# Something easy to work on?



## catphish (Jul 30, 2017)

I'm interested in building a "simple" EV. In the past I've looked at doing a car conversion, but after looking at all the details, found it a bit daunting.

I'm now thinking that I might have more luck working on a simpler vehicle like a kart or buggy. Are there any obvious choices for vehicles that would be particular simple to get started with. I'm keeping an eye out for simple chassis like buggies that could be chain driven but also interested in any suggestions or pointers that might help me get started.

Thanks!


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## Functional Artist (Aug 8, 2016)

catphish said:


> I'm interested in building a "simple" EV. In the past I've looked at doing a car conversion, but after looking at all the details, found it a bit daunting.
> 
> I'm now thinking that I might have more luck working on a simpler vehicle like a kart or buggy. Are there any obvious choices for vehicles that would be particular simple to get started with. I'm keeping an eye out for simple chassis like buggies that could be chain driven but also interested in any suggestions or pointers that might help me get started.
> 
> Thanks!


1. Find a used go kart/fun kart, preferably with a non-running engine (usually you can get a better deal)
2. Install a motor kit
3. Go have some fun

* Buy a kart in the "nicest/best condition" you can afford, this way you don't have to spend a ton of time & cash restoring the chassis before you can even start on the conversion

To get more detailed ya gotta answer a couple of questions
...how fast do you wanna go?
...how much do you wanna spend?
...how long do you wanna ride?

** The faster or farther you wanna go 
...the more it's gonna cost ya


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## nickC29 (Jul 18, 2018)

Yeah I would agree, thats a simple option. You could check out Killer Motor Sports , they offer buggys and karts on their site.


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## RIPPERTON (Jan 26, 2010)

Ive been scoping out a rental kart design whilst making my "race Kart".
It has to be simple, easy to drive (for kids) and above all cheap.
So far I have a split rear axle which makes for easy steering and a brushed DC motor on each rear wheel both powered by a single DC controller and a couple of lead acid batteries.

2 of these.
https://www.aliexpress.com/store/pr...c24c-46bb-b069-4236044ceca8&priceBeautifyAB=0

1 of these
https://www.ebay.com.au/itm/1500W-4...ller+bicycle&_from=R40&rt=nc&LH_TitleDesc=0|0


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## Functional Artist (Aug 8, 2016)

I understand the want/need for easy steering (especially for kids)
...but, wouldn't dual motors double the power consumption?

Is there a reason you want to avoid the "simple" (1) motor to (1) wheel design? 
..."one wheel peel" as they call it

* I like your split axle/dual motor concept for racing 
...for the additional power & handling it's probably worth "doubling" the power consumption


Another thought

Theoretically, with (1) controller controlling/powering (2) motors

What would happen if (1) wheel was to "break loose" (loose gravel etc.) or start spinning at a different RPM than the other wheel?


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## Functional Artist (Aug 8, 2016)

RIPPERTON said:


> Ive been scoping out a rental kart design whilst making my "race Kart".
> It has to be simple, easy to drive (for kids) and above all cheap.
> So far I have a split rear axle which makes for easy steering and a brushed DC motor on each rear wheel both powered by a single DC controller and a couple of lead acid batteries.
> 
> ...


Wait, a minute

I just looked @ your links

Motors: brushed DC gear motor? 
...why a gear motor? 3,000 RPM @ 6:1 = 500 RPM's (motor output)

Controller: brushless controller?
...brushed motor + brushless controller = ?


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## RIPPERTON (Jan 26, 2010)

Functional Artist said:


> Wait, a minute
> I just looked @ your links
> Motors: brushed DC gear motor?
> ...why a gear motor? 3,000 RPM @ 6:1 = 500 RPM's (motor output)
> ...


