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Discussion Starter #1
Hi,

I stopwatch checked my acceleration starting in 2nd gear going from 2 fixed
points uphill 10% grade between my drive & the neighbors. I tried 7 degrees
mechanical advance and then set it back to neutral on my Prestolite MTC4001
at 96V E-Porsche 16 ni-cads. I got 33 seconds at 7 degrees and 25 seconds
at neutral and it popped up my 30% grade garage better too with neutral
timing. I checked at speed holding hills and it was at 3600 rpms in 3rd
doing 60mph at 250 amps on the same section of highway. I noticed a bit
drop-off above that speed but overall it ran better with better acceleration
set to neutral. I think the low voltage and rpm's are the factor.

The racers are operating at higher voltage and higher RPM's I believe where
the performance is noticed about 5-6k rpm's

Best Regards,
Mark

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Discussion Starter #2
Hi Mark,


It's great to see you doing some real tests and
sharing. 25 to 33 seconds is more than I expected.
Remember a few weeks ago. I said:

"Chances are you have a 4 pole motor. And your 7
degree figure is actual or mechanical degrees. So you
really have it advanced 14 electrical degrees. If you
advanced it 45 mech degrees (90 elect degrees) you
would have zero torque. I am not sure it is a linear
relationship, but it might give you a feeling. 7
divided by 45 equals 0.155. So your 7 degree shift
might result in 16 percent less torque at current
limit.

Acceleration is proportional to torque. So does 7
degrees equal 16% less torque equal 16% slower accel?
Give it try and let us know."

Your tests don't sound 100 percent scientific, but do
show show a trend. Now, if commutation (sparking) was
acceptable, you've got something.

BTW, I didn't realize you had the MTC-4001. The
factory shift was 4.5 degrees. Did you go 7 degrees
further? Or total?

Jeff




--- Mark Hanson <[email protected]> wrote:

> Hi,
>
> I stopwatch checked my acceleration starting in 2nd
> gear going from 2 fixed
> points uphill 10% grade between my drive & the
> neighbors. I tried 7 degrees
> mechanical advance and then set it back to neutral
> on my Prestolite MTC4001
> at 96V E-Porsche 16 ni-cads. I got 33 seconds at 7
> degrees and 25 seconds
> at neutral and it popped up my 30% grade garage
> better too with neutral
> timing. I checked at speed holding hills and it was
> at 3600 rpms in 3rd
> doing 60mph at 250 amps on the same section of
> highway. I noticed a bit
> drop-off above that speed but overall it ran better
> with better acceleration
> set to neutral. I think the low voltage and rpm's
> are the factor.
>
> The racers are operating at higher voltage and
> higher RPM's I believe where
> the performance is noticed about 5-6k rpm's
>
> Best Regards,
> Mark
>
>
_________________________________________________________________
> http://newlivehotmail.com
>
>




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Discussion Starter #3
Hi Mark and all,

Have you tried to tune your motor for best amp draw? It just takes an
ammeter hooked to your setup while running. fix the motor at a steady
voltage then play with the timing untill you draw the least amps. That
should be the sweet spot. Lawrence Rhodes.......
----- Original Message -----
From: "Mark Hanson" <[email protected]>
To: <[email protected]>
Sent: Monday, July 30, 2007 5:26 AM
Subject: Neutral Timing is Better for Commuters


> Hi,
>
> I stopwatch checked my acceleration starting in 2nd gear going from 2
fixed
> points uphill 10% grade between my drive & the neighbors. I tried 7
degrees
> mechanical advance and then set it back to neutral on my Prestolite
MTC4001
> at 96V E-Porsche 16 ni-cads. I got 33 seconds at 7 degrees and 25 seconds
> at neutral and it popped up my 30% grade garage better too with neutral
> timing. I checked at speed holding hills and it was at 3600 rpms in 3rd
> doing 60mph at 250 amps on the same section of highway. I noticed a bit
> drop-off above that speed but overall it ran better with better
acceleration
> set to neutral. I think the low voltage and rpm's are the factor.
>
> The racers are operating at higher voltage and higher RPM's I believe
where
> the performance is noticed about 5-6k rpm's
>
> Best Regards,
> Mark
>
> _________________________________________________________________
> http://newlivehotmail.com
>
 

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Discussion Starter #4
Hi Jeff,

I didn't realize the MTC-4001 was advanced 4.5 degrees, which way? There
were only single holes not 2 options for neutral or advanced so I don't see
how they would manufacture a motor not knowing the direction of the
application. I advanced the motor 7 degrees turning the brush end CCW into
the CW motor direction with the vehicle forward motion and tapped 4 new
1/4-20 holes for that setting.

