# GE 11" SepEx Roll Call & Requests



## toddshotrods (Feb 10, 2009)

There seem to be a handful of us on this site who have this motor. I see you pop up from time to time in threads when the motor comes up. How about an offical roll call to see how many of us there are? Strength in numbers kind of thing...

Also, what do you want or need to make your motor work? I have found PTO discs that have a hub that fits the output shaft. I have the DE mounting pattern digitized and can make pretty much anything you need to get it connected. I'm going to look into having even stronger slip-fit and press-fit hubs made with our pattern for my own racing purposes (later down the road when I have 300+ volts/2K+ amps and sticky tires).

It seems the number one need though, myself included, is control. We all need a field map for this motor so we can purchase suitable controllers that have been/can be programmed to work with it. I have some ideas for that but wanted to see how much interest there really is in it. Demand is leverage.

Any thoughts, comments, suggestions, opinions, welcome.


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## DavidDymaxion (Dec 1, 2008)

If it was significantly cheaper than AC, I think there would be demand for a high power sepex controller.


toddshotrods said:


> There seem to be a handful of us on this site who have this motor. I see you pop up from time to time in threads when the motor comes up. How about an offical roll call to see how many of us there are? Strength in numbers kind of thing...
> 
> Also, what do you want or need to make your motor work? I have found PTO discs that have a hub that fits the output shaft. I have the DE mounting pattern digitized and can make pretty much anything you need to get it connected. I'm going to look into having even stronger slip-fit and press-fit hubs made with our pattern for my own racing purposes (later down the road when I have 300+ volts/2K+ amps and sticky tires).
> 
> ...


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## EVfun (Mar 14, 2010)

The simplest way to control a sep-ex motor is to apply battery pack directly to the armature, but ONLY when the field is powered. So you need a simple watchdog system for that. The motor idle rpm is lowest when the field is the strongest. So you apply maximum field for low speeds and weaken the field to accelerate. You use the clutch to take off from a stop, just like you would with a gas car. This simple system relies on your right foot to limit maximum power. This simple system will also regen back down to the motors idle speed, making for very interesting throttle behavior (if you suddenly release the throttle at a high speed it will decelerate fast while applying generous regen to the batteries. Refinements can be built in from this point to make behavior more docile.


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## toddshotrods (Feb 10, 2009)

DavidDymaxion said:


> If it was significantly cheaper than AC, I think there would be demand for a high power sepex controller.


True but this one is kind of an isolated case. There aren't a great deal of these motors out there, that I know of. There are some people here on DIYEC with the motors, but they're being shy.  I just wanted to see if there are enough of us to warrant having the field map done for this particular motor, and convincing one or two controller manufacturers to accomodate us.

I'm actually planning to convert to series down the road, but want to experiment with SepEx for a while first.


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## toddshotrods (Feb 10, 2009)

EVfun said:


> The simplest way to control a sep-ex motor is to apply battery pack directly to the armature, but ONLY when the field is powered. So you need a simple watchdog system for that. The motor idle rpm is lowest when the field is the strongest. So you apply maximum field for low speeds and weaken the field to accelerate. You use the clutch to take off from a stop, just like you would with a gas car. This simple system relies on your right foot to limit maximum power. This simple system will also regen back down to the motors idle speed, making for very interesting throttle behavior (if you suddenly release the throttle at a high speed it will decelerate fast while applying generous regen to the batteries. Refinements can be built in from this point to make behavior more docile.


Sounds interesting but I'd rather have a field map and a SepEx controller.


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## DavidDymaxion (Dec 1, 2008)

EVfun: That's what I'm mostly doing right now, direct switch to motor and and using the clutch. Field weakening is next. Right now I change speeds by shifting. 

Since the field has more inductance than the armature, switching to both at the same time would lead to a jump in rpm (and presumably current), and then it would settle to idle speed. I now do 2 switches so I can get the field current going first. I'm planning to do a reed switch (I think that's what it is called) to make sure there is field current before the armature contactor will switch on.

I can get 1000 Amps of regen! Caution, regen can break the rear wheels loose.


EVfun said:


> The simplest way to control a sep-ex motor is to apply battery pack directly to the armature, but ONLY when the field is powered. So you need a simple watchdog system for that. The motor idle rpm is lowest when the field is the strongest. So you apply maximum field for low speeds and weaken the field to accelerate. You use the clutch to take off from a stop, just like you would with a gas car. This simple system relies on your right foot to limit maximum power. This simple system will also regen back down to the motors idle speed, making for very interesting throttle behavior (if you suddenly release the throttle at a high speed it will decelerate fast while applying generous regen to the batteries. Refinements can be built in from this point to make behavior more docile.


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## Tesseract (Sep 27, 2008)

toddshotrods said:


> ...
> It seems the number one need though, myself included, is control. We all need a field map for this motor so we can purchase suitable controllers that have been/can be programmed to work with it. I have some ideas for that but wanted to see how much interest there really is in it. Demand is leverage.
> 
> Any thoughts, comments, suggestions, opinions, welcome.


Good idea, Todd. How about adding a poll to this thread (you can still do that) with the following choices: "Have a SepEx motor"; "Want a SepEx"; "Have/Want AC instead". 

I suspect that those people contemplating SepEx - because of easy regen braking - would probably also be interested, or even prefer, AC (either BLDC or ACIM).

That said, it isn't quite as easy as coming up with a field map for a SepEx controller to work well, and deriving the field map could be a major chore. Qer and I have kicked around ways to do that automatically in software and didn't really come to any good conclusions. We'd probably need a lot of help from the likes of Jeff Major to actually make something useful. That said, another member here (BatteryPoweredToad) generously offered his SepEx motor to us in the hopes we could use it to develop a controller. If there is reasonable demand we just might take him up on it.

That said, I tried driving just the armature of a WarP9 on our dyno with my test controller while a single 200Ah LFP cell powered the field and let me tell you, my Soliton1 didn't like that one bit. There's no inductance in the armature to speak of and the current control loop inside the Soliton1 needs at least a couple of microhenries to work properly. No desaturation errors, but current was all over the place and tended to oscillate. Probably a nausea-inducing ride would result.

EDIT: David Dymaxion - you're suspicions are correct in that a SepEx controller wouldn't be much cheaper than an AC inverter.... yes, the H-bridge for the field is a lot lower power, but you still need the extra power devices and terminals and the control software is much more complex than it is for a series dc motor... just look at the manual for a Curtis sepex controller to see what I mean.


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## toddshotrods (Feb 10, 2009)

Tesseract said:


> Good idea, Todd. How about adding a poll to this thread (you can still do that) with the following choices: "Have a SepEx motor"; "Want a SepEx"; "Have/Want AC instead"...


