Mini Tesla Design Help

[mr kart]

Hi, I'm in the process of designing an electric go kart. I'm 14 and live in Bristol, UK (a city) so can't have anything loud so no petrol engines.
I'm using the axle, steering and wheels from a petrol ex-racing kart that I've bought second hand.
My aim with this build is to match a 5hp petrol karts performance and get about 30mph out of it.
I want to design and build a light frame, which I feel confident in doing, to make it as efficient as possible. I was also wondering about suspension and the pros and cons, any opinions?
In terms of parts I was looking at a 2000w 48v Boma motor, a combination of multistar lipo batteries ~20ah from hobbyking. I have looked at controllers and chargers but I would appreciate any recommendations as I don't know much about them.
Because I'm using lipo batteries I was wondering about using a BMS or arduino to monitor charging/discharging. I build and fly drones so know quite a bit about lipos and how they work.
I saw a thread mentioning a sort of kart shed or pod for charging and storage which I like the idea of.

I'll try and get cad designs out ASAP but I don't have the kart to take measurements from. yet.

Any questions answered.
Any help or opinions would be greatly appreciated.

Gabe

 

[Functional Artist]

Howdy &

Mini Tesla, sounds like a kuhl project.


Designing is one thing

...building it as another


Are you thinking

...thin wall tube or thicker walled pipe?

...using square or round material?

...bending or mitered corners/angles?

...do you have or access to any type of a bender?

...do you have a welder or skills?


Suspension

...its definitely easier on your back

but,

...it adds weight, complicates the build & in some situations, can affect performance


If, where your plan on riding it more off-road lumpy/bumpy, suspension will help cushion you & your electrical components

...but, if it's mostly smooth/paved suspension NOT so much


I have used a 1,800 watt 48V brushless Boma motor on a Dingo co kart

It moves right along but, top speed so far has been ~20 mph

It currently has

...(4) 12V 22AH SLA (sealed lead acid) bat trees

...a 9 tooth motor sprocket & a 54 tooth sprocket on the rear & #35 chain (6:1)

...& 16" tall rear tires


Check it out

https://www.youtube.com/watch?v=zYWuGJTC0jQ

 

[mr kart]

hi and thanks for the reply. This is the first go kart project i have undertaken although I have a petrol go kart which i got second hand and fixed up to working condition. I have just started to learn to weld with an ark welder.
I have watched a ton of YouTube videos so feel pretty confident in designing a frame in regards to strength and steering geometry etc. I wanted to use 16/20mm round pipe/tube hopefully with bends although i don't have access to a bender. i could buy one or see if anyone i know has one.
i haven't decided yet about suspension, it would make a smooth ride over rough asphalt or a field but it would be added complexity that with my experience, might go wrong.

my thoughts on design ideas

Cool El Dingo kart Functional Artist, something to compare my build to. Must be quite heavy with the SLA batts. Do you know how much it weighs roughly? and another question, where did you get that motor sprocket? the Boma motors come with smaller chain/sprockets don't they?

Any help appreciated
Gabe

 

[mr kart]

Update!

Got a go kart

I know a bit about go karts, but has this kart got good parts?
This is what i know:

• 25mm, (1inch) Axle
• 11x7.5 inch rear tyres
• 10 inch front tyres
• Tillet racing seat
• 4hp gx120 honda engine
• 15t cluch
• 66t sprocke
• Hydraulic 'Solo' brake

i tested it yesterday but the engine kinda 'stalled' when i gave it throttle... I think it is something to do with the carburetor because i cleaned out the fuel line, filter and carb bowl.
Im i right?

ow, and i know the gear ratio is really high, will get another sprocket soon.

I'm planning on using everything but the frame and engine, so building my own frame and an electric motor.

Still designing the frame, with no suspension though.

 

[voided]

Man, wish I could find nice racing karts like that around here. I only find ones that literally came off the race track or something someone still wants brand new price for..

As for building another frame. Why? That's a great starting point. I'd make it electric and figure out all of the wiring , battery, motor and controller stuff and mount it on it.. then decide which way Togo if you don't like it.

 

[Functional Artist]

Yup, I'd roll with that too.

At least use it as a

...rolling lab for you to learn how the propulsion system part works

...to play with & have some fun

...whilst your building your frame

...then switch your "working" propulsion system to your "new" kart

 

[mr kart]

Clearance?

Ok. That's a plan.

One question though, is there any way of raising the front end of the chassis?
I know I can replace the rear bearings with pillow blocks or cut down the mounts...
I could cut and re-weld the spindle brackets lower?
Is it hard to bend the frame?
Don't mind about the paint.

I really need a higher clearance ideally.

 

[Ebrownie]

Bigger tires. Get some 14" tires and it will raise the kart nearly 2".

 

[mr kart]

hi everybody,

i need some help deciding on a 2000w motor controller.
i have seen different types like an actual bike controller but do i need it to be that complicated? or just a scooter control relay.

Any opinions and help welcome.

 

[Functional Artist]

hi everybody,

i need some help deciding on a 2000w motor controller.
i have seen different types like an actual bike controller but do i need it to be that complicated? or just a scooter control relay.

Any opinions and help welcome.

What motor do you have in mind?

Brushed or brushless?