(Advance DC engineer said their motors are *not* advanced since they don't
know the user direction or application).

best Regards,
Mark

Date: Mon, 30 Jul 2007 07:46:29 -0700 (PDT)
From: Jeff Major <[email protected]>
Subject: Re: Neutral Timing is Better for Commuters
To: [email protected]
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit
Message-ID: <[email protected]>


Hi Mark,


It's great to see you doing some real tests and
sharing. 25 to 33 seconds is more than I expected.
Remember a few weeks ago. I said:

"Chances are you have a 4 pole motor. And your 7
degree figure is actual or mechanical degrees. So you
really have it advanced 14 electrical degrees. If you
advanced it 45 mech degrees (90 elect degrees) you
would have zero torque. I am not sure it is a linear
relationship, but it might give you a feeling. 7
divided by 45 equals 0.155. So your 7 degree shift
might result in 16 percent less torque at current
limit.

Acceleration is proportional to torque. So does 7
degrees equal 16% less torque equal 16% slower accel?
Give it try and let us know."

Your tests don't sound 100 percent scientific, but do
show show a trend. Now, if commutation (sparking) was
acceptable, you've got something.

BTW, I didn't realize you had the MTC-4001. The
factory shift was 4.5 degrees. Did you go 7 degrees
further? Or total?

Jeff




--- Mark Hanson <[email protected]> wrote:

>Hi,
>
>I stopwatch checked my acceleration starting in 2nd
>gear going from 2 fixed points uphill 10% grade between my drive & the
>neighbors. I tried 7 degrees mechanical advance and then set it back to
>neutral
>on my Prestolite MTC4001 at 96V E-Porsche 16 ni-cads. I got 33 seconds at
>7
>degrees and 25 seconds at neutral and it popped up my 30% grade garage
>better too with neutral timing. I checked at speed holding hills and it
>was
>at 3600 rpms in 3rd doing 60mph at 250 amps on the same section of
>highway. I noticed a bit drop-off above that speed but overall it ran
>better
>with better acceleration set to neutral. I think the low voltage and rpm's
>are the factor.
>
>The racers are operating at higher voltage and
>higher RPM's I believe where the performance is noticed about 5-6k rpm's
>
>Best Regards,
>Mark
>
>
_________________________________________________________________
>http://newlivehotmail.com
>
>




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Discussion Starter #5
Mark,

MTC-4001 was designed for Jet Ind ElectraVan. It used
the Subaru tranny with reverse. So the MTC motor
would only be driven one direction. I forget which,
CW or CCW. But Prestolite used a 4 terminal frame,
S1,S2,A1,A2, and put an external jumper strap from S2
to A2. So the user would have a two terminal
unidirectional motor to work with. Because the
rotation direction was known ahead of time, the
standard MJU-2x comm end head was used which had the
holes for frame mount offset 4.5 degrees. These MJU-2
die cast comm end heads were used for unidirectional
pump motors and reversible traction motors on
Prestolite's standard line for lift trucks. One MJU-2
version with holes neutral for reversible, and
different versions with holes offset one way or the
other for unidirectional pump motors. This is
apparent when you look at the screw heads in the MJU-2
casting. There is a relief. If the screw is in the
middle of the relief, it is neutral. But there is
room such that the holes can be drilled 4.5 degrees
either way.

The 4 terminal frame was used on the MTC-4001 for
standardization of subassemblies and also to give the
user access to the field in case he wished to used
field weakening.

Like I said, I don't recall which was the standard
rotation for MTC-4001. But if you're using the
original equipment strap, you're going the correct
way. That would be A1 to S1 or A2 to S2. That strap
went parallel to the shaft axis. If you have the S to
A jumper skewed around the frame, then it is contrary.

So, it sounds to me like you went from 4.5 to 11.5
degrees advanced. Would explain larger than expected
loss of torque. I suspect the first few degrees of
advance not to diminish torque as much as further on.

Is this a Jet vehicle? Got it on the EValbum?

Hope this helps.

Jeff

--- Mark Hanson <[email protected]> wrote:

> Hi Jeff,
>
> I didn't realize the MTC-4001 was advanced 4.5
> degrees, which way? There
> were only single holes not 2 options for neutral or
> advanced so I don't see
> how they would manufacture a motor not knowing the
> direction of the
> application. I advanced the motor 7 degrees turning
> the brush end CCW into
> the CW motor direction with the vehicle forward
> motion and tapped 4 new
> 1/4-20 holes for that setting.
>
> (Advance DC engineer said their motors are *not*
> advanced since they don't
> know the user direction or application).
>
> best Regards,
> Mark
>
> Date: Mon, 30 Jul 2007 07:46:29 -0700 (PDT)
> From: Jeff Major <[email protected]>
> Subject: Re: Neutral Timing is Better for Commuters
> To: [email protected]
> MIME-Version: 1.0
> Content-Type: text/plain; charset=iso-8859-1
> Content-Transfer-Encoding: 8bit
> Message-ID:
> <[email protected]>
>
>
> Hi Mark,
>
>
> It's great to see you doing some real tests and
> sharing. 25 to 33 seconds is more than I expected.
> Remember a few weeks ago. I said:
>
> "Chances are you have a 4 pole motor. And your 7
> degree figure is actual or mechanical degrees. So
> you
> really have it advanced 14 electrical degrees. If
> you
> advanced it 45 mech degrees (90 elect degrees) you
> would have zero torque. I am not sure it is a
> linear
> relationship, but it might give you a feeling. 7
> divided by 45 equals 0.155. So your 7 degree shift
> might result in 16 percent less torque at current
> limit.
>
> Acceleration is proportional to torque. So does 7
> degrees equal 16% less torque equal 16% slower
> accel?
> Give it try and let us know."
>
> Your tests don't sound 100 percent scientific, but
> do
> show show a trend. Now, if commutation (sparking)
> was
> acceptable, you've got something.
>
> BTW, I didn't realize you had the MTC-4001. The
> factory shift was 4.5 degrees. Did you go 7 degrees
> further? Or total?
>
> Jeff
>
>
>
>
>
--- Mark Hanson <[email protected]> wrote:
>
> >Hi,
> >
> >I stopwatch checked my acceleration starting in 2nd
> >gear going from 2 fixed points uphill 10% grade
> between my drive & the
> >neighbors. I tried 7 degrees mechanical advance
> and then set it back to
> >neutral
> >on my Prestolite MTC4001 at 96V E-Porsche 16
> ni-cads. I got 33 seconds at
> >7
> >degrees and 25 seconds at neutral and it popped up
> my 30% grade garage
> >better too with neutral timing. I checked at speed
> holding hills and it
> >was
> >at 3600 rpms in 3rd doing 60mph at 250 amps on the
> same section of
> >highway. I noticed a bit drop-off above that speed
> but overall it ran
> >better
> >with better acceleration set to neutral. I think
> the low voltage and rpm's
> >are the factor.
> >
> >The racers are operating at higher voltage and
> >higher RPM's I believe where the performance is
> noticed about 5-6k rpm's
> >
> >Best Regards,
> >Mark
> >
>



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Discussion Starter #6
Hey all

I haven't had the time I've wanted to address my
thoughts toward brush timing like I'd like. Rather
than watch another timing thread go by I thought I'd
throw some thoughts at the group.

Most DC motors are designed to be ran neutral and at a
particular voltage, and in fact I spent most of my
first 25 years building motors making sure they went
out that way (older forklift motors had adjustable
brush rings). It wasn't until I ran into Wayland that
I had to start learning how and when to throw them out
of wack, so to speak.

So why advance the brushes when neutral is more eff?

The first issue (for those that are new) is when the
motor commutator arcs in what's been termed a
flashover. This is caused by using higher voltages
than the motor was intended for, which causes the
field magnetics to shift which in turn causes the
brushes to arc as they are no longer "in tune" with
the fields. By advancing the brushes they line up
with the fields when the motor is seeing that higher
voltage and is running harder.

By advancing the brushes you also see the motors power
band shift further up the RPM scale. I've had reports
of both "love" and "hate" increased advancement. The
problem is "when to advance"?

It was just last year that Pat Sweeney flashed his
daily driver ADC motor, when he did it a second time,
he sent it to me, where I found it running in neutral.
After some cleanup and a few parts and setting it via
the OEM advancement holes he's had no issues, besides
a little loss on his takeoff 8^(

Sometimes lifes a trade off, lose a little eff, or
repair your motor a lot 8^P Now this doesn't apply to
lower voltage EV's as much, but again that depends a
lot on what motor one is using compared to what
voltage it's being run at.

I haven't heard from Bill as to when the brush shift
was taking place on Killacycle, or how well he and
scotty thought it was working but it was, I thought, a
successful test of an on the fly brush timing shift.
Being able to smoothly adjust the timing on DC motors
as they run (just like an ICE) would help squeeze both
better eff as well as performance.

As I'm running short of time my advise to those in
doubt is to advance the brushes and avoid themselves
the costs of motor repairs. As Jeff's done a great
write up on this MTC motor, I thought I'd post a bit
for those not using the standard fare motors 8^)

BTW Jeff, I know exactly what you meant with the MJU
plates 8^) I'll see if I can dig some plates out (if
I have any) and grab some pics of the different hole
positions per your description.

Anyway, yeah neutrals better for you dailies... right
up to the point when you zorch your motor. IMO it's
kind of like condom use, do you really want to chance
"not" using it 8^) Of course the higher the juice
flow the more that it's needed 8^o

Hope this helps
Had fun
Jim Husted
Hi-Torque Electric




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Discussion Starter #7
Hey Jim, I pretty much agree with you on this. If in doubt advance. When
you mention high voltage you do not mention parameters. High voltage is a
very nebulous term. When I was first involved with EVs I would say that 120
volts was high voltage. Advanced DC motors used to come with three sets of
holes, one neutral, one advanced about seven degrees and one for clockwise
rotation. This worked great up to about 144 volts. When Advanced DC set
their brushes to neutral for Sparrows and upped the rating of their stock 8
inch to a name plate rating of 156 volts they ran into all kinds of
problems. They almost drove one small controller manufacturer out of
business. They did not realize that people do not go in reverse as fast as
they do in forward. This little piece of information that was missing from
their brains was disastrous for many consumers. Like I said, it is all
nebulous and depends on the motor and the voltage but I personally would
never recommend that a commuter vehicle run no advance above say 96 volts. I
guess this may just be my opinion. You should ask some of the early Sparrow
owners and others for real life scenarios.