Yeah wrong link but you know what I mean.
Power cant be consumed it is applied or exerted.
Energy is consumed and 2 motors alone wont consume more energy as long you are driving the same speed as you were with one motor. With low speed karts you must have differentiation between the drive wheels and 2 DC motors is a good way of doing it.
If one wheel spins there is still torque being applied to the non spinning wheel.
"One Wheel Peel" ? I would like to think we are a little more sophisticated than that around here. We prefer to exercise our design dexterity.
The gear reduction is so you dont need a massive sprocket hanging off the axle rubbing the chain in the dirt and with 1000W you wont be going fast anyway. You will need torque to get up grassy hills.


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## Functional Artist (Aug 8, 2016)

RIPPERTON said:


> Yeah wrong link but you know what I mean.
> Power cant be consumed it is applied or exerted.
> Energy is consumed and 2 motors alone wont consume more energy as long you are driving the same speed as you were with one motor. With low speed karts you must have differentiation between the drive wheels and 2 DC motors is a good way of doing it.
> If one wheel spins there is still torque being applied to the non spinning wheel.
> ...


 
Your (3) criteria:
simple, easy to drive (for kids) and above all cheap.

I asked about "one wheel drive" because it seemed to meet "all' of your "goals"
…maybe, using a differential would too
...& ICE "powered" low speed (kids) karts have used the (1) engine, (1) wheel drive concept for decades

As far as, power consumption/energy consumption, what ever you want to call it

(2) motors weigh twice as much as (1)
...added weight = losses
…& using (2) motors also doubles the (converting electrical energy to mechanical power) "losses"

You might wanna "think thru" the (2) motors controlled by (1) speed controller concept

Lets say, your crusing along, your motors are pulling/consuming 10A each & you go off the edge of the road a bit & (1) wheel starts spinning freely (no load) 
Does the non-freely spinning wheel/motor "now" consume 
...less "energy" because the freely spinning wheel/motor is consuming more?
...or does the non-freely spinning wheel/motor consume more "maybe twice" the "energy" than the freely spinning wheel, because it's load has "suddenly doubled"?
...can & how "well" will the speed controller handle a situation like this? (if it can, how many times?)

Design dexterity?

If you wanna show your "design dexterity" 
...why are you doing a steel framed "Power Wheels" type kart?

Show us/design a (4) motor, (4) wheel drive, articulating kart

Here is a kids kart with a 24V 450W brushed motor/speed controller with an 8.2:1 gear ratio & (2) 12V 12AH SLA batteries
…avg amp draw ~15A 
...max amp draw ~30A 
...top speed ~10 MPH
...but, watch the "MASSIVE" voltage sag on the meter 
https://www.youtube.com/watch?v=uBT9B0sqNe4


*Sorry for "Hijacking" this thread
...but, there are some pointers in there


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## Glocker40 (Dec 20, 2015)

Maybe start with a electric golf cart to learn on.


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## rmay635703 (Oct 23, 2008)

Get a Miles ZX40 or a 1981 Comutacar 

Both are cheap
Already EV
Very simple
Street legal 

And ready to mod

Otherwise the 1970 Subaru 360 is about the most simplistic 
Vehicle you will find for conversion, save maybe a VW


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## brian_ (Feb 7, 2017)

Functional Artist said:


> I understand the want/need for easy steering (especially for kids)
> ...but, wouldn't dual motors double the power consumption?


No. There's nothing fixed about the power consumption of a motor, let alone all motors being the same. Each motor's power consumption will depend on the applied voltage (a single controller connected to two motors in parallel means that each motor will get the same voltage) and the motor speed.

The total power consumption of the dual motors will be no different from the power consumption of a single-motor system, unless the motor (single and dual) have different efficiencies at the point each is operating.

There is no reason to assume that each motor in the dual-motor system would be the same as the motor used in a single-motor system. A rational person would consider two small motors to be an alternative to one large motor.



Functional Artist said:


> Theoretically, with (1) controller controlling/powering (2) motors
> 
> What would happen if (1) wheel was to "break loose" (loose gravel etc.) or start spinning at a different RPM than the other wheel?


The faster-spinning motor will typically take less current and produce less torque. Whether the faster motor will take in (and put out) more or less power than the slower one depends on motor characteristics and where in the operating range the speeds and loads are.


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