# Modifying an 11 inch GE motor



## GE11 (Oct 24, 2011)

Ok guys,

I have an 11 inch GE forklift motor that I would like to modify for Higher voltage. Here are the 2 things I know...

1) the armature has to have the high speed bands cut into it. For this I would take the armature and put it on a lathe and cut slot bands into it. Two rows. But my question is.. What type of material and resin do I use to do this? Looking at the GE High voltage 9 inch motors for EVs, it looks to be some sort of string with some sort of resin. 

Does anyone know how this process is done?

2) is to advance the timing of the brushes this is not that difficult...

thanks for your help..


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## remy_martian (Feb 4, 2019)

Sounds like you're describing "Micarta"...red-necks make knife handles with it these days, but it was the go-to pcb material in the 30's& 40's.

You don't make it - it comes in various shapes, usually sheets and plates, but I haven't looked for rods, etc.


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## GE11 (Oct 24, 2011)

Well when i look at the Armature of my 9 inch GE motor it looks like some sort of cord strand if you would..


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## GE11 (Oct 24, 2011)




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## GE11 (Oct 24, 2011)

If you notice the 9 inch Armature on the right is from a high voltage high RPM motor.. I need to make the bigger 11 inch armature on the left like this one..


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## remy_martian (Feb 4, 2019)

Are you planning on dropping it on the Russians? Because your plans on grooving and raising the RPM will likely make it frag into same-sized chunks of shrapnel.

You can never have the left motor turn at the RPM of the one on the right all else being equal. The mass and radius both say "nuh uh". Physics is a biotch

You might be able to wrap it in carbon filament, but you'd have to run it to destruction to assess the gains.

I have to ask - why all this labor when you can pick up a 10,000 rpm 200hp for $600?


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## GE11 (Oct 24, 2011)

well no.. the one on the right turns at 6500 ... The one on the left with speed band modification could still not turn like the one on the right...But adding the bands does alow me to increase the RPM on the one on the left.... I just need to know what those bands are..


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## remy_martian (Feb 4, 2019)

If I had to guess, it is likely wound glass filament, using the rotor as a mandrel, that's post-cured in an industrial oven. Not sure if that needs to be done in a controlled atmosphere or not.

Again, if you screw up those grooves (they are engineered and QA inspected before winding), it will fail spectacularly...can I have your stuff after it does? 😂


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## kennybobby (Aug 10, 2012)

The laminations are made of a high Silicon steel with really good magnetic permeability, but it is very soft and "gummy"--it is usually stamped into the desired shape because precision machining is not feasible.

The strapping could be fiberglass tape or kevlar cord bonded with an epoxy resin

You might want to practice on some cheap motor that doesn't matter to see if acceptable machining is possible.


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## Duncan (Dec 8, 2008)

I think you are concentrating on the wrong bits
I have seen some grenaded DC motors - it was the Commutator that let go 
The armature is slightly further out so it will see higher G loads - but it is also inherently a LOT stronger under that loading than the commutator 

Kennybobby mentions that the steel is fairly soft - but that is still steel with its 20 tons/square inch strength

Just looking at your photographs the "bands" will do nothing to help the strength of the rotor - look at the direction of the laminations

The com will fail first - the armature will fail a long time later and would fail by having the windings thrown out of the slots 

I have just found that I have been running my 11 inch Hitachi at 6800 rpm (I had a 4.44:1 diff not the 4.1:1 I thought it was

What rpm are you trying to obtain?


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## GE11 (Oct 24, 2011)

Duncan said:


> I think you are concentrating on the wrong bits
> I have seen some grenaded DC motors - it was the Commutator that let go
> The armature is slightly further out so it will see higher G loads - but it is also inherently a LOT stronger under that loading than the commutator
> 
> ...


Man you bring up a fantastic point here! There are alot of people running the 11 inch forklift motor and the only thing they are doing is advancing the brushes, which I can do. 
Man this is a great point. So you running your 11 inch motor at 6800 rpm with no issues? My hope to run a 1000 amp controller later on. For now I have a 500 amp Paul and Sabrina. But as soon as i can find an affordable 1000 amp controller I will go 1000 amps...I presently have a 9 inch motor how would this handle a full 1000 amps motor amps?

thanks man for your help!


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## remy_martian (Feb 4, 2019)

Commodity prices are up - good time to be scraping your copper puddle off the asphalt


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## GE11 (Oct 24, 2011)

remy_martian said:


> Commodity prices are up - good time to be scraping your copper puddle off the asphalt


Not sure what you mean sir??


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## remy_martian (Feb 4, 2019)

You can't just keep shoving amps into a small motor without overheating the windings. @Duncan drag races at 1/8th mile events...his ampere brags are for 5 or so seconds.


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## GE11 (Oct 24, 2011)

remy_martian said:


> You can't just keep shoving amps into a small motor without overheating the windings. @Duncan drag races at 1/8th mile events...his ampere brags are for 5 or so seconds.


Thats why I was wanting to see peoples real life experiences. I have a 9 inch GE and an 11 inch GE forklift. It is good to know that people are using the 11 inch motor at EV voltages with only advancing the timing which I can do. So if I upgrade to 1000 amps I know I can use a 11 inch motor without modifying it.


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## remy_martian (Feb 4, 2019)

1000 amps for what?


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## GE11 (Oct 24, 2011)

The thing I realizing is that the 11 inch motor can be used without modifications if I stay under 5500 RPM...


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## remy_martian (Feb 4, 2019)

Again, it's in drag racing. 

What do you need the high RPM for?


