# Curtis 1238 replacement?



## remy_martian (Feb 4, 2019)

I thought those things weren't street legal? 

Anyway, Google & eBay -- did you bother to look?


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## Hondo8 (Jan 5, 2020)

remy_martian said:


> I thought those things weren't street legal?
> 
> Anyway, Google & eBay -- did you bother to look?


The Curtis 1238 controller is on Ebay however I need the model confirmed, and the model of the charger so I can find one of those as well. The manual simply states it is a Curtis 3 phase AC motor controller with no model number. 
There is also a "Programming issue" as these require a model #1313 Programmer. (I'd bet dip switches would have done a better job). 
This puts me at $1400 for the controller and $600 for the programmer. I wonder if buying a smart car drive motor and transmission mounted sideways is a better investment at $1400.

Note: These are left hand drive DOT approved, with all glass and original 13" tires USA spec. Bumpers are a different matter with the original controller limiting the output to 25 mph, for safety regulations.


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## brian_ (Feb 7, 2017)

remy_martian said:


> I thought those things weren't street legal?





Hondo8 said:


> These are left hand drive DOT approved, with all glass and original 13" tires USA spec. Bumpers are a different matter with the original controller limiting the output to 25 mph, for safety regulations.


The 25 mph limit suggests that the ZX40S was not approved as a normal motor vehicle, but only as a low-speed vehicle... still street-legal - at least on some jurisdictions - just with limitations.


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## brian_ (Feb 7, 2017)

Hondo8 said:


> The Curtis 1238 controller is on Ebay however I need the model confirmed...
> The manual simply states it is a Curtis 3 phase AC motor controller with no model number.
> This puts me at $1400 for the controller and $600 for the programmer. I wonder if buying a smart car drive motor and transmission mounted sideways is a better investment at $1400.


You could just compare specs (operating voltage and power limit) and wiring (since you have a cut-off wiring harness) of the Curt Instruments controllers with the vehicle, to find the right model.



Hondo8 said:


> This puts me at $1400 for the controller and $600 for the programmer. I wonder if buying a smart car drive motor and transmission mounted sideways is a better investment at $1400.


If you could just plug in the Smart components and drive, yes, but there would be a lot more work than that to mount the Smart drive unit and to control the Smart motor... which needs a lot more voltage than the battery of the Miles would provide.


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## Hondo8 (Jan 5, 2020)

If you could just plug in the Smart components and drive, yes, but there would be a lot more work than that to mount the Smart drive unit and to control the Smart motor... which needs a lot more voltage than the battery of the Miles would provide.[/QUOTE]

My existing Curtis system is 72 volt with 6 expensive batteries ( $2500.) with a small Amp Hour availability. 35-45 miles on a 6 hour charge is abysmal performance for a $20,000. factory built motor vehicle. My current estimate to revive this $500. truck is about $6000 in parts, that makes my decision for me and takes me to the Smart EV recycled option. No one has offered a generic upgrade solution, so the 9" motor mated to the 2 wheel drive Toyota designed transmission, batteries and 4 on 100 mm rear axle, will be out of the truck and on EBay by Sunday.

My comments regarding the Smart and Tesla drive motors; The only system that is publicly sorted out for re-use, (Documented) is the Tesla Model S system. The batteries are a little pricey, however you can both cool and heat them easily to match charging requirements due to weather, and they are readily available plus the drive motors have controllers mounted to the motor and gear reduction transmission, which gives me 4 wheel drive options. as I will have a spinning axle output facing forward. 
* Tesla and Smart traction motors are both "Gear reduced one speed, and simple to mount, as both have rubber mounting ears and both will give ample power to a 1500 lb. mini truck. for the upgrade to the Tesla, the infinite burnout capability would likely be worth the extra $1500.


Time for a new thread.. Tesla vs. Smart drive systems.


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## brian_ (Feb 7, 2017)

Hondo8 said:


> My existing Curtis system is 72 volt with 6 expensive batteries ( $2500.) with a small Amp Hour availability. 35-45 miles on a 6 hour charge is abysmal performance for a $20,000. factory built motor vehicle. My current estimate to revive this $500. truck is about $6000 in parts, that makes my decision for me and takes me to the Smart EV recycled option. No one has offered a generic upgrade solution, so the 9" motor mated to the 2 wheel drive Toyota designed transmission, batteries and 4 on 100 mm rear axle, will be out of the truck and on EBay by Sunday.


It looks like you are planning a complete powertrain replacement, including battery. That's a very different situation from just replacing the controller!



Hondo8 said:


> ... they are readily available plus the drive motors have controllers mounted to the motor and gear reduction transmission, which gives me 4 wheel drive options. as I will have a spinning axle output facing forward.


If you don't use both outputs of the drive unit, you will need to lock the Smart or Tesla differential... or you'll just have the unused output spinning and the other one getting no torque. Zero EV offers a ready-made spool to eliminate the differential, although only for the Tesla large drive unit.

Regardless of 2WD or 4WD, the gear reduction of the drive unit plus the gear reduction of a separate axle assembly will likely be excessive. Zero EV offers a 4.5:1 reduction gear set (again for the large drive unit only) to replace the stock 9.7:1 to address this; I doubt this is available for any other drive unit.

An alternative might be to place the drive unit in its normal orientation but at the rear axle, and build or adapt an independent suspension around it. This is a lot of work, but has been done. It would not provide 4WD, but would eliminate differential and gearing concerns, and would leave more space for battery packs.



Hondo8 said:


> Tesla and Smart traction motors are both "Gear reduced one speed, and simple to mount, as both have rubber mounting ears and both will give ample power to a 1500 lb. mini truck. for the upgrade to the Tesla, the infinite burnout capability would likely be worth the extra $1500.


Power, maximum speed, and torque are all limited by the battery, not just the drive unit... but yes, if you put in enough battery any production EV drive unit will be more than enough for a low-speed vehicle.

Any Tesla drive unit seems like an extremely heavy thing for the little Miles.


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## remy_martian (Feb 4, 2019)

Yeah - I agree the (large) Tesla drive unit would tear the little truck apart. 

I'd replace the 9 inch motor with an 11 inch, keep the trans, toss a few more batteries in, buy a ready made controller and Bob's your uncle. If you really wanted to get ambitious, you could replace the rear diff, but I wouldn't mess with it.

OR

Use the *small* front drive unit from a Tesla, but now you have a headache for controllers, wiring, deadly voltages, etc. And nobody says the truck can't be front wheel drive...

As an aside,

" The only system that is publicly sorted out for re-use, (Documented) is the Tesla Model S system"

All the CAN messages are documented somewhere?


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## remy_martian (Feb 4, 2019)

There's a 100kW Rinehart brushless DC controller on eBay right now. 100V min voltage.

With that, get a BLDC motor to adapt to the transmission and then add battery as needed.


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