EV Digest 4310
Topics covered in this issue include:
1) 300zx progress
by Jeff Shanab <[EMAIL PROTECTED]>
2) Tzero/EV article on front page of Sunday San Francisco Chronicle
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
3) Re: Mechanical PWM Controllers
by Jeff Shanab <[EMAIL PROTECTED]>
4) Re: Direct Drive Racing Driveline
by Seth Allen <[EMAIL PROTECTED]>
5) Re: 300zx progress
by Ryan Stotts <[EMAIL PROTECTED]>
6) Re: Direct Drive Racing Driveline
by Seth Allen <[EMAIL PROTECTED]>
7) Re: Mechanical PWM Controllers
by James Massey <[EMAIL PROTECTED]>
8) Re: Got my taperlock hub off!
by David Dymaxion <[EMAIL PROTECTED]>
9) Re: Re EV water/aircraft, jet ski's , cats, tris, WIG's and Swaths and
airboats
by Lock Hughes <[EMAIL PROTECTED]>
10) [Fwd: Re: Direct Drive Racing Driveline]
by "Christopher Robison" <[EMAIL PROTECTED]>
11) Re: Human Powered alternator, was Treadmill motor that...
by "Peter VanDerWal" <[EMAIL PROTECTED]>
12) Re: Treadmill motor that could be used for EV accesory power
by "Peter VanDerWal" <[EMAIL PROTECTED]>
13) Re: Treadmill motor that could be used for EV accesory power
by "David Chapman" <[EMAIL PROTECTED]>
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Well it is far far from done but everyone always mentions their first
run. Mine measured in feet, out of the garage to put the windows back
in, into the street to turn around and back into the garage for the
night. the clutch pedal is on the floor and teh rear brakes drag
audibly, the controller was my right hand on a set of jumper cables from
under the hood to a battery in the passenger seat. :-) I wasn't sure
the battery would pull me up my driveway, but it just made it.
but... not bad for a tiny SLI battery. It is encouraging,
--- End Message ---
--- Begin Message ---
Sunday, April 24, 2005. Front page EV article. Picture of a Tzero.
Lawrence Rhodes
Bassoon/Contrabassoon
Reedmaker
Book 4/5 doubler
Electric Vehicle & Solar Power Advocate
[EMAIL PROTECTED]
415-821-3519
--- End Message ---
--- Begin Message ---
I need cheap :-(
Lee, others. Could you fill in the chart for 1000A, 300V pack, 9" motor
type : mechanical, contactor&resistor
cost :
pro: inexpensive, simple
con: not smooth, noisey, ineffcient when in between steps, hard to
make over 400 amps
type : mechanical, rotary PWM+external freewheel diodes
cost : ~500.00
pro: inexpensiveish, medium complexity, hopefully smooth without
wastefull resistors
con: big bulky, electricaly noisey, unproven/new design, scooter motor
driven commutator may take more energy than the resistors would burn.
type : SCR
cost :
pro: durable
con: noisey rf and audio
type : IGBT
cost :
pro: more eff than previous, better at high voltages than mosfets,
subject to change weekly
con:
type : Mosfet
cost : $2500.00
pro: more eff than previous, better at high currents than IGBTs,
subject to change weekly, zilla is feature and saftey feature packed.
con: none, see cost.
--- End Message ---
--- Begin Message ---
http://www.roadranger.com/NASApp/cs/ContentServer?
pagename=Roadranger%2FeTpageDetail%2Fouter&Node=Literature+Center&c=Page
&cid=1047969111619
under "literature center" there is a driveshaft section
On Apr 24, 2005, at 8:38 PM, Christopher Robison wrote:
http://www.roadranger.com/NASApp/cs/BlobServer?
blobcol=urldata&blobheader=application%2Fpdf&blobkey=id&blobtable=Mungo
Blobs&blobwhere=1082226640691
--- End Message ---
--- Begin Message ---
Jeff Shanab wrote:
> the controller was my right hand on a set of jumper cables from
> under the hood to a battery in the passenger seat.
Any sparks?