Roderick

Roderick Wilde
Vintage Golf Cart Parts
Specializing in Parts for Harley and many other mature carts
www.vintagegolfcartparts.com
E-mail: [email protected]
Phone: 360-385-4868
P.O. Box 221
Port Townsend, WA 98368


----- Original Message -----
From: "Jim Husted" <[email protected]>
To: <[email protected]>
Sent: Monday, July 30, 2007 8:57 PM
Subject: Re: Neutral Timing is Better for Commuters


> Hey all
>
> I haven't had the time I've wanted to address my
> thoughts toward brush timing like I'd like. Rather
> than watch another timing thread go by I thought I'd
> throw some thoughts at the group.
>
> Most DC motors are designed to be ran neutral and at a
> particular voltage, and in fact I spent most of my
> first 25 years building motors making sure they went
> out that way (older forklift motors had adjustable
> brush rings). It wasn't until I ran into Wayland that
> I had to start learning how and when to throw them out
> of wack, so to speak.
>
> So why advance the brushes when neutral is more eff?
>
> The first issue (for those that are new) is when the
> motor commutator arcs in what's been termed a
> flashover. This is caused by using higher voltages
> than the motor was intended for, which causes the
> field magnetics to shift which in turn causes the
> brushes to arc as they are no longer "in tune" with
> the fields. By advancing the brushes they line up
> with the fields when the motor is seeing that higher
> voltage and is running harder.
>
> By advancing the brushes you also see the motors power
> band shift further up the RPM scale. I've had reports
> of both "love" and "hate" increased advancement. The
> problem is "when to advance"?
>
> It was just last year that Pat Sweeney flashed his
> daily driver ADC motor, when he did it a second time,
> he sent it to me, where I found it running in neutral.
> After some cleanup and a few parts and setting it via
> the OEM advancement holes he's had no issues, besides
> a little loss on his takeoff 8^(
>
> Sometimes lifes a trade off, lose a little eff, or
> repair your motor a lot 8^P Now this doesn't apply to
> lower voltage EV's as much, but again that depends a
> lot on what motor one is using compared to what
> voltage it's being run at.
>
> I haven't heard from Bill as to when the brush shift
> was taking place on Killacycle, or how well he and
> scotty thought it was working but it was, I thought, a
> successful test of an on the fly brush timing shift.
> Being able to smoothly adjust the timing on DC motors
> as they run (just like an ICE) would help squeeze both
> better eff as well as performance.
>
> As I'm running short of time my advise to those in
> doubt is to advance the brushes and avoid themselves
> the costs of motor repairs. As Jeff's done a great
> write up on this MTC motor, I thought I'd post a bit
> for those not using the standard fare motors 8^)
>
> BTW Jeff, I know exactly what you meant with the MJU
> plates 8^) I'll see if I can dig some plates out (if
> I have any) and grab some pics of the different hole
> positions per your description.
>
> Anyway, yeah neutrals better for you dailies... right
> up to the point when you zorch your motor. IMO it's
> kind of like condom use, do you really want to chance
> "not" using it 8^) Of course the higher the juice
> flow the more that it's needed 8^o
>
> Hope this helps
> Had fun
> Jim Husted
> Hi-Torque Electric
>
>
>
>
>
> ____________________________________________________________________________________
> Fussy? Opinionated? Impossible to please? Perfect. Join Yahoo!'s user
> panel and lay it on us.
> http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7
>
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.476 / Virus Database: 269.10.25/926 - Release Date: 7/29/2007
> 11:14 PM
>
>
 

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Discussion Starter #8
Dumb question time:
Can you rig an advance mechanism that would retard/advance the brushes in relation to RPM and/or volts/amps?


David C. Wilker Jr.
USAF (RET)

---- Jim Husted <[email protected]> wrote:
Hey all

I haven't had the time I've wanted to address my
thoughts toward brush timing like I'd like. Rather
than watch another timing thread go by I thought I'd
throw some thoughts at the group.

Most DC motors are designed to be ran neutral and at a
particular voltage, and in fact I spent most of my
first 25 years building motors making sure they went
out that way (older forklift motors had adjustable
brush rings). It wasn't until I ran into Wayland that
I had to start learning how and when to throw them out
of wack, so to speak.

So why advance the brushes when neutral is more eff?