 

[mr kart]

its a boma 2000w brushless 48v

http://www.ebay.co.uk/itm/Electric-...251458&hash=item360e5c2134:g:6-kAAOSwXY5ZR7Xa

 

[Functional Artist]

I have one of those Boma brushless motors it zips right along

check it out

https://www.youtube.com/watch?v=J6cieW7gNU8

The sticker on mine says 48V 1,800W

This is the one I have

http://www.ebay.com/itm/E-Bike-Brus...d=302254514683&_trksid=p2047675.c100005.m1851

I have never seen one labeled as 2,000W before


A 1,800W is the closest controller I could find

http://www.ebay.com/itm/48V-1800W-B...d=112522415366&_trksid=p2047675.c100005.m1851

Do you notice in the picture of the 2,000W motor

...it looks like there is a sticker (sloppily) over another sticker

Hmmm

...could it be a relabeled 1,800W?

 

[mr kart]

yeah you might be right about the sticker now that i look at it...

is 1800w able to get my go kart anywhere near 30mph?
thats my aim anyway.

without using dual motors is their any other motors that are more powerful than that? like 2000w - 2500w?

 

[Functional Artist]

yeah you might be right about the sticker now that i look at it...

is 1800w able to get my go kart anywhere near 30mph?
thats my aim anyway.

without using dual motors is their any other motors that are more powerful than that? like 2000w - 2500w?

1,800W get to 30 mph? Maybe if its really light & has ~5:1 gearing


Other motors? Sure but, they start getting expensive when you get over 2,000W (both motors & accessories (speed controllers, contactors, high amp fuses etc.)

Here is an example:

https://www.goldenmotor.com/

Golden Motor
Brushless DC motor ($258.00)

Model: HPM3000B -- High Power BLDC Motor
1. Voltages: 48/72V
2. Rated power: 2-3KW
3. Peak power: 6KW
4. Speed: 3000-5000rpm
5. Rated torque: 10 Nm
6. Peak torque: 25 Nm
7. Efficiency: >90%
8. Dimensions: 18cm dia. 12.5cm height
9. Weight: 7.3kg(air),8kg(water)
10. Cooling: air or liquid cooling


Speed controller ($260.00)

Model: VEC200
Voltage:48V/72V/96V
Rated continuous current:80A
Maximum phase current: 200A
Motor control mode:FOC
Driving methodirect torque control
Dimensions: 170mm(L) x 120mm(W) x 50mm(H)
Weight:1.9kg

 

[mr kart]

ok so i think i have found a motor.

http://www.hyperpowersports.com/products/brushless-2000-watt-60v-motor-w-mouting-bracket.html

and a motor controller

http://www.hyperpowersports.com/products/replacement-2000w-60v-controller.html

only problem is i don't really know how to wire it. i could buy a load of parts of there website which are compatible but i live in UK so shipping is expensive. i know there will be cheap stuff on eBay but i don't know if it will work with the controller.

 

[Functional Artist]

ok so i think i have found a motor.

http://www.hyperpowersports.com/products/brushless-2000-watt-60v-motor-w-mouting-bracket.html

and a motor controller

http://www.hyperpowersports.com/products/replacement-2000w-60v-controller.html

only problem is i don't really know how to wire it. i could buy a load of parts of there website which are compatible but i live in UK so shipping is expensive. i know there will be cheap stuff on eBay but i don't know if it will work with the controller.

I have seen "that" same looking motor labeled as

...48V 1,600W

...48V 1,800W

...48V 2,000W

...& now as a 60V 2,000W


Main stuff you need:

motor/controller

battery pack

fuse holder/fuse

throttle controller (twist, thumb or pedal)

on/off switch (key)

on/on switch (forward/reverse)

on/off/on switch (speed selector)


IF they are all wired the same, here is a wiring diagram I drew up

 

[mr kart]

Got a motor

I think i know which speed controller to buy.

have my eye on this one:

http://www.ebay.co.uk/itm/Electric-...781452?hash=item466ca9da0c:g:c5MAAOSwsW9Y0nu7

thanks Functional Artist for the wiring diagram, just to be sure...
will this controller will work with my motor? it does have 5 hall sensors.

of course i will have to buy switches and throttles...
is there anything else i would need?

i have a battery charger and i will get some batteries/BMS for lipo.

and i am pretty sure the sprocket on my motor will fit a 219 chain?
or will i have to find new sprockets and chains..?

[edit]
just read the previous reply, now know what i need

 

[Functional Artist]

Looks like it's about the same as the one you linked previously.

It should work

Why didn't you order the motor & controller together?

You know they would work together.


What sprocket came on your motor?

...most Boma motors have an 11tooth sprocket for a 8mm chain


* 60V 2,000W should be fun

 

[Konykart]

What do you think about total price 1000 dollars for controller, motor, pedal and battery 20 Ah ?
I am thinking about it but it is too expansive only for power. Sure these is from china.

---------- Post added at 07:52 AM ---------- Previous post was at 07:47 AM ----------

I am working on mini Tesla car for 1 person. Look at it here
https://m.facebook.com/story.php?story_fbid=733742773500479&id=669602993247791

 

[Konykart]

What do you think about total price 1000 dollars for controller, motor, pedal and battery 20 Ah ?
I am thinking about it but it is too expansive only for power. Sure these is from china.

---------- Post added at 07:52 AM ---------- Previous post was at 07:47 AM ----------

I am working on mini Tesla car for 1 person. Look at it here
https://m.facebook.com/story.php?story_fbid=733742773500479&id=669602993247791

Did you solve design of mini tesla?
Whats your opinion?