--- End Message ---
--- Begin Message ---
I am still looking at the equations. I need to calculate the minor
diameter for a 1.878" spline and take a shot at the stress
concentration factor. The equations so far make the setup look marginal
(depending on use and assumptions) if I assume a 1.625" minor diameter
on that spline in 4140N or 4140 tempered at 1000F. I left the
machinery's handbook at work, so I can't look it up this weekend.
Unfortunately in a case like this, geometry is what gets you. Better
materials aren't really the fix. The right geometry is.
The best solution is to leave the end of the motor at 2" diameter and
smooth. Fortunately this is an option. Until the spline numbers came
out marginal, I wasn't going to mention it. I did this on the Super 7
truck and this joint has ~50,000 miles on it. Basically you need a
companion flange and flange yoke. The companion flange you should get
machined. Either from scratch or modify a purchased flange. You bore it
to the appropriate clearance, clean it and bond the companion flange to
the smooth motor shaft. You then bolt the flange yoke to the companion
flange. This is the only thing that holds the front of the drivetrain
to the back of the drivetrain together on those big Kenworth hybrid
trucks. In that case, it is the the most overdesigned joint on the
truck. It is a 2.25" motor shaft, but the torque is similar. The road
is on one side and an 820 ft-lb diesel and two 420 ft-lb induction
motors are on the other side.
The bonding agent is a special formulation from Loctite made for this
(it isn't threadlocker).
Done this way, you can use 1144 steel at 1600 ft-lbs or higher. At
least that is what the preliminary math is saying. BTW, these
calculations are for a fatigue application. The assumptions aren't
perfect, and lean towards the conservative, as you are limited in the
number of times you can apply the torque. On the other hand We have
made no effort to estimate the effects of trauma from ordinary use like
hitting a pothole, or wheelspin.
BTW-This solution requires a slip joint somewhere.
I will try to remember the machinery's handbook tomorrow find the minor
diameter of the spline in question.
Seth
On Apr 24, 2005, at 8:38 PM, Christopher Robison wrote:
Apparently I'm just not getting it. I don't think I'm seeing the right
stuff on the Roadranger website.
All I've found that mentions dimensions is here:
http://www.roadranger.com/NASApp/cs/BlobServer?
blobcol=urldata&blobheader=application%2Fpdf&blobkey=id&blobtable=Mungo
Blobs&blobwhere=1082226640691
...and in the section for "transmission applications" (don't know what
the
other sections are for) on page 15 of the pdf, the largest spline for a
1410 yoke is 1.616".
Please describe how to navigate to the data you're seeing, or at least
let
me know the part number for the 1.878" 1410 yoke. Fortunately, they
have a
distributor here in town (Austin Drivetrain) who should be able to get
it
for me. BTW -- what is the C/L to end of spline dimension on that?
Assuming I go with that part, is the final question, whether a 2" 4140
shaft narrowed to a 1.878" 30-tooth spline will withstand 1600ft-lbs of
torque without twisting? Depending on how close to the edge we are, I
imagine the yoke plunge distance to allow for may be helpful -- I'll
try
to figure that out if it becomes necessary.
I'll ask the driveline folks tomorrow about the U-joint RPM/angle
relationship.
--chris
Seth Allen said:
Unfortunately, I don't have a PDF handy of the speeds you can run
driveshafts at when at a certain compound angle. That is at my old
job.
If you want to go with a 1410 or 1350 series U-joint that seems
reasonable. I will leave the determination about angle and speed up to
you. If I can find a reference then I can help you through the math.
For an unmultiplied torque driveshaft connected to an electric motor
or
diesel engine or both I will tell you what I did. It worked for this
application, which is pretty similar to yours. We had 1710 series
parts
as that is what came on the truck so we re-used them, also so they
would be a stocked service part for that particular Kenworth. Overkill
for the torque we were running, but easier than ordering smaller parts
in this case.
We used a companion flange connected to a flange yoke to a driveshaft.
The companion flange was custom, in that it integrated a B-loc clamp.
This isn't necessarily what you want to do.
When I browse www.roadranger.com I found a 1410 splined yoke at 1.972"
diameter, but it isn't involute, so it migh tbe more costly to get
made. A 1.878" involute spline was available in a 1410 series. A
1.750"
spline was available in 1350 series.