Might as well because this thread isn't what I thought it was going to be...



Tesseract said:


> ...We'd probably need a lot of help from the likes of Jeff Major to actually make something useful. That said, another member here (BatteryPoweredToad) generously offered his SepEx motor to us in the hopes we could use it to develop a controller. If there is reasonable demand we just might take him up on it...


I was trying not to name names yet, but that's pretty much what I was thinking. I was thinking about taking my motor to Major (we're both in Ohio), if he was willing (haven't even discussed this with him yet), and splitting the cost between us for him to develop the field map. It would be completely "open source" available here on the forum for anyone. I figured if there was a field map people could even go to the existing manufacturers (Kelly, Curtis, Alltrax, etc) and get one now. I'm just throwing numbers off the top of my head, but say there were enough people to bring the cost down to $100-200 a piece (for the field map) - that would be a cheap way to get a decent controller. At least in my opinion it would be.

No offense to EVnetics - you know I love that billet masterpiece you guys created - I just figured there probably isn't enough demand for this particular motor to warrant developing a new controller. I didn't realize there is _no_ interest. I thought for sure the people who are building commuters would want a normal plug-n-play controller.

Anyone can follow through with this idea, but the clock may be ticking for me. I will be following up on a lead for coils to convert mine to series this week. I'm learning that there are more knowledgeable electric motor people and sources here in Central Ohio than I would have thought. I could be forever converted to series before summer.


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## toddshotrods (Feb 10, 2009)

^^^ Poll added - please weigh in. It's anonymous, no one will know your secret!


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## EVfun (Mar 14, 2010)

I would certainly like to do an EV with sep-ex, but that is not the current project. One EV at a time, but perhaps a future revision to the buggy. If I do a sep-ex EV my goal is *power* under the right foot so I most likely wouldn't want a controller. I will just use a power rheostat or small scooter size controller for the field. Max field for "idle" and reduce the field to rev it up. Some circuit to verify the presence of a field before switching the armature contactor on with a good old SW200 contactor. I would need another circuit to switch on the brake lights for moderate or greater regen and perhaps an "oh no" circuit open the SW200 if regen goes way high and the throttle is completely off (driver training not to suddenly release the throttle.) Since this motor setup "idles" I can even use a standard alternator for 12v power (and other ICE engine accessories.)


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## AmpEater (Mar 10, 2008)

Sorry to be tardy to the party. 

I've got one!

But I'm probably going to be doing my own controller thing. Was definitely considering a Kelly, but disappointed at lack of peak current. Also considering using a Kelly high amp PM w/ regen controller on armature and separate control for the field. Can get em up to 1800 amps.

I think we'd see way more interest if you could get SepEx motors at common suppliers like EVComponents. 

The few of us that have 11" GE SepEx probably all got them from the same place, and probably got all that were readily available.


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## toddshotrods (Feb 10, 2009)

Tesseract said:


> Good idea, Todd. How about adding a poll to this thread (you can still do that) with the following choices: "Have a SepEx motor"; "Want a SepEx"; "Have/Want AC instead"...


Great idea Jeff! Four votes (including mine) in no time, compared to days of wandering in the desert.




AmpEater said:


> Sorry to be tardy to the party.
> 
> I've got one!...


I was getting ready to PM you Amp! Welcome to the party, the spiked punch is over there...


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## DawidvC (Feb 14, 2010)

Tesseract said:


> That said, I tried driving just the armature of a WarP9 on our dyno with my test controller while a single 200Ah LFP cell powered the field


You will need more voltage to get to the right field for starting the motor. Such a low field voltage would lead to problems with the motor inductance as you have experienced. Most motors have a minimum field requirement that should be respected, even if you ignore its limitation. It would be better to start with pack voltage (if it is compatible with the maximum field voltage) to power the field, and see how your controller will run. 

BTW do you guys need more info on sepex controllers. All the DC motors at work are sepex, and I have quite a lot of info. Please let me know specifics and I will post it for you.

Regards
Dawid


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## Tesseract (Sep 27, 2008)

DawidvC said:


> You will need more voltage to get to the right field for starting the motor....


DawidvC, I assure you I knew exactly what I was doing. This was a series DC motor (Netgain WarP 9) I press-ganged into running as a SepEx, so the field resistance is extremely low (e.g. - 3.5 milliohms for this WarP 9).


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## DawidvC (Feb 14, 2010)

My apologies, Tesseract. I *assumed* you were using a sepex motor.

Dawid


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## toddshotrods (Feb 10, 2009)

Well, I understand why there were no replies. I am the only person out of seven people, so far, who is even interested in a "normal" controller! I just assumed there was a need.

My plan was to put a rheostat on the field (at pack voltage) along with my 48 volt Alltrax series controller on the armature to make the vehicle move. I wouldn't be doing any street driving, as it's not registered yet, and definitely no performance feats - just putting aorund like a big gof cart at events. From info in the "Who's Running a Large SepEx" thread I was going to set the field for 45amps, for safety. If I don't score a set of series coils and the help I need to get the motor converted in a couple/few weeks, I will probably go ahead with this plan until I can convert.

Will it work?


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## Tesseract (Sep 27, 2008)

toddshotrods said:


> ...
> My plan was to put a rheostat on the field (at pack voltage) along with my 48 volt Alltrax series controller on the armature to make the vehicle move.
> ...
> Will it work?


Probably not unless you insert an external inductor in series with the armature. Also, generated voltage (Aka "Eg" or "BEMF") is proportional to RPM and field current, so 48V might not get you much in the way of RPM.

BTW - you can kludge the external inductor by filling some copper tubing with sand and then wrapping it around some PVC sewer pipe (say, 4"). Use about 25' and space the turns about the same as the tubing diameter and you should get enough inductance to smooth the current out enough for a controller to not _choke_.

Mind you, this sort of air core coil radiates EMF like a mo-fo... definitely not FCC approved.


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## major (Apr 4, 2008)

toddshotrods said:


> My plan was to put a rheostat on the field (at pack voltage) along with my 48 volt Alltrax series controller on the armature to make the vehicle move. I wouldn't be doing any street driving, as it's not registered yet, and definitely no performance feats - just putting aorund like a big gof cart at events. From info in the "Who's Running a Large SepEx" thread I was going to set the field for 45amps, for safety. If I don't score a set of series coils and the help I need to get the motor converted in a couple/few weeks, I will probably go ahead with this plan until I can convert.
> 
> Will it work?


Hi todd,

Sounds good in theory. But then there is always that little thing about theory to practice. 

