# [EVDL] E-tek vs Perm PMG



## EVDL List (Jul 27, 2007)

Guys,

I am trying to determine the best motor for a small scooter.
I am leaning towards doing a proof of concept with a 24V 600W
like the ones at cloud electric, and then maybe migrating to
something larger like a Perm PMG-080 or Mars E-Tek. I have a
few questions.

Are there design formulas that can give someone an idea of 
how a motor will perform? For example, if I have a X pound
scooter (with rider and all) producing Y ft-lb of torque at
the wheel edge, how fast will it accelerate on level ground
and how fast, for example, on a M% grade. How would I
determine the top speed? Although I can calculate the change 
in torque from motor shaft to tire edge with relatively straight
forward math, are there reasonable ways to estimate losses in the
drive train? Can I just apply a blanket N% loss for drive
train and say that is good enough? I lack access to the tools
to cut my own gears, so I am likely to start with chain drive to
the test vehicle, and then later move to something like a single
90 degree spline gear and perhaps later to one of the bicycle
grade CVTs (continuous variable transmission).

How do folks feel about brushed versus brushless? It seems brushed
motors are a lot cheaper, but need regularly examinations and replacement
every few hundred hours. Using this back and forth for work means
1-2 hours a day, and that means every few months replacing the brushes.
For a test design, I will likely consider a $100 motor an expendable
part of the learning process. For a real design, I want to make it last.

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Hi Janet,

Whats the rationale behind this project?
Are you wanting to manufacture these things? Or do you just want one for
yourself?
If you jjust want one for yourself, you are probably better off buying an
already manufactured electric bike.

The manufactured bikes use 3-phase AC motors built into the back wheel.

Have a look on the www.visforvoltage.org forums to see what other people ar
riding.
I personally am riding an emax, continuous power 1500w (actually I run it at
2500w cont, 4000w peak, but its cold here) and im getting max speed
60-70kmh, 0-60kmh in 6-7secs.

Matt

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Janet Plato
Sent: Wednesday, 23 July 2008 11:28 PM
To: [email protected]
Subject: [EVDL] E-tek vs Perm PMG

Guys,

I am trying to determine the best motor for a small scooter.
I am leaning towards doing a proof of concept with a 24V 600W like the ones
at cloud electric, and then maybe migrating to something larger like a Perm
PMG-080 or Mars E-Tek. I have a few questions.

Are there design formulas that can give someone an idea of how a motor
will perform? For example, if I have a X pound scooter (with rider and all)
producing Y ft-lb of torque at the wheel edge, how fast will it accelerate
on level ground and how fast, for example, on a M% grade. How would I
determine the top speed? Although I can calculate the change in torque from
motor shaft to tire edge with relatively straight forward math, are there
reasonable ways to estimate losses in the drive train? Can I just apply a
blanket N% loss for drive train and say that is good enough? I lack access
to the tools to cut my own gears, so I am likely to start with chain drive
to the test vehicle, and then later move to something like a single 90
degree spline gear and perhaps later to one of the bicycle grade CVTs
(continuous variable transmission).

How do folks feel about brushed versus brushless? It seems brushed motors
are a lot cheaper, but need regularly examinations and replacement every few
hundred hours. Using this back and forth for work means
1-2 hours a day, and that means every few months replacing the brushes.
For a test design, I will likely consider a $100 motor an expendable part of
the learning process. For a real design, I want to make it last.

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/ For subscription
options, see http://lists.sjsu.edu/mailman/listinfo/ev


--
No virus found in this incoming message.
Checked by AVG. 
Version: 7.5.524 / Virus Database: 270.5.2/1562 - Release Date: 19/07/2008
2:01 PM


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

On Wed, 23 Jul 2008 08:27:51 -0700 (PDT), Janet Plato <[email protected]>


> wrote:
> 
> 
> > How do folks feel about brushed versus brushless? It seems brushed
> ...


----------



## EVDL List (Jul 27, 2007)

John,

Thanks for replying. My current ill-formed plan is to gather
data and make a plan. What I want is likely not feasible with
current technology, so I am heading towards buying and building
things for experience' sake. Perhaps a 24V 9AH battery, a 24V 
600W motor, and making first an electric skateboard, and then 
an electric scooter like a mini-bike or vespa. Such a device 
would be underpowered, and actually only could run for 5-10 
minutes, just long enough to gather test data. I expect it
would cost around $1,000 when finished.

The experience would prove useful for building a more expensive
device when technology improves.

Anyway, right now the point is purely intellectual, and I have
no intention of building anything, only engineering something and
then determining what it would cost to build and how I would expect
it to perform.

Thanks for your time,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Janet,

What do you think about the ZERO motorcycle? A little pricey at $7,450.
2kWh of lithium. A replacement battery pack that plugs in quickly is
$2,950. A second charger - $449.
http://www.zeromotorcycles.com/zero-x.php Not street legal, but
possible?

