Electric Kart QS138 96V

[Edvin]

It's about time I start posting about my project and get input from the very talented people around here at endless!

The idea about a electric go kart has been there for a while but finally an Tony Kart without motor came out for sale (early 2024) and I pulled the trigger and purchased it. It's the perfect fit for my build - my requirements were a proper racing chassi with front brakes for decent money.

Said and done, went and picked it up.



Started assembly of wheels, seats etc to get a feeling for it and where I could mount the motor


I will keep you guys posted, but the spec is as follows:

QS138 90H
Fardriver ND96680
Gear ratio 2,86:1 (14 front : 40 back)
26S8P Custom Molicel P42A battery pack
Sub 100kg race-ready

The build is almost finished and I will make this a build thread that doesn't drag out too much on time (fingers crossed). Hopefully someone can pickup something from my learnings and mistakes, and that this thread can ignite some fruitful conversations.

 

[Speedgeezer]

Awesome stuff. I had a Tonykart 125cc Shifter about 25 year ago than later Trackmagics. I ran the 125 Heavy at 425 lbs.
Not impressed with TK brakes, I would upgrade to Brembo's, otherwise a really easy chassis to tune.
Sprockets are cheap. Mounting looks OK if the chain clears the bar but I would put the drive sprocket outboard myself. Too bad it isn't water cooled with a radiator - it has the pump. Looks like 500mm axle. Buy a soft & hard axle for tuning.
Will the sinewave driver hard start or is ramped on the start?

Keep us posted.

 

[Dui ni shuo de dui]

Doing the exact same thing is on my to do list, hopefully someday!
I will follow this thread with great interest.

I suggest you get a more powerful Fardriver if you still can. This one won't be too weak, but it won't be as crazy as it could be

 

[dominik h]

Same on my list.
I already have QS138 90H V3 , ND72680 and ND96850 and a lot of batteries....
Still missing the kart frame.

 

[Edvin]

Doing the exact same thing is on my to do list, hopefully someday!
I will follow this thread with great interest.

I suggest you get a more powerful Fardriver if you still can. This one won't be too weak, but it won't be as crazy as it could be

Just find the right chassis and thats your start
I actually aquired the ND96680 already, and of course I missed out on the CANBUS options () so my dash-panel will be limited at a start (until I must upgrade )

I worked out the gearing to be 100km/h without any field weakening and 137Nm of torque. I have a few other sprockets that I can choose from to get other gear ratios depending on need/track. Currently selected 14:40.



With ~250A @96VDC and say 10% losses I would be pumping in about 21,6kW in, and if possible to use the boost current of 330A that would be roughly 28,5kW. It would be comparable to a Rotax 125 kart-engine of ~24kW

 

[Edvin]

Did some digital mocking up with motor, controller and battery placement.

Designed clamps and motor mount, will orient the motor to have the axis pointing inward as it is with the original combustion engine on this frame, also the rear axle has a key-way for the sprocket-holder in this location.






Some lasercutting, bending and milling of the clamps and the motor is mounted

 

[j bjork]

Cool, there have been a few cart builds on the forum, but I can only think of one where there has been results posted.
And that is Nuxlands build: Electric kart
It seems like heat has been a big problem from what I remember, and that is with a bigger motor.

 

[yabert]

Awesome work! I really like it.

 

[Edvin]

Cool, there have been a few cart builds on the forum, but I can only think of one where there has been results posted.
And that is Nuxlands build: Electric kart
It seems like heat has been a big problem from what I remember, and that is with a bigger motor.

Cooling this will def. become a issue. Hope the track close by will let me do some testing so I can iterate fast on different solutions
I have a few ideas how to cool it but need to start gathering some baseline data before digging to deep into those solutions

Nuxlands build is a really good source for inspiration, and has been for this build.

 

[yabert]

One point is chain will make a lot of noise compare to a belt.
But I bet you will not hear it anymore pass 70-80 km/h

 

[SlowCo]

Great project!
Enjoy building it. I'll follow your progress with interest.