First, 45 amps on the field with a rheostat? Pretty big rheostat there

Secondly, if Tesser had trouble stabilizing armature current with his controller, you think an Alltrax will handle it? I don't know. But you may need to put a big inductor on the output of the controller.

Now if you just want to tool around at low speed and not get fancy with the controller, you don't need an adjustable field. So nix the rheostat and figure a normal field current, set it with a fixed resistor (or battery tapping) and forget it. Then do all your speed control with the armature chopper. The inductor need not be complex or expensive. Maybe just welding cable wrapped around and old transformer core or some other steel object, like the frame 

Might be able to get it to work.

major


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## DavidDymaxion (Dec 1, 2008)

If you just want to putt about slowly, what about putting the field and armature in series? You'd need to limit to about 50 Amps, but would take care of the armature inductance problem.


toddshotrods said:


> ... My plan was to put a rheostat on the field (at pack voltage) along with my 48 volt Alltrax series controller on the armature to make the vehicle move. I wouldn't be doing any street driving, as it's not registered yet, and definitely no performance feats - just putting aorund like a big gof cart at events. From info in the "Who's Running a Large SepEx" thread I was going to set the field for 45amps, for safety. If I don't score a set of series coils and the help I need to get the motor converted in a couple/few weeks, I will probably go ahead with this plan until I can convert.
> 
> Will it work?


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## toddshotrods (Feb 10, 2009)

Tesseract said:


> Probably not unless you insert an external inductor in series with the armature...Mind you, this sort of air core coil radiates EMF like a mo-fo... definitely not FCC approved.


Bzzzzzt, Crackle, Scrrrrrrrr! 



Tesseract said:


> ...Also, generated voltage (Aka "Eg" or "BEMF") is proportional to RPM and field current, so 48V might not get you much in the way of RPM...


Yeah, I realize it's going to be pretty slow. You really can't drive much faster than people walk through shows, so hopefully no one will realize that I really _can't_ drive much faster! 



major said:


> Hi todd,
> 
> Sounds good in theory. But then there is always that little thing about theory to practice.
> 
> First, 45 amps on the field with a rheostat? Pretty big rheostat there...


You guys know I have no idea what the heck I'm doing with an electric motor! I'm just repeating ideas I've heard in my thread and around the forum. I do, however, have enough sense to check with someone that does know before I start hooking stuff up!  I did miss it on the motor though, I was certain that it was a series motor - not! 




major said:


> ...Now if you just want to tool around at low speed and not get fancy with the controller, you don't need an adjustable field. So nix the rheostat and figure a normal field current, set it with a fixed resistor (or battery tapping) and forget it. Then do all your speed control with the armature chopper. The inductor need not be complex or expensive. Maybe just welding cable wrapped around and old transformer core or some other steel object, like the frame
> 
> Might be able to get it to work.


That doesn't sound too bad.


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## toddshotrods (Feb 10, 2009)

DavidDymaxion said:


> If you just want to putt about slowly, what about putting the field and armature in series? You'd need to limit to about 50 Amps, but would take care of the armature inductance problem.


I think I am going to need more than 50amps on the arm. It's really lighweight but also direct drive, so I expect to use more current than that to get it moving.


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## GerhardRP (Nov 17, 2009)

Tesseract said:


> That said, I tried driving just the armature of a WarP9 on our dyno with my test controller while a single 200Ah LFP cell powered the field and let me tell you, my Soliton1 didn't like that one bit. There's no inductance in the armature to speak of and the current control loop inside the Soliton1 needs at least a couple of microhenries to work properly. No desaturation errors, but current was all over the place and tended to oscillate. Probably a nausea-inducing ride would result.


Why not wire the field coils of another warp9 (or other motor) in series with the test motor armature... The Soliton shouldn't know the difference.
Gerhard


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## Tesseract (Sep 27, 2008)

GerhardRP said:


> Why not wire the field coils of another warp9 (or other motor) in series with the test motor armature...


The sorta renders the whole exercise moot, dontcha think?


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## GerhardRP (Nov 17, 2009)

Tesseract said:


> The sorta renders the whole exercise moot, dontcha think?


This thread is confused.. I thought you were trying to get a field map.. people were suggesting kluges for inductance insertion...hence my post.
I guess you are trying to make a low-inductance tolerant controller, which is another matter.


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## toddshotrods (Feb 10, 2009)

GerhardRP said:


> This thread is confused.. I thought you were trying to get a field map.. people were suggesting kluges for inductance insertion...hence my post.
> I guess you are trying to make a low-inductance tolerant controller, which is another matter.


The thread's original purpose is pointless. I assumed that people who had 11" GE SepEx motors were dying to get their paws on a "normal" controller, and that the lack of a field map was standing in the way. It's obvious from the vote tally that there is no interest in purchasing an existing SepEx controller, programmed for this specific motor, so the thread naturally shifted to how to cobble up a system to use the motor.

People are just offering ideas and suggestions to do it. In that regard, the direction the thread is going is serving the purpose, because 30% (as of this post) of the people peeking in here are looking for some other way to make their EVs go.

I didn't have a chance to call today, but I now have the main lead I needed for the series coils. I going to try to call tomorrow and see how much and how soon I can get them. I also dug up the contact info for a motor building shop here that I had lost. I met the guy at a show last year, but couldn't find his brochure. He seemed to be pretty knowledgeable, and I believe he has been rebuilding motors for a number of years. My plan is to convert sooner than later and putt around with my little Alltrax, until the time is right for me to order one of those shiny billet power pills Tesseract and Qer sell!


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## DawidvC (Feb 14, 2010)

Your project look so nice everybody thought you need a soliton with field controller to drive the motor, not something small 

Dawid


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## toddshotrods (Feb 10, 2009)

DawidvC said:


> Your project look so nice everybody thought you need a soliton with field controller to drive the motor, not something small
> 
> Dawid


Thanks Dawid.  That was the plan for a little while, but eventually I realized that nothing will satisfy my appetite for excess but the gut-wrenching torque of a series motor! I was going to do this to learn, and benefit others here on the board, while I finish developing rest of the vehicle. This forum has contributed so much to my efforts, I figured the money and time spent would be a nice thank you. Now that I realize the lack of interest in it, I am going to invest that time and money into the series conversion.


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## GerhardRP (Nov 17, 2009)

toddshotrods said:


> Thanks Dawid.  That was the plan for a little while, but eventually I realized that nothing will satisfy my appetite for excess but the gut-wrenching torque of a series motor! I was going to do this to learn, and benefit others here on the board, while I finish developing rest of the vehicle. This forum has contributed so much to my efforts, I figured the money and time spent would be a nice thank you. Now that I realize the lack of interest in it, I am going to invest that time and money into the series conversion.


