Electric Go Kart Story – Part 2

Taking Action – Modifying An Electric Starter Motor

Part 1 – What inspired me to do an Electric Go Kart Conversion discussed the motivation in doing an Electric Go Kart Conversion. This article is going to discuss what I had to do to get an Electric Motor onto the Go Kart and the modifications I had to make.

Acquiring The Appropriate Sprocket

In early March 2011, I decided to take massive action and get my Electric Go Kart going. I already had some electric starter motors which I was going to use for my Electric Go Kart. With any Electric Car Conversion, it is vital to get the drive train working right. Things like knowing the direction of the electric motor, which way to mount the motor and what transmission method from the motor to the wheels are important.

I first started visiting various motorbike shops and places that sold sprocket. I was going to attach a sprocket to my electric motor which was a a modified starter motor of a small industrial engine. The motorbike shops and shops that sold sprockets did not have sprockets with a pitch required for a go kart chain. A week later, I was in Sydney and bought an engine sprocket from Kart One (part number SK11TY – 11T Yamaha sprocket) for $16. When I was at Kart One, I had my electric motor with me. I told the person at Kart One that I wanted to build an electric go kart. He was very keen to help me find a sprocket that would fit my electric motor. He also mentioned that Electric Go Karts were gaining popularity in the UK Kart Hire scene.

Other Concerns Entering My Mind

Just before getting my sprocket welded to the starter gear, I also had other concerns enter my mind. I had gaps in my knowledge that needed addressing. I had been told that I’ll need a motor controller, but I could not work out why. I was confused about various types of Direct Current (DC) Electric Motors. When I did 2 years of an Electrical Engineering degree (which I never finished as I ended up doing Computer Science instead), I was confused by what the lecturer said. I never got it rectified until recently. I decided to buy Electric Conversion Made Easy with video tutorials by Gavin Shoebridge and it cleared up a lot of things. After reading his book and watching his video tutorials, I was able to put the puzzle together and I had a clear idea of where I was heading with the whole Electric Go Kart conversion process. I understood DC motors better and I understood the reasons and applications of a motor controller. The book brought to my attention the importance of knowing which way to mount the motor. It also explained the various parts and the purpose of those parts. This meant that I now knew what various parts were called, what their purpose was and what they looked like. With the concerns and confusion out of the way, I was able to focus on the tasks ahead.

 

 

Attaching Sprocket To Electric Motor

During the week, I was trying to work out the best way to attach the sprocket to the motor. I ended up getting Rudd Engineering in Goulburn to weld the sprocket to the starter gear. Welding the sprocket and starter gear together was difficult for the following reasons:

1. the starter gear had a rubber base which had to stay intact. This makes it difficult to apply lots of heat during the welding process.
2. the metals used for the starter gear and the go kart engine sprocket were very dissimilar. This makes welding it very difficult.
3. the starter gear or the engine sprocket had porosity which makes welding extra difficult.

As a result, it was MIG welded together which was not their preferred method, but the rubber base on the starter gear added complexity to the job (ie. had to ensure the rubber base did not melt or distort).

You might ask why didn’t I get the engine sprocket welded directly to the shaft of the electric starter motor instead of the starter gear. The answer to that question is that if I burnt the electric motor, I would have the sprocket stuck to the burnt electric motor. Since, I had several of these electric starter motors, if I burnt one electric motor, then, I could easily transfer the sprocket to a spare and identical electric starter motor.

 

Modification Of Electric Starter Motor

When I got the starter gear with sprocket back, I attached it to the starter motor, packed it washers so the starter gear would not throw out and attached the clip. The weld joint which Rudd Engineering did for me is still intact so I’m very happy with the job they did. Once, this step was done, the rest of the electric go kart conversion came together relatively easily.

 

Attaching Electric Motor To Go Kart

The next step was to mount the electric motor onto the go kart. I used a piece of angle iron as my engine mount. The electric motor was mounted to the angle iron and the angle iron was mounted to the go kart using exhaust clamps.  I wanted to enable a degree of adjustment in the location of the electric motor so that the chain could be tensioned appropriately. Once, I got it mounted, I attached some battery cables to a battery and gave it a test run which you can see in the video below.

 

 

As you can see in the video, my Electric Go Kart makes a bit of noise . After achieving that small milestone, I added a solenoid push button switch so that the motor could be activated at the push of button instead of having to put the battery cable on and off the battery. This solenoid push button switch permits high current electricity to flow through it, hence, why I did not have to run cables via a relay.

See part 3 – when the rubber hits the ground, where I discuss some of the problems I faced. Some of these problems may be faced when you do your Electric Car Conversion, so feel free to learn from my mistakes.

 

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: build an electric go kart, electric car conversion, Electric Go Kart, Electric Starter Motor, electriccarconversionblog.com/electric-go-kart-story-part-2, go kart conversion, go kart engine sprocket
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