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SWF
18 October 2011, 1150
Hello all. I'm a new member and have been following the EV scene closely for quite a few years, but have just started my first EV.

I am in the process of converting a 2004 Polaris Sportsman ATV, and would like some comments on motor selection for this project.

First some specs on the machine and stock engine:
- original stock weight of about 700lbs, and after conversion expect the weight will be closer to 800lbs
- specs of stock engine: max of 37HP @ 6600rpm and 33 ft/lbs @ 5400rpm on the crankshaft
- on-demand all-wheel drive
- two speed (hi-low) transmission that will be driven by motor with synchronous belt system. Assuming 1:1 input into transmission, a motor RPM of 5000 translates to ground speeds of 25 and 55 km/hr in low and hi range.

I will be powering with a 72 - 96V lithium pack, probably TS or CALB cells.

So now the questions on motor selection. I am trying to decide between a AC-20 HPEV motor, or dual K91-4003 ADC motors. I'm leaning towards the AC-20 motor, mainly because it will be simpler than a dual motor approach, and also because of the higher rpm range of the AC motor. I also have a motor length limit of about 13" for the motor body, preventing me from using the larger ADC motors. Assuming I use the AC20 motor and a Curtis 1238-7501 controller, Id like input on the following:

- Based on what I have read on the specs for the AC-20 motor, I suspect it will give equivalent or better performance than the original engine, but want input considering the weight of the machine.

- Most of the time I will be operating at low speeds and low load, but want to confirm this motor can handle low-rpm (<500) high load conditions when necessary.

- Will the motor be able to handle the vibration and general bouncing around that it will get on the ATV? The ATV has full independent suspension and the vibration will probably not be considerably worse than on a motorcycle. I have read about problems with the encoder coming loose (probably not really vibration related), and want to know if there are other issues that could come up with the motor getting bounced around.

- I assume that I will have to build some kind of enclosure for the motor to keep dirt and dust out. Should I plan on a powered ventilation system?

Any other considerations that I should think about?

Thanks for the help.

frodus
18 October 2011, 1158
Get a 1238-7601 if you're gonna get a package.

And let me know when you're ready, I'm a reseller for HPEVS.

It sounds like the right motor for you, more torque than you originally had at 0RPM. Go for 96V if you can fir them in there.


what kind of range are you looking for?

SWF
18 October 2011, 1454
Get a 1238-7601 if you're gonna get a package.

And let me know when you're ready, I'm a reseller for HPEVS.

It sounds like the right motor for you, more torque than you originally had at 0RPM. Go for 96V if you can fir them in there.


what kind of range are you looking for?

Thanks for the comment, and I'll keep you in mind for the motor when I'm ready to buy. I noticed that you had a few AC20s for sale from other projects earlier this year.

I basically plan to get as many cells into the frame as possible without altering the appearance of the machine. The ATV frame has quite a bit of space and the frame and suspension have lots of carrying capacity. I'm building up some mock cells now to see the best way to orient the cells. The 130Ah CALB cells may end up being the best use of space. Given the choice between 24 130Ah cells vs 28 100Ah cells, would the preference be to use the higher voltage pack?

frodus
18 October 2011, 1520
Let me know on the motor, I'll help any way I can! Where are you located? I might have a line on an AC20 -12387501 combo.... getting more details on it.

go with higher voltage, the torque gets pulled out to a higher RPM with that higher voltage. Consider maybe even going to 32 cells in series and building a 96V system. I can help on charger as well.

SWF
19 October 2011, 0644
Let me know on the motor, I'll help any way I can! Where are you located? I might have a line on an AC20 -12387501 combo.... getting more details on it.

go with higher voltage, the torque gets pulled out to a higher RPM with that higher voltage. Consider maybe even going to 32 cells in series and building a 96V system. I can help on charger as well.

Any concerns about the motor being able to handle the vibration and bouncing in the ATV, and any of the other questions I had in the original post?

I will likely make a purchase in the next week or two, so keep me in the loop if you happen to find a lightly used motor/controller.

frodus
19 October 2011, 0928
Most of the questions aren't really issues, you're definitely on the right track. I think it's a great motor for this application. Good size, great RPM range, great HP.....Low RPM power is fine, Definitely force air cool it if you plan on enclosing it. Have a filtered entry and exit and blow air into the motor. The motors have a built in fan that you could remove if you duct air into the end of the motor so that it blows through.

As far as vibration, just support the end, and the middle of the motor, like I have:
http://www.evfr.net/coppermine/albums/5-14-11/normal_Picture_008.jpg

And I found out more about that motor, it's available now, slightly used just to test that it worked, PM me for details. It's from a buddy that gave up on his conversion.