Is this an interpolled motor? If so, a Soliton might be happy with the inductance there.
You *can* get the same torque as a series wound from a sepex if you simply program the ampere turns to match...instead of programming for optimum efficiency consistant with the power demand.
Gerhard


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## toddshotrods (Feb 10, 2009)

GerhardRP said:


> Is this an interpolled motor? If so, a Soliton might be happy with the inductance there.
> You *can* get the same torque as a series wound from a sepex if you simply program the ampere turns to match...instead of programming for optimum efficiency consistant with the power demand.
> Gerhard


Be patient with me, my knowledge of electric motors is growing _slowly_ from next to nothing.  I would love to invest the time to really learn more but right now there aren't enough hours in the day for what's currently on my plate.

I don't know if my motor has interpoles. I haven't been inside it yet, and the only way I know of to tell is by whether there are eight rows of bolts on the main case, instead of the normal four that hold the field coils. My motor only has four rows of bolts for the field coils. Is there another way to tell? Does anyone have knowledge of the motor I have, and know whether it does or not?

Jim has pics of one on his site, that he converted to series, but I wouldn't know an interpole from a stripper pole.  Here's the link, if someone wants to take a peek.

Edit = In the midst of my goofiness, I forgot to add that I assume the little coils between the field coils in the motor on Jim's site are the interpoles. It also has eight rows of bolts, which I don't.





GerhardRP said:


> ...If so, a Soliton might be happy with the inductance there... You *can* get the same torque as a series wound from a sepex if you simply program the ampere turns to match...


Whadda ya think about this Jeff?


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## toddshotrods (Feb 10, 2009)

I noticed something today. I visited a fellow member's shop the other day and he had both series and SepEx 11" GE motors there. One of the first things I noticed about them was the series motor had a much larger diameter armature. Seeing it up close helped me understand better why Jim stacked two sets of coils to convert the SepEx motor he did.

Well, today I was out in the garage looking at all my parts, thinking through everything, and I noticed that my SepEx motor has the bigger armature and smaller field coils. My field windings appear to be the size of the series motor, which would means one set should do the trick and the conversion should be much simpler.









Major, Jeff, anyone, if you're still subscribed to this thread I have a question for all the other people with these motors. Since I was basing the 50 amp saturation point on the "Who's Runnning Larger SepEx..." thread. Does this mean that there could be different field maps and different saturation ratings for GE 11" SepEx motors with different sized armatures and field coil windings? I'd hate to see someone burn up their motor using information that doesn't apply to it!


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## major (Apr 4, 2008)

toddshotrods said:


> I noticed something today. I visited a fellow member's shop the other day and he had both series and SepEx 11" GE motors there. One of the first things I noticed about them was the series motor had a much larger diameter armature.


Yeah, todd,

Motor design ain't just a cookbook. If your 2 motors have exactly the same part #, good bet they are the same. Just because they have the same frame diameter and manufacturer, doesn't mean squat as far as to what is inside those mothers.

I see a lot of guys make assumptions about these motor and just sit back and smile. Maybe they're right, maybe not. And because these fork motors are designed for OEMs, you're unlikely as heck to find any data on them. Even 2 Hyster 9 inch series motors by GE could be vastly different.

Regards,

major


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## toddshotrods (Feb 10, 2009)

major said:


> ... Even 2 Hyster 9 inch series motors by GE could be vastly different...


That was I was thinking, because these are all 11" GE forklift motors and I think I have seen at least a half different noticeable differences.




major said:


> ...And because these fork motors are designed for OEMs, you're unlikely as heck to find any data on them...


Tell me about it, I couldn't find squat. 




major said:


> ...If your 2 motors have exactly the same part #, good bet they are the same...


That offers a little hope, because there are a few us on here with the same part number. I believe we all bought the motors from the same guy on Ebay. I think the part number for the motor he tested in the other thread is the same as mine.

As I said, I'm not too concerned about it because I am determined to go series now. I don't think I am going to mess with the SepEx crap at all. Even if it delays my first parking lot ride for a little while, I would just rather not be bothered with rigging stuff.

Thanks for replying - I just want the people who are planning to experiment to be informed.


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## Tesseract (Sep 27, 2008)

toddshotrods said:


> Whadda ya think about this Jeff?


Dunno... depends on the inductance of the interpole coils. The Soliton1 regulates current very well - to within +/- 4A - down to about 4uH. From 4uH down to about 1uH it rapidly gets sloppier but is probably still drivable (dunno for sure as we don't have any motors with such low inductance). \

Here's the deal, though... the armature of a large DC motor - whether it's a series, shunt, or SepEx - will invariably have several turns shorted by the brushes because the brushes almost always span two or more comm bars. This results in shorted turns that reduce the inductance of the non-shorted turns down to what is called in transformers, anyway, the leakage inductance (as if there was no core material present). That inductance value is approximately 20nH per inch... So it would take 50 inches of wire between the brushes just to reach the 1uH minimum for the Soliton1 to regulate current at least somewhat well (+/-20A or so).

Will the interpoles provide at least 1uH of additional inductance? My guess - never having seen the motor in question, mind you - is that they will. That said, how can we test this? Hmmm.. actually... maybe BatteryPoweredToad's offer still stands... I'll shoot him a PM.


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## steiner (Dec 8, 2008)

Todd,

Sorry for being late to the party. I am the one that did the field mapping (with a great deal of help from Major) on the 11" GE motor. I am currently running this motor with 49 amps into the field and a 72 volt 800 amp Kelly controller on the armature. Everything works fine. The armature is powered directly from 5 cells (no controller - simply on/off). I really only got this motor to test a direct drive application on the vehicle I am building (1400 lbs). As I am sure you know, the price wasn't bad.

At 72 volts it is a little faster than I wanted. I raised the field current from 43 amps to 49 amps by adding an additional cell (4 to 5). This slowed the vehicle from 41 mph to 36 mph. Ideally I want a top speed of 25 mph and with more torque than it currently is producing. I don't know how much higher I can go with the field current before diminishing returns (saturation).


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## toddshotrods (Feb 10, 2009)

steiner said:


> Todd,
> 
> Sorry for being late to the party. I am the one that did the field mapping (with a great deal of help from Major) on the 11" GE motor. I am currently running this motor with 49 amps into the field and a 72 volt 800 amp Kelly controller on the armature. Everything works fine...


No prob, thanks for showing up fashionably late and for sharing your progress/results.  Can you clarify some of the details please?



steiner said:


> ...72 volt 800 amp Kelly controller on the armature. Everything works fine...