One thing that jumps out is that if a driveshaft is rated for much
more
torque than you need, but the spline diameters are smaller than your
2" maximum, then barring truly exotic materials (and I would bet long
odds against it) the stresses in the shaft will be low enough for this
to work.
If that turns out to not be the case and we need the whole 2"
diameter,
then I have a solution that is inexpensive. And it works really well.
(Keith hinted at this solution earlier) For that matter, it might be
the best solution, but I will start on math for a 1410 involute spline
first. Let me know if (when) you find a reference for driveshaft
compound angle and speed.
Seth
On Apr 24, 2005, at 3:14 PM, Christopher Robison wrote:
Seth Allen said:
The max rotational speed dictates the angle you can run U-joints at,
hence the question.
Do you have a breakdown for this? Assuming I'll never go over 5krpm
(and
if I do, it will be an unplanned, probably catastrophic
circumstance),
is
the standard 3 degrees too much?
Also, I was looking at U-joint specs online (e.g. the Neapco catalog)
and
noticed that as joint sizes go up, max speed ratings go way down.
Then
again, perhaps the catalog was being excessively pessimistic, as the
torque ratings seemed pretty low as well.
At any rate, perhaps CV joints would be a better fit for that reason
--
being designed mainly for FWD half shafts, the assumption is to be
able to
handle the full torque at the wheels...
I can't help feel a bit discouraged though, as I have spent the
entire
morning browsing through manufacturers' and vendors' sites linked
from
www.sema.org, and so far have had no luck finding any sort of
reference to
CV joints used in this way. This may not be the best cross section
of
the
automotive performance aftermarket, and I certainly haven't even
gotten to
half the sites they link to, but I'm beginning to feel like I'd be
very
much on my own.
I guess I was thinking U-joint and CV joints being steel. I forgot
you
want a CF or other light material driveshaft.
I've talked to the folks at Inland Empire (iedls.com) over the phone,
and
they say they can make me an aluminum or carbon fiber shaft set up
for
1410-series U-joints. The more I think about it, the more I like this
plan. All that remains would be to find the longest and
largest-diameter
spline format I can (up to the diameter of the motor shaft) for a
slip
yoke and give Netgain the go-ahead to start making the motor.
CV joints would also be a great way to go, theoretically better in
many
ways. Again, the only thing making me hesitant about CV joints is my
complete failure to find any information about using them for
anything
but
FWD or IRS setups. If anyone has a URL, please don't be shy!
I wasn't able to find anything on the Roadranger site you mentioned
either; a search for "CV JOINT" or "CV" in their parts search page
yields
zero hits. I'm finding their site really hard to navigate in general;
perhaps there's something I'm missing. On the other hand I can't
help
thinking anything I find there would be far heavier than I want,
anyway.
I haev heard explanations about cryo treatments. Mostly from sales
types. Never used it. If we get to the point where we are worried
about
better material properties then we are too close to the edge ofthe
design envelope because at this point we don't have the system
defined
well enough to understand all the possible loads. In my opinion, at
least.
You're probably right about this; I brought it up mainly to get
opinions
on it. Unfortunately, I don't have accurate information on the peak
torque the motor will produce, nor do I expect to have such data
before I
complete the truck. I'm suggesting 1600ft-lbs as a planning figure,
hoping
that this will turn out to be a comfortable exaggeration. I won't
get
this much torque at 2000A, but later on with a bypass I'd like to
have
*some* confidence that I can hit the switch without breaking the
driveline.
I understand that other forces contribute to the overall picture,
shock
loads due to potholes and gear play in the differential, etc. Can
these
factors be quantified? (Would knowing the mass of the armature help?)
Are
they even important? What additional information is needed in order
to
get
a better handle on the design envelope?
--chris
Seth
On Apr 23, 2005, at 11:55 PM, Christopher Robison wrote:
Seth Allen said:
Do you have an estimate of maximum output speed? Or tire size and
top
speed. This is a concern when it comes to driveshaft angle,
especially
for u-joints.
Netgain has tested the motor out to 6000 RPM, but claim that the
absolute
maximum should be 5000 without serious modifications (kevlar comm
wrap,
ceramic bearings etc), which seems reasonable for a motor of this
size. My
choice of rear end and tire diameter will be constrained by this.
Perhaps
7000 RPM could be a comfortable planning figure for determining the
physical characteristics of the driveline...(?)