The first issue (for those that are new) is when the
motor commutator arcs in what's been termed a
flashover. This is caused by using higher voltages
than the motor was intended for, which causes the
field magnetics to shift which in turn causes the
brushes to arc as they are no longer "in tune" with
the fields. By advancing the brushes they line up
with the fields when the motor is seeing that higher
voltage and is running harder.

By advancing the brushes you also see the motors power
band shift further up the RPM scale. I've had reports
of both "love" and "hate" increased advancement. The
problem is "when to advance"?

It was just last year that Pat Sweeney flashed his
daily driver ADC motor, when he did it a second time,
he sent it to me, where I found it running in neutral.
After some cleanup and a few parts and setting it via
the OEM advancement holes he's had no issues, besides
a little loss on his takeoff 8^(

Sometimes lifes a trade off, lose a little eff, or
repair your motor a lot 8^P Now this doesn't apply to
lower voltage EV's as much, but again that depends a
lot on what motor one is using compared to what
voltage it's being run at.

I haven't heard from Bill as to when the brush shift
was taking place on Killacycle, or how well he and
scotty thought it was working but it was, I thought, a
successful test of an on the fly brush timing shift.
Being able to smoothly adjust the timing on DC motors
as they run (just like an ICE) would help squeeze both
better eff as well as performance.

As I'm running short of time my advise to those in
doubt is to advance the brushes and avoid themselves
the costs of motor repairs. As Jeff's done a great
write up on this MTC motor, I thought I'd post a bit
for those not using the standard fare motors 8^)

BTW Jeff, I know exactly what you meant with the MJU
plates 8^) I'll see if I can dig some plates out (if
I have any) and grab some pics of the different hole
positions per your description.

Anyway, yeah neutrals better for you dailies... right
up to the point when you zorch your motor. IMO it's
kind of like condom use, do you really want to chance
"not" using it 8^) Of course the higher the juice
flow the more that it's needed 8^o

Hope this helps
Had fun
Jim Husted
Hi-Torque Electric




____________________________________________________________________________________
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Discussion Starter #9
You would first have to know how the neutral plane of the fields advances with increasing voltage, current and RPM. This would be no trivial task to figure out for any particular motor. And it would most likely be as different for different motors as the Torque curves. That being said though there is already one example of a single step shift at some point in the RPM band for Killacycle. For them its good before and good after the shift, so I guess it works. To vary the timing continuously with RPM may be add a little more complexity than its worth. But I'm sure it can be done, and most likely will someday as these racers start fighting for hundredths of seconds :)

Mike,
Anchorage, Ak.

> -----Original Message-----
> From: [email protected] [mailto:[email protected]]On
> Behalf Of David Wilker
> Sent: Monday, July 30, 2007 9:14 PM
> To: [email protected]
> Cc: Jim Husted
> Subject: Re: Neutral Timing is Better for Commuters
>
>
> Dumb question time:
> Can you rig an advance mechanism that would retard/advance the brushes in relation to RPM and/or volts/amps?
>
>
> David C. Wilker Jr.
> USAF (RET)
 

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Discussion Starter #10
Yes, you can, and it's even easier if you do it in
software (using IGBTs instead of brushes and
commutators). Oops, I hope I'm not fanning the AC/DC
debate :)


> > Dumb question time:
> > Can you rig an advance mechanism that would
> retard/advance the brushes in relation to RPM and/or
> volts/amps?
> >
> >
> > David C. Wilker Jr.
> > USAF (RET)
>
>




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Discussion Starter #11
It's probably been covered before, but interpoles in a dc motor are the
automatic electric way to change brush timing to reduce arcing. The field
magnetic strength is shifted in proportion to armature current.






On Tue, 31 Jul 2007 05:39:08 -0700 (PDT), Steven Ciciora wrote
> Yes, you can, and it's even easier if you do it in
> software (using IGBTs instead of brushes and
> commutators). Oops, I hope I'm not fanning the AC/DC
> debate :)
>
> > > Dumb question time:
> > > Can you rig an advance mechanism that would
> > retard/advance the brushes in relation to RPM and/or
> > volts/amps?
> > >
> > >
> > > David C. Wilker Jr.
> > > USAF (RET)
> >
> >
>
>
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> Check out fun summer activities for kids.
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fr=oni_on_mail&p=summer+activities+for+kids&cs=bz
 

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Discussion Starter #12
Can you rig an advance mechanism that would retard/advance the brushes in relation to RPM and/or volts/amps?


The more advanced brushless DC motor controllers (UQM, for example) do this automagically - it's only software. I know my brushless DC controllers do not (Solectria BRLS-240 + BRLS-16) but when timing the motors (you still have an adjustable hall-effect sensor), you can have the timing pretty much anywhere and there's no arcing. But that's silicon instead of carbon for my commutator. :)

Mechanically it is possible, you need to have guides that allow you to attach some kind of servo to move the brushes - like the contact breaker plate in an old mechanical distributor.