You mean a Kelly series controller right?



steiner said:


> I am currently running this motor with 49 amps into the field ...The *armature* is powered directly from 5 cells (no controller - simply on/off)...


I am assuming that was a typo and you meant to say the field is powered directly from 5 cells?

What type of cells are you referring to (brand-size-voltage-amperage-etc)? Are they wired series or parallel?

What limits the field to 49 amps? Is that all the cells you're referring to have available?



steiner said:


> ...As I am sure you know, the price wasn't bad...


Yeah, the price was great. Even with the SepEx thing to overcome, I am happy with my purchase. I have a nice stout base to build on.



steiner said:


> ...At 72 volts it is a little faster than I wanted. I raised the field current from 43 amps to 49 amps by adding an additional cell (4 to 5). This slowed the vehicle from 41 mph to 36 mph....


That surprised me. What is your vehicle, and why do you want to limit it to 25mph? Assuming you are running direct drive, what ratio is your final drive?

Sorry to ask so many questions. I would like to compare doing what you did to converting to series now.


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## steiner (Dec 8, 2008)

Yes, I am running a Kelly controller designed for a PM/Series motor. I already had this controller from another vehicle that was running dual PM motors.

Your right...typo error. It is the field that is powered by 5 cells. The 5 cells that I am using are 50 Ahr Hi-Power cells. I had originally planned on wiring two of these in parallel (10 total cells) to give me 100 Ahr of capacity but since I am only running tests that drain 20 to 30 Ahr out I just left it at 5 cells for now. The armature is powered from twenty four 90 Ahr Thundersky cells connected in series.

The five cells for the field are wired in series. The voltage of these five cells determines the amount of current through the field windings (V=IR). If you increase the voltage (4 to 5 cells), you will increase the current. An interesting situation occurs. As you drive the vehicle, the voltage of the 5 cell pack decreases slightly. This is the equivalent of field weakening and the top speed of the vehicle increases. 

My vehicle is an off-road 4x4 utility vehicle. With a top speed of 25 mph it can also qualify as a neighborhood electric vehicle (NEV).

The direct drive feeds directly into the front and rear differential. This is why I needed a dual output shaft. The differential is 3.666:1 ratio and the tires are 25" in diameter. The vehicle actually has very good on-road performance and I would be very happy with it if that was my primary application.

As I mentioned, this motor was simply for testing the direct drive. I really don't like the motor due to its massive weight. The first version of this vehicle that I built used dual PM motors (Mars) and combined they weighed about 80 lbs vs 250 lbs for this motor. However, they required a 3:1 gear reduction. The major reason I went to Lithium batteries was to reduce the weight and increase the performance. With this motor I simply added most of the weight of lead acid batteries back into the vehicle.


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## toddshotrods (Feb 10, 2009)

Thanks so much steiner. I think I can handle that, as temporary solution for creeping around. It'll give me time to locate some series coils, and get some other stuff in order. 4 or 5 cells on a on/off switch for the field, and a normal setup on the armature is nice, neat, and clean.

Yeah, that motor is definitely overkill for your app but, as you said, couldn't beat the price.


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## toddshotrods (Feb 10, 2009)

Now that we know this will work - steiner is living proof - I have a question. Can I accomplish the same thing with a fixed resistor (as major suggested) on a wire from the pack (and and on/off switch), or do I have to have a separate pack for the field to get the same results he's getting?

I am going to be running 48 volts, so a 1 ohm resistor would give me 48 amps out right {{cringe}}?! If that's right, what are the watts supposed to be? I saw them up to 50 watts. Is that big enough?


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## Tesseract (Sep 27, 2008)

toddshotrods said:


> ...I am going to be running 48 volts, so a 1 ohm resistor would give me 48 amps out right {{cringe}}?! If that's right, what are the watts supposed to be? I saw them up to 50 watts. Is that big enough?


The relevant equation is I²R, so 48*48*1 here... that's 2304W.


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## major (Apr 4, 2008)

steiner said:


> An interesting situation occurs. As you drive the vehicle, the voltage of the 5 cell pack decreases slightly. This is the equivalent of field weakening and the top speed of the vehicle increases.


Hey steiner,

Probably the bigger reason for the field weakening as you drive it is due to the heating of the field coils. This increases the resistance and decreases the field current.

major


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## DavidDymaxion (Dec 1, 2008)

Don't forget your field has some resistance -- mine had 1 Ohm, so it limits a 48 V pack to about 48 A with no other resistors.

My motor gets pretty hot in 10 or 15 minutes on 48 V, so be careful to check you aren't overheating your field. Regen makes this worse, since it raises the voltage and hence current even higher, and then you get the double whammy of heating ~ I^2.


toddshotrods said:


> Now that we know this will work - steiner is living proof - I have a question. Can I accomplish the same thing with a fixed resistor (as major suggested) on a wire from the pack (and and on/off switch), or do I have to have a separate pack for the field to get the same results he's getting?
> 
> I am going to be running 48 volts, so a 1 ohm resistor would give me 48 amps out right {{cringe}}?! If that's right, what are the watts supposed to be? I saw them up to 50 watts. Is that big enough?


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## major (Apr 4, 2008)

toddshotrods said:


> I am going to be running 48 volts, so a 1 ohm resistor would give me 48 amps out right {{cringe}}?! If that's right, what are the watts supposed to be? I saw them up to 50 watts. Is that big enough?


Hey Todd,

If in fact you have the same motor as steiner, then the field is about 0.33 ohms. So to get the 48 amps in the field from the 48 volt battery, you need a 0.67 ohm resistor in series with it. About 1540 watts in the resistor and about 760 watts in the field.

major


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## major (Apr 4, 2008)

major said:


> Hey Todd,
> 
> If in fact you have the same motor as steiner, then the field is about 0.33 ohms. So to get the 48 amps in the field from the 48 volt battery, you need a 0.67 ohm resistor in series with it. About 1540 watts in the resistor and about 760 watts in the field.
> 
> major


Todd,

If your motor has the coils in series parallel (connected inside), you could reconnect them to series and increase the field resistance to 1.3 ohms. Then to get the equivalent excitation as the S/P at 48A, you would need 24A with them in series. This takes the needed resistor to 0.7 ohms at 403 watts. 

Maybe you should 1.) measure the field resistance and 2.) open it up and take some photos.

major


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## toddshotrods (Feb 10, 2009)

Hmmm, I not getting my notifications sometimes. I didn't even know you guys had posted. I came back to try to wrap my head around the last posts I remembered, and found all this new stuff. 

First thanks for the answers and ideas.