FWIW, I'd like to have a rear end gear setup for racing that allows
me
to
hit redline at 110-120mph or so, and another for street driving
that
maxes
out at around 75mph for higher RPMs and better efficiency (with the
side
effect of harder launches). I've got the formulas in a spreadsheet,
but of
course the ratios I choose will depend on the wheels and tires I
end
up
with.
Some platings affect the fatigue strength. In general, I wouldn't
do a
plating. There should be grease most any place there will be
splines,
so I don't think there is a reason to plate. And all the other
drivetrain parts will likely be steel or painted steel, wo why be
different.
Or aluminum, or carbon fiber. :o) At any rate, it doesn't seem
necessary. One process I might be interested in is cryo-hardening;
I
understand it is helpful in increasing abrasion resistance which
might
be
helpful for the splines, and has some strengthening aspects as well
(though the extent of this is debated). Do you have any
information
or
experience with this?
--chris
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
--- End Message ---
--- Begin Message ---
At 07:07 PM 24/04/05 -0700, you wrote:
I need cheap :-(
Lee, others. Could you fill in the chart for 1000A, 300V pack, 9" motor
You need cheap? then 450A, 144V instead of 1000A, 300V! Design an upgrade
path, invest in a 300V zilla, run it initially at 120V or 144V and upgrade
system components as $ allow.
type : contactors & resistor
cost :
Depends on how many amps you are expecting/intending, and how many steps
(how smooth). e.g, with the pack in 6 x 48V blocks: 48V + resistor, 48V
(all in paralell), 96V (series pairs in paralell), 144V (series triples in
paralell), 288V (all in series =:^O). Alternatively 8 x 36V blocks: 36V +
resistor, 36V (all in paralell), 72V (series pairs in paralell), 108V
(series triples in paralell), 144V (series quad), 288V (all in series). Or
12 x 24V packs (very smooth). But with a shunt motor instead of a series
motor, can be cheaper to build, half (or more) of your steps are on the
field (lower cost contactors).
pro: inexpensive, simple
Not necessarily inexpensive, due to the amps you are wanting to switch.
Easy to repair, if one part dies you can probably limp home on the
remainder. Easy to carry your own spares. THE most efficient once off the
starting resistor.
con: not smooth, noisey, ineffcient when in between steps, hard to make
over 400 amps
Can be smooth, depends on the design. Clicky-clack - stick in in a
sound-attenuating box. Easy to make too many amps, like 2000A+ since you
have no current control except the driver.
type : mechanical, rotary PWM+external freewheel diodes
cost : ~500.00
Depending on if you are paying for the machining work, maybe 5 to 10 times
that amount. If you can do it yourself, maybe that price.
pro: inexpensiveish, medium complexity, hopefully smooth without
wastefull resistors
Maybe inexpensiveish, maybe approaching the efficiency of a contactor
controller. Can't actually think of any real pro's, other than if you are
very mechanically minded you can build and maintain it yourself.
con: big bulky, electricaly noisey, unproven/new design, scooter motor
driven commutator may take more energy than the resistors would burn.
Mechanically complex, no older designs to refer to, no knowlege pool. Maybe
unreliable for any reason (many unknowns). If it fails you are probably
stranded, since murphys law makes it be so. May require an actual
controller for the scooter motor driving the system.
type : SCR
cost :
If you can find anyone building one, otherwise build one adapted from
proven designs that are probably available in the public domain now. Or get
a lower-amp one and uprate all of the power parts and run the control from
a DC/DC.
pro: durable
Um, "bulletproof" comes to mind. Apart from the control electronics they
are simple to work on from a mechanical perspective. Probably the cheapest
way to make very high amps (2500+ would cost proportionally little more
than 1000). Current limiting can be implemented. Probably lower cost
overall than a multiple step high-amp contactor controller.
con: noisey rf and audio
Should be no more RF (radio) noisy than any other electronic controller.
Even contactor controllers generate RF noise, but they produce RF clicks
when changing. SCR control requires a lot of analogue design theory, modern
design is very digital, hence the modern trend for transistorised control
of various flavours.
type : IGBT
cost :
At 300V, I don't know of any currently made other than Otmars' Zilla
controllers.
pro: more eff than previous, better at high voltages than mosfets,
subject to change weekly
Maybe more efficient than SCR controller, maybe not. Depends on the design.
