Electric Go Kart Story – Part 5

Replacing Electrical Switches & Electric Motor

Hi,

in this post, I discuss the different switches used to operate the traction Electric Motor. I went through a few switches and will eventually put some circuit diagrams to illustrate what was done.

Saturday 9 April 2011 and Sunday 10 April 2011

A different switch to activate the motor was installed. In my pile of old car parts, I found an indicator stalk which came out of a Volvo I had a while back. The switching part for the high beam did not work, so I had to use the other terminals used to activate a turn signal. A solenoid relay was used to feed the high current to the Electric Motor, so that no high current was going through the indicator stalk. My dad put a rubber band to make the switch spring back. Driving this Electric Go Kart felt like driving a car using the cruise control.It felt like a drive by wire system. This system worked until the stalk on the indicator stalk broke, but just before it broke, a number of friends took it for a drive and they appeared to have fun with it.

On the Saturday, I burnt out an Electric Motor due to getting beached on my front yard. The bottom of my Electric Go Kart bottomed out and the rear wheels got stuck in the ground. When I pressed the button to try to move my Electric Go Kart, the Electric Motor was in locked rotor position and I kept the power to the motor on for too long, thus burning out the motor. When an Electric Motor is in locked rotor position and current is applied, since there is no back EMF, the resistance going through the Electric Motor windings is lowered and thus, more current is flowing through the Electric Motor windings. Thankfully, I had a spare Electric Motor which I was able to change in under 10 minutes, including changing over the sprockets from the old Electric Motor to the new Electric Motor.

 

Lessons Learnt: When you do your Electric Car Conversion ensure you have mechanisms in place to ensure you protect your Electric Motor from burning out and also from over revving.

 

Saturday 16 April 2011

I walked into Autoone in Goulburn and bought a push button switch. It is on only when you push the button and as soon as you release the button, the switch is off.  The brand is Narva and the rating is 16 amps at 12 Volts and 8 amps at 24 Volts.  There were so many different types of switches to choose from and I was appreciative that the person at Autoone was interested in helping me find the right type of switch for my Electric Go Kart. Interestingly, this staff member does Speedway racing and he really knew his car parts. He also pointed out that when I go above 24 Volts with my Electric Go Kart in the future that I will need to change alot of my switches and electrical parts.

Lessons learnt: Check the voltage and amperage rating of your electrical parts. If you increase the voltage or amperage of your Electric Car Conversion in the future, remember to check the voltage and amperage ratings of wires, fuses, circuit breakers, contacters, wires, controllers, etc. Also, check how the switches operate. For example, some switches when you press them stay on until you press them again. Others are only on when you hold them down. There are many styles of switches so take the time to check that you get the switches that behave in the way you need them to behave.

After I bought the switch, I fitted it to my go kart, initially, to my steering column, but I found it a bit tricky to drive as I had to have my hand of the steering wheel. I then decided to relocate it to the steering wheel, just like how the Ferrari 430 Scuderia has the start button on the steering wheel. In the future, I would like to add a manettino switch so I can change various parameters of my Electric Go Kart and later on add more telemetry on the steering wheel.

 

For the next few weeks in April 2011, I did not do much work on my Electric Go Kart. Instead, I was having fun driving it and learning how to drift with it. My dad drifts so easily with my Electric Go Kart, but I seem to struggle. I think one of the techniques is how you move your body weight around the kart as you turn and get it into a drift.

In late April/early May 2011, I ran into some brake problems with my go kart with the brakes binding after being applied. It had a cable operated braking system instead of a hydraulic braking system. I would prefer to have a cable operated braking system because it means that I do not have to change brake fluid and I don’t have to worry about leaking brake fluid. I’m trying to keep the maintenance of my Electric Go Kart as simple as possible so that I can spend more time having fun with it.

One of the other benefits I’ve enjoyed with having an Electric Go Kart is that I don’t have to worry so much about maintenance. I don’t have to do oil changes (like on 4 stroke gasoline engines) or mix fuel (like on a 2 stroke gasoline engine). I don’t have to worry about changing spark plugs, changing air filters, changing oil filters or adjust valve clearances. If I don’t drive my Electric Go Kart for several months, I don’t have to worry about fuel going stale in the tank or starting problems due to carby issues or having to change the oil. Also, I don’t have to worry about oil leaks.

After I get the brakes sorted (which has nothing to do with the Electric Motor conversion), I will look at battery options and Motor Controllers (Electric Go Kart Story – Part 6) to extend the range of my Electric Go Kart and see if I can increase my speed.

Check out the other parts to the Electric Go Kart Story:

Part 1 – What Inspired Me To Do An Electric Go Kart Conversion

Part 2 – Taking Action – Modifying An Electric Starter Motor

Part 3 – When The Rubber Hits The Ground

Part 4 -Extra Parts Added To Electric Go Kart – Adding A Touch Of Professionalism

Part 5 – Replacing Electrical Switches & Electric Motor

Part 6 – Building A Motor Controller For Electric Go Kart

Part 7 – What I’m Looking For When Upgrading The Motor Controller On The Electric Go Kart

Part 8 – Doubling The Voltage To The Modified Electric Starter Motor To Increase Speed To The Electric Go Kart

 

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Tags: electric car conversion, Electric Go Kart, Electric Motor, motor for electric go kart
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