-Dale
 

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Discussion Starter #13
Couldn't you do it just like the old distributer spark advance system?
Physically rotate the device in relation to its normally operating
position.
Old distributors used the vacuum from the engine to do it.

Dale Ulan wrote:
> Can you rig an advance mechanism that would retard/advance the brushes
> in relation to RPM and/or volts/amps?
>
>
> The more advanced brushless DC motor controllers (UQM, for example) do
> this automagically - it's only software. I know my brushless DC
> controllers do not (Solectria BRLS-240 + BRLS-16) but when timing the
> motors (you still have an adjustable hall-effect sensor), you can have
> the timing pretty much anywhere and there's no arcing. But that's
> silicon instead of carbon for my commutator. :)
>
> Mechanically it is possible, you need to have guides that allow you to
> attach some kind of servo to move the brushes - like the contact
> breaker plate in an old mechanical distributor.
>
> -Dale

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Discussion Starter #15
--- Dale Ulan <[email protected]> wrote:

> The more advanced brushless DC motor controllers
> (UQM, for example) do this automagically - it's only
> software. I know my brushless DC controllers do not
> (Solectria BRLS-240 + BRLS-16) but when timing the
> motors (you still have an adjustable hall-effect
> sensor), you can have the timing pretty much
> anywhere and there's no arcing. But that's silicon
> instead of carbon for my commutator. :)
>
> Mechanically it is possible, you need to have guides
> that allow you to attach some kind of servo to move
> the brushes - like the contact breaker plate in an
> old mechanical distributor.

Hey Dale, all

I haven't much insight into the UQM motors or the
like, but from what I've heard I could build 2
complete racers for the cost of a single motor 8^o
With that said I hope people don't mind if I continue
to tinker with these old dinosaurs in hopes that I can
help those with sub-standard incomes and motors 8^)

George posted about interpoled motors and in fact FT
brought me down a couple (slightly used) Kostov 9"ers
that are still down at the shop. I discovered that an
ADC8 armature fits almost directly into them 8^) By
mod'ing in some ADC brushes and holders I believe a
much beefier and tougher motor could result.
Otmar EVen teased me that he'd have to bring out his
old regen controller (if he could find it) if I got
around to making such a critter when I showed him 8^)

I guess it's my hope that I'll get to have a few more
years before the silicon life forms take over the
carbon life forms 8^P

Looking back at what I posted in my very first post,
that I felt I could help the DC guys, I feel that many
goals have been met at least in some form 8^) On the
other hand I can't believe over two years has gone by
with so much more still to explore.

FWIW I've already gone through 8 AC lift motors for
Winco Foods and just got a call from Johns work that
someone was needing a Crown AC motor gone through
(have no idea why yet) Being these aren't that old I
personally don't see the longevity yet of these
smaller type AC units. I am however (as an old DC
motor dog) hoping to learn some new tricks 8^)

Got to run
Cya
Jim Husted
Hi-Torque Electric
The old record player type motor guy 8^P







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Discussion Starter #16
I have seen a patent where a second set of brushes sense the armature
voltage and cause a small motor to rotate the brushes to minimize this
voltage. As I remember, this was intended for railway motor use.

Being no motor expert by far, I may be all wet, but this thread
surprises me because, as I understand it, the need for brush advance is
due to "armature reaction". This is where the magnetic field developed
by the armature, which is normally perpendicular to the stator field,
causes an effective shift in the stator field. This makes the "magnetic
neutral" position of the brushes different than the "geometric neutral".
I would expect this effect to be more at low rpm/high torque(high
current and high fields) than at lower current and high RPM.

Perhaps inductance, hysteresis and eddy currents are the dominat factors
at high RPM and need the same sort of brush offset. Without further
reflection, it would seem so since the main problem with lack of brush
offset is at high RPM and high voltage.

Allen

-----Original Message-----
From: David Wilker [mailto:[email protected]]
Sent: Tuesday, July 31, 2007 12:14 AM
To: [email protected]
Cc: Jim Husted
Subject: Re: Neutral Timing is Better for Commuters

Dumb question time:
Can you rig an advance mechanism that would retard/advance the brushes
in relation to RPM and/or volts/amps?


David C. Wilker Jr.
USAF (RET)

---- Jim Husted <[email protected]> wrote:
Hey all

I haven't had the time I've wanted to address my
thoughts toward brush timing like I'd like. Rather
than watch another timing thread go by I thought I'd
throw some thoughts at the group.

Most DC motors are designed to be ran neutral and at a
particular voltage, and in fact I spent most of my
first 25 years building motors making sure they went
out that way (older forklift motors had adjustable
brush rings). It wasn't until I ran into Wayland that
I had to start learning how and when to throw them out
of wack, so to speak.

So why advance the brushes when neutral is more eff?