Secondly, how do you come up with 2304, 1540, or 403, watt resistors? Sorry for all the elementary questions. I hope to learn all this stuff eventually, but I can only cram so much in this little peanut at a time. Between learning new stuff for business and school, I am usually at my limit.



major said:


> ...Maybe you should 1.) measure the field resistance and 2.) open it up and take some photos. major


I can measure the resistance tomorrow, if a standard digital multimeter is sufficient. I'll look into opening the motor up. If I promise myself (and believe myself) that I'll put it right back, I may be able to do that soon.


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## major (Apr 4, 2008)

toddshotrods said:


> Secondly, how do you come up with 2304, 1540, or 403, watt resistors?


Power (watts) = I²R or V*I. An extension of the basic Ohm's Law, V = I*R. Just trying to figure what voltage and current you need on the field and how to get that by adding a series resistor to use a 48V battery. 



> I can measure the resistance tomorrow, if a standard digital multimeter is sufficient.


Better than nothing. Take a zero on it first by touching the two probes together. Multimeters suck below 0.1 ohm. A decent one can do well at 1/3 ohm and higher, where I think you are.

major


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## toddshotrods (Feb 10, 2009)

Sorry, I didn't communicate my question very well. I understand the equations - uh, I mean I understand that the equations provide the hard numbers. What I meant to ask is, how do you physically build (or where do you buy) a resistor with those specs. I'm guessing that it's a combination of resistors. How are they combined or assembled to come up with say 1540 watts. Is it like series and parallel wiring batteries to get the volts and/or current needed?



major said:


> ...Better than nothing. Take a zero on it first by touching the two probes together. Multimeters suck below 0.1 ohm. A decent one can do well at 1/3 ohm and higher, where I think you are.
> 
> major


Cool, I hope mine is good enough. Actually, I hope it's where I think it is. I haven't used it since before I moved. I know where it _should_ be...



major said:


> If in fact you have the same motor as steiner...


We have the same part number on the motor, and purchased them from the same place (through Ebay). That was verified in the thread where he did the fied testing.


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## steiner (Dec 8, 2008)

Major,

You are probably right about the resistance changing in the field coils due to temperature. I didn't think about that. Overall this motor doesn't heat up very much due to its large thermal mass.

Todd,

Why can't you simply tap off 12 volts from your 48 volt pack to power the field windings? I had some extra cells laying around otherwise this is what I was going to do. Obviously you need to watch the cells that are being drained by the field windings and the controller as they will certainly be the first to get to a low voltage value. Are you using lithium or lead acid?

I wouldn't try to measure the field resistance with a meter. As major said, low resistance is difficult to measure accurately. Just put a low voltage battery across the field terminals and measure both the voltage and current while it is connected. This will give you both V and I. Plug it into V=IR or R=V/I. Keep in mind I have had the 5 cells (about 16 volts) connected for 20 minutes continuously without any problems as I drive the vehicle around in my neighborhood.


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## toddshotrods (Feb 10, 2009)

steiner said:


> ...Todd,
> 
> Why can't you simply tap off 12 volts from your 48 volt pack to power the field windings? I had some extra cells laying around otherwise this is what I was going to do. Obviously you need to watch the cells that are being drained by the field windings and the controller as they will certainly be the first to get to a low voltage value. Are you using lithium or lead acid?...


No reason I couldn't. I just figured if I was going to have 48 volts there and could simply throw a resistor in line from that it would be easier. Silly me.  I guess I thought there was a reason you used that 5 cell setup, and not your main pack.

I will be using lead for this. I am planning on A123s when it's time for performance, but right now I just want it to move.



steiner said:


> ...Keep in mind I have had the 5 cells (about 16 volts) connected for 20 minutes continuously without any problems as I drive the vehicle around in my neighborhood.


So, if I had a separate 12v lead battery just for the field, and wired it with an on/off switch, I should move and not burn anything up?  You have knowledge of what you're doing, so it's a little easier for you to experiment. I see myself hooking up wires, smelling funny smells and wondering how much it's gonna cost me - because I didn't ask enough annoying questions! 




steiner said:


> ...I wouldn't try to measure the field resistance with a meter. As major said, low resistance is difficult to measure accurately. Just put a low voltage battery across the field terminals and measure both the voltage and current while it is connected. This will give you both V and I. Plug it into V=IR or R=V/I. Keep in mind I have had the 5 cells (about 16 volts) connected for 20 minutes continuously without any problems as I drive the vehicle around in my neighborhood.


That'll work.


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## steiner (Dec 8, 2008)

Todd,

By all means, ask all the questions you want.

The only issue about the field wiring is keep in mind you will be flowing about 40 to 45 amps when you connect the battery to the field terminals. I used some 4 ga. battery cables (over kill) from Autozone to make these connections. I had a spare contactor that I use to actually complete the circuit. It will require a very heavy duty switch if you don't use a contactor. A starter solenoid would work also.


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## toddshotrods (Feb 10, 2009)

steiner said:


> ...By all means, ask all the questions you want...


 You're a pretty brave guy! 

I'm actually catching on guys. As I said, eventually I would like to learn more so that I really know what the heck I'm doing, but for now I need enough "surface knowledge" to make good decisions. Between the three of you, I understand now why your 16 volts works. The key piece that made all the information was when when major said these motors actually have around .33 ohms of resistance in the field. That gave me a lot of numbers to plug into the Ohm's Law calculators and see how different combinations affect things. Yes, I cheat - due to time/available-brain-power restrictions. 

So, I know I have the option of just sticking a separate pack on the field, with a contactor and switch, and calling it a day. I would rather have around 15-16 volts, like you have steiner, to get up close to 50 amps. Like you, I don't need speed right now, and I would rather run it with full field current. I am concerned with maintaining the voltage/current with the single lead battery and ending up with not much current in the field. Your little lithium pack seems perfect for this. I can pick up 5 A123s locally for the same price the extra 12v lead battery would cost, but how do I charge them?

I want to compare using a resistor with the main pack, for convenience. If I can accomplish this for the same money I may go with it. My number one question right now is how do I (physically) come up with a .67 ohm/1540 watt resistor? I will also look at connecting the field coils in series, and using a smaller resistor, but would like to see what the current setup would cost in time and money.

I will try to verify the resistance in my field today.