Not sure what you mean "subject to change weekly".
con:
Fixed forward voltage drop, so less efficient at lower currents than other
methods.
type : Mosfet
cost : $2500.00
Don't know about that at 300V. If that is the price of a 300V Zilla, I
believe that it is an IGBT controller.
pro: more eff than previous, better at high currents than IGBTs,
subject to change weekly, zilla is feature and saftey feature packed.
More efficient at lower currents than IGBTs, due to fixed on-resistance. At
higher voltages most industrial controllers use IGBTs.
con: none, see cost.
Conclusion:
Contactor controllers: Clicky-clack noisy, Pack-shorting levels of amps
capability, hard to current control. Very efficient once off the starting
resistor.
Mechanical PWM: mechanically complex, unknown current capability and
current control capability, efficiency losses in all sorts of ways, no
knowlege pool.
SCR control: Can get good control, depends on the design.
IGBT control: At 300V, use a Zilla, get all the good features and
reliability. Protect the pack and the motor withouy all sorts of extra bits.
Mosfet control: Unlikely to be available at 300V.
IGBT or Mosfet can be home-built using high-power modules that would be
cheaper than the "coffee-can fill" of designing a controller that would be
commercially viable to build with sophisticated design techniques. What is
your time worth? I looked at home building, looked at the cost of the
modules and the time it would take and bought a Zilla.
Hope this helps, but is just my $0.02
James Massey
Launceston, Tasmania, Australia.
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--- Begin Message ---
This list is too awesome for words, thanks to all! Hard to imagine
how people did conversions before the EVDL! Thanks to James Massey,
Phil Marino, Seth Allen, Roland Wiench, Ryan Stotts, Steve Clunn, and
Neon John for their great responses. This message answers all the
posts:
The three threaded holes to back off a taperlock is a great idea. In
my case, the Porsche flywheel bolts barely have room between them and
the pilot bearing hole. Given the diameter of the electric motor
shaft, there is barely enough room for the tightening bolts. You�d
have to go to just three tightening bolts, or have a huge flange on
the center split piece. This is a custom taperlock from Electro Auto,
they did a good job engineering it given the constraints of the
Porsche flywheel bolt pattern and pilot shaft.
I had said a couple thousands off, but that was a mistake (I divided
by 2 twice). The total dial indicator swing was 8 thousandths, so I
was 4 thousandths off center. I may be being a perfectionist, but
thought a 2nd try was worth the effort. If I can�t do better, I�ll
test run it up and do the Wayland trick of adding and moving around
washers for balance.
Seth worried that he hoped my motor bearing were OK after the slide
hammer. I had that worry, too, so I did it with the motor vertical.
The slide hammer would have to lift the whole weight of the armature
to hammer the bearings, so I think I was safe. My hammer taps were
light. Motor still spins as smooth by hand as ever.
Thanks to Roland for watching for removal bolts going in the back,
and to watch for cracks for bolts close to the edge.
Ryan: Your first picture
<http://www.mechaps.com/mps/mcf1/bilder/3%20JAW%20GEAR%20PULLER%20SET.gif>
is exactly what I used, except I had to bolt to the lower set of
holes. The one nice thing I liked was it pushed against the motor
shaft, so no bearing abuse.
Neon John: Sounds like maybe I got lucky using the gear puller,
luckily I didn�t break my flange off! The air hammer is a good idea I
had not thought about.
Steve Clunn: It�s thanks to your videos I am using the dial
indicator. That�s a great idea I don�t recall seeing or hearing about
elsewhere. I hadn�t thought to file the center split part, but
that�ll be last resort!
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
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EVer's are pretty consumed with aspects of efficiency for the
(relatively) tiny amounts of power aboard, but the human-powered folks
(wheeled and boats) work with even tinier power levels.
Last I heard, the speed record holder (at sprints) for H-P boats is
still "Decavitator" (her name a combo of "decapitator" and cavitation):
http://lancet.mit.edu/decavitator/
Anyway, just backing up jerrys thoughts on two hulls... and yeah,
hydrofoils are fun but not practical much!
