# ATV conversion - Looking for parts ideas



## AmaToolBox (May 11, 2017)

I've got a Honda TRX300EX that has a totally blown engine, and rather than put in a gas one, I've decided to try to pull off my first EV conversion. I've been following along and I understand the parts I need, but, given the volume of information I am hoping I could get some part/vendor recommendations from those dabbling in this market already. I am good with electronics (I can follow a schematic without an issue) and I can weld/fabricate when necessary.

While I know by default the ATV will not be as fast, which is fine given the quad only hits trails at most (barely leaves the yard), I would like it to have some pep.

Looking for a combination of:
Engine + controller (preferably one that can do reverse or i'll end up having to incorporate a gear box). I've already settled in on trying to get to 48 volts, and with the space from taking out the engine/tank, i should be able to fit 4 full size car batteries (i know that's not the right kind, just noting space) so I have room.

I'll probably mount the electric engine right on the bearing holder (a few mount points are available), so that leaves the whole current engine area for batteries/controller space.

What's everyone's thoughts? i'm not looking to go 50, but 30 would be nice.

and i'd like to be able to do 30 sustained for 2 hours


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## brian_ (Feb 7, 2017)

First, the normal terminology is electric "*motor*", not "engine". But we know what you mean.

Almost any motor can be reversed, but if you use a brushed DC motor you'll need a set of contactors to switch wiring connections, and you'll need to modify the field winding connection if it is a series-wound motor (as most are). Any controller used with an AC motor should handle reversing.

The transmission of the Honda TRX300EX is built into the engine case, so I assume that you are planning to remove the original engine _and transmission_, and drive the chain to the rear axle directly from the motor. This will leave the motor turning quite slowly, so you might need another stage of chain drive to gearing. You might get away with just a large sprocket on the axle and the smallest possible sprocket on the motor.


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## AmaToolBox (May 11, 2017)

Yes, the transmission and motor are shot on the quad (in pieces)

Have any recommendations for a gearbox/transmission for an EV quad?





brian_ said:


> First, the normal terminology is electric "*motor*", not "engine". But we know what you mean.
> 
> Almost any motor can be reversed, but if you use a brushed DC motor you'll need a set of contactors to switch wiring connections, and you'll need to modify the field winding connection if it is a series-wound motor (as most are). Any controller used with an AC motor should handle reversing.
> 
> The transmission of the Honda TRX300EX is built into the engine case, so I assume that you are planning to remove the original engine _and transmission_, and drive the chain to the rear axle directly from the motor. This will leave the motor turning quite slowly, so you might need another stage of chain drive to gearing. You might get away with just a large sprocket on the axle and the smallest possible sprocket on the motor.


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## SidewaysWagon (Jan 30, 2018)

Honestly for an ATV, you may want to consider hobby brushless motors. Something like this: 
https://hobbyking.com/en_us/turnigy-rotomax-150cc-size-brushless-outrunner-motor.html?___store=en_us
With this controller:
https://hobbyking.com/en_us/turnigy-dlux-250a-hv-14s-60v-esc.html?___store=en_us
Could be perfect. Super simple, easy to program brake/reverse just via the motor controller, no need for contactors like with brushed systems. Just over 13hp on 14s lipo pack, and much lighter and more compact than any brushed system would be. (Incredibly light compared to the original gas engine too)

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## AmaToolBox (May 11, 2017)

Thanks. Given that motor design, i'm not sure if it will have enough torque to push the heavy quad. May work for my son's small one...






SidewaysWagon said:


> Honestly for an ATV, you may want to consider hobby brushless motors. Something like this:
> https://hobbyking.com/en_us/turnigy-rotomax-150cc-size-brushless-outrunner-motor.html?___store=en_us
> With this controller:
> https://hobbyking.com/en_us/turnigy-dlux-250a-hv-14s-60v-esc.html?___store=en_us
> ...


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## SidewaysWagon (Jan 30, 2018)

AmaToolBox said:


> Thanks. Given that motor design, i'm not sure if it will have enough torque to push the heavy quad. May work for my son's small one...


Brushless outrunners are generally much better torque-wise than the equivalent power inrunner, whether brushed or brushless. Comes from having a larger effective radius to the rotor. The only issue you may have is that it is a sensorless motor, and therefore may hang up when starting from a complete stop. You could get around this by going with an FOC-capable controller, which I can look for now.
This will have a great deal more torque than any brushed system of a similar size or wattage.

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## AmaToolBox (May 11, 2017)

SidewaysWagon said:


> Brushless outrunners are generally much better torque-wise than the equivalent power inrunner, whether brushed or brushless. Comes from having a larger effective radius to the rotor. The only issue you may have is that it is a sensorless motor, and therefore may hang up when starting from a complete stop. You could get around this by going with an FOC-capable controller, which I can look for now.
> This will have a great deal more torque than any brushed system of a similar size or wattage.
> 
> Sent from my Pixel using Tapatalk


I called the vendor too, they said the motor design requires high air flow, and was intended for propeller based applications apparently. They said it could work, but recommend a cooling fan/sink setup.


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