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## Batterypoweredtoad (Feb 5, 2008)

Tesseract said:


> Dunno... depends on the inductance of the interpole coils. The Soliton1 regulates current very well - to within +/- 4A - down to about 4uH. From 4uH down to about 1uH it rapidly gets sloppier but is probably still drivable (dunno for sure as we don't have any motors with such low inductance). \
> 
> Here's the deal, though... the armature of a large DC motor - whether it's a series, shunt, or SepEx - will invariably have several turns shorted by the brushes because the brushes almost always span two or more comm bars. This results in shorted turns that reduce the inductance of the non-shorted turns down to what is called in transformers, anyway, the leakage inductance (as if there was no core material present). That inductance value is approximately 20nH per inch... So it would take 50 inches of wire between the brushes just to reach the 1uH minimum for the Soliton1 to regulate current at least somewhat well (+/-20A or so).
> 
> Will the interpoles provide at least 1uH of additional inductance? My guess - never having seen the motor in question, mind you - is that they will. That said, how can we test this? Hmmm.. actually... maybe BatteryPoweredToad's offer still stands... I'll shoot him a PM.


Hi Jeff, The offer still stands. I have been cleaning the garage a little and I could really use the space.


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## major (Apr 4, 2008)

toddshotrods said:


> What I meant to ask is, how do you physically build (or where do you buy) a resistor with those specs.


Something like this. http://www.postglover.com/roundedgewound.html

You can buy similar resistors from Allied, Newark, etc for like $200 each. Often times you can find them on the used/surplus market for as little as $10.





major


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## toddshotrods (Feb 10, 2009)

major said:


> Something like this. http://www.postglover.com/roundedgewound.html...


Thanks major, that really helps with planning and decisions.

One other thought/question before I make a final decision on which way I am going. Is it possible to use a small e-bike/scooter type series controller to do this? Something like this.

I asked because it's in the same price range as the resistor or dedicated battery. With a potentiometer and amp gauge it seems like it would be possible to adjust the current going in the field manually as the battery voltage decreased. How would PWM affect the field?


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## major (Apr 4, 2008)

toddshotrods said:


> Is it possible to use a small e-bike/scooter type series controller to do this? Something like this.
> 
> I asked because it's in the same price range as the resistor or dedicated battery. With a potentiometer and amp gauge it seems like it would be possible to adjust the current going in the field manually as the battery voltage decreased. How would PWM affect the field?


Sure, good idea. That is how a SepEx controller supplies the field current, with PWM. The field inductance smoothes it out nicely. I wonder if you can find one which is reversible, to give you contactorless reverse.

major

ps....What is the continuous current rating of that controller?

pps....Nevermind, 60A. Just saw that. Looks like a winner ;-)


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## toddshotrods (Feb 10, 2009)

major said:


> Sure, good idea. That is how a SepEx controller supplies the field current, with PWM. The field inductance smoothes it out nicely. I wonder if you can find one which is reversible, to give you contactorless reverse.
> 
> major
> 
> ps....What is the continuous current rating of that controller?


Wow! I thought that one was going to get shot down like a big plump turkey in late November! 

Actually, it isn't my idea. I think it's Tesseract's. I think it was in a discusssion with him about a Soliton-based SepEx controller, in which he said something about a small controller for the field. It just came back to me while thinking through all of this.

Continuous current rating for that one is 60 amps. I picked the one that matched my 48 volt pack and seemed to have a high enough continuous rating to supply 50 amps, no matter what. They have some smaller 50 amp controllers, but they only do 30 amps continuous.

I'll see if there are any reversible small controllers.


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## toddshotrods (Feb 10, 2009)

major said:


> ...Nevermind, 60A. Just saw that. Looks like a winner ;-)


I'm soooo shocked! Persistence pays, eh?

I might just go with it and do the reversing contactor deal. For an extra 30 bucks I am tempted to go with the 24-72 volt version just to give myself room in case I find a great deal on a 72 volt controller. I could bump this 48 volt Alltrax down to the e-bike and have both setups running cheaply, until I get my hands on a Soliton. Then I would bump the 72 down to the bike, and start a new project for the 48 volt Alltrax. 

There is a pin-out on the controller for a coil driver - what's that?


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## GerhardRP (Nov 17, 2009)

toddshotrods said:


> With a potentiometer and amp gauge it seems like it would be possible to adjust the current going in the field manually as the battery voltage decreased.


Actually, I think you will want to computer control the current to get the most efficient balance between field current and armature current depending on your RPM and power demand. 
You will need a really good field map.
Gerhard


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## major (Apr 4, 2008)

toddshotrods said:


> There is a pin-out on the controller for a coil driver - what's that?


Not sure about this one, but some controllers will handle precharge and turn on the main contactor.


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## toddshotrods (Feb 10, 2009)

GerhardRP said:


> Actually, I think you will want to computer control the current to get the most efficient balance between field current and armature current depending on your RPM and power demand.
> You will need a really good field map.
> Gerhard


This is just a temporary band-aid. I'm not looking for efficiency or performance, just basic movement. I want to do what steiner is doing.



GerhardRP said:


> ...You will need a really good field map.
> Gerhard


I'm done with that. I'm converting to series. This may just buy me enough time to go straight into my custom-wound coils instead of old forklift parts just to move now.


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## major (Apr 4, 2008)

GerhardRP said:


> Actually, I think you will want to computer control the current to get the most efficient balance between field current and armature current depending on your RPM and power demand.
> You will need a really good field map.
> Gerhard


Yeah Gerhard,

That would be optimal, but compared to a fixed resistor or separate battery for the field, this ain't too shabby of an approach.

major


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## toddshotrods (Feb 10, 2009)

major said:


> Not sure about this one, but some controllers will handle precharge and turn on the main contactor.


Cool, I'll ask them about it before I order it. So far, so good. I'm waiting for someone to realize some reason this won't work.  I'd rather find out now, than post purchase.


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## major (Apr 4, 2008)

toddshotrods said:


> Cool, I'll ask them about it before I order it. So far, so good. I'm waiting for someone to realize some reason this won't work.  I'd rather find out now, than post purchase.


Hey Todd,

This guy http://home.earthlink.net/~evtkw/controller/maincontrollerpage.html uses a separate Kelly controller on his field.

major


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## toddshotrods (Feb 10, 2009)

major said:


> Hey Todd,
> 
> This guy http://home.earthlink.net/~evtkw/controller/maincontrollerpage.html uses a separate Kelly controller on his field.
> 
> major


Thanks Major! I am stoked!  This thread was worth its weight in gold for me, I hope it has been/will be as beneficial to others. All I have to do is finish the motor mounts, get it installed and connected to the rear end, and start hooking stuff up!

I'm running behind today, so I may have to test the field tomorrow or sometime over the weekend.

...exhale.


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## scoot440 (Mar 24, 2010)

Thanks everybody! I am the other guy who voted on the survey - I have a big Sepex GE that I will be putting into a '61 Econoline (with the original 3-speed tranny and a clutch) later this summer. Very informative thread!