AFAIK, air props have been banned from HPV competitions since
Decavitator days...
But one of these days, I'd like to have an EV airboat - think Florida
airboat light.
A two seater, like Decavitator with two hulls, but twin air props (in
cages) and designed speed range only zero to twenty knots, for
sheltered waters...
Twin props for steering (joystick fly by wire.) Electric props might
spin in the wind to regen when the craft is beached or anchored?
Way more fun than any jetski I think. Just no wavejumping!
just more 2 cents(Cdn)
Lock
--- jerry dycus <[EMAIL PROTECTED]> wrote:
> Hi Lee and All,
> --- Lee Hart <[EMAIL PROTECTED]> wrote:
> > Andrew Goldschmidt wrote:
> > >> I have always wanted to build an electric jetski,
> > but did not
> > >> know where to go for info. Any advice on the
> > feasability would
> > >> be appreciated.
> >
> > jerry dycus wrote:
> > > While it will work, it won't for long as any
> > planning watercraft
> > > needs much more power to go fast for long. Also
> > the small jets
> > > are very low eff. On the water to go reasonably
> > fast for longer
> > > distances, us a Cat/tri hulls set up with
> > length/beam ratios of
> > > between 8 and 10-1.
> >
> > I've seen some human powered catamarans that zipped
> > right along.
> > Extremely long skinny twin hulls -- in fact they
> > were round aluminum
> > pipes that ran 75% submerged. Given the feeble power
> > source, I would
> > think that they would be a good design basis for an
> > EV.
>
> In displacement style boats as all of them, drag
> comes in 2 forms, skin friction and wave making ,IE,
> bow waves-wave making.
> Lowest drag comes from hulls that are between 8-1
> to 12-1 length to beam ratios.
> Shorter than that and the bow wave gets bigger and
> extra power is needed to overcome that drag.
> Longer than that and the friction from the extra
> wetted surface/skin friction becomes higher thus
> slowing it down.
> For a heavier weight, the 8-1 ratio is best and on
> lightweight ones the 12-1 is better.
> If the hulls are round and mostly or completely
> submerged, SWATH's, the skin friction goes up for a
> given weight.
> So best is usually a U shaped hull of low surface
> area and since ours need to carry battery weight,
> around the 8-1/9-1 L/B ratios for best speed at the
> lowest power, highest eff.
> This doesn't mean they need to be slow as they can
> easily cruise at 20mph+ eff.
> The props should be as large as possible and slow
> turning for most eff.
> To compare, remember the America's Cup race where
> they pitted a 128' monhull against a 60" cat and the
> cat whipped it badly.
> Also on aircraft, having 2 props the same size
> driven by the same hp as 1, will be much more eff and
> put out about 1.6-1.8x the thrust thru lower power
> loading for the same power.
> This is why helicopters need large rotors to
> carry weight while being eff enough to do it.
>
> >
> > I've also seen human-powered hydrofoils. The speed
> > they were getting
> > make me guess they were pretty efficient as well.
>
> If done right, hydrofoils are very eff but have
> drawbacks like can be launched only in deeper water
> and will foul by seaweed, plastic bags, ect which can
> ruin your whole day ;-O.
> On a US Navy Hydrofoil missle patrol boat, 136' long
> cruising 55knots in the Gulf Stream in the Fla Straits
> off Miami, got fouled by a whale and sent the whole
> crew to the hospital, $1,000,000+ damage to the boat
> and lets not talk about the poor whale!
> I use to live next to them in Key West and it took
> the whole bow, front foil out into a twisted mess!
> While I like hydro foils, I don't use or build them
> for those reasons.
> There is another form of boat call the Wing In
> Ground Effect craft that is like a seaplane that never
> really gets airborne, instead gets out of the water
> and flies, planning on air trapped between the bottom
> of the wings and the waters surface, eff carrying
> twice the load of an airplane would higher up.
> This would get twice the range of a planning boat
> under electric power but that still not worth it as it
> just goes from say 4 miles to 8-10 miles with both
> boats optimised. Though better if you have $100k of
> li-ions!!
>
> >
> > Finally, of course there is the air car. Once you've
> > used the power for
> > lift (which is about the same at any speed), your
> > speed over the water
> > is basiclly only limited by how smooth the water is.