The first issue (for those that are new) is when the
motor commutator arcs in what's been termed a
flashover. This is caused by using higher voltages
than the motor was intended for, which causes the
field magnetics to shift which in turn causes the
brushes to arc as they are no longer "in tune" with
the fields. By advancing the brushes they line up
with the fields when the motor is seeing that higher
voltage and is running harder.

By advancing the brushes you also see the motors power
band shift further up the RPM scale. I've had reports
of both "love" and "hate" increased advancement. The
problem is "when to advance"?

It was just last year that Pat Sweeney flashed his
daily driver ADC motor, when he did it a second time,
he sent it to me, where I found it running in neutral.
After some cleanup and a few parts and setting it via
the OEM advancement holes he's had no issues, besides
a little loss on his takeoff 8^(

Sometimes lifes a trade off, lose a little eff, or
repair your motor a lot 8^P Now this doesn't apply to
lower voltage EV's as much, but again that depends a
lot on what motor one is using compared to what
voltage it's being run at.

I haven't heard from Bill as to when the brush shift
was taking place on Killacycle, or how well he and
scotty thought it was working but it was, I thought, a
successful test of an on the fly brush timing shift.
Being able to smoothly adjust the timing on DC motors
as they run (just like an ICE) would help squeeze both
better eff as well as performance.

As I'm running short of time my advise to those in
doubt is to advance the brushes and avoid themselves
the costs of motor repairs. As Jeff's done a great
write up on this MTC motor, I thought I'd post a bit
for those not using the standard fare motors 8^)

BTW Jeff, I know exactly what you meant with the MJU
plates 8^) I'll see if I can dig some plates out (if
I have any) and grab some pics of the different hole
positions per your description.

Anyway, yeah neutrals better for you dailies... right
up to the point when you zorch your motor. IMO it's
kind of like condom use, do you really want to chance
"not" using it 8^) Of course the higher the juice
flow the more that it's needed 8^o

Hope this helps
Had fun
Jim Husted
Hi-Torque Electric





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Discussion Starter #18
Allen,

The armature reaction and field distortion causes
arcing at the high currents in the series motor, which
is mostly at lower RPM. Arcing also occurs at high
voltage due to the higher voltage between comm
segments. Also it will increase with RPM because the
current is forced to chance faster in the armature
coil which has inductance.

So the best location for the brush is a function of
all of the above.

Jeff


--- "Bukosky, Allen" <[email protected]> wrote:

> I have seen a patent where a second set of brushes
> sense the armature
> voltage and cause a small motor to rotate the
> brushes to minimize this
> voltage. As I remember, this was intended for
> railway motor use.
>
> Being no motor expert by far, I may be all wet, but
> this thread
> surprises me because, as I understand it, the need
> for brush advance is
> due to "armature reaction". This is where the
> magnetic field developed
> by the armature, which is normally perpendicular to
> the stator field,
> causes an effective shift in the stator field. This
> makes the "magnetic
> neutral" position of the brushes different than the
> "geometric neutral".
> I would expect this effect to be more at low
> rpm/high torque(high
> current and high fields) than at lower current and
> high RPM.
>
> Perhaps inductance, hysteresis and eddy currents are
> the dominat factors
> at high RPM and need the same sort of brush offset.
> Without further
> reflection, it would seem so since the main problem
> with lack of brush
> offset is at high RPM and high voltage.
>
> Allen
>
> -----Original Message-----
> From: David Wilker
> [mailto:[email protected]]
> Sent: Tuesday, July 31, 2007 12:14 AM
> To: [email protected]
> Cc: Jim Husted
> Subject: Re: Neutral Timing is Better for Commuters
>
> Dumb question time:
> Can you rig an advance mechanism that would
> retard/advance the brushes
> in relation to RPM and/or volts/amps?
>
>
> David C. Wilker Jr.
> USAF (RET)
>
> ---- Jim Husted <[email protected]>
> wrote:
> Hey all
>
> I haven't had the time I've wanted to address my
> thoughts toward brush timing like I'd like. Rather
> than watch another timing thread go by I thought I'd
> throw some thoughts at the group.
>
> Most DC motors are designed to be ran neutral and at
> a
> particular voltage, and in fact I spent most of my
> first 25 years building motors making sure they went
> out that way (older forklift motors had adjustable
> brush rings). It wasn't until I ran into Wayland
> that
> I had to start learning how and when to throw them
> out
> of wack, so to speak.
>
> So why advance the brushes when neutral is more eff?
>
>
> The first issue (for those that are new) is when the
> motor commutator arcs in what's been termed a
> flashover. This is caused by using higher voltages
> than the motor was intended for, which causes the
> field magnetics to shift which in turn causes the
> brushes to arc as they are no longer "in tune" with
> the fields. By advancing the brushes they line up
> with the fields when the motor is seeing that higher
> voltage and is running harder.
>
> By advancing the brushes you also see the motors
> power
> band shift further up the RPM scale. I've had
> reports
> of both "love" and "hate" increased advancement.
> The
> problem is "when to advance"?
>
> It was just last year that Pat Sweeney flashed his
> daily driver ADC motor, when he did it a second
> time,
> he sent it to me, where I found it running in
> neutral.
> After some cleanup and a few parts and setting it
> via
> the OEM advancement holes he's had no issues,
> besides
> a little loss on his takeoff 8^(
>
> Sometimes lifes a trade off, lose a little eff, or
> repair your motor a lot 8^P Now this doesn't apply
> to
> lower voltage EV's as much, but again that depends a
> lot on what motor one is using compared to what
> voltage it's being run at.
>
> I haven't heard from Bill as to when the brush shift
> was taking place on Killacycle, or how well he and
> scotty thought it was working but it was, I thought,
> a
> successful test of an on the fly brush timing shift.
>
> Being able to smoothly adjust the timing on DC
> motors
> as they run (just like an ICE) would help squeeze
> both
> better eff as well as performance.
>
> As I'm running short of time my advise to those in
> doubt is to advance the brushes and avoid themselves
> the costs of motor repairs. As Jeff's done a great
> write up on this MTC motor, I thought I'd post a bit
> for those not using the standard fare motors 8^)
>
> BTW Jeff, I know exactly what you meant with the MJU
> plates 8^) I'll see if I can dig some plates out
> (if
> I have any) and grab some pics of the different hole
> positions per your description.
>
> Anyway, yeah neutrals better for you dailies...
> right
> up to the point when you zorch your motor. IMO it's
> kind of like condom use, do you really want to
> chance
> "not" using it 8^) Of course the higher the juice
> flow the more that it's needed 8^o
>
> Hope this helps
> Had fun
> Jim Husted
> Hi-Torque Electric
>
>
>
>
>
>
________________________________________________________________________
> ____________
> Fussy? Opinionated? Impossible to please? Perfect.
> Join Yahoo!'s user
> panel and lay it on us.
>
http://surveylink.yahoo.com/gmrs/yahoo_panel_invite.asp?a=7
>
>
>
>