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## GE11 (Oct 24, 2011)

remy_martian said:


> 1000 amps for what?



This is what I want to build... but I will keep the original Blue color and will go with around 72V to 96V to start with... I dont have a Warp 11, but I do have a GE 11 inch forklift motor...It is almost exactly like the Warp 11 except for the bands on the Armature. So I hope that I can use one of those when I bump up to 1000 amps..


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## GE11 (Oct 24, 2011)

GE11 said:


> This is what I want to build... but I will keep the original Blue color and will go with around 72V to 96V to start with... I dont have a Warp 11, but I do have a GE 11 inch forklift motor...It is almost exactly like the Warp 11 except for the bands on the Armature. So I hope that I can use one of those when I bump up to 1000 amps..


 sorry I left this off:


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## remy_martian (Feb 4, 2019)

What car? Is it for racing?


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## GE11 (Oct 24, 2011)

remy_martian said:


> Again, it's in drag racing.
> 
> What do you need the high RPM for?


around 55oo RPM max really... If you go higher voltage the RPM will inherently be higher


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## GE11 (Oct 24, 2011)

remy_martian said:


> What car? Is it for racing?


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## Duncan (Dec 8, 2008)

Couple of things
I have run a few 1/4 mile drags as well as the 1/8th - I have found that I was hitting 6800 rpm at the end of the 1/4 mile
But I do use my car for track event - still set to 1200 amps

I would treat current and voltage/rpm as separate issues -
High current will cause heat - and melt things - this is a current multiplied by time issue - with the cooling fan adding to the complexity
My motor is one hour rated at 1400 rpm and 200 amps - at 4 times that rpm (5600rpm) it will be getting 4 times the cooling flow so 800 amps?? - probably not as much of an increase as that but some increase 
Even your smaller motor should be good for 1000 amps and a few seconds - and it will only take a few seconds for it to accelerate your car to the speeds/rpms where the current will fall off naturally

You need high voltage to achieve high torque at high rpms
High Voltage can lead to a "Zorch" where the current goes across the commutator - nasty
High rpms can lead to the commutator bursting

Your target of 5500rpm is nicely conservative - the loads on the com will be about 30% less than at my 6800rpm (squared relationship) 

IMHO the bands around the armature do bugger all as that is NOT the weakest link

96 volts will NOT be enough to overspeed either a 9 inch or an 11 inch motor - UNLESS it is completely unloaded - declutched or in neutral

Running a 1000 amps at those voltages will give you the effect I had with a 120 volt battery
Takes off like a scalded cat - then stops accelerating completely at about 60 mph


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## GE11 (Oct 24, 2011)

Duncan said:


> Couple of things
> I have run a few 1/4 mile drags as well as the 1/8th - I have found that I was hitting 6800 rpm at the end of the 1/4 mile
> But I do use my car for track event - still set to 1200 amps
> 
> ...


Man!

Thank you Thank you so much!! Right now I have my settup in a Karmen Ghia... The 9 inch motor is from a Bradley GTE and has the Clutch.. while the 11 inch is a 325744 hyster motor made by GE... These 325744 Hyster motors are made almost Identical to the Warp 11. Is I went with the GE 11 I will loose the ability of a clutch


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## Duncan (Dec 8, 2008)

GE11 said:


> Man!
> 
> Thank you Thank you so much!! Right now I have my settup in a Karmen Ghia... The 9 inch motor is from a Bradley GTE and has the Clutch.. while the 11 inch is a 325744 hyster motor made by GE... These 325744 Hyster motors are made almost Identical to the Warp 11. Is I went with the GE 11 I will loose the ability of a clutch


For your setup you cannot easily lose the gearbox - so IMHO you may as well stick with the 9 inch - especially with the lower voltages - the bigger motors have more back EMF so they require more volts for higher revs


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## Frank (Dec 6, 2008)

I would definitely be going with a higher voltage pack (and bigger controller too). Most stock brushes are good up to around 150V but if you can get some Helwig "red top" brushes you can easily go 190 (some go to 200+ but I've never gone more than 195). It depends on what your expectations/usage is.


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## onegreenev (May 18, 2012)

A controller with 1 or 2 thousand amps doesn’t mean I’ll be dumping that into the motor all the time. It is to launch the vehicle but within seconds you are well below those amperage loads once you are moving. It’s just the nature of the beast. Just be sure you advance the brushes so you don’t zorch. As for exploding your beastie? It happens because you over rev the limits of the commutator. I’ve never seen the com banded. Only the armature and I believe it is Kevlar. Old school may be fiberglass but for strength you want Kevlar. The 9” GE motor can handle the high current too just like the Warp9.


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## GE11 (Oct 24, 2011)

onegreenev said:


> A controller with 1 or 2 thousand amps doesn’t mean I’ll be dumping that into the motor all the time. It is to launch the vehicle but within seconds you are well below those amperage loads once you are moving. It’s just the nature of the beast. Just be sure you advance the brushes so you don’t zorch. As for exploding your beastie? It happens because you over rev the limits of the commutator. I’ve never seen the com banded. Only the armature and I believe it is Kevlar. Old school may be fiberglass but for strength you want Kevlar. The 9” GE motor can handle the high current too just like the Warp9.


 Thank you Buddy... I am going to pull the motor in a day or two to work on this clutch! I have a video of it running..


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## remy_martian (Feb 4, 2019)

Launch is not a problem for most EV's. Are you drag racing this or is it a street car?


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## GE11 (Oct 24, 2011)

remy_martian said:


> Launch is not a problem for most EV's. Are you drag racing this or is it a street car?


street only..


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