>
> While true on land, hovercraft in water, they make
> waves, drag just like any planning boat!!! Though once
> you can get them on plane, like other planning boats,
> the do ok but no where near as good as a Cat/Tri at
> 1/5 or so power use.
>
>
> > Truly enormous
> > speeds would be possible, even as an EV.
> >
> > Maybe a craft that was some combination of these
> > three techniques? :-)
>
> Best combo is the Cat hulls with 2 good size props
> for speed, eff and load carrying capacity.
> That's why I can and have built 32' cruising cats
> that can go 25mph under power or sail. Something no
> other kind of boat can match while carrying a full
> load.
> It was fun 1 night after a Reggae concert on the
> beach in Key West where 10 girls and 4 guys took off
> in 25knot winds and did 25knots with 20' high rooster
> tails!!! Now that's a party!!! With a Lanteen rig no
> less for those who know what that is!
>
> HTH's,
> Jerry Dycus
> > --
> > Ring the bells that you can ring
> > Forget your perfect offering
> > There is a crack in everything
> > That's how the light gets in
> > -- Leonard Cohen, from "Anthem"
> > --
> > Lee A. Hart 814 8th Ave N Sartell MN 56377
> > leeahart_at_earthlink.net
______________________________________________________________________
Post your free ad now! http://personals.yahoo.ca
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Oops -- forgot, can't send you email directly, Seth...
--chris
---------------------------- Original Message ----------------------------
Subject: Re: Direct Drive Racing Driveline
From: "Christopher Robison" <[EMAIL PROTECTED]>
Date: Sun, April 24, 2005 11:45 pm
To: "Seth Allen" <[EMAIL PROTECTED]>
--------------------------------------------------------------------------
I'm confused -- the yokes in the attachment you sent are end yokes, not
slip yokes. The length of the spline doesn't seem nearly enough to allow
sufficient travel.
How would these work for me?
--chris
Seth Allen said:
>
> On Apr 24, 2005, at 8:38 PM, Christopher Robison wrote:
>
>> http://www.roadranger.com/NASApp/cs/BlobServer?
>> blobcol=urldata&blobheader=application%2Fpdf&blobkey=id&blobtable=Mungo
Blobs&blobwhere=1082226640691
>
>
>
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With a high efficiency generator and proper gear selection, a multispeed
transmission between the pedals and generator is probably unnecessary.
Humans have a fairly wide peak efficiency band (typically from 80-90 RPM,
with nearly peak efficiency from 70-100 rpm)
Using a high efficiency PM generator, a small change in RPM (5-10%) can
result in a 50% or more change in output power when operating at a fixed
voltage.
This means that people with a wide variety of output power capacities can
pedal the same generator by just changing pedal RPM slightly.
This actually represents a problem. Anyone who has tried to maintain a
constant cadence within 1 or 2 RPMs knows how difficult this can be,
especially if you are driving and not watching your cadence. Obviously
pedalling too fast is probably not much of a problem; but slowing down,
and having your power drop way off, is easy to do.
My next design will use synchronous rectification with MPPT to try to
stabalize the output power regardless of input RPM. This will allow you
to dial in a custom power output and keep the RPMs at 80-90.
Anyway, with a well designed pedal generator, a multispeed transmission
just adds unnecessary weight, complexity, and friction.
>
> The human is a high torque beast, I put out as much torque as my
> mitsubishi truck engine. (ok, not so high), but relative to rpm it is :-)
-snip-
>
> you may want to consider keeping the bike transmission, this steps up
> the rpm and allows the user to adjust to they're current "fitness level"
> or to "spin" I pedal 100rpm
>
>
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Yes it is possible to build a generator that will work at 70-80 RPM,
unfortunately it would be huge. In order to get the necessary number of
poles and fast enough speed at the coils, it woul probably need to be
approx 2 feet in diameter.
It's better (in my opinion) to use a generator that will work with a
single stage speed increaser. Something like a 5:1 ratio. Assuming an
80-90 RPM pedal speed, this works out to about 400-450 rpm. This is
doable with generators designed for windmills.