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Discussion Starter #19
--- Roderick Wilde <[email protected]> wrote:

> Hey Jim, I pretty much agree with you on this. If
> in doubt advance. When
> you mention high voltage you do not mention
> parameters. High voltage is a
> very nebulous term. When I was first involved with
> EVs I would say that 120
> volts was high voltage.

Hey Rod, all

There lies the problem when trying to address proper
advancement or EVen proper motor sizing needs as those
parameters are almost never the same from one user to
the next. It's really like one big electric grab bag
or box of chocolates with just about EVery flavor one
could imagine. With that said it gets tough trying to
generalize without leaving someone out of the equation
or EVen worse down a wrong path. I also try to not bog
down the list with novella length postings 8^)

> Advanced DC motors used to
> come with three sets of
> holes, one neutral, one advanced about seven degrees
> and one for clockwise
> rotation.

They still do on the 8's and 9's (at least the ones
I've seen. The ADC 8's are almost a mirror image to
the their 9's as to the differences in degrees for
opposite rotation. While the eight's are set 10
degrees for CCWDE and about half as much for CWDE the
9's are set at 10 for CWDE and only about half that
for CCWDE. Both advances will get you the same RPM
and power output. The Warp 9's are set at 12.5
degrees in both direction which throws another twist
into the mix and shows how different motors are
affected differently.

Added to this, is my belief that all electric motors
(okay well at least the DC ones) are female 8^) and
they all have their own (lets call it personality) 8^o
I mean EVen you racers don't have flashovers all that
often these days and I've often pondered if it was
some form of motor PMS, LMAO!!! No different than
when you want to go race but the ol' lady gets pissy
and says "I SAID YOU AIN"T RACING TONIGHT" and shoots
you that plasma bolt stare 8^( Few if any of the ones
I've seen have offered any real data as to why it
decided to pitch a fit on that occassion while
normally EVerythings good, other than it just decided
to be a bitch and wreck a good time 8^o (just kidding
now, no female hate mail)8^)

In two years John and Tim have only had two major
flashovers (at least major ones needing attention)
over who knows how many times it got throttled. The
only common thing that I noticed was that on both
occasions Woodburn and again last March was that both
times it was with a brand new battery pack. Not sure
how it fits in but something I noticed.

Anyway I'm just standing on the backs of all you guys
who got us here and trying to see how much more we can
squeeze out of them and guilty of having a little fun
as I'm doing it. Sorry about the cleats BTW, LMAO!
8^P
Got to run
Cya
Jim Husted
Hi-Torque Electric





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Discussion Starter #20
I was thinking if i had an adjustable rigging that is spring returned
and advanced with a cable, I could try a "real McCoy" set up.

An adjustable set of counterweights spin relative to the motor rpm and
pull on a plate containing a bearing with the cable mounted on it.

It might also make an interesting hood ornament if we have that contest
again.
 
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