I am collecting parts for a motorcycle, a little on the heavier side.
6.7 inch series DC motor etc... Project is moving slowly due to budget
constraints. (read - I am president of the local cheap skates club,
founding member).

However, I did put a small motor on my bicycle, and a 36 volt DeWalt
tool battery. Look at E-bay item number 260263757429 for the Kollmorgan
motor, it has a controller inside. Fun!

Alan 

-----Original Message-----
(snip)
I have a motorcycle license and tens of thousands of miles of
experience, so the moped limitation on speed/power is a non-issue
for me in that regard, but maxi-scooters need maxi-power.

What I'd really like is something along the lines of the jackal
with NiMH or Li, a bit more battery capacity and a bit less motor.
http://www.thunderstruck-ev.com/jackal_performance.htm

The jackal is around $4K, and uses 4x12V 20AH VRLA. NiMH 
is hard to get above 13AH, you end up building strings and 
charging them is tedious. The Nilar batteries seem interesting
but they are 24V/9AH NiMH for $250:
http://nilar.com/index.php?pageID=33

Link to buy is here, stating $250 price:
http://www.pluginconversions.com/phevs1.html

So doubling the Jackal's battery load means 8 of these for $2,000
in 4 parallel clusters of 2 series batteries. Plugging in 48V, 
36AH capacity means a modest 864 Watts for an hour at 50% DOD, and 
maybe 1,728 Watts, about 2.35 HP, very rarely if you want to push 
them a bit to climb an occasional hill.
(snip)
Janet



_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Alan,

Thanks for replying, my email client ate my longer reply,
so this is a shorter version.

> Janet,
>
> What do you think about the ZERO motorcycle? A little pricey at
> $7,450. 2kWh of lithium. A replacement battery pack that plugs
> in quickly is $2,950. A second charger - $449.
> http://www.zeromotorcycles.com/zero-x.php
> Not street legal, but possible?

The zero-x is nice, but not street legal. I need a commuter
vehicle. It should be possible to add signals though, although at
$7.5K this is more than I am willing to spend. Enertia make a
nice machine at $15K for 35-40 mile range, but also larger.
I need to find links to mid size motors, I can find lots of
350-650W scooter motors, and things like the Perm PMG-80, PMG-132 and
ETek, which are too large. I'd like to find something that can
make 1-3HP continuous and 3-8HP peak witgh 24-48V. I'd consider
buying the zero-x frame but they do not sell frames, and even
batteries are only available to customers.

Oh, and I managed to dig up some high school physics, so with
a little bit of assumption and some calculus I think I can start
determining what cost in energy I will pay for the performance I
want. Does anyone have links to estimate values of rolling 
resistance, coefficient of drag and such for commercial motorcycles.

I appreciate the links, they give me ideas,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Janet, here's another motorcycle start up in case you haven't come across
this one.. This might be more in line with your ideas. Its more pricey than
the Zero, but street legal.

http://www.enertiabike.com/

On Thu, Jul 24, 2008 at 10:59 AM, Janet Plato <[email protected]>


> wrote:
> 
> > Alan,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

> I'd like to find something that can
> make 1-3HP continuous and 3-8HP peak witgh 24-48V.

Sounds like a golf cart motor to me!

-Jon Glauser
http://jonglauser.blogspot.com
http://www.evalbum.com/555


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> I need to find links to mid size motors, I can find lots of
> 350-650W scooter motors, and things like the Perm PMG-80, PMG-132 and
> ETek, which are too large. I'd like to find something that can
> make 1-3HP continuous and 3-8HP peak witgh 24-48V.

I think the larger Crystalyte hub motors can do this, the 5300 series. 
They are fairly cheap, and reasonably efficient.

You might want to check with these folks to be sure:
http://www.ebike.ca/store/
They've done a bunch of experimenting with these and should have a good
idea of what they are capable of.



_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Janet,

Another option might be something like the BugE. Bigger than a bike or
scooter but smaller than a car.

I've got a Mars BLDC (Etek like) motor on mine with a wheel motor on the
way. It's still in build, but I may get a chance to try it in the
cul-de-sac this week end. Right now I have no data or experience to talk
about, just a couple of pictures on the BugE-list page-
http://autos.groups.yahoo.com/group/BugE_list/

The BugE is not the end-all but has some very nice features. It's small and
light enough to make a great test/learning platform. For instance the wheel
motor (shipped yesterday . A bigger vehicle would need at least two,
with controllers, and likely four. Changing from 48v to 72v means a change
from 4 to 6 AGM batteries and $300.

The stock setup cost $5500 to $6500 depending on the normal stuff. Rated at
30 mile and a top speed of 50mph isn't bad. 