> peter,
> As you suggest in a personal low speed light weight ev
> designed for either commuting of touring every little
> bit helps. With a designed for human power generator
> even if it is only 75 watts constant that off sets how
> much battery energy you require to accomplish your
> goal of distance. The problem is there are no
> specifically designed for human power generators. all
> the ones I have found are not really designed to make
> elecrticity at 60-70 rpm which is what one can
> constantly pedal. instead the generators i have found
> take the slow speed human energy and dilute it by
> mechanical means to go faster. in other words the
> generators are designed to produce power at high rpms
> and the mechanical/friction losses use up much of the
> human power. Is there no way to make a perm mag
> generator that will have the correct number of poles
> and windings to generate electricity at 60 rpm? I
> don't know much about electricity but maybe there is
> someone on the list who does and can explain this to
> me
>
> thanks
> keith
> --- Peter VanDerWal <[EMAIL PROTECTED]> wrote:
>
>> > With a more efficient generator, I am sure that
>> you could charge up a
>> > personal electric vehicle of some sort. Perhaps
>> an electric bicycle.
>
>>
>> With an efficient enough pedal powered generator,
>> personal EVs have some
>> advantages. Keeping your workout at a constant level
>> regardless of terain
>> or traffic for example, or energy banking at stops.
>
>
>
>
> __________________________________
> Do you Yahoo!?
> Yahoo! Small Business - Try our new resources site!
> http://smallbusiness.yahoo.com/resources/
>
>
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--- Begin Message ---
Peter is giving good advice. I was tinkering with something like this a few
years back and I ended up looking at the generator from a military surplus
hand crank radio power supply, try Fair Radio to see if they have any left.
Kinda rare anymore, they were out when I was looking for one, had to settle
for a NOS replacement genset unit. They require a large gearing up tho. I
forget what the output voltage was, I can look on my generator if you like.
Also if you are handy I would advise looking into DIY Dual Disc Axial Flux
low speed alternators. Google on Hugh Piggot, he wrote a few books on
building these. www.scoraigwind.com . Edwin Lenz also has a good DDAF
alternator site www.windstuffnow.com which I highly recommend, lots of
easy to understand explanation of theory and hes a really nice guy to boot.
If you decide to build one of these I recommend you check with Edwin for neo
magnets and parts. You can also get some deals on E-bay for neos and can
even strip them out of old hdds. I have a couple of them in the works right
now but I am tinkering with alternate methodology for building the stators
so not much to report yet. Good luck, David Chapman.
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, April 25, 2005 12:10 AM
Subject: Re: Treadmill motor that could be used for EV accesory power
Yes it is possible to build a generator that will work at 70-80 RPM,
unfortunately it would be huge. In order to get the necessary number of
poles and fast enough speed at the coils, it woul probably need to be
approx 2 feet in diameter.
It's better (in my opinion) to use a generator that will work with a
single stage speed increaser. Something like a 5:1 ratio. Assuming an
80-90 RPM pedal speed, this works out to about 400-450 rpm. This is
doable with generators designed for windmills.
peter,
As you suggest in a personal low speed light weight ev
designed for either commuting of touring every little
bit helps. With a designed for human power generator
even if it is only 75 watts constant that off sets how
much battery energy you require to accomplish your
goal of distance. The problem is there are no
specifically designed for human power generators. all
the ones I have found are not really designed to make
elecrticity at 60-70 rpm which is what one can
constantly pedal. instead the generators i have found
take the slow speed human energy and dilute it by
mechanical means to go faster. in other words the
generators are designed to produce power at high rpms
and the mechanical/friction losses use up much of the
human power. Is there no way to make a perm mag
generator that will have the correct number of poles
and windings to generate electricity at 60 rpm? I
don't know much about electricity but maybe there is
someone on the list who does and can explain this to
me
thanks
keith
--- Peter VanDerWal <[EMAIL PROTECTED]> wrote:
> With a more efficient generator, I am sure that
you could charge up a
> personal electric vehicle of some sort. Perhaps
an electric bicycle.
With an efficient enough pedal powered generator,
personal EVs have some
advantages. Keeping your workout at a constant level
regardless of terain
or traffic for example, or energy banking at stops.
__________________________________
Do you Yahoo!?
Yahoo! Small Business - Try our new resources site!
http://smallbusiness.yahoo.com/resources/
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