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## major (Apr 4, 2008)

scoot440 said:


> Thanks everybody! I am the other guy who voted on the survey - I have a big Sepex GE that I will be putting into a '61 Econoline (with the original 3-speed tranny and a clutch) later this summer. Very informative thread!


Nice to hear from you. Good luck with it and keep us posted so the next guy might learn from you


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## Tesseract (Sep 27, 2008)

Can I go back and change my vote? I am now the proud owner - thanks to fellow member batterypoweredtoad - of a real ass-whompin' GE 13" SepEx...


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## AmpEater (Mar 10, 2008)

Tesseract said:


> Can I go back and change my vote? I am now the proud owner - thanks to fellow member batterypoweredtoad - of a real ass-whompin' GE 13" SepEx...


Jealous....didn't know you could 'em in a SepEx version....if you decide that ~350 lbs is too much for your application give me first dibs, I'd take it.

If you measure it you'll find that it's more like 13.5"..... thats alot of motor


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## toddshotrods (Feb 10, 2009)

Tesseract said:


> Can I go back and change my vote? I am now the proud owner - thanks to fellow member batterypoweredtoad - of a real ass-whompin' GE 13" SepEx...


If you share what that vote would be, and what you plan to do with that ass-whomper!


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## JRP3 (Mar 7, 2008)

Tesseract said:


> Can I go back and change my vote? I am now the proud owner - thanks to fellow member batterypoweredtoad - of a real ass-whompin' GE 13" SepEx...


 Looks as if we'll be seeing a Sepex Soliton soon  SolitEx? Sepliton?


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## Tesseract (Sep 27, 2008)

Yeah, a real beast, huh?

The plan is to use this as a regenerative dyno load and MAYBE develop a SepEx controller as a consequence. However, making a commercial SepEx controller is a bit problematic because every motor is different and attempting to store field maps for each of them is dumb, while making the end user program all the relevant data is a recipe for disaster. I suppose we could simplify the controller by making field current proportional to armature current in drive mode, and fixing the field current in regenerative mode. This would only require that the end user program in the S2-60 limits for field and armature currents (and voltages!) as well as the absolute maximums. Also a minimum field current... very important with a SepEx motor.

Anyway, the original plan was to make a "slave" controller that could work with the Soliton1, but we aren't so sure about that one. It's the most flexible solution, but since we didn't consider that possibility it would always be a kludge. Redesigning the Soliton1's control board would help a lot, and it is under consideration, but that's a lot of work for a very SMALL market. Except that, like a bad 80's hair band, SepEx seems to be "big in Europe", so maybe worth pursuing... but 1000A seems to a bit much for their Clio's and such, so this might be a better candidate for the contemplated "Soliton Jr." (not the real name, just what we are calling the proposed 300V/500A controller).

Anyway, I got a SepEx and, frankly, I'm afraid to use it!


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## Batterypoweredtoad (Feb 5, 2008)

Tesseract said:


> Can I go back and change my vote? I am now the proud owner - thanks to fellow member batterypoweredtoad - of a real ass-whompin' GE 13" SepEx...


It was nice to meet you Jeff. It was fun chatting about everything electric! As much as I picked your brain, I think I might owe you another motor or two! 

Enjoy that beast, I hope it is useful for you.


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## Georgia Tech (Dec 5, 2008)

Tesseract said:


> Yeah, a real beast, huh?
> 
> The plan is to use this as a regenerative dyno load and MAYBE develop a SepEx controller as a consequence. However, making a commercial SepEx controller is a bit problematic because every motor is different and attempting to store field maps for each of them is dumb, while making the end user program all the relevant data is a recipe for disaster. I suppose we could simplify the controller by making field current proportional to armature current in drive mode, and fixing the field current in regenerative mode. This would only require that the end user program in the S2-60 limits for field and armature currents (and voltages!) as well as the absolute maximums. Also a minimum field current... very important with a SepEx motor.
> 
> ...


I have the series version of this motor...man if these motors had interpoles it would be the badest motor on the planet...

I sure wish I knew of someone who used one in an EV the seires or sepex version...


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## toddshotrods (Feb 10, 2009)

If anyone has this motor and has already purchased a PTO disc from SSB Tractors to match the splined output shaft, I have two adapters already machined and ready to be assembled with Spicer flange yokes. There are at least two different PTO disc hubs. These adapters are machined for the 10-bolt hub. It has a centering ring (that the actual PTO disc fits on) of 2.549", and overall diameter of 3.872", and the ten bolts are on a 3.25" bolt circle.

The adapters can be purchased as is for you to finish, or we can finish them for you. The flange yokes have to be machined to fit in the recess, and the recess in the adapter machined a little bit to receive the hubs.









I also have one more hub (the one on the right), already removed from a PTO disc.









PM me if you're interested...


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## Georgia Tech (Dec 5, 2008)

toddshotrods said:


> If anyone has this motor and has already purchased a PTO disc from SSB Tractors to match the splined output shaft, I have two adapters already machined and ready to be assembled with Spicer flange yokes. There are at least two different PTO disc hubs. These adapters are machined for the 10-bolt hub. It has a centering ring (that the actual PTO disc fits on) of 2.549", and overall diameter of 3.872", and the ten bolts are on a 3.25" bolt circle.
> 
> The adapters can be purchased as is for you to finish, or we can finish them for you. The flange yokes have to be machined to fit in the recess, and the recess in the adapter machined a little bit to receive the hubs.
> 
> ...


I need one for a ford.... a 302/351W crank...I have the PTO coupling from SBC tractor....Just need a way to couple it to a 302 Fly wheel...


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## toddshotrods (Feb 10, 2009)

Georgia Tech said:


> I need one for a ford.... a 302/351W crank...I have the PTO coupling from SBC tractor....Just need a way to couple it to a 302 Fly wheel...


I just sent you a PM.


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## green caveman (Oct 2, 2009)

Todd,



toddshotrods said:


> The thread's original purpose is pointless. I assumed that people who had 11" GE SepEx motors were dying to get their paws on a "normal" controller, and that the lack of a field map was standing in the way. It's obvious from the vote tally that there is no interest in purchasing an existing SepEx controller, programmed for this specific motor, so the thread naturally shifted to how to cobble up a system to use the motor.


EV project has been on the back burner due to other projects, so I'm really jumping in late...

I've bought a Sepex/Regen controller from Chennic to run with this motor, but haven't even had a chance to power it up yet. As soon as I have any hard data on this controller success/failures/need for help, etc. I'll post it.

Are you willing to share the bolt pattern for the motor? We're about to take the transmission down to the local machine shop to get that measured, but my life would be easier if we didn't also have to get the motor measured. Mainly because two people can move the transmission, but we don't have any good way to move the motor.


----------

