size and not knowing the effect of the slip
joint means I have to stop here until you decide on a spline. It also
may be that you need to harden the armature just to make a good slip
joint surface. But I don't know about that.
Seth
On Apr 23, 2005, at 2:21 AM, Christopher Robison wrote:
Seth Allen said:
Ok, before I start, I will make a few assumptions and such:
1: You don't want to greatly increase cost, so a material that doesn't
need a rough machining, heat treat and grind to size is desirable
I agree with this (I've got plenty of other parts of the truck that are
also demanding my money), though I'm not sure even what kind of
neighborhood to shoot for. Am I looking at a thousand bucks no matter
what
I do, or am I just trying to save a hundred or so? I've already spent
a
few grand; a couple hundred well-placed dollars aren't so much of an
issue, but adding half the cost of the motor would be difficult.
2: You need some plunge on the output
I'm not sure what this means. Are you referring to the need for a slip
yoke, or sliding element somewhere along the driveline? If so, yes --
I am
not willing to lock down the rear end (at least not permanently); I
need
to allow for some suspension travel.
3: a standard interface is nice
I have bought from Inland Empire in the past; they make a wide variety
of
slip yokes. In general though, yes, standard == good.
4: you want it sized for fatigue life at peak torque (many dragstrip
runs)
Agreed. The motor will be heavy and expensive to ship, making the cost
of
replacing the shaft pretty high, if I'm to have Netgain doing it.
Warfield
has a location in Dallas I'm told, but they don't work on the Warps.
All
in all, I'd like the shaft to last. :o) I'm willing to spend a little
more now to help with this.
5: you will not be getting it plated
I can't say without more information. What would be the benefit of
plating, and with what material? Is it expensive? Would it be worth
it? If
you're talking about aesthetics (chrome plating or whatever), then no.
I
just don't want it rusting. :o)
If all this is right, then a suggestion for a steel might be a
pre-hardened AISI 4140 which is fairly common and fairly easy to
machine. It won't be fully hard, but you won't have to do the heat
treat and grind to size.
I will make a note of this -- thank you!
As for an output. I have done standard yokes with slip joint
driveshafts for trucks. Not sexy, but they work. But your torque is
actually quite low if this is direct drive to the rear diff.
Compared to the potential if I had a transmission, yes, the torque is
pretty low. It seemed high to me, but that was during my search for a
suitable manual transmission. On the other hand, the existing
driveshaft
on my truck probably doesn't even see a third as much torque, flooring
it
in first gear. The input shaft on my transmission is only rated for 175
ft-lbs; I don't have the ratios handy but output torque can't be too
spectacular. In fact, in 1st I guess I probably get less peak torque at
the *wheels* today than I'll eventually get out of this motor. In that
sense, it's not so bad. :o)
A CV joint
can easily handle this torque and requires no alignment of the yokes
or
concern over driveshaft angle. A CV flange on the output of the motor
with whay would normally be an IRS halfshaft could work quite well.
I am not quite familiar with the setup you're referring to. Is it
possible
to get something like this that is long enough, and lightweight? I
have
been assuming the need for a traditional driveshaft and a slip-yoke on
the
motor, in part because of the arrangement of the motor and
differential.
I'm planning on putting the motor under the passenger compartment,
between
the seats, where the transmission is now. I would put it further back,
but
I'd like to put battery boxes between the frame rails. I've been
planning
on using a large diameter aluminum or carbon fiber shaft between the
battery boxes to reduce spinning mass. Can I have this same arrangement
with CV joints?
When you speak of CV joints, I'm imagining the three rollers at the
end of
a shaft which fits in a cup with three deep corresponding grooves,
allowing both the CV torque transfer as well as a small amount of
sliding
motion. Is this the sort of thing you're referring to?
It
is what I would do, but some people really refer U-joints.
At this point, I don't think I have enough knowledge to have a valid
preference. I have come to certain conclusions based on what I've
learned
so far, but of course nothing is really concluded until I start
actually
acquiring the parts. Until then, the more I can learn, the better. I'm
OK
with CV joints (actually, I like the idea of the smooth torque
transfer,
and not having to worry about matching angles and such), I just don't
know
what else about my driveline plans would have to change.
If that is
the case, then at www.roadranger.com there are loads of U-joint specs
there. ANd they will specify the spline options. Let me know what your
preference is (CV joint or U-joint) and we can wade through the
options
and once a spline is found, see if it will work. Your torque is so low
that with half-hard 4140 and an easily cut involute spline on a ~2"
diameter that I think there will be no problem with fatigue life, even
after effects like corrosion are figured in.
What are the corrosion properties of 4140? What kind of degradation
can I
expect, mechanically and aesthetically, assuming this will be
subjected to
water and road grime? For the most part though, this sounds like what
I'm
looking for. Can we say that 1144 is out of the picture? I understand
it
responds well to heat treating, though I don't know if this will give
me
what I want.
I will see what info I can dig up on CV joints used in this
application.
Although I'm hesitant about using techniques that aren't popular in
racing, I realize the operating parameters here are a bit different and
may call for an unusual solution. Mainly, if we can plan a driveline
that's lightweight, can span from the cab to the differential, can
tolerate the torque and the RPM (I'll be running a 5.0-5.3 or so rear
end
ratio, not quite sure yet), then I won't have much rational cause to
disagree.
--chris
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