# Curtis 1238 question



## mizlplix (May 1, 2011)

Has anyone ran the "Motor optimization" routine on their Controller/motor combination?

Miz


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## frodus (Apr 12, 2008)

If you already bought it as a set, do NOT do that.... they're already set up for the correct parameters for your AC15/20/31/35/50.

If you're experimenting with another motor, take note of all the settings for your motor before you start...


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## mizlplix (May 1, 2011)

I have the AC50 dialed in nicely for my car. Yes, I have everything documented well.

But I am installing a slightly larger motor and direct drive. My car only weighs 1,900 Lbs and runs good in high gear only on the AC50, so....

All the 1238 manual says on it is:


> Use the AC Motor Characterization Procedure,
> which has the controller “learn” the AC motor
> parameter data. The procedure should take about
> 30 minutes to complete and can be done on the
> ...


I just wondered what this mysterious procedure was. I can not find it in the manual. They say to call Curtis on everything.......

Thx, Miz


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## frodus (Apr 12, 2008)

It's to tune a new motor with unknown parameters.

If you're not going to use it with the HPEVS AC50 anymore, then you'll likely need to tune it and use this.

What motor are you using?


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## mizlplix (May 1, 2011)

The motor in question is being wound ATM. It has an 8" X 7 1/2" stator and an aluminum finned housing / bell ends. 















Being splined for a Turbo 400 slip yoke. 









First phase in......


The controller will not be able to fully exploit the new motor (like using a 1238 on an AC70 or AC24LS), but it will have increased torque at a lower RPM and will be limited to 5,000 or so.

This whole idea came about because I noticed my 1,900 Lb. car would take off and drive in high gear only quite nicely. I would normally up shift between 5,000-6,000 RPMs and my usual cruise is at 2,700 RPMs/40 MPH. At which time I started thinking about direct drive. 

My 0-60 MPH time is 10.5 seconds with the AC50.

The new motor will lose that extra RPM (I don't use) and increase the lower Torque (which is more useful). 

Most of my controller parameters are dialed in for my car/driving needs(I will probably need to lighten up the regen some) But, I will need to perform the motor optimization routine.

Which is not outlined or detailed on how-to-do. So, I guess I will run it and find out. (driveshaft not installed)

Miz


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## kennybobby (Aug 10, 2012)

Thanks for sharing the info and some cool pictures, looks like you have a fun project. Looks like you are putting down about 30 hp at the wheels--that is awesome for diy.

i've used a 300 hp Baldor VFD that had a "tuning" section also--seems to me it was trying to match the inverter output to the impedance of the motor plus cables, i.e. inductance and resistance, and the acceleration and velocity ramps based upon the inertia of the motor and the load.

i'm curious about the size wire/# of turns was originally in that motor, and what are you putting in there? i'm guessing it looks like 20AWG. Also what voltage is it being wound for? thanks,


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## frodus (Apr 12, 2008)

mizlplix,

email me, I'll send you the sheet on how to do it.


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## Ivansgarage (Sep 3, 2011)

kennybobby said:


> Thanks for sharing the info and some cool pictures, looks like you have a fun project. Looks like you are putting down about 30 hp at the wheels--that is awesome for diy.
> 
> i've used a 300 hp Baldor VFD that had a "tuning" section also--seems to me it was trying to match the inverter output to the impedance of the motor plus cables, i.e. inductance and resistance, and the acceleration and velocity ramps based upon the inertia of the motor and the load.
> 
> i'm curious about the size wire/# of turns was originally in that motor, and what are you putting in there? i'm guessing it looks like 20AWG. Also what voltage is it being wound for? thanks,


Kenny The motor is being wound for 70 volts, 18 gauge heavy build wire
rated for over 200 degrees, 2 turns, 12 in hand. The insulation is allso
rated for over 200 degrees 5-5 for slot paper and 3-3 for coil seperator 
and phase insulation.

----------------------


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## kennybobby (Aug 10, 2012)

*Re: poles and phases?*



mizlplix said:


> The motor in question is
> 
> 
> 
> ...


It looks like it's going to be a 4-pole 3-phase, but wouldn't you want to add poles to make it run slower rpm for a given ac frequency?


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## mizlplix (May 1, 2011)

As in anything automotive, gearing is everything. Gearing can optimize or kill. 

It is being rewound 4 pole because 4 pole is perfect for my needs. Good torque at the RPM range my car is geared for. Simple.

-It was originally 2 pole, but as a 2 pole I don't need the extra RPM and it would be down some on torque.

-6 pole would have more torque, but it would be a little short on RPM for my gearing.........

-As a 4 pole motor, I will have a top speed of 70 MPH or so. AND decent torque, (which is a good thing as it will be direct drive).

The 8" diameter rotor will be more RPM limited as compared to an AC50 for example (Which has about a 6" rotor). A 6 pole motor with a 8" rotor would be RPM challenged for my needs.

It is important to know what you need.

Miz


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## kennybobby (Aug 10, 2012)

Thanks for sharing, that does sound like a perfect match. Looks like a nice job on cutting in those splines also--you guys do some good work.


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## Ivansgarage (Sep 3, 2011)

*Re: poles and phases?*



kennybobby said:


> It looks like it's going to be a 4-pole 3-phase, but wouldn't you want to add poles to make it run slower rpm for a given ac frequency?


Kennybobby thats 1 phase 4 poles and it won't be a (given ac frequency)
it will be a variable AC frequency.


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## Ivansgarage (Sep 3, 2011)

kennybobby said:


> Thanks for sharing, that does sound like a perfect match. Looks like a nice job on cutting in those splines also--you guys do some good work.


Thanks Kenney, Between Miz and I we have over 120 years experiance.

*Just too old farts in cahoots.*

*---------*


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