With a higher efficiency motor, regenerative breaking, 5%-10% more power in
the battery pack I hope to get the range in the high 30s. If you fill the
battery compartment with LiFePO4 batteries you should be at 50 plus...
(space becomes the limit)

Greg
-- 
View this message in context: http://www.nabble.com/E-tek-vs-Perm-PMG-tp18613519p18639012.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> I think the larger Crystalyte hub motors can do this, the
> 5300 series. They are fairly cheap, and reasonably efficient.
>
> You might want to check with these folks to be sure:
> http://www.ebike.ca/store/
> They've done a bunch of experimenting with these and should
> have a good idea of what they are capable of.

I'll look this over later, thanks. It seems like they do not
provide much by way of motor data, they give you speed in KPH
as a function of voltage and say torque is a non issue. They
would probably work for a bicycle, but it would be nice if they
gave values for power consumption, torque, HP and the like. Perhaps
I can find that data on the web, and then buy from them if it seems
useful.

Cheers,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Janet,

Some people have reported that their Etek motors get too hot under load,
or that they wear out brushes quickly under load. If you do not find a
more suitable smaller motor, would the Etek work? It is 20.8 pounds, 12
to 48 volts, and is listed as 6 HP continuous and 20 peak, but that is
likely at the higher voltage. One seller on E-bay that has worked on
golf carts with the Etek says they are about 3.5 HP "consistent" and
12-14 peak HP. This seller has a used Etek on E-bay, but it is the type
that bolts to a golf cart's rear axle. I wonder if this motor has a
bearing in each end, or does it use the input shaft of the rear axle for
support like other golf cart motors do? Anyway, here is the E-bay item
number 330255461831 Dale Henderson of this list has two Etek motors
on his chopper style motorcycle, as he was able to get one hot on his
first motorcycle. http://www.evalbum.com/1179 

Alan 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of Janet Plato
Sent: Thursday, July 24, 2008 11:00 AM
To: [email protected]
Subject: Re: [EVDL] E-tek vs Perm PMG

Alan,

Thanks for replying, my email client ate my longer reply,
so this is a shorter version.

> Janet,
>
> What do you think about the ZERO motorcycle? A little pricey at
> $7,450. 2kWh of lithium. A replacement battery pack that plugs
> in quickly is $2,950. A second charger - $449.
> http://www.zeromotorcycles.com/zero-x.php
> Not street legal, but possible?

The zero-x is nice, but not street legal. I need a commuter
vehicle. It should be possible to add signals though, although at
$7.5K this is more than I am willing to spend. Enertia make a
nice machine at $15K for 35-40 mile range, but also larger.
I need to find links to mid size motors, I can find lots of
350-650W scooter motors, and things like the Perm PMG-80, PMG-132 and
ETek, which are too large. I'd like to find something that can
make 1-3HP continuous and 3-8HP peak witgh 24-48V. I'd consider
buying the zero-x frame but they do not sell frames, and even
batteries are only available to customers.

Oh, and I managed to dig up some high school physics, so with
a little bit of assumption and some calculus I think I can start
determining what cost in energy I will pay for the performance I
want. Does anyone have links to estimate values of rolling 
resistance, coefficient of drag and such for commercial motorcycles.

I appreciate the links, they give me ideas,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev



_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Not sure if anyone mentioned this EV bike yet, MSRP $4499.

http://www.x-tremescooters.com/electric_mopeds/xm-3500li/xm-3500li.html

These are just released, so probably no way to know how good they are yet.

>From the website
" The XM-3500Li is the first of it's kind street legal electric powered
moped / motorcycle running on lightweight high powered Lithium batteries and
a 3500 Watt rear hub motor with REGEN capability (charges moped while in
use). The XM-3500Li E-Moped is the fastest & lightest e-moped available &
because it's running on 19 small light weight Lithium Ion batteries, the
driving distances can be up to 80 Miles on a single charge + the battery
life can be 7 to 10 years and can be charged up to 2000 times, with proper
battery care."


On Thu, Jul 24, 2008 at 10:59 AM, Janet Plato <[email protected]>


> wrote:
> 
> > Alan,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

> Bryan McNaughton wrote:
> 
> > Not sure if anyone mentioned this EV bike yet, MSRP $4499.
> >
> ...


----------



## EVDL List (Jul 27, 2007)

>> I think the larger Crystalyte hub motors can do this, the
>> 5300 series. They are fairly cheap, and reasonably efficient.
>>
>> You might want to check with these folks to be sure:
>> http://www.ebike.ca/store/
>> They've done a bunch of experimenting with these and should
>> have a good idea of what they are capable of.
>
> I'll look this over later, thanks. It seems like they do not
> provide much by way of motor data, they give you speed in KPH
> as a function of voltage and say torque is a non issue. They
> would probably work for a bicycle, but it would be nice if they
> gave values for power consumption, torque, HP and the like. Perhaps
> I can find that data on the web, and then buy from them if it seems
>

one of the tabs along the top is "simulator" you can enter data about the
battery pack, controller, throttle position, etc and it will produce a
graph of torque vs rpm vs efficiency




_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Janet,
>
> Another option might be something like the BugE. Bigger
> than a bike or scooter but smaller than a car.
>

Thanks Greg, I am familiar with the Bug-E, it's kind of cute.
I would be interested in hearing your experiences as you move
forward building it.

> The BugE is not the end-all but has some very nice features.

Nothing is an end all, I think a lot of people forget that. We
each have different needs, wants and budgets, so what works for
one might not work for another. For now, I want to acquire inexpensive
experience. I am prepared to sink some costs into the learning
process, but I am not ready to buy a vehicle, perhaps later. Ideally
the grand or so I spend learning will leave me with some parts I can
re-use later, but we shall see. I do find the links interesting, 
they give me ideas. I might end up buying something one day, since
buying is almost always cheaper than engineering from scratch for
the first time.

In the mean time, my learning will be vicarious, it's far cheaper 
to learn from what others have done than to do for one's self.

I am curious thought, what people think of the Perm PMG-80 as
compared to an Etek or Etek-R, as far as I can tell nobody has
actually answered that question. Also, I just found the NPC-4200
black max, which seems interesting but might be too small for continuous
duty. You can get them from many places, but for side by side listing
robotcombat.com has nice listing with useful details:

http://www.robotcombat.com/products/EMS-PMG080.html
http://www.robotcombat.com/products/ETK-ETEKRT.html
http://www.robotcombat.com/products/NPC-4200.html

Cheers,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Hi Alan,

> Janet,
>
> Some people have reported that their Etek motors get too hot
> under load, or that they wear out brushes quickly under load.
> If you do not find a more suitable smaller motor, would the
> Etek work? It is 20.8 pounds, 12 to 48 volts, and is listed
> as 6 HP continuous and 20 peak, but that is likely at the
> higher voltage.

I have not done the math yet, but I suspect it would work fine,
based on the various projects that use it or a motor like it and
claim a certain level of performance. The PERM PMG_80 is a 7lb
motor, the Etek 22 or so, so sure it's 3 times heavier, but 15 lbs
is not the end of the world. It's just easy to watch the vehicle
specifications creep further and further away from ideal, one
compromise at a time. I just need to be patient and think this 
through. Ignoring the extra pounds, I would expect that a 48V
40A controller would ensure the ETEK never drew more than 
48*40= 2.6HP (ignoring the 25% or so losses from motor efficiency
and drive train). I wonder if any controllers can be programmed
to allow a 5-10 second surge, and then throttle to a certain level.
I have to believe they exist.

I appreciate the links (even though I have seen most of them),
since seeing other real devices actually in production helps improve
one's intuition as to what will work. When you see 5 vehicles 
all using a 6-12 HP motor and claiming a certain level of performance
you can suspect that you might see similiar performance, even without
doing the math. When you see 100 ebikes all using 600W with 120lb
riders, you might suspect it won't work so well with a 50lb chassis
and 120lbs of batteries... even without doing the math.

I appreciate everyone's comments, this is interesting.

Cheers,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

> Not sure if anyone mentioned this EV bike yet, MSRP $4499.
> http://www.x-tremescooters.com/electric_mopeds/xm-3500li/xm-3500li.html
> These are just released, so probably no way to know how good they
> are yet.

Hi Bryan, I am familiar with these, but do not care for the scooter 
styling. Still it's very tempting, along with the Vectrix and other
similiar e-scooters. It comes close to what I want. It will be
interesting to see if the battery packs for the maxi-scooter market
ever makes it to the hobbiest. I have to suspect they won't, for
liability reasons if nothing else.

Cheers,

Janet





_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------



## EVDL List (Jul 27, 2007)

Janet,

Well said... most everything is a set of trade-offs and weighted choices.

I looked at the Perms but they were a lot more money in the same class, at
least the ones I found. They are spec-ed as high efficiency. There's also
a motor the sun races use, still better and still more expensive.
http://home.earthlink.net/~glraymond/pentadpg.html
http://www.ngmcorp.com/products.htm (Solar Utility now NuGen)

The different motor types also have their own strengths and weaknesses. 
Trying to match specs has been interesting. I don't know if I'll have a
"Smoking BugE" (check YouTube) or a turtle. One of the reasons I got a
programmable controller, I can limit the high end at least.

Greg
-- 
View this message in context: http://www.nabble.com/E-tek-vs-Perm-PMG-tp18613519p18654778.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.


_______________________________________________
For general EVDL support, see http://evdl.org/help/
For subscription options, see http://lists.sjsu.edu/mailman/listinfo/ev


----------

